Current concepts in the rehabilitation of the overhead throwing athlete

Effects of scapular taping on grip strength and hand function: a randomized controlled cross-over study

BACKGROUND

Grip strength and hand function are critical for upper extremity performance. Although scapular stability is essential for upper extremity functioning, the effects of scapular taping on hand function and grip strength remain unknown.

PURPOSE

Investigating the immediate effects of scapular taping techniques on grip strength and hand function in healthy individuals.

METHODS

Fifty-nine participants (22.15 ± 1.35 years) received Kinesio Taping (KT), Rigid Taping (RT), and Sham Taping in random order with a three-day washout. Grip strength (gross grip, 2-point, 3-point, lateral pinch) and, hand function (Purdue Pegboard Test (PPT), Moberg Pickup Test (MPT), and Minnesota Hand Dexterity Test (MHDT) were conducted immediately after interventions.

RESULTS

RT statistically significantly increased 2-point, and 3-point pinch strength compared to the sham taping (p = .006, d = 0.19, p = .031, d = 0.30). No statistically significant differences were observed in remaining outcomes (p > .05). There were no statistically significant differences between KT-RT or KT-Sham in any of the outcome measures (p > .05, d < 0.2). A moderate negative correlation was detected between 3-point and lateral pinch strength and the PPT Both Hands sub-score (r=-0.372, p = .044; r=-0.351, p = .006). A weak negative correlation was found between gross grip strength and the MPT Eyes Open sub-score (r=-0.294, p = .024).

CONCLUSION

This study demonstrates the effect of scapular taping on enhancing fine grip strength and offers a potential approach to improving distal performance of the upper extremity. Further research involving diverse populations, and long-term follow-up is needed to validate these findings and determine their potential implications for clinical practice.

Utilizing the Pronated Forearm Technique for Measuring Glenohumeral External Rotation in Baseball Players

BACKGROUND

Alterations in glenohumeral internal rotation (GIR), glenohumeral external rotation (GER), and total range of motion (TROM) have been linked with increased injury risk. GER capacity has been measured routinely with the forearm in neutral rotation (GERN), but a recent study reported GERN was greater than GER with the forearm in pronation (GERP) in Minor League pitchers. This work has not yet been replicated or extended to other groups.

HYPOTHESIS

GERP would be significantly less than GERN in Independent League baseball pitchers, and there would be no difference in GERP or GERN measurements between this new group and the previous group of Minor League pitchers.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Goniometric measurements were recorded for bilateral GIR, GERN, and GERP, and resulting TROM for 37 Independent League baseball pitchers. These data were compared with the previous study. All motions were compared individually between groups, between throwing and nonthrowing arm, and both within and between techniques (forearm neutral or pronated).

RESULTS

GERP was significantly less than GERN for both arms within each group tested (P < 0.01). Independent League pitchers had greater between arm differences for GIR (-16.9° vs -6.9°), GERN (+15.1° vs -0.6°), and GERP (+13.1° vs -5.9°) compared with Minor League pitchers. TROM for the Independent League pitchers was not statistically different for either measurement technique, while TROM for the throwing arm of the Minor League pitchers was statistically reduced with varying effect sizes (d = 0.35-0.99) compared with the nonthrowing arm (P < 0.01).

CONCLUSION

This study confirmed earlier findings that the pronated forearm resulted in decreased GER capacity, illustrating the adaptive response to throwing and the need to evaluate for this variable.

CLINICAL RELEVANCE

GERP should be evaluated in all groups of pitchers, but there may be variations within tested groups.

Relationship between Range of Motion and Isometric Shoulder Strength in Elite Team Handball Players

Background

The prevalence of overuse shoulder injuries is unfortunately common in team handball, potentially impacting sport participation and quality of life after players' professional careers. Shoulder rotational strength and glenohumeral range of motion have been proposed to influence the development of shoulder injuries.

Purpose

This study aimed to compare external and internal shoulder rotation range of motion and isometric strength among elite male and female handball players with current shoulder pain, previous shoulder pain, and no shoulder pain.

Study design

An explorative cross-sectional study.

Methods

Maximal isometric shoulder internal and external rotator strength and shoulder internal and external rotation range of motion were measured and compared between sexes and among players with current shoulder pain, previous shoulder pain, and no shoulder pain. All data distributions were tested for normality with the Shapiro-Wilk test, histograms, and qq plots. An ANOVA was used to compare the internal and external shoulder range of motion and strength.

Results

A total of 136 elite team handball players, 57 women (1.74±0.06 m, 72.4 ± 8.3 kg, and 22.4±4.9 years) and 79 men (1.89±0.08 m, 90.8 ± 11.8 kg, and 22.3 ± 5.2 years) participated. A significant difference in maximal internal (p<0.001) and external (p=0.004) shoulder rotator strength was found between sexes, with no significant difference in range of motion. When categorized by groups, male athletes in the no-pain group had greater internal rotator strength than males in the current and previous pain groups (p<0.042). Furthermore, female athletes in the no-pain group showed significantly less internal and external rotation range of motion compared to those playing with shoulder pain and those with previous pain.

Conclusion

Greater maximal isometric shoulder strength was found for men than women, primarily of the internal rotators, among all three groups. However, the men in the no-pain group had greater strength of the internal rotators than the two other groups. Range of motion was comparable between sexes, but the women without shoulder pain demonstrated significantly less internal and external rotation range of motion compared to those playing with shoulder pain and those with previous pain.

Level of evidence

3.

A study of effective exercise methods and resistance intensity for selective strengthening of the infraspinatus muscle

BackgroundTo selectively strengthen target muscles, resistance intensity as well as limb position should be considered.ObjectiveThis study aimed to identify the most effective exercise positions and the optimal resistance intensity to selectively strengthen the infraspinatus muscle.MethodsThis study included 18 healthy men who underwent four different external rotation (ER) exercises in prone external rotation (PER), side-lying wiper, sitting external rotation, and standing external rotation (STER) exercise by varying the shoulder positions under low, medium, and high resistance intensity conditions randomly. Infraspinatus and posterior deltoid muscle activities and the infraspinatus to posterior deltoid activity ratio were measured based on ER exercise positions and resistance intensities.ResultsThis study revealed a significant interaction and main effects of exercise position and resistance intensity on muscle activity and muscle activity ratio. Both muscle activities were increased as the resistance intensity increased, but the muscle activity ratio was decreased. Infraspinatus muscle activity and muscle activity ratio were higher in the PER and STER exercises than in other exercises.ConclusionWe indicate that PER and STER are effective exercises to selectively strengthen the infraspinatus muscle. Additionally, performing the exercise at low or medium resistance intensity rather than high resistance intensity is recommended to activate the infraspinatus selectively while minimizing the involvement of the posterior deltoid.

Utilization of Interval Throwing Programs: Analysis of Athletic Trainer, Physical Therapist, and Physician Perspectives

CONTEXT

A common component within rehabilitation recommendations for baseball pitchers is employment of an interval throwing program. However, there is a lack of a consistent set of advocated guidelines for program content and implementation for athletes at the professional and collegiate levels.

DESIGN

Cross-sectional study.

METHODS

A survey was developed to obtain clinician views regarding the composition and implementation of interval throwing programs for baseball pitchers. The survey was divided into demographic information and sections on criteria to begin throwing programs, frequency of throwing, soreness management, warm-up components, program components and regulation of a program, and criteria to achieve permitting live throwing. Clinicians including physicians, physical therapists, and certified athletic trainers who evaluate and treat musculoskeletal injuries among baseball pitchers at the professional-level and/or collegiate-level clinician received the survey. Responses were tabulated and compared between the professional-level clinician and collegiate-level clinician groups using chi-square analyses with statistical significance set at P ≤ .05.

RESULTS

The survey was completed by 166 clinicians (collegiate level = 81, professional-level clinician = 85). There were no statistical differences between groups for allowing warm-up throws, program regulation, maximum distance allowed, managing soreness, or criteria to achieve before permitting live throwing. Between-group differences included criteria to begin a program (≤.03), warm-up distance (P ≤ .02), nonthrowing warm-up methods (P ≤ .04), non-warm-up distance (P ≤ .01), using ratings of perceived exertion (P < .01), throwing frequency (P < .01), and program components (P ≤ .04).

CONCLUSIONS

Responses appear to mirror interval throwing program designs previously reported in the literature but there are modifications and additions utilized by clinicians at different playing levels.

Kinematic Sequence Differences Between Trained Baseball Players and Untrained Adolescent Individuals

An overhead throwing motion is a common gross motor skill often taught in early childhood to improve physical activity participation. Yet, research investigating motor efficiency in overhead throws often focuses on improving performance in trained individuals. This project compares kinematic sequencing between trained and untrained youth. After a brief warm-up, untrained high school students (N = 9) and trained high school and college students (N = 10) threw a weighted tennis ball for accuracy (N = 10 throws). Upper extremity angular velocities were collected using 3-dimensional inertial sensor motion capture. Kinematic sequencing of joints and segments (pelvis, trunk, shoulder, elbow, and wrist) was assessed using Kruskal-Wallis test; Friedman and Wilcoxon tests identified group differences between sequences. Seven independent kinematic sequences were identified (N = 2 unique trained; N = 3 unique untrained; N = 2 shared). The rankings for the trained group maintained a mostly consistent pattern with only elbow and wrist joints producing similar rankings. The untrained group lacked that consistency with similar rankings of elbow versus wrist and shoulder versus elbow. Trained individuals threw with a more efficient proximal-to-distal sequencing pattern than the untrained participants, specifically at the trunk and shoulder. Continuous training of gross motor skills beyond initial skill development is necessary to maintain motor proficiency.

Clinical outcomes and return-to-play in dynamic anterior glenohumeral capsular ligament tensioning procedure for overhead-throwing athletes with traumatic shoulder dislocation on the throwing side

BACKGROUND

Although arthroscopic Bankart repair for shoulder instability after a traumatic shoulder dislocation is a standard procedure, return-to-play rates for overhead-throwing athletes with shoulder instability on the throwing side have been reported to be lower than those in nonoverhead athletes or in nonthrowing shoulders. A recent technical report showed that the dynamic anterior glenohumeral capsular ligament tensioning (DAGHT) procedure in abducted external rotation, which mimics the late cocking phase of the throwing motion during surgery, may provide optimal tensioning of the anterior glenohumeral ligament. This study compared clinical outcomes and return-to-play after arthroscopic Bankart repair between DAGHT and a conventional procedure for overhead-throwing athletes with traumatic dislocation on the throwing side.

METHODS

We retrospectively examined patients with traumatic anterior shoulder dislocation who underwent arthroscopic Bankart repair. The inclusion criteria were being an overhead-throwing athlete, having the injury on the throwing side, evidence of anterior shoulder dislocation, and evidence of Bankart lesions on magnetic resonance imaging. Clinical scores were evaluated using Jobe's postoperative grading system; the Kerlan-Jobe Orthopaedic Clinic Overhead Athletes Shoulder and Elbow Score; the Western Ontario Shoulder Instability Index; the Disabilities of the Arm, Shoulder, and Hand sports module; return to play; and return to the same level.

RESULTS

Thirty-four patients (8 females and 26 males; mean age, 18.0 ± 4.0 years) were divided into 2 groups: 16 with shoulder stabilization in the resting position (control group) and 18 with shoulder stabilization with DAGHT (DAGHT group). Jobe's score was significantly greater in the DAGHT group than in the control group (88.9% and 18.8% in excellent rate, respectively; P < .001). External rotation at abduction and the Kerlan-Jobe Orthopaedic Clinic, Western Ontario Shoulder Instability Index, and Disabilities of the Arm, Shoulder, and Hand scores were significantly greater in the DAGHT group than in the control group (94.5 vs. 85.0; 81.1 vs. 55.7; 83.8 vs. 58.4; 11.8 vs. 27.0; P = .008, <.001, <.001, and =.019, respectively). Although return-to-play rates were not significantly different between the control and DAGHT groups (93.8% vs. 100%; P = .47), return-to-the-same-level rates were significantly better in the DAGHT group than in the control group (77.8% vs. 37.5%; P = .035).

CONCLUSION

Arthroscopic shoulder stabilization with the DAGHT procedure on the throwing side of overhead-throwing athletes resulted in lesser restriction of external rotation, better clinical outcomes, and higher return-to-the-same-level rate than arthroscopic shoulder stabilization with conventional tensioning. The DAGHT procedure in abduction and external rotation may represent a solution for a traumatic shoulder instability on the throwing side in overhead-throwing athletes.

Dynamic Anterior Glenohumeral Capsular Ligament Tensioning During Arthroscopic Shoulder Stabilization in Overhead-Throwing Athletes

Although the most common surgical treatment for traumatic anterior shoulder instability is arthroscopic Bankart repair (ABR), which has shown good postoperative results, a potential risk of postoperative external rotation deficit exists. For overhead-throwing athletes, recovery of postoperative range of motion during abduction and external rotation is essential to return to preinjury performance levels. We consider that the key to returning to play after ABR on the dominant side in overhead-throwing athletes is to simultaneously gain anterior stability and mobility of the shoulder. However, no gold standard method for determining the appropriate tension of the glenohumeral capsular ligaments in overhead-throwing athletes exists. This Technical Note presents the dynamic anterior glenohumeral capsular ligament tensioning in the abduction and external rotation positions during ABR for the dominant side in overhead-throwing athletes. We consider this surgical technique to be reliable for traumatic anterior instability of the dominant shoulder in athletes who wish to return to overhead-throwing sports.

The Impact of Fascial Manipulation® on Posterior Shoulder Tightness in Asymptomatic Handball Players: A Randomized Controlled Trial

This prospective study aimed to determine the impact of Fascial Manipulation® by Stecco (FM) on the range of motion (ROM) of internal rotation (IR) and horizontal adduction (HADD) in asymptomatic handball players, representing significant risk factors for shoulder injuries. A randomized controlled trial was conducted, with participants randomly assigned to either the investigated group (N = 29) receiving a single session of FM or the control group (N = 27) receiving no treatment. The ROM for IR and HADD were measured before, immediately after, and one month after the FM session. The investigated group experienced a statistically significant acute increase in glenohumeral IR (14 degrees, p < 0.001) and HADD (14 degrees, p < 0.001) compared to the control group (p < 0.001). The positive effects of FM persisted one month post-treatment, with increased IR ROM by 12 degrees (p < 0.001) and HADD ROM by 11 degrees (p < 0.001). Participants in the investigated group reported lower subjective tightness/stiffness immediately after (p < 0.001) and one month after treatment (p = 0.002) compared to the control group. This study demonstrates that a single application of FM effectively improves glenohumeral ROM in the dominant throwing shoulder of asymptomatic handball players. It highlights the immediate and sustained positive effects of FM on IR and HADD. These findings support the use of FM as an effective method for enhancing shoulder ROM and reducing subjective tightness/stiffness. The study was registered at ClinicalTrials.gov (NCT06009367).

Shoulder External Over Internal Rotation Ratio Is Related to Biomechanics in Collegiate Baseball Pitching

Altering baseball pitching mechanics affects both performance and the risk of injury. The purpose of this study is to investigate the relationships of shoulder external over internal rotation ratio (SEIR) and other shoulder rotational properties during physical exam and biomechanics of pitching for 177 collegiate baseball pitchers. The shoulder range of motion was quantitatively measured using a custom-made wireless device. Pitching motion data were collected at 240 Hz, and a custom program was created to calculate the throwing arm motion and loading during baseball pitching. Linear regression and analysis of variance tests were performed to investigate the relationships between the shoulder physical exam outcomes and throwing arm biomechanics. SEIR had significant correlations with shoulder horizontal adduction angle at foot contact, maximum shoulder external rotation angle, maximum shoulder linear velocity, and elbow angle at ball release. SEIR groups had significant differences in shoulder proximal force, adduction torque, internal rotation torque, and horizontal adduction torque, and in elbow medial force and varus torque. Glenohumeral internal rotation deficit and total rotational motion deficit had no relationships with throwing arm motions or joint loadings. Shoulder health should be monitored to improve understanding of pitching mechanics in collegiate baseball pitchers.

The effect of rehabilitation time on functional recovery after arthroscopic rotator cuff repair: a systematic review and meta-analysis

Objective

We compared the effects of early and delayed rehabilitation on the function of patients after rotator cuff repair by meta-analysis to find effective interventions to promote the recovery of shoulder function.

Methods

This meta-analysis was registered in PROSPERO (CRD42023466122). We manually searched the randomized controlled trials (RCTs) in the Cochrane Library, Pubmed, Cochrane Library, EMBASE, the China National Knowledge Infrastructure (CNKI), the China VIP Database (VIP), and the Wanfang Database to evaluate the effect of early and delayed rehabilitation after arthroscopic shoulder cuff surgery on the recovery of shoulder joint function. Review Manager 5.3 software was used to analyze the extracted data. Then, the PEDro scale was employed to appraise the methodological quality of the included research.

Results

This research comprised nine RCTs and 830 patients with rotator cuff injuries. According to the findings of the meta-analysis, there was no discernible difference between the early rehabilitation group and the delayed rehabilitation group at six and twelve months after the surgery in terms of the VAS score, SST score, follow-up rotator cuff healing rate, and the rotator cuff retear rate at the final follow-up. There was no difference in the ASES score between the early and delayed rehabilitation groups six months after the operation. However, although the ASES score in the early rehabilitation group differed significantly from that in the delayed rehabilitation group twelve months after the operation, according to the analysis of the minimal clinically important difference (MCID), the results have no clinical significance.

Conclusions

The improvement in shoulder function following arthroscopic rotator cuff surgery does not differ clinically between early and delayed rehabilitation. When implementing rehabilitation following rotator cuff repair, it is essential to consider the paradoxes surrounding shoulder range of motion and tendon anatomic healing. A program that allows for flexible progression based on the patient's ability to meet predetermined clinical goals or criteria may be a better option.

Throwing Shoulder Adaptations Are Not Related to Shoulder Injury or Pain: A Preliminary Report

BACKGROUND

Overhead throwing in baseball and softball athletes induces shoulder adaptations theorized to increase risk of shoulder musculoskeletal injury (MSI) and/or pain due to range of motion (ROM) deficits.

HYPOTHESIS

Shoulder ROM adaptations are associated with a higher risk for developing shoulder MSI and pain.

STUDY DESIGN

Prospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 60 National Collegiate Athletic Association Division I athletes cleared for full athletic participation and free from upper extremity MSI in the last 4 weeks (age, 19.0 ± 1.2 years; weight, 82.1 ± 13.7 kg; height, 178.6 ± 11.2 cm; softball, n = 23; baseball, n = 37). Passive glenohumeral internal rotation (IR), external rotation (ER), and horizontal adduction (HA) ROM were measured with the scapula stabilized and used to categorize participants with/without external rotation gain (ERG), external rotation insufficiency (ERI), glenohumeral internal rotation deficit (GIRD), pathological GIRD, and posterior shoulder tightness (PST) before the competitive season. Groups were then compared to assess the incidence of shoulder MSI prospectively and prevalence of shoulder pain at the initial evaluation.

RESULTS

Baseball and softball athletes demonstrated significantly less IR ROM in the dominant shoulder (50.6° ± 9.4°) compared with the nondominant shoulder (59.1° ± 8.6°; P < 0.01) and significantly more ER ROM (dominant, 104.6° ± 12.1°; nondominant, 97.7° ± 12.0°; P < 0.01). Incidence of shoulder MSI was 15% but was not significantly related to any shoulder adaptations. No significant relationship was found between prevalence of pain and any shoulder adaptations in the 27% of athletes with pain.

CONCLUSION

Increased ER and decreased IR ROM adaptations in intercollegiate overhead throwing athletes do not appear to be correlated to risk of shoulder MSI or pain.

CLINICAL RELEVANCE

The findings of this level 3 prospective study provide clinicians working with overhead athletes information regarding shoulder MSI risk and pain. It is recommended that clinicians should not use ROM adaptations exclusively to determine increased risk of shoulder MSI.

Can resistance training improve throwing performance in handball players? A Systematic review and meta-analysis

BACKGROUND

Throwing is one of the most important movement in handball. Throwing performance is crucial for success in handball.

OBJECTIVE

Τo investigate the level of evidence for the effect of resistance training (RT) on throwing performance in handball players.

METHODS

Systematic searches of Pubmed, Medline complete, Cinahl, Sport Discus and Scopus were undertaken for peer reviewed articles published between 18 March 1995 to 18 March 2023. Randomized, controlled, clinical studies, written in English, aiming to investigate the effect at least one modality of RT on throwing performance (velocity or/and accuracy) in handball players were considered for inclusion in the study. The eligible studies were assessed for methodological quality using the Physical Therapy Evidence Database (PEDRO) scale. The Best Evidence Synthesis (BES) approach was used for synthesizing and reporting the results. Furthermore, the random-effects model was used for the meta-analysis and the Q-statistic was used to test the null hypothesis that all studies in the analysis share a common effect size.

RESULTS

One hundred ninety-eight studies were identified, of which 30 were included. A total of 727 handball players (males = 388, females = 292) were included. 28 of the 30 studies were rated as high methodological quality studies (PEDRO score > 70%) while the rest of the studies were rated as moderate methodological quality studies (PEDRO score ≤ 60%). The mean effect size for the effectiveness of resistance training (RT) in improving jumping throw, running throw, and standing throw velocity were 1.128 (95% CI 0.457 - 1.798), 1.756 (95% CI 1.111 - 2.400), and 1.098 (95% CI 0.689 - 1.507) correspondingly. Traditional weight training using barbells in mostly compound lifts yielded the most significant and robust results. Other RT modalities such as elastic bands, medicine balls, core training and ballistic training showed no significant results or positive effects due to the limited number of the studies.

CONCLUSION

Strong evidence exists only for the effectiveness of RT using barbells in increasing throwing velocity. In contrast, the remaining RT modalities, while yielding positive results, have limited support due to limited number of studies and the high heterogeneity between studies. Furthermore, there is insufficient evidence to support various forms of RT in increasing throw distance. Finally, medicine ball training and elastic band training demonstrated no benefits in improving throwing accuracy.

TRIAL REGISTRATION

PROSPERO ID: CRD42023393574.

Elbow valgus stress during towel drills in college baseball players

BACKGROUND

In baseball players with elbow injuries, towel drills are clinically used before initiating active throwing exercises to gradually increase stress across the elbow. However, elbow valgus torque during towel drills remains unknown. Moreover, towel drills and active ball throws might have different relationships between biomechanical metrics, such as elbow stress, arm slot, and arm speed. Therefore, the aims of this study were 1) to demonstrate the difference in elbow valgus stress between towel drills and active ball throws and 2) to evaluate the correlation between elbow valgus torque and other biomechanical metrics including arm slot and arm speed in towel drills and active ball throws.

METHODS

Seventeen healthy college baseball players performed three towel drills using a face towel, short foam tube, and long foam tube, followed by full-effort throwing on flat ground. Each participant completed five consecutive trials of each task, and the elbow valgus torque, arm slot, and arm speed were measured using wearable sensors. One-way repeated analysis of variance and post-hoc tests were used to determine the differences in biomechanical metrics among the tasks. Furthermore, the correlation between the elbow valgus torque and other metrics was evaluated using Pearson correlation coefficients.

RESULTS

Elbow valgus torque was lower in towel drills compared to that of active ball throws; however, the stress during towel drills using a face towel reached almost 80% of the maximum effort of active ball throws. There was no relationship between elbow valgus stress and arm slot in either the towel or active ball throw tasks. However, a higher arm speed was associated with greater elbow valgus torque in towel drills, whereas no relationship between elbow stress and arm speed was found in active ball throws.

CONCLUSION

Precaution must be taken in athletes following a progressive throwing program because elbow valgus stress reaches almost 80% of the full-effort throw, even when using a face towel in a towel drill. Hence, the subjective intensity must be controlled even in towel drills to gradually increase the medial elbow stress. Moreover, the mechanisms underlying changes in elbow stress may differ between towel drills and active ball throws. Future investigations on the difference between towel drills and active ball throws may help understand the underlying mechanism of alterations in elbow valgus torque during the throwing movement.

Damage for gain: The useful damage of the Pitcher's paradox

INTRODUCTION

Sport-specific adaptations of the glenohumeral joint may arise in adolescent overhead athletes who begin high-performance sports early in life. Research mainly addresses overuse injuries, leaving gaps in prevention, with adults studied more than youths.

OBJECTIVE

This study aims to investigate sport-adaptations of the glenohumeral joint in asymptomatic adolescent volleyball players to identify potential shoulder injury risk factors.

DESIGN

Observational study.

SETTING

Clinical screening campaign conducted at the Physical Medicine and Rehabilitation Unit of Policlinic Hospital in Catania, Italy.

PARTICIPANTS

Forty asymptomatic under-16 athletes were evaluated.

INTERVENTIONS

Shoulder internal rotation (IR) and external rotation (ER), range of motion (ROM), total-rotation ROM, glenohumeral IR deficit (GIRD), general joint laxity using Beighton score, apprehension, relocation, O'Brian tests, and ultrasound (US) glenohumeral distance were tested bilaterally. Variables such as the player's position, the age they began the sport, limb dominance, weight, and height were also considered.

RESULTS

The median US glenohumeral distance was at 0.42 ± 0.26 cm, which is consistent with the range found in non-dislocated shoulders of a healthy non-athletic population. The ER ROM was significantly greater in the dominant shoulder than the contralateral one (P = 0.0001), and there was a significant correlation between the ER ROM of attackers and their US glenohumeral distance (P = 0.0413). Furthermore, shoulder IR ROM and US glenohumeral distance were not significantly different between the dominant and contralateral limbs (P = 0.05). None of the athletes presented GIRD. Other tests, including the Beighton score, apprehension, and relocation tests, yielded no significant differences between the dominant and contralateral limbs.

CONCLUSIONS

Despite an increased shoulder ER in the dominant limb, the glenohumeral joint remains stable, suggesting that greater ROM in ER does not equate to instability in overhead athletes without hyperlaxity. Nevertheless, increased ER impacts glenohumeral distance in attacker volleyball players. This finding suggests that the shoulder morphological adaptation process starts early in attackers.

Relationship between shoulder and elbow range of motion and ultrasonographic structural abnormalities in the elbow of Taiwanese high school baseball players

BACKGROUND

Ultrasonographic structural abnormalities are regarded as one of the risk factors of elbow injuries. Elbow injuries are commonly associated with decreased shoulder/elbow range of motion (ROM). The purpose of this study is to determine the relationship between shoulder/elbow ROM and elbow ultrasonographic structural abnormalities in Taiwan high school baseball players.

METHODS

A total of 533 Taiwan high school baseball players were enrolled. Physical examinations including measurements on shoulder/elbow ROM and elbow sonographic examinations were performed and recorded by professional physicians. The analyses were conducted in three subgroups according to their defensive position because the training programs were different. All players pooled, pitchers-only, and fielders-only, due to several demographic differences among these subgroups. In all the subgroups, univariate analyses were conducted separately for participants with and those without elbow ultrasonographic structural abnormalities, and then multivariate analyses were conducted to identify factors significantly related. The odds ratios (ORs) were used to estimate the risk of elbow ultrasonographic structural abnormalities.

RESULTS

Demographic data showed that pitchers had taller body height (P < 0.001) and greater elbow flexion/extension ROM (P < 0.001). When all players were pooled, significant risk factors included started playing baseball at an younger age (OR = 1.202; 95% CI = 1.064-1.357; P = 0.003), longer experience of official baseball (OR = 1.154; 95% CI = 1.038-1.283; P = 0.008), lower total shoulder rotation angle (OR = 1.007; 95% CI = 1.000-1.014; P = 0.050), and less total elbow arm angle (OR = 1.052; 95% CI = 1.017-1.088; P = 0.003) For pitchers, significant risk factors included longer experience of official baseball (OR = 1.342; 95% CI = 1.098-1.640; P = 0.004), lower total shoulder rotation angle (OR = 1.016; 95% CI = 1.004-1.027; P = 0.006), and lower total elbow arm angle (OR = 1.075; 95% CI = 1.024-1.129; P = 0.004) (Table 5). There were no significant risk factors for elbow structural abnormalities in fielders.

CONCLUSION

For Taiwan high school pitchers, longer official baseball experience, decreased shoulder total rotational angle, and decreased elbow total flexion/extension angle, were related to ultrasonographic structural abnormalities in elbows.

Rehabilitation of the painful elbow

Although lateral elbow pain and medial ulnar collateral ligament injury are common musculoskeletal pathologies in overhead athletes, the evidence supporting specific interventions for managing these conditions is scarce. Management of these conditions has been guided mostly by expert opinion rather than empirical evidence, yet the lack of comparative data in the literature has not negatively affected return-to-play rates following surgery. However, an understanding of what is known regarding unimodal and multimodal treatments for lateral elbow pain and medial ulnar collateral ligament injury is needed for clinicians to select evidence-based treatment pathways and highlight what is not known to develop future high-quality investigations.

Rehabilitation of the painful shoulder

Managing the painful shoulder in overhead athletes can be difficult because of a lack of time-loss injuries in overhead sports and focusing primarily on either pathoanatomic causes or movement impairments. Although managing the painful shoulder can be challenging, the combination of identifying pathoanatomic causes with movement impairments can provide a more focused rehabilitation approach directed at the causes of shoulder pain. Understanding the potential influence of scapular positioning as well as mobility and/or strength impairments on shoulder pain can help clinicians develop more directed rehabilitation programs. Furthermore, sports-specific methods such as long toss or the use of weighted balls for achieving physiological or performance-based gains have limited empirical evidence regarding their clinical and performance-based benefits, which may impede the rehabilitation process. Applying a comprehensive evaluation approach prior to and throughout the treatment process can assist clinicians with selecting the most appropriate treatment based on patient need. Reconsidering traditional treatments based on existing evidence may help refine the treatment process for overhead athletes with shoulder pain.

Development and Performance Evaluation of a Smart Upper-Limb Rehabilitation Exercise Device

User-friendly rehabilitation medical devices can enhance health and the quality of life through the convergence of information communication and medical technology. Muscle contraction enables bodily movement, and the assessment of muscle strength is crucial. Muscle contraction includes isometric, isotonic, and isokinetic types. Many individuals with physical disabilities rely on wheelchairs due to lower-limb paralysis. There is a substantial correlation between the level of upper-limb functional recovery and the quality of daily life. This study aimed to design and evaluate a device that utilizes various muscle contractions to enhance the effectiveness of upper-limb rehabilitation exercises. The results from the isometric performance assessment showed percentage error rates of >30% for 5-30 kg. Correction equations were employed, and the isometric performance assessment resulted in error rates below 2.1% for 5-30 kg. Isokinetic performance assessment using video analysis evaluated a consistent wire speed from 10 cm/s to 70 cm/s with an average error rate of 0.91% across all speeds. This study demonstrates the ability to accurately measure various muscle contractions and showcases the potential for real-time feedback. This highlights how such a device could be helpful for target groups, including older adults and individuals with disabilities, during upper-limb rehabilitation exercises.

Biomechanical Characteristics of Scapular and Glenohumeral Movements during Pitching Motion in Injury-prone College Baseball Pitchers

OBJECTIVES

The coordination of glenohumeral (GH) and scapular movements is central to the injury prevention of baseball pitchers. However, there is no objective data establishing the direct relationship between pitching injuries and associated GH and scapular movements. Therefore, this study demonstrated the biomechanical differences in the scapular and GH movements during pitching between injury-prone pitchers and healthy college baseball pitchers.

METHODS

A total of 30 collegiate baseball pitchers were classified into two groups according to their injury status: injury-prone group (n = 15) and control group (n = 15). We obtained pitching motion data using three-dimensional motion analysis technique.

RESULTS

The horizontal abduction angles of the GH joint during cocking and acceleration phases were considerably greater in the injury-prone pitchers (19.0° at stride foot contact [SFC], -4.0° at maximum external rotation [MER], and -0.3° at ball release) than those in healthy controls (11.7° at SFC, -10.0° at MER, and -6.9° at ball release). Additionally, in the cocking phase, the amount of angular change in the scapular external rotation (ER) was significantly smaller in the injury-prone group than that in the control group (mean difference, -13.0).

CONCLUSION

These results suggest that the injury-prone pitchers have less internal rotation of the scapula and a more horizontal abduction of the GH joint during the cocking and acceleration phases. Therefore, sports medicine practitioners may need to pay considerable attention to the coordination of scapular and GH horizontal movements during pitching for prevention of shoulder injuries.

Rehabilitation of Annular Pulley Injuries of the Fingers in Climbers: A Clinical Commentary

ABSTRACT

The annular pulley ligaments of the fingers are one of the most injured anatomical structures in those who participate in climbing. Despite this, there is a paucity of guidance clearly describing the rehabilitation and physical preparation parameters to return to sport following such injuries. The foundation of effective rehabilitation is the judicious application of progressive loading to increase the morphological and material properties of the damaged tissues. We maintain the optimal management of the climbing athlete after a traumatic annular flexor pulley system rupture should be grounded in the principles of strength and conditioning.

Scapular kinesiotaping improves upper extremity functionality in healthy active subjects

OBJECTIVE

The aim of this study was to investigate the effect of scapular kinesiotaping and sham-taping applications on upper extremity functionality in healthy active subjects.

METHODS

In total, 60 participants were randomly divided into two groups: scapular kinesiotaping group (n=30) and sham-taping group (n=30). While scapular kinesiotaping was applied to the kinesiotaping group, scapular rigid taping was applied to the sham-taping group. At the end of the third day of the taping application, the individuals were re-evaluated.

RESULTS

Participants in the scapular kinesiotaping group showed improvement in upper extremity functionality and quality of life after taping (p<0.05). In the sham-taping group, there was no statistically significant difference after taping (p>0.05).

CONCLUSION

Scapular kinesiotaping is effective in improving upper extremity functionality in healthy active subjects.

Normative Values of Isometric Shoulder Strength Among Healthy Adults

Background

Normative data is useful for comparing measured values of strength with population norms and can avoid the issues associated with limb symmetry index. The available normative shoulder strength values are limited by constraints on research designs and variability in subject groups which prevents this data being successfully extrapolated to the greater population.

Purpose

The purpose of this study was to establish normative isometric strength values for various movements of the shoulder that are specific to function and rotator cuff strength. A secondary goal of this study was to analyze the effect of age, gender, weight, height, activity level and arm dominance on shoulder strength.

Design

Observational cohort study.

Methods

Subjects in four age groups (20-29, 30-39, 40-49, 50-59) were included in this study-200 males (40.0 ± 11.6 years, 179.1 ± 6.5 cm, 81 ± 13.0 kg) and 200 females (40.1 ± 11.5 years, 165.3 ± 7.4sm, 64.4 ± 11.6 kg). Bilateral isometric strength measurements were taken with a handheld dynamometer testing seven shoulder movements. Tables of normative strength data were constructed. Multivariate analyses were performed to analyze the effects of age, gender, weight, height and activity level on isometric shoulder strength.

Results

Men were stronger than women (p<0.001). Age was not associated with most strength measures with the exception of dominant arm abduction (p<0.004), non-dominant arm abduction (p<0.028) and non-dominant arm scapular plane abduction (p<0.004) which had a negative association with strength. Weight was positively associated with strength (p<0.001). Activity level was positively associated with all strength measures (p<0.05) except dominant sided abduction (p=0.056). There were no statistically significant differences between dominant and non-dominant sides.

Conclusion

This normative data may be useful to the clinician, as it permits a standard against which to compare shoulder strength for various age groups. Clinicians can have confidence that the uninvolved limb, if symptom free, can be used as an adequate benchmark for strength measures.

Levels of Evidence

Level 3©The Author(s).

The effects of biofeedback training for efficient activation of infraspinatus on proprioception and EMG activity during shoulder external rotation

The purpose of this study investigated which biofeedback (BF) training enables efficient activation of the infraspinatus muscle that affect joint position sense (JPS) and force sense (FS) of the shoulder joint. Twenty healthy males participated and performed three external rotation (ER) exercises under three randomly assigned training conditions: 1) non-biofeedback (NBF), 2) BF and 3) force biofeedback (FBF). Each exercise was performed at intervals of one week between training conditions. After performed the ER exercise under each training condition, the relative error (RE) was calculated at shoulder ER 45° and 80°, and then shoulder ER force were measured to determine the JPS error and FS error, respectively. Muscle activity of infraspinatus and posterior deltoid were measured and compared between training conditions. The RE of shoulder ER 45° and 80° were significantly lower under the FBF conditions than other training conditions (P < 0.05). The RE of shoulder ER force were also significantly lower under the FBF conditions compared to those under the other training conditions (P < 0.05). The activity of the infraspinatus muscle was significantly higher under the FBF conditions during all three ER exercises than other training conditions (p < 0.05). We suggest that BF trainings can be useful to improve the proprioception of shoulder joint as well as activation of infraspinatus muscle while performing the ER exercises.

Do the Testing Posture and the Grip Modality Influence the Shoulder Maximal Voluntary Isometric Contraction?

Assessing and monitoring shoulder strength is extremely important during rehabilitation. A fixed dynamometer represents a valid and inexpensive assessment method. However, it has not been studied whether posture and grip modality influence shoulder muscle strength. The aim of this study was to compare shoulder strength values between sitting and standing positions and between the handle and cuff grip modalities. A total of 40 volunteers were divided into a posture (PG) and a handle-cuff group (HCG). Participants in the PG were asked to perform a maximum voluntary isometric contraction (MVIC) for shoulder flexion, extension, ab-adduction, and intra-extra rotation in standing and sitting positions. The HCG participants were tested in a standing position while holding a handle or with a cuff around their wrist. PG showed higher forces in the standing position for shoulder flexion (p = 0.009); internal rotation showed higher values in the sitting position (p = 0.003). ER/IR ratio was significantly higher in the standing position (p < 0.001). HCG showed higher significant forces during cuff modality in all positions and grip modalities, including the ER/IR ratio (p < 0.05). Different body positions and grip modalities influenced the assessment of shoulder strength as recorded by a fixed dynamometer; therefore, these factors should be carefully considered when carrying out a shoulder strength assessment, and we encourage the development of assessment guidelines to make future clinical trial results comparable.

Changes in Elbow Stress and Ball Velocity During Reduced Effort Pitching: A Marker-Based Motion Capture Analysis

BACKGROUND

Baseball pitchers often participate in throwing programs that involve throwing at reduced effort levels to gradually increase the amount of stress experienced across the elbow. It is currently unknown how reduced effort pitching compares with maximum effort with respect to elbow stress and ball velocity.

PURPOSE/HYPOTHESIS

The purpose was to determine the correlation between elbow stress and ball velocity with reduced effort pitching. We hypothesized that decreased perceived effort would disproportionately correlate with elbow stress and ball velocity.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ten healthy male high school baseball pitchers threw 5 pitches from a regulation pitching mound at 3 effort levels: maximum effort, 75% effort, and 50% effort. Elbow stress, specifically elbow varus torque, was calculated for all pitches using a validated marker-based 3-dimensional motion capture system. Ball velocity was measured using a Doppler radar gun. Intrathrower variability was calculated for each effort level.

RESULTS

Elbow stress and ball velocity decreased with reduced effort throws (P < .001 and P = .003, respectively). However, the reductions in elbow stress and ball velocity were not proportional. At 75% effort throws, elbow stress measured 81% (intraclass correlation coefficient [ICC], 0.95), and ball velocity measured 90% (ICC, 0.80) of maximum, respectively. At 50% effort throws, elbow stress measured 75% (ICC, 0.93), and ball velocity measured 85% (ICC, 0.87) of maximum. Intrathrower reliability was excellent for elbow stress and ball velocity, with all ICCs ≥0.80.

CONCLUSION

Pitching at a reduced effort level resulted in decreased elbow stress and ball velocity. However, for every 25% reduction in perceived effort, elbow stress decreased by a mean 13%, and ball velocity decreased 7.5%. When baseball pitchers attempt to throw at a reduced effort of maximum, throwing metrics do not decrease proportionately.

CLINICAL RELEVANCE

While pitching at a reduced effort of maximum decreases elbow stress and ball velocity, the decrease is not proportional, subjecting the elbow to more stress than intended. This has significant clinical importance to pitchers, coaches, and medical professionals in the setting of injury prevention and return to sports.

Pitching Biomechanics and Shoulder Function in Baseball Pitchers with Scapular Dyskinesis

The primary purpose was to investigate the influence of scapular dyskinesis (SD) on pitching biomechanics and shoulder function in high school baseball pitchers. The secondary purpose was to identify possible factors associated with shoulder function in pitchers with SD. Thirty-eight pitchers were classified into the SD group (n=26) or the non-SD group (n=12). They were evaluated with the Kerlan-Jobe Orthopaedic Clinic shoulder and elbow (KJOC) scale and clinical measurements of shoulder characteristics, and with measurements of scapular kinematics, muscle activation, and ball speed during fastball pitching. Compared to the controls, the pitchers with SD had less scapular external rotation (difference=11.3 degrees, ES=0.92, p=0.012) during overall pitching and less upper trapezius (UT) activation during the late cocking (difference=7.1%, ES=0.79, p=0.019) and acceleration phases (difference=12.5%, ES=0.75, p=0.035). Higher UT activation during the late cocking phase was significantly associated with higher KJOC scores (standardized β=0.415, p=0.039). In conclusion, deficits in scapular external rotation and decreased UT activation during pitching were found in pitchers with SD. Higher UT activation may be important for shoulder function in pitchers with SD.

Clinical shoulder measurements related to joint loads in collegiate pitchers

Background

Pitchers are prone to upper extremity injury due to repetitive high joint loads. Clinical measures of shoulder strength and range of motion (ROM) have shown links to injury risk in pitchers, however, these factors have rarely been studied in relation to throwing joint loads. The purpose of this study was to identify which clinical ROM and isokinetic strength variables were related to peak shoulder and elbow joint torques in collegiate pitchers.

Methods

Thirty-three healthy collegiate pitchers participated in this study. Fastball velocity, shoulder concentric and eccentric strength, and passive shoulder ROM variables were analyzed using a Lasso regression to determine what factors influenced shoulder internal rotation torque and elbow varus torque.

Results

Fastball velocity was selected by the Lasso as indicator of increased shoulder and elbow torque. Passive shoulder external rotation ROM was also selected as an important factor in joint loading with increased shoulder external rotation ROM being related to lower joint loads. The bilateral ratio of shoulder internal rotator concentric strength was related to peak shoulder and elbow torques with an increase in the bilateral ratio of shoulder strength leading to reduced joint torques. Increases in the eccentric external rotator to concentric internal rotator strength (functional ratio) of the dominant arm and increases in dominant arm eccentric internal rotator strength were both related to increases in each joint torque.

Conclusion

Results from the study indicate that pitch speed, passive shoulder external rotation ROM, and the isokinetic shoulder strength profile including internal rotator strength and functional strength ratio of pitchers are related to joint loading during the pitch and may be important to monitor in relation to injury risk and/or during rehabilitation. These results provide insight into the role that both shoulder ROM and rotator cuff strength play in the dynamic stabilization of the elbow and shoulder during pitching.

A Number of Modifiable and Nonmodifiable Factors Increase the Risk for Elbow Medial Ulnar Collateral Ligament Injury in Baseball Players: A Systematic Review

PURPOSE

To analyze the current literature regarding risk factors associated with medial ulnar collateral ligament (MUCL) injury in baseball players and to serve as a robust source for identifying modifiable risk factors that once optimized, have the potential to reduce injury risk.

METHODS

Comprehensive search of the available literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Studies were included if they evaluated risk factors for MUCL injuries in the elbow of baseball players. Risk of bias assessment was performed via Methodological Index for Non-randomized Studies (MINORS) scoring system. The Oxford Centre for Evidence-Based Medicine was used to determine level of evidence. Variables of interest; player age, position, shoulder motion, humeral retrotorsion, joint laxity, strength, balance, geography, velocity, pitch count, pitch types, throwing volumes, and throwing mechanics were recorded.

RESULTS

Twenty-one studies were included in this systematic review. MINORS scores ranged from 75 to 87%, and variables demonstrated significant heterogeneity. Performance-based risk factors for MUCL injury included: increased pitch count (both annual and per game), higher percentage of fastballs thrown, smaller pitch repertoire, and/or a loss of pitching velocity. Biomechanical studies demonstrated the relationship between decreased shoulder range of motion (total ROM, ER, IR, and abduction), increased humeral retrotorsion, increased elbow valgus opening in the throwing arm, lower Y-Balance score, and increased lateral release position to increased MUCL injury.

CONCLUSION

Risk factors for MUCL injury can generally be categorized into 4 primary groups: 1) various player demographics and characteristics, 2) throwing too hard (high velocity), 3) throwing too much (pitch count/volume), and 4) throwing with poor mechanics. In this systematic review, the most significant nonmodifiable risk factors for MUCL injuries included: increased glenohumeral retrotorsion and elbow valgus opening. The most consistent modifiable risk factors included: total shoulder range of motion, pitch count, pitch selection, Y balance score, and lateral release position. Pitch velocity was inconsistent in literature, but most studies found this as a risk for injury. These risk factors may serve as appropriate targets for future evidence-based injury mitigation strategies.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II-IV studies.

Bibliometric and visualized analysis of scientific publications on rehabilitation of rotator cuff injury based on web of science

Background

Since the discovery of rehabilitation as an intervention for rotator cuff injury, its impact on the recovery of rotator cuff injury has attracted crucial attention, and the number of related studies is increasing worldwide. There were no bibliometric and visualized analysis studies in this field. This study aimed to investigate the research hotpots and trends in the rehabilitation of rotator cuff injury via bibliometric and visualized analysis and to identify the future development of clinical practice.

Method

The publications regarding rehabilitation of rotator cuff injury from inception to December 2021 were obtained from the Web of Science Core Collection database. The trends of publications, co-authorship and co-occurrence analysis and visualized analysis were carried out using Citespace, VOSviewer, Scimago Graphica software, and R Project.

Results

A total of 795 publications were included in this study. The number of publications significantly increased yearly. The United States published the highest number of related papers and the papers published by the United States had the highest citations. The University of Laval, the University of Montreal and Keele University were the top 3 most contributive institutions. Additionally, the Journal of Shoulder and Elbow Surgery was the journal with the highest number of publications. The most common keywords were "rotator cuff", "rehabilitation", "physical therapy", "management", and "telerehabilitation".

Conclusion

The total number of publications has shown a steady upward trend. The cooperation between countries globally was still relatively lacking, and therefore it is necessary to strengthen cooperation between different countries and regions to provide conditions for multi-center, large sample, and high-quality research. In addition to the relatively mature rehabilitation of rotator cuff injury such as passive motion or exercise therapy, telerehabilitation has also attracted much attention with the progress of science.

Advances in the Treatment of Rotator Cuff Tears: Management of Rotator Cuff Tears in the Athlete

Unique biomechanical factors in the overhead and throwing athlete lead to a spectrum of rotator cuff pathology, usually with progressive lateralization of the supraspinatus footprint. Initial comprehensive nonoperative management is indicated for all athletes. Progression to arthroscopic debridement, repair of concomitant injuries, and possible rotator cuff repair with a transosseous equivalent technique are the current management strategies for athletes when nonoperative management fails.

Risk factors for shoulder injuries in handball: systematic review

BACKGROUND

Handball is a sport with a high number of severe injuries. The shoulder is one of the most commonly injured joints, with an average prevalence of 17-41%.

OBJECTIVE

The primary aim is to identify the most significant risk factors related to shoulder injuries in handball. The secondary aim is to propose recommendations based on the available evidence concerning potential injury prevention strategies.

METHODS

Systematic searches of PubMed, MEDLINE, CINAHL, Proquest, SPORTDiscus, Web of Science, EMBASE, and Scopus were undertaken for peer reviewed articles published between 15 July 1995 and 15 July 2019. The same search strategy was repeated on 24 April 2022. Prospective cohort studies, written in English and published in a journal with a peer-review process aiming to investigate at least one modifiable or/and a non-modifiable potential risk factor for shoulder injuries, specifically in handball players, were included. Only papers published after 1995 were included. The methodological quality of the eligible studies was assessed using the modified version of the Downs and Black Checklist. The Best Evidence Synthesis (BES) approach was used for synthesizing and reporting the results.

RESULTS

1849 studies were identified, of which 8 were included. A total of 2536 (males = 1354, females = 1182) participants of which 2522 were handball athletes, were included. Four of the eight studies were rated as high methodological quality studies (> 85%) while the rest were rated as medium (50-85%). The risk factors for shoulder injuries in handball identified in the studies were strength imbalances (n = 6), glenohumeral range of motion (ROM) imbalances (n = 5), scapular dyskinesis (n = 5), incorrect dosage of training load (n = 2), previous injury (n = 1), sex (n = 2), player's position, school grade, playing level (n = 1), altered shoulder joint position sense (n = 1).

CONCLUSION

Overall, from all the risk factors evaluated, there was strong evidence that the weakness of the shoulder external rotator muscles and the female sex increase the probability of shoulder injury in handball athletes. Nevertheless, the evidence for the other risk factors was moderate due to the methodological quality and the limited number of studies.

PROTOCOL REGISTRATION

PROSPERO ID: CRD42020138233.

Active range of motion of the shoulder: a cross-sectional study of 6635 subjects

Background

Normative data for passive range of motion are well established, but daily living is comprised of active motion. The purpose of this study was to establish normative values for active range of motion of the shoulder across age, sex, and arm. Our hypotheses were that active range of motion of the shoulder (1) decreases with age group, (2) differs between males and females, and (3) differs between the right arm and left arm.

Methods

Shoulder active range of motion was captured with an eight-camera markerless motion capture system. Data were collected for a heterogenous sample of 6635 males and females of all ages. For each subject, 6 shoulder motions were collected with maximum values measured: external rotation, internal rotation, flexion, extension, abduction, and horizontal abduction. Three-way repeated measures analyses were performed, with 2 between-subject factors (age group and sex) and 1 within-subject factor (arm). The unadjusted threshold for statistical significance was α = 0.05.

Results

External rotation decreased with age (approximately 10° decrease from below 30 years to above 60 years). External rotation was approximately 5° greater in the right arm, whereas internal rotation was approximately 5° greater in the left arm. Flexion decreased with age (approximately 15° decrease from below 20 years to above 60 years). For age groups from 10 to 59 years, extension and horizontal abduction were approximately 5° to 10° greater in females than males. Abduction was greater for females than males. Abduction was also greater in younger people (aged 10-29 years) than older people.

Conclusion

In general, active range of motion of the shoulder decreases with age. Sex (male/female) and arm side (right/left) also influence shoulder range of motion.

Effectiveness of Pilates Training on Body Composition and Isokinetic Muscular Strength in Adolescent Baseball Players

Body composition and muscular strength are important for baseball skills and successful performance. Conditioning training programs have the potential to enhance athletic performance via physiological changes. In this single-group interventional study, we investigated the effect of 8 weeks of Pilates training (PT) on contralateral and regional body composition, and isokinetic muscular strength in knee and trunk flexion/extension in adolescent baseball players. In our results, PT increased both right- and left-sided lean mass in the trunk. Following PT, work per repetition and average power showed significant increases in the flexion and extension of the left knee only. PT significantly decreased the peak torque of the trunk flexor and increased the average power of the trunk extensor. In addition, the ratio of the trunk flexion/extension strength of peak torque showed a decreasing trend, whereas that of work and average power did not change significantly following PT. In conclusion, PT evenly improved lean mass on both the right and left sides of the body. Knee and trunk strength increased after PT. Our findings suggest that PT may be a useful strategy for enhancing athletic performance in regard to the muscular strength of adolescent baseball players.

Handball-specific loading acutely reduces the acromiohumeral distance in experienced handball players and in non-handball experienced athletes

Context

When playing handball, the preservation of the subacromial space, which can be quantified by the acromiohumeral distance (AHD), plays a crucial role for shoulder health of handball players. Acute effects of handball-specific loading on the subacromial space with consideration of individual adaptions resulting from long-term handball-specific loading experience have yet to be determined in order to prevent injuries such as e. g. an impingement of the supraspinatus tendon.

Objective

To (1) assess the acute effects of handball-specific loading on the AHD in healthy experienced handball players (HB) and non-handball experienced athletes (CG) and (2) to assess the AHD behavior in relation to individual intrinsic factors to identify possible risk factors and the effect of handball-specific experience associated adaptations.

Participants

20 HB (10m; 10f) and 20 CG (10m; 10f); 24 ± 5 years.

Intervention

Handball-specific loading protocol.

Main outcome measures

The AHD was measured by ultrasonography at 0° and 60° abduction pre and post intervention. Isometric shoulder strength was measured with hand-held dynamometry. Shoulder range of motion (ROM) was measured with goniometry.

Results

Handball-specific loading led to significantly reduced AHD in the dominant shoulder in the 60° abducted position in both groups (HB: −1.7 ± 2.0 mm; p = 0.001, d = 0.69; CG: −1.1 ± 2.0 mm; p = 0.024, d = 0.37) and in the non-dominant shoulder in 0° (−0.7 ± 1.5 mm; p = 0.038, d = 0.35) and 60° abducted position (−1.3 ± 1.8 mm; p = 0.004, d = 0.69) in HB only. Handball-specific loading enhanced AHD reduction when elevating the shoulder from 0° to 60° in both groups and arms. Larger shoulder abduction strength affected the maintenance of the AHD positively. HB demonstrated less shoulder strength compared to CG, while ROM did not differ.

Conclusions

Handball-specific loading can affect the ability to preserve the subacromial space which might put handball players at risk for shoulder injuries. Poor shoulder strength can aggravate this mechanism. Therefore, implementation of strengthening exercises of the external rotator and abductor muscles in the training schedule may improve shoulder health of handball players.

Correlation analysis of national elite Chinese male table tennis players’ shoulder proprioception and muscle strength

BACKGROUND

Shoulder is the most injured part in table tennis players, and it takes multiple roles in transmitting power and striking the center of the ball during the stroke. Proprioception is strongly correlated with high level of athletic performance. It is customary to assume that there is a correlation between proprioception and muscle strength and therefore proprioceptive assessment and rehabilitation is often neglected.

AIM

To investigate the correlation between isokinetic muscle strength and proprioception in the internal and external rotation muscle groups of elite Chinese male table tennis players, to provide reference for physical training and rehabilitation of elite table tennis players.

METHODS

A total of 19 national elite table tennis players from the Chinese National Table Tennis Team were recruited in this research. All of them had more than 10 years training experience and had participated major competitions such as the National Games and World Youth Championships. IsoMed 2000 was used to test the peak torque of internal and external rotation isokinetic concentric contraction of the athletes' bilateral shoulder joints at low speed (60°/s) and high speed (180°/s) respectively; IsoMed 2000 was used to conduct the Joint Position Reproduction test to evaluate the athletes' proprioceptive ability capacity at low speed (60°/s) and high speed (180°/s) respectively. If the data satisfied the normal distribution, the correlation between the differences in peak torque s and angles in different directions was analyzed using a Pearson simple linear model; otherwise, Spearman correlation analysis was used. The comparison of proprioceptive ability between the table tennis racket-holding hand and non-racket-holding hands was performed using independent samples t-test if the data satisfied a normal distribution; otherwise, the Mann-Whitney U test was used.

RESULTS

There was no direct linear correlation between the strength and proprioceptive correlation analysis at slow speed (60°/s) and fast speed (180°/s) in the racket-holding hand; At the slow speed (60°/s) and fast speed (180°/s), there was no correlation between muscle strength and proprioception in the non-racket-holding hand except for the internal rotation variable error (VE) and external rotation relative peak torque, which showed a moderate positive correlation (r = 0.477, P < 0.05), (r = 0.554, P < 0.05). The internal rotation’s constant error (CE) and VE were 1.06 ± 3.99 and 2.94 ± 2.16, respectively, for the racket-holding hand, and -3.36 ± 2.39 and 1.22 ± 0.93, respectively, for the non-racket-holding hand; the internal rotation’s CE, VE of the racket-holding hand was lower than that of the non-racket-holding hand, and there was a highly significant difference (P < 0.01).

CONCLUSION

There was no correlation between muscle strength and proprioceptive function in the internal and external rotation of the racket-holding hand’s shoulder in elite Chinese male table tennis players. These results may be useful for interventions for shoulder injuries and for the inclusion of proprioceptive training in rehabilitation programs.

Anterior glenohumeral capsular ligament reconstruction with hamstring autograft for internal impingement with anterior instability of the shoulder in baseball players: preliminary surgical outcomes

BACKGROUND

Shoulder pain and dysfunction are common in baseball players, and although "internal impingement" is recognized as one of the most common pathologies of shoulder dysfunction, the optimal surgical treatment for internal impingement with anterior instability of the shoulder remains controversial. This study evaluated baseball players' preliminary outcomes following anterior glenohumeral capsular ligament reconstruction for internal impingement with anterior instability of the shoulder.

METHODS

Twelve baseball players (all male; mean age, 20.5 ± 2.2 years) with internal impingement and anterior instability managed via anterior glenohumeral capsular ligament reconstruction were examined. The mean follow-up period was 25.3 ± 4.6 months. Anterior glenohumeral capsular ligament reconstruction was performed with a knee hamstring autograft for balanced stability and laxity with two major targets: to prevent hyperangulation and translation in horizontal abduction and to mimic the individual arm cocking position at the final decision of tension. Preoperative and final follow-up evaluations were performed using Jobe's postoperative grading system; the Kerlan-Jobe Orthopaedic Clinic Overhead Athletes Shoulder and Elbow Score; Disabilities of the Arm, Shoulder and Hand sports module; plain radiographs; and magnetic resonance imaging.

RESULTS

Jobe's postoperative grading system score, the Kerlan-Jobe Orthopaedic Clinic Overhead Athletes Shoulder and Elbow Score, and the Disabilities of the Arm, Shoulder and Hand sports module score improved significantly from 20.4 ± 12.2, 28.4 ± 8.3, and 80.2 ± 11.1 points preoperatively to 88.8 ± 13.6, 80.8 ± 7.7, and 22.4 ± 18.7 points postoperatively, respectively (P < .001, .0025, <0.001, respectively). Both clinical and imaging evaluations revealed improved internal impingement with anterior instability after anterior glenohumeral capsular ligament reconstruction. The mean external rotation at abduction significantly decreased from 113° preoperatively to 104° postoperatively. At follow-up, 10 of the 12 athletes (83.3%) returned to their prior competitive level. Plain radiographs and magnetic resonance imaging revealed no obvious loosening of the graft or screws.

CONCLUSIONS

Anterior glenohumeral capsular ligament reconstruction resulted in preferable clinical outcomes for young baseball players who experienced pain during the throwing motion. Stabilization of the glenohumeral joint with autografting of the knee hamstring may thus represent a solution for internal impingement with anterior instability in overhead throwing athletes.

Verification of Shoulder External Rotators Strength Measurement Using a Suspension Scale

Background

Of the shoulder external rotators, the infraspinatus and teres minor are the key muscles that contribute to the dynamic stability of the shoulder. It is crucial to properly measure the strength values to evaluate muscle function and training load for shoulder external rotators. A suspension scale (SPS) can measure the mass of the suspended object, and it may be possible to apply it to measure strength. However, the utility of strength measurements using an SPS has not been clarified in previous studies. In this study, we aimed to investigate the intra-rater reliability of measuring the strength of shoulder external rotators using an SPS and the relationship between strength measurement using an SPS and a handheld dynamometer (HHD).

Methodology

The participants were 10 healthy males with 20 shoulders (24.5 ± 2.5 years old; height = 172.8 ± 5.4 cm; weight = 69.6 ± 8.1 kg). Upper extremity strength was measured at 90° shoulder abduction, 90° external rotation, 0° horizontal adduction/abduction, 90° elbow flexion, and 0° forearm pronation/supination in the prone position. The isometric strength of shoulder external rotation was measured with the SPS and HHD, and one examiner measured the maximum strength value. The intra-rater reliability of the two methods using SPS and HHD was evaluated using the intraclass correlation coefficient (ICC_1,2), standard error of measurement (SEM), minimum detectable change (MDC), and Bland-Altman analysis. The relationship between the SPS and HHD was calculated as the correlation coefficient between the strength values of SPS and HHD.

Results

The intra-rater reliability of the strength measurement of shoulder external rotators using SPS was ICC_1,2 0.98 (95% confidence interval = 0.95-0.99), and SEM and MDC were 0.3 and 0.9, respectively. The measurements using SPS had no fixed and proportional biases. A significant positive correlation was observed between SPS and HHD (r = 0.94, p < 0.01).

Conclusions

The SPS is an alternative to the HHD for measuring the strength of shoulder external rotators. Thus, measuring the strength of shoulder external rotators using an SPS may be applied as a cost-effective and portable assessment method for shoulder function.

Disabled Throwing Shoulder: 2021 Update: Part 2-Pathomechanics and Treatment

The purpose of this paper is to provide updated information for sports healthcare specialists regarding the disabled throwing shoulder (DTS). A panel of experts, recognized for their experience and expertise in this field, was assembled to address and provide updated information on several topics that have been identified as key areas in creating the DTS spectrum. Each panel member submitted a concise presentation on one of the topics within these areas, each of which were then edited and sent back to the group for their comments and consensus agreement in each area. Part two presents the following consensus conclusions and summary findings regarding pathomechanics and treatment, including (1) internal impingement results from a combination of scapular protraction and humeral head translation; (2) the clinically significant labral injury that represents pathoanatomy can occur at any position around the glenoid, with posterior injuries most common; (3) meticulous history and physical examination, with a thorough kinetic chain assessment, is necessary to comprehensively identify all the factors in the DTS and clinically significant labral injury; (4) surgical treatment should be carefully performed, with specific indications and techniques incorporating low profile implants posterior to the biceps that avoid capsular constraint; (5) rehabilitation should correct all kinetic chain deficits while also developing high-functioning, throwing-specific motor patterns and proper distribution of loads and forces across all joints during throwing; and (6) injury risk modification must focus on individualized athlete workload to avoid overuse. LEVEL OF EVIDENCE: V, expert opinion.

The Effects of Fatigue on Muscle Synergies in the Shoulders of Baseball Players

BACKGROUND

Muscle synergies are defined as the central nervous system's organizational structure for movement. Muscle synergies change after muscular fatigue, with certain synergies assuming the primary role to compensate for fatigue within another muscle synergy. Owing to the high eccentric forces imposed upon the external rotators (ie, posterior rotator cuff), pitchers that continue to throw while fatigued are at a significantly higher risk of shoulder and/or elbow injury; however, the neuromuscular compensation strategies of baseball players in response to fatigue are currently unknown.

HYPOTHESIS

Players would utilize the same muscle synergy structure following external rotation (ER) fatigue; however, muscle coefficients of nonfatigued muscles would increase (ie, compensate for the external rotators) after fatigue.

STUDY DESIGN

Cross-sectional study conducted in a controlled, laboratory setting.

METHODS

Nine players from an intercollegiate competitive club baseball team voluntarily participated in this study. Surface electromyography was used on 14 muscles of the glenohumeral and scapulothoracic joints of the dominant arm during a reaching protocol. Players completed a baseline reaching protocol (prefatigue), then an ER fatigue protocol until maximum concentric ER was reduced by 40%, and finally repeated the same reaching protocol (postfatigue). Principal component analysis was used to extract muscle synergies, the variance accounted for (VAF) of each synergy, and muscle coefficients. Prefatigue was compared with postfatigue using paired t tests for all dependent variables.

RESULTS

Four muscle synergies were extracted for both pre- and postfatigue. The VAF for the ER/abduction synergy decreased significantly (prefatigue, 34.6%; postfatigue, 32.4%; P = 0.03), showing a decreased reliance on ER/abduction during the reaching task after fatigue. Within synergy 1, the pectoralis major muscle coefficient (-0.489 vs -0.552; P = 0.01; effect size = 1.68) decreased significantly from prefatigue to postfatigue, indicating that the pectoralis major assumed more of an antagonist role during ER/abduction. Within synergy 2 (forward reaching), there were no significant changes in VAF or muscle coefficients observed. For the third synergy, muscle coefficients increased for the serratus anterior (P = 0.02) and middle deltoid (P = 0.01), whereas in the fourth synergy, the pectoralis major (P = 0.01) increased and teres major (P = 0.01) and biceps brachii (P = 0.05) muscle coefficients decreased.

CONCLUSION

The decreased VAF of the ER/abduction synergy after fatigue indicate that other muscles within that synergy could not fully compensate to maintain function. Interestingly, the changes in muscle coefficients suggest that players relied less on the internal rotation (IR) synergy and more on the cross-body synergy following fatigue. This may be due to imbalances between ER and IR while maintaining balance between cross-abduction and adduction.

CLINICAL RELEVANCE

Clinicians may consider implementing low-load, high-repetition training programs to develop posterior shoulder endurance and prolong the onset of muscular fatigue.

Effect of Clubbell Training on Glenohumeral Internal and External Rotation, Muscle Function, and Ball Velocity in Baseball Pitchers

OBJECTIVES This study examined the effects of clubbell exercises in a pitcher training program on the range of motion (ROM), muscle function, and its subsequent influence on pitching velocity. Additionally, this study aimed to develop an optimal training program to prevent injury while improving pitcher performance.METHODS Eighteen pitchers were included and equally divided into clubbell exercise and control groups. Clubbell training was conducted through 60-minute sessions twice a week for 12 weeks. Internal/external rotational (IR/ER) ROM, IR/ER muscle strength, muscle endurance, muscle power, and pitching velocity were measured before and after the intervention.RESULTS The IR (<i>p</i> = 0.051) and total ROM (TROM; <i>p</i> = 0.05) of the throwing arm decreased in the control group but increased in the clubbell exercise group, with an observed tendency of interaction. In the non-throwing arm, the ER ROM was significantly different between the two groups (<i>p</i> <0 .05), also with an observed tendency of interaction (<i>p</i> = 0.055). IR peak torque per body weight at 60°/sec significantly increased in both groups over the exercise period (<i>p</i> < 0.01). Total work per body weight and average power of IR at 180°/sec increased in both groups over the exercise period (<i>p</i> < 0.01). The pitching velocity decreased in both groups throughout the exercise period (<i>p</i> < 0.05).CONCLUSIONS Although 12 weeks of clubbell training had limited effects on ROM, the findings revealed that this exercise could be effective in improving pitching performance, preventing injuries, and maintaining long-term performance. Further studies are recommended for a more detailed assessment.

Relationship between scapular control during isometric shoulder flexion and scapular motion during baseball pitching: a cross-sectional study

Background

A baseball pitcher with decreased scapular control may not be able to achieve suitable scapular motion at maximum shoulder external rotation (MER) of baseball pitching during the pitching action. It is common clinically to compare scapular control of the throwing and non-throwing arms to detect side-to-side differences. However, it remains unclear whether scapular control is different between the throwing and non-throwing arms. Moreover, no data exist on the relationship between scapular control and scapular motion at MER of pitching. Primarily, this study aimed to compare scapular control during isometric shoulder flexion between the throwing and non-throwing arms. Secondly, this study aimed to investigate the relationship between scapular control during isometric shoulder flexion and scapular motion at MER of pitching.

Methods

Fifteen healthy collegiate baseball pitchers (age, 20.2 ± 1.9 years; height, 1.76 ± 0.05 m; body mass, 73.3 ± 6.7 kg) were recruited. An optical motion tracking system was used to assess scapular motion. Scapular control was defined as the amount of change in the scapular internal rotation angle, downward rotation angle, and anterior tilt angle during isometric shoulder flexion. We assessed scapular position at MER of pitching.

Results

No significant differences were detected for any of the scapular angles during isometric shoulder flexion between the throwing and non-throwing arms. The amount of change in the scapular internal rotation angle, scapular downward rotation angle, and scapular anterior tilt angle during isometric shoulder flexion had a significant relationship with the scapular downward rotation angle at MER.

Conclusions

No side-to-side difference was noted in scapular control during isometric shoulder flexion in healthy collegiate baseball pitchers at the group level. Further studies are required to understand the side-to-side differences at the individual level. Additionally, there was a relationship between scapular control during isometric shoulder flexion and scapular position at MER. These findings suggest that clinicians may consider using isometric shoulder flexion to assess scapular control in baseball pitchers.

Throwing Injury Prevention Strategies with a Whole Kinetic Chain-Focused Approach

Purpose of Review

This review examines the relationship between the baseball pitching motion and the kinetic chain. The goal was to determine the underlying causes of a deficiency in throwing mechanics throughout a throwing motion, and to provide an evidence-based approach on how to prevent injuries caused by a lack of proper mechanics. In doing so, we sought to provide a warm-up strategy that can be added to every baseball player’s daily on-field routine that is tailored to each phase of the throwing motion.

Recent Findings

To help minimize the risk of injury to overhead throwing athletes, a thorough understanding of the throwing motion is critical. Throwing a ball places extreme stress on the body, notably the shoulder and elbow joints. With a clear understanding of the biomechanics of throwing, we can develop an injury prevention routine to minimize unnecessary stresses throughout the kinetic chain.

Summary

The throwing cycle is a complex motion that places various stresses throughout the thrower’s body, from the ankle to the core, and from the back to the shoulder and elbow. A thorough understanding of the mechanics of this motion, along with specific exercises to target the specific actions of each phase, may allow for throwers, regardless of their age and experience, to minimize injury risk.

Magnetic Resonance Imaging Findings of the Asymptomatic Shoulder May Impact Performance, Not Future Injury List Placement in Major League Baseball Pitchers

Purpose

To evaluate preseason shoulder magnetic resonance images (MRIs) obtained from pitchers entering either major or minor league baseball (MLB) and correlate findings with subsequent injury, operative repair, and placement on the injured list (IL).

Methods

Preseason-MRI of the throwing shoulders of professional-level baseball pitchers, taken during routine evaluations at a single organization (2004-2017) were retrospectively reviewed. Publicly available databases were queried to exclude pitchers with known injuries prior to pre-signing imaging. Three blinded reviewers reviewed all MRI scans independently to evaluate for the presence of abnormalities in the rotator cuff (RTC), labrum, capsule, long-head of the biceps tendon (LHBT), and humeral head. Binary imaging findings were correlated to future placement on the IL for subsequent shoulder complaints. Bivariate statistics using Student’s t-tests and Fisher exact tests (both α = .05) were used in this study.

Results

A total of 38 asymptomatic pitchers with shoulder MRIs were included. Pitchers had a mean (±SD) age of 28.2 ± 4.9 and had pitched an average of 119.6 ± 143.8 career games. Pitchers with partial articular-sided RTC tears (P = .04) or intra-articular BT hyperintensity (P = .04) on preseason MRI demonstrated an association with the need for future surgery. Pitchers with evidence of labral heterogeneity demonstrated greater total career pitch counts (10,034.1 vs 2,465.3; P = .04). Evidence of a posterior-superior humeral cyst was associated with decreased strikeouts per 9 innings (6.1 vs 8.0; P = .039) and total strikeout percentage (16.1% vs 23.2%; P = .04).

Conclusion

Although there was a significant difference in the percent of various radiographic findings between the injured and healthy cohort, no MRI findings were predictive of future IL placement or duration of placement. The presence of a posterior superior humeral cyst was associated with decreased strikeout rates at 2 and 3 years, the presence of a labral tear was associated with decreased earned run average (ERA) at 3 years and decreased career strikeout percentages, and increased capsular signal was associated with decreased 5-year ERA.

Level of Evidence

Level IV, retrospective study.

Chronic Adaptations of Shoulder Muscle Synergies in Healthy Baseball Players

BACKGROUND

Previous research has demonstrated that muscle synergy structure can adapt owing to training and injury; however, muscle synergies have not been evaluated in baseball players.

HYPOTHESIS

The throwing arm would have a similar muscle synergy structure but different levels of individual muscle activity within each synergy, relative to the nonthrowing arm.

STUDY DESIGN

Cross-sectional study in a controlled laboratory setting.

METHODS

Fourteen healthy competitive baseball players were included. Participants were tested bilaterally during a center-out planar reaching task using the KINARM robot, where kinematic data and surface electromyography data from 14 glenohumeral and scapular muscles were synchronized. Principal component analysis was used to extract muscle synergies, the variance accounted for (VAF) of each synergy, and individual muscle coefficients. The dominant (DOM) arm was compared with the nondominant (NDOM) arm using paired t tests for all dependent variables.

RESULTS

The same number of muscle synergies were extracted on the DOM and NDOM arms, along with no differences in VAF. In the first synergy, the infraspinatus (DOM 0.798 vs NDOM 0.587, P = 0.038) and lower trapezius (DOM 0.872 vs NDOM 0.480, P = 0.005) muscle coefficients significantly increased on the DOM arm. The second synergy had a significantly increased anterior deltoid (DOM 0.764 vs NDOM 0.374, P = 0.003) and a significantly decreased posterior deltoid (DOM -0.069 vs NDOM 0.197, P = 0.041) muscle coefficient on the DOM arm.

CONCLUSION

The DOM shoulder exhibits a higher proportion of infraspinatus and lower trapezius muscle activation during the external rotation and abduction synergy. Also, the DOM shoulder has increased muscle activation of the teres major and latissimus dorsi during the internal rotation synergy, and increased muscle activation of the pectoralis major during the cross-body adduction synergy, compared with the NDOM shoulder.

CLINICAL RELEVANCE

By exploring these neuromuscular adaptations, the improved understanding of muscle synergy adaptations in baseball players will help optimize injury prevention and rehabilitation techniques.

Effects of Adding Aquatic-to-Land-Based Physiotherapy Programs for Shoulder Joint Position Sense Rehabilitation

There is limited evidence regarding the effects of aquatic-based physiotherapy on shoulder proprioception following post-traumatic injury to the joint. The main aim of this study was to investigate the effects of additional aquatic-based rehabilitation to a land-based physiotherapy program on shoulder joint position sense (JPS) rehabilitation. Forty-four individuals (mean age 44.50 ± 10.11) who had suffered a post-traumatic shoulder injury less than five months previously were pseudo-randomly allocated equally into a control group (9 females, 13 males) and experimental group (6 females, 16 males). Both groups received individualized standard land-based physiotherapy on average for 50 min per session, with five sessions per week for four consecutive weeks. The experimental group received an additional 30 min of personalized aquatic-based therapy during each session. Shoulder JPS was assessed by flexion (60°), extension (25°), abduction (60°), internal rotation (35°) and external rotation (35°) positions prior, halfway through, and after the intervention. Shoulder JPS improved significantly for all positions for both the control group (p < 0.03) and the experimental group (p < 0.01). No significant differences between the control group and the experimental group were found for change in shoulder JPS over time. Our results indicate that shoulder JPS can be significantly improved among individuals with post-traumatic injury to the joint through four weeks of personalized physiotherapy. The addition of aquatic-based exercises to standard land-based therapy did not, however, show significant benefits, and thus cannot be recommended for the improvement of shoulder JPS based on our findings.

Range of motion and muscle function on shoulder joints of young handball athletes

BACKGROUND

The detection of primary risk factors through the assessment of shoulder range of motion (ROM) and muscle function could prevent injuries in the initial stages of the handball (HB) practice.

OBJECTIVE

To compare shoulder ROM, muscle strength and muscle extensibility between throwing and non-throwing shoulders in young HB athletes and between non-HB athletes.

METHODS

A cross-sectional study was designed. Participants aged between 14-16 years that practice physical activity regularly were included and divided in two groups. The HB group included volunteers who practiced HB, the control group included volunteers who practiced other activities. The variables measured were internal rotation and external rotation ROM, maximum isometric strength, and extensibility of the tissues of the posterior part of the throwing and non-throwing shoulder.

RESULTS

Thirty-seven subjects were included. The HB group (n= 19) showed greater ROM in both shoulders compared to the control group (n= 18) (p< 0.05). The throwing shoulder of the HB group showed less internal rotation ROM, greater external rotation ROM and greater internal rotation strength when compared to the non-throwing shoulder (p< 0.05).

CONCLUSIONS

The results of the study suggest that young HB athletes present differences in shoulder ROM compared to non-HB athletes. Also, HB athletes showed differences in ROM and strength between the TS and non-TS. Hence, the assessment of the shoulder ROM and muscle function should be taken into consideration to avoid injuries in this population.

A Review of Upper Extremity Peripheral Nerve Injuries in Throwing Athletes

Peripheral nerve injuries in the upper extremities may be common in throwing athletes as the throwing motion places extreme stress on the dominant arm. The combination of extreme stress along with repetitive microtrauma from throwing uniquely places the throwing athlete at elevated risk of upper extremity peripheral nerve injury. However, because symptoms can be non-specific and frequent co-exist with pathology in the upper extremity, the diagnosis of peripheral nerve injury is often delayed. Diagnosis of peripheral nerve injuries may require a combination of history and physical exam, diagnostic imaging, electrodiagnostic testing, and diagnostic ultrasound guided injections. The primary management should include physical therapy focusing on throwing mechanics and kinetic chain evaluation. However, some athletes require surgical intervention if symptoms do not improve with conservative management. The purpose of this focused narrative review is to highlight upper extremity peripheral neuropathies reported in throwing athletes and to provide an overview of the appropriate clinical diagnosis and management of the throwing athlete with a peripheral nerve injury. This article is protected by copyright. All rights reserved.

Comparison of Glenohumeral Range of Motion Deficits in Youth, Collegiate, and Professional Baseball Players

BACKGROUND

Examining range of motion deficits across levels of baseball competition can result in a better understanding of the extent of altered range of motion patterns and identify competition levels that may require preventative interventions that target the deficits.

PURPOSE

The purpose of this study was to compare shoulder range of motion in baseball players across levels of competition and compare the prevalence of glenohumeral internal rotaton deficit (GIRD) and total arc of motion differences (TAMD) between competition levels in pitchers and position players.

STUDY DESIGN

Prospective descriptive cohort.

METHODS

Passive internal and external rotation range of motion was measured bilaterally. Individuals with current pain in the arm, shoulder, elbow or shoulder surgery within the prior two years were excluded. Measurements were taken during pre-season physical examinations. Players were divided into seven groups: 12u (11-12 years; n=30), 14u (13-14 years; n=30), High School 1 (HS 1; 15-16 year; n=42), High School 2 (HS 2; 17-18 years; n=25), College (n=22), Professional 1 (Pro1; 17-22 years; n=37) and Professional 2 (Pro2; 23 and older; n=37). Multiple one-way analyses of variance were performed to determine differences between groups. Tukey test for post-hoc analysis was employed to determine which competition levels were significantly different.

RESULTS

Two-hundred and twenty-three male baseball players ages 11-26 participated. The 12u (53.7°) and 14u (54.2°) groups had significantly less internal rotation than HS1 (65.2°), HS2 (63.9°), College (62.3°), Pro1 (64.9°), and Pro2 (64.5°) players (p<0.0001). The 12u, 14u, HS1, college, and Pro2 groups had greater than 50% of players with total arc of motion differences >5°. Conclusions: Range of motion alterations exist across ages and levels of competition with 12u and 14u players having less internal rotation than the older groups and youth pitchers having less total range of motion than HS1.

LEVEL OF EVIDENCE

2.