Current concepts in the rehabilitation of the overhead throwing athlete

Acute effects of doorway stretch on the glenohumeral rotational range of motion and scapular position in high-school baseball players

Background

Pectoralis minor tightness has been thought to affect the scapular position. Despite the wide implementation of doorway stretch in clinical practice owing to its apparent effectiveness in stretching the pectoralis minor, limited studies have investigated its influence on the glenohumeral rotational range of motion (ROM). This study aimed to examine the acute effects of doorway stretch on the glenohumeral rotational ROM and the correlation between the scapular position and ROM.

Materials and Methods

In total, 34 male high-school baseball players participated in this study. Outcomes included the pectoralis minor muscle length, glenohumeral rotational ROM, and scapular position. The distance between the sternocostal joint of rib 4 and the coracoid process was measured as the pectoralis minor length. Internal and external rotation ROM with the shoulder abducted at 90° were measured. The scapular position was defined by the following two measurements: the distance between the surface and the posterolateral corner of the acromion as well as the scapular index. The participants performed doorway stretch by abducting and externally rotating the shoulder at 90° and flexing the elbow at 90°. The outcomes were compared before and after stretching. Furthermore, the correlation between these changes was investigated.

Results

Pectoralis minor muscle length and glenohumeral internal rotation ROM was significantly higher after stretching than before, and the scapular position also significantly changed (P < .01 for both). A moderate correlation was found between the degree of change in the glenohumeral internal rotational ROM and scapular position (r = 0.44, P < .01).

Discussion

Our results indicated that doorway stretch significantly increased the pectoralis minor muscle length and glenohumeral internal rotation ROM and significantly altered the scapular position. Furthermore, a significant correlation between the degree of change in the scapular position and glenohumeral internal rotation ROM was observed. These results suggest that doorway stretch could be beneficial for improving the scapular position and glenohumeral internal rotation ROM, which are considered the cause of throwing injuries. Furthermore, the glenohumeral ROM may be affected by the scapular position.

Muscle Contraction Has a Reduced Effect on Increasing Glenohumeral Stability in the Apprehension Position

PURPOSE

Glenohumeral instability accounts for 23% of all shoulder injuries among collegiate athletes. The apprehension position-combined shoulder abduction and external rotation-commonly reproduces symptoms in athletes with instability. Rehabilitation aims to increase glenohumeral stability by strengthening functional positions. However, it is unclear how much glenohumeral stability increases with muscle contraction in the apprehension position. The purpose of this study was to determine whether the ability to increase translational glenohumeral stiffness, a quantitative measure of glenohumeral stability, with muscle contraction is reduced in the apprehension position.

METHODS

Seventeen asymptomatic adults participated. A precision-instrumented robotic system applied pseudorandom, anterior-posterior displacements to translate the humeral head within the glenoid fossa and measured the resultant forces as participants produced isometric shoulder torques. Measurements were made in neutral abduction (90° abduction/0° external rotation) and apprehension (90° abduction/90° external rotation) positions. Glenohumeral stiffness was estimated from the relationship between applied displacements and resultant forces. The ability to increase glenohumeral stiffness with increasing torque magnitude was compared between positions.

RESULTS

On average, participants increased glenohumeral stiffness from passive levels by 91% in the neutral abduction position and only 64% in the apprehension position while producing 10% of maximum torque production. The biggest decrease in the ability to modulate glenohumeral stiffness in the apprehension position was observed for torques generated in abduction (49% lower, P < 0.001) and horizontal abduction (25% lower, P < 0.001).

CONCLUSION

Our results demonstrate that individuals are less able to increase glenohumeral stiffness with muscle contraction in the apprehension position compared with a neutral shoulder position. These results may help explain why individuals with shoulder instability more frequently experience symptoms in the apprehension position compared with neutral shoulder positions.

Superior training efficacy of beginning movement load training for the baseball throwers

Background

Superior shoulder motion with rotator cuff activation are essential for the performance of the throwing athletes. The present study compared the novel beginning movement load training (BMLT) and popular throwers ten program regarding the training efficacy of baseball throwers. We hypothesized that the BMLT contributed the superior training efficacy than popular throwers ten program.

Methods

Forty adult baseball players were randomized into study group and control group equally. In study group, the cyclic shoulder motion was repeatedly operated 3 days in a week and lasted for 6 weeks using three different BMLT training machines. As for control group, three popular cyclic training in the throwers ten program were adopted for the shoulder trainings as the same protocol in study group. The evaluations before and after training included the static range of motion (ROM), the maximal voluntary isometric contraction (MVICs) of the target muscle (pectoralis major, middle deltoid and supraspinatus) and throwing velocity.

Result

After 6-week course, study group had significant wider static ROM in saggital adduction (p = 0.002), coronal internal rotation (p = 0.018) and external rotation (p = 0.044) than in control group. The maximal voluntary isometric contraction (MVIC) ratio of middle deltoid/supraspinatus was significant lower in study group (Study:Control = 1.14 ± 0.76:3.56 ± 5.57, p = 0.049) which indicated the enhanced supraspinatus maximal contraction in the study group after training. In addition, the study group had significant improvement in throwing speed (117 ± 10 vs. 109 ± 10 km/h, p = 0.040).

Conclusion

The BMLT contributed the superiority in range of motion, recruitment of supraspinatus and throwing velocity than the popular thrower’s ten program. It could be a favourable training for the overhead activity.

Effects of Dry Needling in Teres Major Muscle in Elite Handball Athletes. A Randomised Controlled Trial

Objective: To determine the effects of dry needling (DN) in active myofascial trigger points in the teres major muscle compared to an untreated control group in pain during throwing actions, shoulder range of motion (ROM), strength, and extensibility of the tissues in professional handball (HB) athletes. Methods: A randomised, single-blinded, controlled clinical trial was designed. Thirty HB athletes with shoulder pain were randomly assigned to the DN group (n = 15) or control group (n = 15). The DN group received a single session of ultrasound-guided DN technique in the teres major muscle. The control group received no intervention. Pain intensity during throwing actions (Numeric Pain Rating Score), shoulder ROM (inclinometer), isometric strength (hand-held dynamometer), and extensibility (inclinometer) were measured before and after treatment. Results: DN group showed statistically significant improvements with large effect sizes for pain intensity (p < 0.001; E.S: 1.3), internal rotation ROM (p < 0.001; E.S: 3.0) and extensibility (p < 0.001; E.S: 2.9) compared to the control group. No statistically significant differences were found for isometric strength (p > 0.05). Conclusion: A single session of DN in the teres major muscle was effective for improving pain intensity during throwing actions, internal rotation ROM and extensibility in HB athletes with shoulder pain.

Shoulder Range of Motion Deficits in Youth Throwers Presenting With Elbow Pain

BACKGROUND

Glenohumeral internal rotation deficit (GIRD) and total arc of motion difference (TAMD) have been associated with elbow injuries in throwing athletes.

HYPOTHESIS

Youth pitchers with elbow pain will have greater GIRD and TAMD compared with youth pitchers without elbow pain.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Glenohumeral range of motion of 25 consecutive throwing athletes presenting with elbow pain and that of a matched control group of 18 asymptomatic throwing athletes were compared. Bilateral glenohumeral internal rotation, external rotation, and horizontal adduction at 90° were measured and GIRD and TAMD were then calculated. An analysis of variance was performed to compare range of motion between throwers with and without elbow pain.

RESULTS

The average GIRD of the elbow pain group was 32.7° compared with 14.5° in the control group (P < 0.05). The average TAMD in the elbow pain group was 28.3° compared with 6.7° in the control group (P < 0.05). GIRD and TAMD were present in 88% (22 of 25) and 96% (24 of 25) of the elbow pain group versus 33.3% (6 of 18) and 55.6% (10 of 18) of the control group, respectively.

CONCLUSION

Compared with asymptomatic youth pitchers, those presenting with elbow pain have a statistically significant GIRD and TAMD.

CLINICAL RELEVANCE

This study suggests that a GIRD and TAMD may predispose youth pitchers to present with symptomatic elbow pain.

Professional Baseball Player Type and Geographic Region of Origin Impacts Shoulder External and Internal Rotation Strength

BACKGROUND

Shoulder strength deficits are implicated in arm injuries and performance deficits in baseball players.

PURPOSE

To characterize shoulder external (ER) and internal (IR) rotation strength in professional baseball players, and compare strength across player type (pitchers, position players) and geographic origin (North America, Latin America).

STUDY DESIGN

Cross-sectional.

METHODS

Minor league professional baseball players from North America and Latin America (n=242; age=22.4±2.3 years; n=135 pitchers and n=107 position players; n=162 North American and n=80 Latin American players) volunteered at spring training. Bilateral shoulder IR and ER isometric strength was measured in sitting with the arm at the side using a handheld dynamometer stabilized on a wall via a specialized jig. Strength was normalized to body weight, and compared using t-tests between player type and geographic area of origin (p < 0.05).

RESULTS

Position players had greater strength in ER, IR and ER:IR (ER:0.7-2.7N/kg; IR:1.3-3.8N/kg; ER:IR ratio 0.36-1.22) compared to pitchers (ER:0.5-2.5N/kg; IR:0.6- 4.2N/kg; ER:IR ratio 0.44-1.16) on the throwing arm. North American pitchers had lower ER [MD= -0.4 (95%CI:-0.7,-0.2);p=0.002] and IR [MD= -0.2 (95%CI:-0.4,-0.1);p=0.006] than Latin American pitchers on the throwing arm. There were no differences between geographic groups for position players.

DISCUSSION/CONCLUSIONS

Player position and geographic origin influence shoulder rotational strength values in professional baseball players. Position players have 14 - 20% higher ER and IR isometric strength than pitchers. Moreover, Latin American pitchers exhibited 11.8% greater ER strength and 16.7% greater IR strength as compared to North American pitchers. Normative values can be used to determine player deficits, declines in performance, and targets for return to play after injury.

LEVEL OF EVIDENCE

Level II.

Correlation of glenohumeral internal rotation deficit with shear wave ultrasound elastography findings for the posterior inferior shoulder capsule in college baseball players

BACKGROUND

The glenohumeral internal rotation deficit (GIRD), primarily caused by the tightness of the posterior capsule, is a major risk factor for shoulder injuries in overhead throwing athletes. Quantitative evaluation of posterior capsular thickness and tightness can help determine the relationship between the posterior inferior capsule and GIRD. One previous study has assessed posterior capsule tightness using shear wave elastography (SWE), in college baseball players; however, it did not address the cutoff value of capsular elasticity that could be considered as abnormal capsular tightness. We aimed to re-evaluate effectiveness of SWE in quantifying posterior shoulder capsule tightness in college baseball players and determine the cutoff value of abnormal capsular elasticity that can predict impending throwing-related shoulder injuries associated with GIRD.

METHODS

Twenty-four college baseball players were enrolled in this study. External and internal rotation of the shoulder joint was assessed. The participants were classified into the GIRD group if their throwing shoulder showed >20° of internal rotation loss compared with their nonthrowing shoulder. In a longitudinal ultrasonographic scan of the posterior inferior capsule, shear wave (SW) velocity and thickness were measured at the point nearest to the labrum on both shoulders.

RESULTS

Of the 24 subjects, 6 had a GIRD. The mean value of the SW velocity in the throwing shoulder was greater in the GIRD group than in the non-GIRD group (P = .006). The SW velocity difference between the throwing and nonthrowing shoulder was also greater in the GIRD group than in the non-GIRD group (P < .001). There was no significant difference in the thickness of the posterior inferior capsule between both groups. In correlation analysis, the difference in the SW velocity was more strongly correlated with the GIRD than with the SW velocity in the throwing shoulder. When we assume that a 20° GIRD is indicative of a shoulder at risk, the cutoff SW velocity in the throwing shoulder is 4.81 m/s and the SW velocity difference is 0.77 m/s.

CONCLUSION

The SW velocity is closely associated with posterior shoulder capsular tightness and may be of quantitative value in baseball players.

Rehabilitation Following Posterior Shoulder Stabilization

Posterior shoulder instability has been noted in recent reports to occur at a higher prevalence than originally believed, with many cases occurring in active populations. In most cases, primary surgical treatment for posterior shoulder instability-a posterior labral repair-is indicated for those patients who have failed conservative management and demonstrate persistent functional limitations. In order to optimize surgical success and return to a prior level of function, a comprehensive and focused rehabilitation program is crucial. Currently, there is a limited amount of literature focusing on rehabilitation after surgery for posterior instability. Therefore, the purpose of this clinical commentary is to present a post-surgical rehabilitation program for patients following posterior shoulder labral repair, with recommendations based upon best medical evidence.

LEVEL OF EVIDENCE

5.

The infraspinatus muscle activity during pitching motion in baseball players with shoulder instability

BACKGROUND

Shoulder microinstability is often overlooked, which can be problematic, especially in overhead athletes. The slipping phenomenon is defined as posterior or lateral sliding of the humeral head in an elevated arm. When the shoulder is close to the end range of stability, the infraspinatus is highly activated and keeps the shoulder in the glenoid cavity. This study aimed to examine the characteristic physical function and infraspinatus activity during the pitching motion in baseball pitchers with shoulder instability.

METHODS

Twenty-one male baseball pitchers participated and were divided into 2 groups based on radiograph findings at zero position: slipped (group S) and nonslipped (group N) groups. Physical function using Hara test and infraspinatus muscle activity during pitching were evaluated.

RESULTS

The infraspinatus muscle activity during the acceleration phase was significantly greater in group S (59.5 ± 33.0%MVC) than in group N (33.0 ± 16.9%MVC) (P < .05). Positive rate of the Hara test in group S was significantly high in the loose test and elbow push test.

CONCLUSIONS

This study shows that baseball pitchers with slipping phenomenon have capsular laxity and scapular instability that indicate high infraspinatus muscle activity during the acceleration phase. Therefore, repetitive pitching with hyperactivity of the infraspinatus on the slipping shoulder may cause fatigue and dysfunction.

Junior and Collegiate Tennis Players Display Similar Bilateral Asymmetries of Humeral Retroversion

CONTEXT

Overhead throwing athletes consistently display significant bilateral differences in humeral retroversion (HRV). However, there is limited evidence regarding HRV asymmetries in tennis players despite similarities between the overhead throw and tennis serve.

OBJECTIVE

To determine if junior and collegiate tennis players demonstrate bilateral differences in HRV, and whether the magnitude of the side-to-side difference (HRVΔ) was similar across different age groups.

DESIGN

Cross-Sectional Study Setting: Field-Based Patients or Other Participants: Thirty-nine healthy tennis players were stratified into three age groups: Younger Juniors (n = 11; age = 14.5 ± 0.5 years), Older Juniors (n = 12; age = 17.1 ± 0.9 years), and Collegiate (n = 16; age = 19.6 ± 1.2 years).

MAIN OUTCOME MEASURES

Three-trial means were calculated for HRV for the dominant and nondominant limbs, and HRVΔ was calculated by subtracting the mean of the nondominant side from the dominant side. Paired-sample t-tests were utilized to determine bilateral differences in HRV, while a one-way ANOVA was used to compare HRVΔ between groups.

RESULTS

For all three groups, HRV was significantly greater in the dominant arm compared to the nondominant arm (Younger Juniors: dominant = 62.8° ± 9.1° vs nondominant = 56.3° ± 6.8°, P = .039; Older Juniors: dominant = 75.5° ± 11.2° vs nondominant = 68.6° ± 14.2°, P = .043; Collegiate: dominant = 71.7° ± 8.5° vs nondominant = 61.2° ± 6.9°, P = .001). However, no significant differences were detected in HRVΔ when compared across age groups (P = .511).

CONCLUSIONS

Consistent with studies involving overhead throwing athletes, tennis players demonstrated significantly greater measures of HRV in the dominant limb. Further, the development of HRV asymmetries appear to have occurred prior to the teenage years as no changes were observed in HRVΔ between age groups.

Nonsurgical Management of Ulnar Collateral Ligament Injuries

Ulnar collateral ligament (UCL) injuries are a common source of pain and disability in the overhead athlete and often result in notable loss of time from competition. Over the past 10 to 15 years, the prevalence of UCL injury and reconstruction has undergone a dramatic increase, making it imperative to determine which patients may benefit from a nonsurgical regimen. Nonsurgical treatment involves a multidisciplinary approach of rehabilitation with tailored physical therapy programs and, in certain cases, biologic adjuncts. Physical therapy protocols should focus on strengthening the periscapular muscles, rotator cuff, core musculature, and flexor pronator mass to help stabilize the injured elbow and prevent injury recurrence before the initiation of a progressive throwing program. The implementation of injury prevention programs has shifted the focus from just the elbow and have included the shoulder, legs, and core in an effort to help decrease the stress on the upper extremity. In addition, biologic therapies such as platelet-rich therapy are promising modalities to augment the conservative treatment of UCL injuries but remain under investigation. The purpose of this study is to review available strategies and outcomes for conservatively treating UCL injuries.

Rehabilitation Following Ulnar Collateral Ligament Reconstruction in Overhead-Throwing Athletes

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The prevalence of ulnar collateral ligament (UCL) injury and UCL reconstruction (UCL-R) continues to rise, causing morbidity in overhead-throwing athletes.

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Postoperative rehabilitation protocols are essential for proper healing of the reconstructed ligament and safely returning athletes to competition, yet there is no uniformly accepted standard of care.

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UCL-R rehabilitation has traditionally been guided by expert opinion and conventional wisdom rather than scientific studies, resulting in substantial variability in rehabilitation practices, time to return to play, and outcomes.

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Current research efforts aim to closely investigate the biomechanical implications of UCL-R and overhead throwing to better guide rehabilitation and to improve competitive performance and outcomes.

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Additional biomechanical and scientific studies on rehabilitation modalities and timing are warranted for systematic analysis, optimization, and standardization of UCL-R rehabilitation.

Shoulder Rotational Strength Profiles of Danish National Level Badminton Players

BACKGROUND

Increased age has been shown to be associated with weaker external rotators and stronger internal rotators of the shoulder in pitchers and tennis players. Whether this age-associated change is present in elite badminton players is unknown.

PURPOSE

To compare the internal and external rotation strength of the shoulder in adolescent and adult elite badminton players.

STUDY DESIGN

Cross-sectional.

METHODS

Thirty-one adolescent (12 females aged 16.8 ± 1.6 years and 19 males aged 17.1 ± 1.6 years) and 29 adult (10 females aged 25 ± 2.9 years and 19 males aged 26.2 ± 4.6 years) national level badminton players were tested pre-seasonally for external rotation (ER) and internal rotation (IR) isometric muscle strength bilaterally, using a hand-held dynamometer. Within-group ER to IR strength ratios were calculated (ER/IR×100%).

RESULTS

The adolescents had stronger shoulder ER than the adults on both sides (p < 0.05). The adult males tended to have stronger IR of the dominant shoulder than the adolescent males (p = 0.071). In the dominant shoulders, the strength ratios for adult females and males were 77% and 78%, respectively, while the same ratio for adolescent females and males were 85% and 99%, respectively. In the non-dominant shoulders, the ER/IR strength ratios for adult females and males were 90% and 87%, respectively, while the ratios for adolescent females and males were 116% and 102%, respectively.

CONCLUSION

This study is the first to demonstrate that in shoulder injury-free national team badminton players, adolescents have stronger shoulder ER than adults on both sides. Therefore, increased age appears to be associated with weaker shoulder ER muscles in elite badminton players.

LEVEL OF EVIDENCE

3b.

Shadow pitching deviates ball release position: kinematic analysis in high school baseball pitchers

Background

Although shadow pitching, commonly called “towel drill,” is recommended to improve the throwing motion for the rehabilitation of pitching disorders before the initiation of a throwing program aimed at returning to throwing using a ball, the motion differs from that of normal throwing. Learning improper motion during ball release (BR) may increase shoulder joint forces. Abnormal throwing biomechanics leads to injures. However, there has been no study of shadow pitching focusing on the BR position. The purpose of the present study was to evaluate the BR position and kinematic differences between shadow pitching and normal throwing. In addition, the effect of setting a target guide for BR position on throwing motion was examined in shadow pitching.

Methods

The participants included in this study were 20 healthy male students who were overhand right-handed pitchers with no pain induced by a throwing motion. Participants performed normal throwing (task 1), shadow pitching using a hand towel (task 2), and shadow pitching by setting a target of the BR position (task 3). A motion capture system was used to evaluate kinematic differences in throwing motions, respectively. Examination items comprised joint angles and the differences in BR position.

Results

BR position of task 2 shifted significantly toward the anterior, leftward, and downward directions compared with task 1. The distance of BR position between tasks 1 and 2 was 24 ± 10%. However, task 3 had decreased BR deviation compared with task 2 (the distance between 3 and 1 was 14 ± 7%). Kinematic differences were observed among groups at BR. For shoulder joint, task 2 showed the highest value in abduction and horizontal adduction among groups. In spine flexion, left rotation and thorax flexion, task 2 was significantly higher than task 1. Task 3 showed small differences compared with task 1.

Conclusions

The BR position of shadow pitching deviated significantly in the anterior, leftward, and downward directions compared with normal throwing. Furthermore, we demonstrated that the setting of BR target reduces this deviation. Thus, the target of BR position should be set accurately during shadow pitching exercises in the process of rehabilitation.

The Effect of Straight-Line Long-Toss Versus Ultra-Long-Toss Throwing on Passive Glenohumeral Range of Motion Recovery After Pitching

BACKGROUND

Repetitive throwing in baseball pitchers can lead to pathologic changes in shoulder anatomy, range of motion (notably glenohumeral internal rotation deficit), and subsequent injury; however, the ideal strengthening, recovery, and maintenance protocol of the throwing shoulder in baseball remains unclear. Two strategies for throwing shoulder recovery from pitching are straight-line long-toss (SLT) throwing and ultra-long-toss (ULT) throwing, although neither is preferentially supported by empirical data.

HYPOTHESIS

ULT will be more effective in returning baseline internal rotation as compared with SLT in collegiate pitchers after a pitching session.

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 24 National Collegiate Athletic Association Division I baseball pitchers with mean age 20.0 ± 1.1 years were randomized to either the ULT group (n = 13; 9 right-hand dominant, 4 left-hand dominant) or SLT group (n = 11; 10 right-hand dominant, 1 left-hand dominant). Measurements (dominant and nondominant, 90° abducted external rotation [ER], internal rotation [IR], and total range of motion [TROM]) were taken at 5 time points across 3 days: before and immediately after a standardized bullpen session on day 1; before and immediately after a randomized standardized ULT or SLT session on day 2; and before practice on Day 3.

RESULTS

ULT demonstrated significantly greater final ER compared with baseline (+10°; P = 0.05), but did not demonstrate significant IR changes. Similarly, SLT demonstrated significantly greater post-SLT ER (+12°; P = 0.02) and TROM (+12°;P = 0.01) compared with baseline, but no significant IR changes. Final ER measurements were similar between ULT (135° ± 14°) and SLT (138° ± 10°) (P = 0.59). There was also no statistically significant difference in final IR between ULT (51° ± 14°) and SLT (56° ± 8°) (P = 0.27).

CONCLUSION

The routine use of postperformance, ULT throwing to recover from range of motion alterations, specifically IR loss, after a pitching session is not superior to standard, SLT throwing. Based on these findings, the choice of postpitching recovery throwing could be player specific based on experience and comfort.

CLINICAL RELEVANCE

The most effective throwing regimens for enhancing performance and reducing residual impairment are unclear, and ideal recovery and maintenance protocols are frequently debated with little supporting data. Two strategies for throwing shoulder recovery from pitching are SLT and ULT throwing. These are employed to help maintain range of motion and limit IR loss in pitchers. The routine use of ULT throwing for recovery and to limit range of motion alterations after a pitching session is not superior to SLT throwing.

The Effect of the Crow Hop on Elbow Stress During an Interval Throwing Program

BACKGROUND

Postoperative rehabilitation protocols after ulnar collateral ligament (UCL) reconstruction typically involve a structured interval throwing program. In an effort to minimize torque placed on the UCL, athletes are often instructed to throw with a crow hop, even at short throwing distances. However, the effect of the crow hop on medial elbow stress is unknown.

PURPOSE/HYPOTHESIS

The purpose was to determine whether elbow stress differs with and without a crow hop across the throwing distances of a typical interval throwing program. We hypothesized that crow hop throws would generate lower torque on the elbow than standing throws at each distance of the interval throwing program.

STUDY DESIGN

Controlled laboratory study.

METHODS

Healthy high school and collegiate pitchers and position players were recruited from the surrounding area. Each player was outfitted with a wearable athletic sleeve and device that recorded elbow torque (Newton-meters), arm slot (degrees), arm speed (revolutions per minute), and shoulder rotation (degrees). Ball velocity (miles per hour) was measured using a radar gun. Players were instructed to perform 3 crow hop throws and 3 standing throws at distances of 30, 45, 60, 90, 120, 150, and 180 feet. A repeated measures analysis of variance was used to compare ball velocity, elbow torque, arm slot, arm speed, and shoulder rotation between crow hop and standing throws at each throwing distance.

RESULTS

Twenty athletes participated in this study (average age, 17.8 years; range, 15-25 years). The average medial elbow torque increased at each distance for both crow hop and standing throws at distances of 30, 45, 60, and 90 feet (P < .05), after which there were no significant increases in elbow torque (P > .05). The average torque was higher for crow hop throws than standing throws at distances of 30 feet (13.9 N·m vs 12.0 N·m; P = .002), 45 feet (21.8 N·m vs 19.3 N·m; P = .005), and 60 feet (28.0 N·m vs 24.5 N·m; P = .02).

CONCLUSION

Crow hop throws generated greater medial elbow torque than standing throws at distances up to 60 feet; however, there were no differences in elbow torque at distances greater than 60 feet between the 2 throw types. For both crow hop and standing throws, elbow stress increased at each distance interval up to 90 feet before plateauing at distances greater than 90 feet. The crow hop throwing technique does not reduce medial elbow stress during a simulated interval throwing program, and it may actually increase torque at shorter throwing distances.

CLINICAL RELEVANCE

The results of our study indicate that it would be prudent for players to initially perform standing throws at shorter distances and only later be allowed to employ a natural crow hop at greater distances to minimize torque placed on the medial elbow during UCL rehabilitation protocols.

Current Concepts in Arm Care Exercise Programs and Injury Risk Reduction in Adolescent Baseball Players: A Clinical Review

CONTEXT

Awareness of important injury risk factors associated with excessive pitching volume has been highlighted in the literature, but injury rates remain high. Shoulder pain in baseball players is associated with various changes in musculoskeletal movements, which presents as measurable impairments throughout the kinetic chain. Baseball coaches and rehabilitation professionals have utilized exercise programs targeting strength and flexibility of the throwing arm to prevent injuries. The purpose of this review is to summarize the current evidence regarding the effectiveness of arm care exercise programs in reducing upper extremity injury rates in adolescent baseball players.

EVIDENCE ACQUISITION

A search of electronic databases, including CINAHL with full text, MEDLINE, and SPORTDiscus was conducted to retrieve available articles in English from the years 2010 through 2020. The search terms injury prevention, exercise, and adolescent baseball were used.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Improving shoulder internal rotation range of motion by stretching the posterior shoulder muscles daily was associated with a 36% risk reduction of shoulder and elbow injuries. Group-based arm care exercise programs that target multiple musculoskeletal impairments demonstrated an approximately 50% reduced risk of elbow injury.

CONCLUSION

For adolescent baseball players, arm care injury prevention programs focusing on important musculoskeletal impairments are effective at reducing injury incidence rates. Multimodal injury prevention programs that improve multiple musculoskeletal impairments are more comprehensive and may result in better injury reduction than programs focusing on a singular impairment.

Epidemiology of injuries in female and male senior Slovenian handball leagues

BACKGROUND

Handball is associated with a high frequency of injuries due to unexpected situations, external disturbances of movement and extreme positions of body segments. The purpose of this study was to identify and analyze injuries among female and male players from all five senior Slovenian handball leagues in the season 2010/2011.

METHODS

We conducted a retrospective epidemiological study using a questionnaire. Data were collected between February and May 2012. Descriptive analysis is provided.

RESULTS

Forty-five percent of all the players were injured, reporting 92 injuries. 0.58 injuries/player occurred, 57 (62%) in females and 35 (38%) in males. Injury incidence in females (27.7 injuries/1000 hours match, 0.97 injuries/1000 hours training) was higher than in men (10.6 injuries/1000 hours match, 0.5 injuries/1000 hours training), respectively. The left- and right-back players were injured most often (41%). Sprain was the most common injury type (55%). Most injuries were severe (29%). The lower limb was injured most frequently (62%). Ankle was injured the most commonly (35%), but ankle injuries were in most cases moderate (38%). More than 70% of knee injuries and 50% of shoulder injuries were severe. In 33%, cause of injury was contact with an opponent/teammate. Thirty-six percent of players reported shoulder and 36% ankle overuse syndromes.

CONCLUSIONS

Present findings showed a higher incidence of injuries in female than in male senior Slovenian handball players in the 2010/2011 season. Preventive programs should focus not only on the acute ankle and knee injuries, but also on overuse syndromes of the shoulder and ankle.

The effects of a humeral head posterior gliding strategy on changes in muscle activities of the infraspinatus during external rotation of the shoulder

Background/aims

It is important that shoulder rehabilitation programmes incorporate exercises that selectively activate the infraspinatus. In this study, changes in infraspinatus and posterior deltoid electromyography activity during a sitting external rotation exercise with and without the use of a humeral head posterior gliding strategy were investigated.

Methods

A total of 12 healthy men participated in this study. The activity of the infraspinatus and posterior deltoid was measured during the sitting external rotation exercise, performed with and without humeral head posterior gliding. Differences in the electromyography activity of the infraspinatus and posterior deltoid, with and without humeral head posterior gliding, were analysed using paired t-tests.

Results

Infraspinatus activity was significantly higher with humeral head posterior gliding than without it (P<0.001). Conversely, posterior deltoid activity was significantly lower with humeral head posterior gliding compared to without it (P<0.001).

Conclusions

Based on these results, humeral head posterior gliding is recommended for the selective activation of the infraspinatus when performing shoulder external rotation exercises, with the shoulder abducted at 90°.

Changes in Muscle Activity among College Pitchers Using 5- to 12-Oz Weighted Baseball

OBJECTIVES Several studies have reported that weighted baseball (WB) training is effective in improving ball speed; however, the weight of the ball suitable for training remains unclear. This study aimed to investigate the changes in muscle activity during pitching using 5- to12-oz WBs and to provide basic data for training programs to improve pitching speed.METHODS The subjects of this study were 10 overhand pitchers who had more than 5 years of experience. Muscle activity was measured and analyzed at 70–85% of throwing baseball maximum effort (TBME) during soft toss (ST) and TBME was evaluated using electromyography.RESULTS As the ball weight increased, muscle activity also increased in all pitching phases. Muscle activity was higher during ST with WBs heavier than 10 or 11oz than during TBME, indicating that the loads on the shoulder and elbow joint muscles increased. Conversely, muscle activity during ST with 5- to 7-oz WBs was lower than that during TBME, although phase and muscle group differences were observed.CONCLUSIONS The results of this study suggest that training with 8- to 10-oz WBs could increase muscle strength and activity, although the effect may vary with fitness level and muscle strength.

RESIDENTS CASE REPORT: MUSCULOCUTANEOUS NERVE INJURY IN A COLLEGIATE BASEBALL PITCHER

Background

Literature regarding musculocutaneous nerve injuries among the athletic population is scarce, with only several reported clinical cases among baseball and softball pitchers.

Purpose

To present a unique case of a musculocutaneous nerve injury to aid in clinician awareness and propose innovative rehabilitation practices that may facilitate improved patient outcomes during recovery.

Case Description

A 23-year-old Division 1 NCAA collegiate baseball pitcher presented with vague anterior arm pain following a pre-season game. The athlete described the pain as an "intense stretch" of his right arm that occurred during his last pitch. The initial evaluation identified tenderness over the right distal bicep. All shoulder and elbow orthopedic tests to assess shoulder impingement, labral pathologies, and glenohumeral instability were unremarkable. Increased neural tension was also noted with upper limb neurodynamic testing of the median and ulnar nerves on the right arm compared bilaterally. Electromyography (EMG) testing confirmed a right upper and mid-brachial plexus stretch injury with the primary involvement of the musculocutaneous nerve. Rehabilitation focused on restoring strength deficits and diminishing neural tension. Blood flow restriction (BFR) was introduced on the uninvolved limb to reduce deficits in bicep musculature strength. Once the athlete regained bicep strength and forearm sensation, he was progressed from flat-ground throwing activities to throwing off the mound.

Outcomes

A reduction in neural tension during neurodynamic testing of the right arm, improvement of bicep brachii deficits seen between the right and left limbs, and restoration of sensation in the right lateral forearm enabled a progressive return to sport.

Discussion

Due to vague reports and inconclusive findings, the initial presentation of musculocutaneous nerve injuries may be mistaken for other conditions such as a biceps brachii strain. Further -documentation of this injury and rehabilitation procedures are needed to enhance patient outcomes.

PERCEIVED SELF-REPORT OF EFFORT DURING ROTATOR CUFF & SCAPULAR REHABILITATIVE EXERCISE IN PATIENTS AFTER SHOULDER SURGERY

Background

Rehabilitation following shoulder surgery involves the use of resistive exercise but dosing of these -exercises historically employs multiple sets of pre-determined repetitions and few reports document the perceived effort encountered by patients during these exercises for both elastic resistance and free-weights. The OMNI-Resistance Exercise Scale (OMNI-RES) has been tested and applied as a measure of perceived exertion (RPE) for resistive exercise but has not gained widespread acceptance as an optimal method for physical therapists to document RPE during rehabilitation of shoulder surgery.

Purpose

To generate descriptive values of RPE encountered during common shoulder exercises of varying resistance in patients following shoulder surgery as well as provide a comparative analysis between perceived exertion ratings of similar exercise movement patterns using elastic and traditional isotonic resistance.

Study Design

Descriptive Cross-sectional Cohort.

Methods

Sixty-six subjects (mean age 53.3 + 12.8 years) were included in this study following shoulder surgery (RC repair n=22, labral repair n=10, SA n=34). Perceived exertion using the OMNI-RES was recorded during performance of seven rotator cuff and scapular rehabilitation exercises at 6- and 12-weeks following surgery.

Results

Mean RPE using OMNI-RES in combined surgical groups ranged between 3.6 and 5.7 (mean = 4.50 + 2.1) across all seven exercises (scale 0 = very easy to 10 = extremely hard). From the external rotation (ER) exercise pair, paired t-tests revealed standing ER w/ Thera-band® (ERB) had a significantly higher OMNI-RES score versus sidelying ER w/ cuff weight (SLERW) (mean: 5.13 vs 4.41, p = 0.001) while the extension exercise pair consisting of standing shoulder extension w/ band (EXTB) and prone extension w/ cuff weight (PEXTW) showed no significant difference in OMNI-RES score (mean: 3.54, 3.67, p = 0.626).

Conclusion

Commonly prescribed resistance exercise in the rehabilitation following shoulder surgery show light-moderate ratings of perceived exertion at both 6 & 12 week post-operative timepoints across three surgical procedures.

Level of Evidence

3b.

Effect of a 12-Week Rehabilitation Exercise Program on Shoulder Proprioception, Instability and Pain in Baseball Players with Shoulder Instability

Background

The shoulder joint has a wide range of motion, but is vulnerable to sport-related injuries. We aimed to evaluate the differences in the proprioception of the shoulder should instability, and shoulder pain in high school baseball players with shoulder instability following a 12-week rehabilitation exercise program.

Methods

We enrolled 13 baseball players with shoulder instability who visited the Orthopedics Department at Konkook University Hospital in Seoul, South Korea and 12 controls without shoulder instability. We examined the dominant shoulder and the non-dominant shoulder for both groups. We restricted participation to individuals who had no other orthomechanical disease in the past six months, except for instability of the shoulder, and no physical limitation to participate in the exercise. We measured the proprioception of the shoulder and shoulder instability, and we also evaluated pain with the Visual Analog Scale before and after the rehabilitation program. To verify the differences between groups, we used a two-way analysis of variance, and a two-way analysis of covariance was used when a significant difference was found at the pretest (baseline between groups).

Results

Proprioception was associated with shoulder instability. The Visual Analog Scale rating improved in the dominant shoulder with instability; and a positive change was found in the dominant shoulder without instability after the rehabilitation program (P < 0.05).

Conclusion

The 12-week rehabilitation exercise program might improve the proprioception and pain of patients with shoulder instability. However, further studies with more participants and a rehabilitation exercise program should be undertaken.

Influence of a Pre-throwing Protocol on Range of Motion and Strength in Baseball Athletes

Though chronic overhand throwing is known to result in range of motion and strength adaptations, there is limited research regarding interventions for maintenance of these characteristics. Therefore, the purposes of this study were to explore the use of a pre-throwing protocol focusing on lumbopelvic-hip complex musculature in high school baseball players and examine its effects on shoulder and hip range of motion and isometric strength over the course of a season. Four exercises were added to the intervention team's warm-up routine. The control and intervention teams' passive bilateral hip and shoulder range of motion and isometric strength were assessed pre/post-season. A multivariate analysis of variance revealed significant differences in delta scores between the teams for multiple shoulder and hip range of motion and isometric strength variables. Key results were the intervention team lost significantly more stride hip external rotation but gained more isometric strength than the control team. The intervention team was also able to better maintain shoulder range of motion than the control team. Practitioners should use the results of this study and consider incorporating exercises that target lumbopelvic-hip complex musculature into their current training program.

["Handball shoulder" in the focus of diagnosis and treatment]

Handball is one of the most popular team sports in Germany. In the diagnosis and treatment of shoulder injuries and shoulder complaints, a distinction must be made between sports-specific adaptation over many years and supposed decompensation. In contrast to throwing sports such as baseball or javelin, intended movement sequences in handball are often disrupted suddenly and abruptly by simultaneous contact with an opponent. This can result in a potential for further injuries. There is usually a gradual transition from a physiologically adapted handball shoulder to a pathological throwing shoulder requiring therapy. A throwing shoulder is characterised by a limitation of performance caused by pain in the shoulder during repeated sports-specific stress. In addition to a thorough clinical examination, MRI is the preferred method of examination due to the fact that changes in a handball shoulder are reflected in muscular tissue, tendons and bone in the form of overstrain reactions (bone bruise). Patients should not only take a break from sports and receive adequate pain treatment, but also undergo a specific physiotherapy regimen. MRI results should always be interpreted in due consideration of symptoms and clinical examination results. Surgery is indicated if there is a lack of improvement after specific pain treatment and physiotherapy, or structural damage corresponding to the symptoms without a chance of recovery or with a higher probability of symptoms and function improving in response to surgery. After surgical treatment, the subsequent rehabilitation plays a major role. Depending on the injury, up to 90 % of the patients may be able to return to sports.

Can a Conservative Rehabilitation Strategy Improve Shoulder Proprioception? A Systematic Review

CONTEXT

Proprioception deficits contribute to persistent and recurring physical disability, particularly with shoulder disorders. Proprioceptive training is thus prescribed in clinical practice. It is unclear whether nonsurgical rehabilitation can optimize shoulder proprioception.

OBJECTIVES

To summarize the available evidence of conservative rehabilitation (ie, nonsurgical) on proprioception among individuals with shoulder disorders.

EVIDENCE ACQUISITION

PubMed, Web of Science, and EBSCO were systematically searched, from inception until November 24, 2019. Selected articles were systematically assessed, and the methodological quality was established using the Dutch Cochrane Risk of Bias Tool and the Newcastle-Ottawa Quality Assessment Scale. The Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines were utilized for this review. The conservative treatments were categorized as follows: (1) conventional therapy, (2) proprioceptive training, (3) elastic kinesiology tape, and (4) other passive therapies.

EVIDENCE SYNTHESIS

Twelve articles were included, yielding 58 healthy control shoulders and 362 shoulders affected by impingement syndrome, glenohumeral dislocations, nonspecific shoulder pain, rotator cuff dysfunction, or subluxation poststroke. The level of agreement between the evaluators was excellent (84.9%), and the studies were evaluated to be of fair to excellent quality (risk of bias: 28.5%-100%). This review suggests, with moderate evidence, that proprioceptive training (upper-body wobble board or flexible foil training) can improve proprioception in the midterm. No decisive evidence exists to suggest that conventional therapy is of added value to enhance shoulder proprioception. Conflicting evidence was found for the improvement of proprioception with the application of elastic kinesiology tape, while moderate evidence suggests that passive modalities, such as microcurrent electrical stimulation and bracing, are not effective for proprioceptive rehabilitation of the shoulder.

CONCLUSIONS

Proprioceptive training demonstrates the strongest evidence for the effective rehabilitation of individuals with a shoulder proprioceptive deficit. Elastic kinesiology tape does not appear to affect the sense of shoulder proprioception. This review suggests a possible specificity of training effect with shoulder proprioception.

Shoulder stiffness after rotator cuff repair: the fate of stiff shoulders up to 9 years after rotator cuff repair

BACKGROUND

Stiffness and retear are 2 common complications of rotator cuff repair. McNamara et al found that postoperative stiffness was associated with lower retear rates at 6 months. This study aimed to determine if stiffness after rotator cuff repair protects the individual from retear up to 9 years after surgery.

MATERIALS AND METHODS

Two groups of patients, 69 with stiff and 63 with nonstiff shoulder, who underwent arthroscopic rotator cuff repair were created based on external rotation measurements at 6 weeks postoperatively. Patients had regular follow-up assessments at 6, 12, and 24 weeks and were instructed to return for a follow-up at least 2 years after surgery. Patients were assessed for range of motion, shoulder function, strength, and rotator cuff integrity using ultrasound.

RESULTS

For patients with postoperative stiffness at 6 weeks, the retear rate at 6 months was 3%, whereas the rate for nonstiff patients was 19% (P = .004). This protective effect of postoperative stiffness persisted up to 9 years after surgery (P = .002). Postoperative stiffness resolved by 5 years after surgery for all measurements except external rotation (50° vs. 61°) (P = .006). Patients with postoperative stiffness had continued improvements in abduction (P < .001), internal rotation (P = .020), and all patient-ranked measurements from the 6-month follow-up to 5 years after surgery. Patients with stiff shoulder had greater overall satisfaction by the final follow-up (P = .028).

CONCLUSIONS

In patients experiencing stiffness after rotator cuff surgery, the repair is less likely to fail at 6 months. Although the stiffness generally resolves by 5 years, this protective effect still persists at 9 years after surgery.

Softball pitching mechanics and shoulder injuries: a narrative review

Softball is the third most popular women's collegiate sport in the United States, with 19,680 total athletes as of the 2015-2016 season. Despite its popularity and growth in recent years, research focusing on the biomechanics of the windmill pitch and its associated shoulder injuries is relatively scarce. The incidence of shoulder injury is highest during the preseason and the beginning of the regular season. The windmill pitch can be divided into distinct phases, with the shoulder experiencing the greatest force during the delivery phase. Significant demands placed on the shoulder during the windmill pitch put pitchers at a higher risk of developing shoulder injuries than position players. Maximum shoulder compression/distraction forces during the windmill pitch have been shown to be comparable to those experienced during the baseball overhand throw, dispelling the myth that the windmill pitch is not taxing on the shoulder. Injuries associated with the high compression/distraction forces include lesions to the rotator cuff, glenoid labrum, and biceps brachii. Pitcher-specific training, cross-training, and whole-body conditioning should be incorporated into current training regimens to decrease the risk of shoulder injuries.

Enhanced rehabilitation guidance after arthroscopic capsulolabral repair of the shoulder: a randomized controlled trial

Objective:

To compare the effects of a 12-month home-based exercise program to usual care in patients after arthroscopic capsulolabral repair of the shoulder.

Design:

Randomized controlled trial.

Setting:

Outpatient physical and rehabilitation medicine clinic.

Subjects:

Forty-five patients (mean age: 35 years; standard deviation (SD): 10 years) who underwent arthroscopic capsulolabral repair due to labral lesion were randomized into an exercise group (EG) or a control group (CG).

Intervention:

The EG received a 12-month home-based additional exercise program with four physiotherapy follow-up visits, while the CG received standard postoperative exercise instructions.

Main measures:

Self-reported shoulder disability was assessed with the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and quality of life with the Short-Form (SF)-36 Health Survey. The function of the operated shoulder was evaluated with strength and range of motion measurements.

Results:

No between-group differences were observed in any of the outcomes at the follow-up. Mean ASES score improved by 16 (95% confidence interval (CI): 10–23) points from the baseline 78 (SD: 17) in the EG and 13 (95% CI: 7–19) points from the baseline 79 (SD: 17) in the CG. Both groups achieved a significant improvement in the dimensions of Physical Functioning, Role-Physical, and Bodily Pain of the SF-36 and in every aspect of strength and range of motion measures. In EG, exercise adherence was moderate (52%) during the first six months and poor (22%) during the last six months.

Conclusion:

Home-based additional exercises with four outpatient follow-up visits did not improve outcome after arthroscopic capsular repair of the shoulder.

Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers

Background

Flexor digitorum superficialis (FDS) muscle provides dynamic stabilization and medial elbow support for ulnar collateral ligament (UCL). The FDS contraction significantly affects the medial joint distance (MJD) through grip contraction. However, it remains unclear whether FDS activity alone contributes to medial elbow stability, or together with the activation of the flexor digitorum profundus during grip contraction, and which finger’s FDS is the main contributor to elbow stability. We investigated the resistive effects of isolated FDS contraction in individual fingers against valgus stress in the elbow joint using stress ultrasonography (US).

Methods

We investigated 17 healthy males (mean age, 27 ± 5 years). Valgus stress US was performed using the Telos device, with the elbow at 30° flexion. MJD was measured for each arm during 3 separate conditions: at rest (unloaded), under valgus load (50 N) (loaded), and under valgus load with FDS contracted in individual fingers (loaded-contracted).

Results

MJD was significantly longer when loaded (5.4 ± 0.4 mm) than unloaded (4.1 ± 0.2 mm, P = 0.007) or loaded-contracted (4.6 ± 0.3 mm, P = 0.003) for each finger. When loaded-contracted, MJD differed statistically between the index and ring fingers (P = 0.03) and between the middle and ring fingers (P = 0.04). However, the difference between the index and middle fingers was not statistically significant (P = 0.08).

Conclusions

Individual FDS contraction, particularly of the index and middle fingers, contributes most to stabilization against valgus stress. Thus, injury care programs should incorporate FDS exercises of these fingers.

Pitcher Shoulder: Update Article

Most shoulder injuries occur due to repetitive overhead movements. Before studying the treatment of these shoulder injuries, it is paramount that health professionals have an understanding of the etiology of and the underlying mechanisms for shoulder pathologies. The act of overhead throwing is an eloquent full-body motion that requires tremendous coordination from the time of force generation to the end of the pitch. The shoulder is a crucial component of the upper-body kinetic chain, as it transmits force created in the lower body to the arm and hand to provide velocity and accuracy to the pitch.

Importance of radar gun inclusion during return-to-throwing rehabilitation following ulnar collateral ligament reconstruction in baseball pitchers: a simulation study

BACKGROUND

Rehabilitation following elbow ulnar collateral ligament reconstruction in baseball pitchers relies on a progression of pitching activities to ensure protection and gradual strengthening of the reconstructed ligament. The purpose of this study was to determine the medial elbow torque associated with pitches at various effort levels and determine whether radar gun assistance improves players' abilities to accurately match partial-effort pitches with true references based on maximum pitch velocity.

METHODS

Thirty-seven healthy high school and collegiate baseball pitchers were included in this study. Participants were excluded if they were injured, recovering from injury, or otherwise not currently pitching at full effort. Pitch parameters were collected using a validated wearable sensor. Participants threw 5 pitches at 50%, 75%, and 100% subjective effort. Pitchers then threw 5 pitches at 50% maximum velocity and 75% maximum velocity, as measured by a radar gun.

RESULTS

Thirty-seven pitchers completed this study. Pitches thrown at 50% and 75% partial effort were significantly faster and generated higher elbow torque than did pitches thrown at 50% and 75% velocity, respectively (P < .001). A 10% decrease in percentage of maximum velocity was associated with a 13% decrease in percentage of maximum elbow torque (β coefficient = 1.3, R² = 0.81, P < .001).

CONCLUSION

Pitchers generate higher-than-intended forces when throwing at 50% and 75% effort during a subjective partial-effort throwing protocol. Use of a radar gun to guide partial-effort throwing during throwing rehabilitation programs may protect the reconstructed elbow from excess medial torque.

Pitching shoulder passive flexibility: torque-angle analysis for external rotation and internal rotation

In this study, a custom device was developed to analyse the pitching shoulder's external rotation (ER) and internal rotation (IR) passive flexibility. We analysed three novel measures: the resistance onset angle (ROA = angle where the shoulder begins stretching), rotational stiffness, and torque at the end range of motion (ROM). The purpose was to conduct a bilateral analysis to determine if there are significant differences between the throwing and non-throwing shoulder. Participants were 30 upper level pitchers (13 division I, 17 minor league). During testing, pitchers laid supine on a treatment table and the arm was secured to a rotational wheel with the shoulder abducted 90° and elbow flexed 90°. Dependent t-tests revealed significant (p < 0.01) and relatively extreme bilateral differences for all three variables. The throwing shoulder had: increased ER ROA (9°), decreased IR ROA (5.3°), increased ER stiffness (17%), increased IR stiffness (34%), increased ER torque (21%), and increased IR torque (30%). Secondary correlation analysis was completed to determine if the torque-angle variables were good predictors of the end ROM. Stiffness correlations were weak for ER (r = 0.35, p = 0.048) and IR (r = 0.42, p = 0.017) but ROA correlations were strong for ER (r = 0.85, p < 0.001) and IR (r = 0.86, p < 0.001).

Glenohumeral Internal Rotation Deficit: Prime Suspect or Innocent Bystander?

PURPOSE OF REVIEW

Glenohumeral internal rotation deficit (GIRD) is a term used in the literature to describe the physiological adaptation that occurs in the dominant arm of the overhead-throwing athlete. The meaning of this term and the clinical significance and the rationale for its treatment have all been described with some ambiguity within the literature. GIRD as a measurement is multivariate. There is an adaptive bony component in humeral retroversion (HR) and muscular contributions in the form of thixotropy which can confound the capsular component of GIRD. Emerging diagnostic tools such as ultrasound can help differentiate between the bony and soft tissue contributions as well as provide a dynamic assessment in the throwing shoulder. The purpose of this review is to describe and differentiate between anatomical GIRD (aGIRD) and pathological GIRD (pGIRD), discuss the clinical significance of pGIRD and values reported within the literature, and describe its measurement and clinical treatment.

RECENT FINDINGS

Recent literature has demonstrated that GIRD alone is not associated with injury risk of the upper extremity in the overhead athlete. Although past literature has demonstrated pGIRD as increasing injury risk, other variables such as external rotation (ER) deficit, horizontal adduction deficit, and shoulder flexion deficit have been associated with injury of the upper extremity while GIRD did not. Further, an appreciation for the difference between adaptive GIRD and pathologic GIRD has recently been emphasized to ensure optimal treatment addresses the pathologic portion of GIRD. The recent focus on early treatment approaches to pGIRD may play a role in its diminished risk association. This review offers the term humeral retroversion (HR) Corrected GIRD as a more clinically sensitive value that may provide the clinician a more precise rationale for the treatment of pGIRD. Currently, diagnostic ultrasound is a reliable and valid method for measuring HR in the overhead-throwing athlete. Future research that validates clinical methods for assessing HR could provide utility for clinical decision-making in the absence of diagnostic ultrasound.

Does a Partial Rotator Cuff Tear Affect Pitching Ability? Results From an MRI Study

Background:

Numerous studies have examined changes in the athletic performance of baseball pitchers after rotator cuff surgery. However, only a few studies have evaluated changes in athletic performance caused by partial rotator cuff tears that are not treated surgically.

Purpose:

To examine the course of partial-thickness rotator cuff tears and its possible effect on the athletic performance of professional pitchers.

Study Design:

Case series; Level of evidence, 4.

Method:

Of 191 professional pitchers who attended our clinic between January 2009 and October 2018, 52 individuals had partial-thickness tears with at least 2 years of follow-up magnetic resonance imaging (MRI) scans and were included in this study. All initial MRI examinations were performed when a season was finished or during the off-season for regular medical check-up purposes. Hence, any abnormal finding on MRI, which suggests damage to the rotator cuff tendon, was assumed to have occurred during the previous season. The mean follow-up MRI period was 40.8 months (range, 24.4-100.9 months). We defined the year before an athlete’s first MRI at our clinic as the year of damage, and we evaluated athletic performance during the season before the damage (pre-damage year 1), the season of the damage (damage year), and 1 and 2 seasons after the damage (post-damage years 1 and 2). We evaluated the changes in 5 statistical performance indicators: earned run average (ERA), fielding independent pitching (FIP), walks plus hits divided by innings pitched (WHIP), winning percentage (WPCT), and innings pitched (IP).

Results:

The partial-thickness tears progressed in 39 of 52 (75%) patients. Of these 39 patients, 34 (87%) were grade 1 in severity and 5 (12.8%) were grade 2 or higher. The ERA of the pitchers did not increase significantly immediately after damage or at post-damage years 1 and 2. WPCT increased significantly compared with pre-damage year 1 (P < .001), and IP decreased significantly during the follow-up period (P < .001). Although no significant decrease in pitching ability was noted based on these 3 indices, significant increases were observed for FIP and WHIP.

Conclusion:

A partial-thickness rotator cuff tear does not have significant influence on the athletic performance of professional baseball pitchers in the short term based on conventional performance indicators. Our findings suggest that WHIP and IP decline significantly at 2 years after damage is noticed.

BASEBALL PLAYERS DIAGNOSED WITH ULNAR COLLATERAL LIGAMENT TEARS DEMONSTRATE GREATER SIDE TO SIDE DIFFERENCES IN PASSIVE GLENOHUMERAL ABDUCTION RANGE OF MOTION COMPARED TO HEALTHY CONTROLS

Background

Numerous studies have shown that baseball players develop range of motion adaptations in their throwing arm. While some of these shoulder range of motion adaptations can lead to greater throwing velocity, excessive changes in shoulder range of motion can increase the risk of injury to the ulnar collateral ligament (UCL).

Purpose/Hypotheses

The purpose of this study was to compare the passive GH-ABD ROM measures of baseball players with a diagnosed UCL tear (UCL group) to a group of age, activity, and position matched healthy controls (CONT group). The primary hypothesis was that baseball players with an UCL tear would have a greater loss of passive glenohumeral abduction range of motion in their throwing shoulder than healthy controls. A secondary hypothesis was that baseball players with an UCL tear would demonstrate similar glenohumeral abduction range of motion in their non-throwing arm and increased side-to-side glenohumeral abduction differences compared to the healthy cohort.

Study Design

Retrospective prospective case-control study.

Results

The UCL group had significantly greater glenohumeral abduction range of motion on their throwing shoulder (132.5 °±8.3 °) than the CONT group (120.19 °±11.2 °, p = 0.000). Similarly, the UCL group had increased glenohumeral abduction range of motion on their non-throwing shoulder (141.2 °±9.5 °) compared to the CONT group (124.1 °±11.4 °, p = 0.000). Additionally, the UCL group had a greater glenohumeral abduction difference (-8.7 °±8.4 °) than the CONT group (-3.8 °±7.7 °, p = 0.001).

Conclusion

In contrast to the original hypotheses, high school and collegiate baseball players that sustained an UCL injury presented with greater glenohumeral abduction range of motion in both their throwing and non-throwing shoulders compared to healthy controls. However, the finding of greater side-to-side glenohumeral abduction range of motion deficits in the UCL group when compared to the matched healthy controls confirms the secondary hypothesis.

Level of Evidence

Level 3.

Reduced shoulder strength and change in range of motion are risk factors for shoulder injury in water polo players

OBJECTIVE

To determine whether pre-season shoulder ROM and strength can be used to identify athletes at risk of future shoulder injury.

DESIGN

Prospective cohort.

SETTING

High performance sports institute.

PARTICIPANTS

76 sub-elite water polo players.

MAIN OUTCOME MEASURES

Mean pre-season shoulder internal (IR) and external rotation (ER) ROM and strength values compared by gender, dominance and prospective injury status.

RESULTS

14-dominant shoulder injuries were recorded. There was a significant difference (p = 0.05) in total ROM difference (TROM) between the prospectively injured and no injury groups (-17.2°(30.4);-0.8°(13.3)), and dominant side ER strength (11.7%(2.4) vs 14.5%(2.8), p = 0.03) and IR strength (16.5%(3.0) vs 21.6%(4.9) as a percentage body weight (PBW) were also significantly different (p ≤ 0.03). Separate significant associations were found between future episodes of shoulder injury and; dominant shoulder TROM difference of ≥7.5°(OR 3.6,95%CI 0.8-16.0), ER strength as a PBW≤12.5%(OR 5.2,95%CI 1.0-27.9), and IR strength as a PBW≤16.8%(OR 13.8,95%CI 2.2-88.0).

CONCLUSION

Pre-season dominant TROM difference, and reduced shoulder IR and ER strength relative to body weight were significant predictors for future shoulder injury. Although further investigation with a larger sample size is required, achieving optimal values on these measures may reduce future episodes of shoulder injury in water polo players.

Relationship Between Glenohumeral Internal Rotation Deficit and Medial Elbow Torque in High School Baseball Pitchers

BACKGROUND

Alterations in throwing mechanics have been identified as a risk factor for overuse injuries in baseball players. Glenohumeral internal rotation deficit (GIRD) has been found to adversely affect throwing mechanics, but the effect of GIRD on medial elbow torque is unclear.

PURPOSE

To investigate the relationship between GIRD and medial elbow torque in high school-aged baseball pitchers.

STUDY DESIGN

Descriptive laboratory study.

METHODS

High school baseball pitchers (14-18 years old) were recruited for participation in this study. Players' height, weight, body mass index, and arm measurements were recorded as well as shoulder and elbow range of motion measurements. GIRD was calculated from the difference between dominant and nondominant shoulder internal rotation. Participants then pitched 5 fastballs at maximum effort while wearing a wireless sensor that recorded elbow torque, arm slot, arm speed, shoulder rotation, and ball velocity. Principal component analysis was performed to determine which variables were associated with elbow torque or ball velocity.

RESULTS

Twenty-three high school pitchers participated in this study; 35% (n = 8) of participants exhibited GIRD of at least 20°. The mean GIRD was 15.3°± 11.2° and was not a predictor of medial elbow torque (P = .205) or ball velocity (P = .333). Ball velocity, age, and height were predictors of medial elbow torque (P = .012, P = .003, and P = .024, respectively).

CONCLUSION

In high school baseball pitchers, GIRD was not associated with medial elbow torque during the pitching motion. Instead, ball velocity, player age, and player height carried greater significance.

CLINICAL RELEVANCE

This study suggests that high school pitchers with GIRD do not have an inherently greater risk for increased medial elbow torque during the throwing motion. It is recommended that pitchers instead assess their ball velocity to evaluate for relative differences in medial elbow torque.

Effect of neuromuscular training on functional throwing performance and speed in asymptomatic cricket players

OBJECTIVE

To determine the effect of neuromuscular training on functional throwing performance and speed among asymptomatic cricket players.

DESIGN

Single-subject A-B-A design.

METHOD

Forty-three male asymptomatic sub-elite cricket players were recruited from Karnataka Institute of Cricket, Bangalore, India, with a mean age of 20.4 ± 2.03 years. Throwing accuracy and throwing speed were measured using Functional Throwing Performance Index (FTPI) and radar gun respectively, at zero, 12, 24 and 30 weeks in accordance with the A-B-A single-subject design. The neuromuscular training of the throwing arm was performed for 12 weeks, two days a week of supervised training including rhythmic stabilization drills were performed. A non-supervised training session including shoulder strengthening programme was conducted three days a week.

RESULT

Participants demonstrated significant improvement in throwing accuracy (p < 0.001) and speed (p < 0.001) after 12 weeks of neuromuscular training. Six weeks post-withdrawal of the neuromuscular training on throwing accuracy was not significant (p = 0.117), However, speed was sustained (p = 0.013).

CONCLUSION

Neuromuscular training showed an improved efficiency in throwing performance following 12 weeks of training in sub-elite cricket players. The sustained effect was not observed following 6 weeks of withdrawal of training.

Variability in Baseball Throwing Metrics During a Structured Long-Toss Program: Does One Size Fit All or Should Programs Be Individualized?

BACKGROUND

The variability of throwing metrics, particularly elbow torque and ball velocity, during structured long-toss programs is unknown.

HYPOTHESES

(1) Elbow torque and ball velocity would increase as throwers progressed through a structured long-toss program and (2) intrathrower reliability would be high while interthrower reliability would be variable.

STUDY DESIGN

Descriptive laboratory study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Sixty healthy high school and collegiate pitchers participated in a structured long-toss program while wearing a validated inertial measurement unit, which measured arm slot, arm velocity, shoulder rotation, and elbow varus torque. Ball velocity was assessed by radar gun. These metrics were compared within and between all pitchers at 90, 120, 150, and 180 ft and maximum effort mound pitching. Intra- and interthrower reliabilities were calculated for each metric at every stage of the program.

RESULTS

Ball velocity significantly changed at each progressive throwing distance, but elbow torque did not. Pitching from the mound did not place more torque on the elbow than long-toss throwing from 120 ft and beyond. Intrathrower reliability was excellent (intraclass correlation coefficient >0.75) throughout the progressive long-toss program, especially on the mound. Ninety-one percent of throwers had acceptable interthrower reliability (coefficient of variation <5%) for ball velocity, whereas only 79% of throwers had acceptable interthrower reliability for elbow torque.

CONCLUSION

Based on trends in elbow torque, it may be practical to incorporate pitching from the mound earlier in the program (once a player is comfortable throwing from 120 ft). Ball velocity and elbow torque do not necessarily correlate with one another, so a degree of caution should be exercised when using radar guns to estimate elbow torque. Given the variability in elbow torque between throwers, some athletes would likely benefit from an individualized throwing program.

CLINICAL RELEVANCE

Increased ball velocity does not necessarily equate to increased elbow torque in long-toss. Some individuals would likely benefit from individualized long-toss programs for rehabilitation.

Arthroscopic Repair of Type II SLAP Lesions in Overhead Athletes

For overhead athletes and, in particular, baseball pitchers, the rates of success and return to play for those who have undergone arthroscopic repair of type II SLAP lesions are poor, ranging from 7% to 62%. The reasons for the poor results and high failure rates in overhead athletes with type II SLAP repairs are multifactorial and are a combination of many factors. These factors include the failure to establish the diagnosis and treat these athletes preoperatively; the inability of the operating surgeon to differentiate normal anatomic variants from pathologic SLAP lesions at the time of surgery; the surgical technique, which may violate the rotator cuff; or the placement of suture anchors, which restricts external rotation and alters overhead throwing mechanics. The proper diagnosis of SLAP lesions can be difficult because SLAP tears rarely occur in isolation and are often associated with other shoulder pathology. A proper history detailing the onset of symptoms and whether there was an acute episode of trauma or a history of repetitive use is critical. It is important to remember that no single physical examination finding is pathognomonic for SLAP tears. When seen in isolation, SLAP tears may mimic impingement syndrome (52%) or even anterior instability (39%). Surgical treatment of type II SLAP lesions should not be undertaken lightly in overhead athletes. If a 3-month rehabilitation period followed by a return to sports over the following 3 months does not allow the athlete to return to his or her preinjury level, diagnostic arthroscopy with SLAP repair is a reasonable option and can yield excellent results using the proper techniques. The technique described in detail in this article and our video can be technically demanding, but with the key points outlined, it can be reproduced and provide excellent results for overhead athletes undergoing SLAP repair. By not violating the rotator cuff, using a mattress configuration and keeping the suture knot away from the articular surface, and by not going anterior to the biceps tendon for repair, external rotation and strength can be preserved, leading to an excellent result with a predictable return to play for overhead athletes.

Baseball Pitchers' Perceived Effort Does Not Match Actual Measured Effort During a Structured Long-Toss Throwing Program

BACKGROUND

During rehabilitation throwing programs, baseball players are commonly asked to throw at reduced levels of effort (ie, 50% effort, 75% effort, etc) to moderate stress to healing tissues. It is currently unknown how changes in players' perceived exertion compares with changes in actual exertion during structured long-toss programs.

PURPOSE

To determine whether decreased effort correlates with decreased throwing metrics, whether metrics decrease proportionally with reductions in perceived effort, and to quantify intrathrower variability.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Sixty male high school and collegiate baseball pitchers participated in a structured throwing program. A motusBASEBALL sleeve was worn by all players, which measured elbow varus torque, arm velocity, arm slot, and shoulder rotation. Ball velocity was measured with a radar gun. Each pitcher threw 5 throws a distance of 120 ft with 3 efforts: maximum effort, 75% effort, and 50% effort. Throwing metrics were compared among the 3 levels of effort to see if each 25% decrease resulted in proportional decreases in elbow varus torque and ball velocity. Intrathrower variability was determined for each throwing metric at each degree of effort.

RESULTS

All throwing metrics decreased as players decreased their perceived effort (P < .001). However, these observed decreases were much smaller in magnitude than the decreases in perceived effort. During the 75% effort throws, elbow varus torque was only reduced to 93% of maximum and velocity dropped to 86% of maximum. Similarly, for the 50% effort throws, elbow varus torque remained 87% of max effort torque, while velocity remained 78% of max. Intrathrower reliability was considered excellent for most metrics (intraclass correlation coefficient, >0.75).

CONCLUSION

For every 25% decrease in perceived effort, elbow varus torque only decreased 7% and velocity only decreased 11%. Thus, when players throw at what they perceive to be reduced effort, their actual throwing metrics do not decrease at the same rate as their perceived exertion.

CLINICAL RELEVANCE

Measured effort decreased with decreasing perceived effort, but these were not proportional. This has significant implications for physical therapists, physicians, trainers, coaches, and athletes to understand and monitor elbow stress during the rehabilitation process.

Review of Shoulder Range of Motion in the Throwing Athlete: Distinguishing Normal Adaptations from Pathologic Deficits

PURPOSE OF REVIEW

Overhand (OH) throwers demonstrate a unique motion profile of the shoulder joint complex. This manuscript reviews normal adaptations in the OH thrower and contrast findings with pathologic motion deficits.

RECENT FINDINGS

Multiple adaptations in range of motion have been associated with increased risk for arm injury. The use of a more conservative cutoff value for glenohumeral internal rotation deficit and horizontal adduction in younger throwers may help reduce injury risk. Deficits in glenohumeral internal rotation, total range of motion, shoulder flexion, and external rotation insufficiency have all been proposed as means to identify OH throwers at risk for arm injury, but conflicting evidence exists. Understanding normal adaptation due to repetitive stress of throwing is essential to effective management of these athletes. Adaptive change in bone and soft tissues is normal and contributes to the unique motion profiles expected in throwers. The causative link between normal adaptation and shoulder and elbow injury remains uncertain.

Distance-Based Throwing Programs for Baseball Players From Little League to High School

An estimated 2.4 million children play baseball in 80 countries. The majority of these children have experienced pain with throwing. A key component to a successful rehabilitation after an upper extremity injury for a baseball player is an interval throwing program, which allows a youth athlete to increase the demands of throwing in a progressive and controlled manner. Numerous interval throwing programs are designed for baseball players of high school age and older, but few exist for the baseball player who is skeletally immature. Our interval throwing programs take into consideration various field dimensions, injury types, and position requirements for youth. Our goal is to create a guide for rehabilitation specialists and players to return to throwing as quickly and safely as possible.