Injury and training history are associated with glenohumeral internal rotation deficit in youth tennis athletes

Comparing shoulder proprioception, upper extremity dynamic stability, and hand grip strength in overhead athletes with and without scapular dyskinesis

INTRODUCTION

Scapular dyskinesis is prevalent among asymptomatic athletes, particularly those involved in overhead activities, and can significantly impact their neuromuscular control. These changes may impair upper extremity function and strength, elevating the risk of injury. Therefore, it is imperative to investigate how scapular dyskinesis affects shoulder proprioception, upper extremity dynamic stability, and hand grip strength in overhead athletes. This study compared these parameters between overhead athletes with and without scapular dyskinesis.

METHODS

The study included twenty asymptomatic professional overhead athletes with scapular dyskinesis and twenty without scapular dyskinesis, identified using the lateral scapular slide test. In this cross-sectional study, shoulder active joint position sense, serving as shoulder proprioception, was measured using an isokinetic dynamometer. Upper extremity dynamic stability and hand grip strength were evaluated using an upper quarter modified star excursion balance test (UQ-mSEBT) and a handheld dynamometer.

RESULTS

The study found that the shoulder active joint position sense was significantly lower in the scapular dyskinesis group compared to the group without scapular dyskinesis (PExternal Rotation = 0.003, PInternal Rotation < 0.001, and PForward Flexion = 0.002). However, the two groups had no significant differences in UQ-mSEBT and hand grip strength scores.

CONCLUSIONS

The results showed that scapular dyskinesis could affect the sense of shoulder active joint position among asymptomatic overhead athletes. However, it did not affect their upper extremity dynamic stability and hand grip strength.

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.

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.

Glenohumeral internal rotation deficit in general population with shoulder pain: A descriptive observational study

Glenohumeral internal rotation deficit (GIRD) is one of the most important factors influencing injury risk in the arm of overhead athletes. Some studies have shown that the GIRD of athletes with shoulder pain was higher than those without shoulder pain, establishing a relation between shoulder pain and GIRD. However, there are no studies that relate to GIRD and shoulder pain or the risk factors that affect GIRD in the population with this ailment. This study aimed to: determine if GIRD could be found clinically and between which values it oscillates in patients with shoulder pain, and explore if there are any potential associations between GIRD and some sociodemographic data, and orthopedic or radiological findings. A descriptive observational study design was adopted to determine if GIRD could be found clinically in patients with shoulder pain and to gain further evidence in the potential associations between GIRD and sociodemographic data, and orthopedic or radiological findings. All those patients without exclusion criteria between October 1,2020 and March 31,2021 were included. Exclusion criteria consisted of being under 18 years old but younger than 80 years old, showing shoulder pain in both shoulders and having a joint prosthesis in at least one of the 2 shoulders, tumor, or infection. A total of 67 patients aged between 25 and 75 years (52.7 ± 11.8 years, 36 male and 31 female). More than 82% of patients with shoulder pain showed a GIRD higher than 20º. The mean GIRD was 37.6 ± 17.09º. The 95th percentile was 66.22º. From sociodemographic data could be extracted that: patients who have children showed a lower GIRD, patients with right shoulder pain, or whose dominance coincided with a painful shoulder showed a higher GIRD. The orthopedic findings revealed that patients with a positive Jobe test showed a lower GIRD. The linear model considering both sociodemographic and orthopedic findings showed that GIRD was reduced by having children and by BMI. GIRD shows a high incidence in patients with shoulder pain. The descendant, BMI, and positive Jobe test were negatively associated with the GIRD.

Treatment of glenohumeral internal rotation deficit in the general population with shoulder pain: An open single-arm clinical trial

BACKGROUND

Maladaptation can provoke important alterations in the arthrokinematics such as an internal rotation reduction in the dominant shoulder compared with the nondominant shoulder known as glenohumeral internal rotation deficit (GIRD). Though the number of studies investigating GIRD in athletic population, there are not studies reporting the efficacy of the GIRD treatment in the nonathlete population, a kind of study required to improve our understanding of patient care with this pathology. This study aimed to describe the efficacy of the GIRD treatment in nonathlete population with shoulder pain.

METHODS

An open single-arm trial with 35 patients was adopted for evaluating the efficacy of GIRD treatment in patients with shoulder pain. All patients with shoulder pain who attended the consultation, accepted, and agreed to participate in the study between October 2020 and March 2021 were included. A treatment sequence including joint manual therapy techniques and soft tissue release techniques was applied in the consultation. Then, patients were instructed to adapt the daily active biological stimulus at home. The IR before (IR0) and after (IR1) the treatment was considered the outcome measure. The GIRD was calculated as the difference between the IR of the non-painful shoulder and the IR of the painful shoulder before (GIRD0) and after treatment (GIRD1). A paired Student t test was used to compare the GIRD of each patient before and after the treatment.

RESULTS

Treatment of the patients significantly increased the IR of the painful shoulder in all the patients (P-value < .0001) So, the mean IR0 was 26.09 ± 14.46º (23.64-28.53), and after the treatment the mean IR1 was 67.98 ± 15.03º (65.48-70.52). The mean difference after the treatment (IR1-IR0) was 41.89 ± 14.74º (39.4-44.39). The treatment also significantly reduced GIRD (P-value < .0001). So, the mean GIRD0 was 42.95 ± 16.26º (40.2-45.7), and after the treatment the mean GIRD1 was -1.05 ± 17.18º (-3.96 to 1.85).

CONCLUSIONS

The treatment administrated in this study significantly increased the internal rotation of the treated and painful shoulder and reduced the GIRD from the first consultation.

LEVEL OF EVIDENCE

Level 3.

Correlation of Glenohumeral Internal Rotation Deficit With Shoulder Pain in Elite Table Tennis Players

OBJECTIVES

The aims of the study were (1) to investigate glenohumeral internal rotation deficit (a difference in internal rotation of 15.6 degrees or more between dominant and nondominant shoulders) and its correlation with self-reported shoulder pain in table tennis players and (2) to find the optimal cutoff point for the difference in the internal rotation range of motion between dominant and nondominant shoulders of self-reported shoulder pain.

DESIGN

The internal rotation range of motion of both shoulders of 46 table tennis players was measured in the supine and side-lying positions, and the external rotation range of motion was measured in the supine position.

RESULTS

Significant differences existed in internal rotation range of motion between the two sides in the supine ( z = 6.53, P < 0.001) and side-lying positions ( z = 5.67, P < 0.001). Self-reported shoulder pain was associated with glenohumeral internal rotation deficit (odds ratio = 6.86, 95% confidence interval = 1.752-26.832, P = 0.006). The cutoff points for the difference in internal rotation range of motion between the sides of self-reported shoulder pain were 17.9 degrees in the supine position and 11.1 degrees in the side-lying position.

CONCLUSIONS

Table tennis players exhibited glenohumeral internal rotation deficit. There was a correlation between glenohumeral internal rotation deficit and self-reported shoulder pain in the past year; therefore, glenohumeral internal rotation deficit may be a risk factor for shoulder pain in table tennis players.

Reliability Analysis of In-person and Virtual Goniometric Measurements of the Upper Extremity

Background

Virtual healthcare has forced clinicians to modify or eliminate parts of the musculoskeletal evaluation such as motion assessment. Although acceptable to excellent levels of in-person goniometric reliability is achievable, reliability of virtual assessments is unknown.

Purpose

To determine if similar upper extremity goniometric measurements could be obtained in-person and virtually.

Study Design

Reliability study; classroom setting.

Methods

Publicly recruited sample over 18 years of age with no upper extremity injuries. Each subject was tested in a standing position with dominant arm facing the clinicians to visualize the landmarks for goniometer placement. Flexion and extension of the shoulder, elbow and wrist were measured. Prior to performing in-person goniometric measurements for each joint, an image was captured of each pre-determined joint position using a mobile device with a camera. This image represented the screenshot on a virtual platform. Four clinicians performed in-person measurements twice during the same session on each subject. The following week clinicians measured virtual images using the same techniques. Inter-rater and intra-rater reliability were determined via intraclass correlation coefficients (ICC).

Results

Inter-rater reliability for five of the six in-person (ICC≥0.81) and virtual measurements (ICC≥0.78 ) were classified as excellent. In-person wrist extension (ICC=0.60) and virtual wrist flexion (ICC=0.65) were classified as good. Intra-rater reliability for individual clinicians were between good and excellent for the in-person measurements (ICC:0.61-0.96) and virtual measurements (ICC:0.72-0.97). There were a greater number of excellent ICC values for the virtual measurements (90%) compared to in-person measurements (70%). There were statistically significant differences between in-person and virtual sessions for five of six measurements (p≤0.006). Only elbow extension did not differ between sessions (p=0.966).

Conclusion

Virtual assessment compared to goniometric measurements showed good to excellent inter- and intra-rater reliabilities (ICC > 0.60), which suggests clinicians can utilize goniometry either in person or on a virtual platform.

Level of Evidence

3b©The Author(s).

Professional tennis players suffer high prevalence of shoulder alterations during the season: a possible tennis shoulder syndrome

PURPOSE

To analyze the shoulder alterations of professional tennis players during the competition season and to compare the differences between their dominant vs. non-dominant shoulders, as well as gender and age differences.

METHODS

Two-hundred and seventy shoulders of (78 men and 57 women) professional active tennis players were assessed during 3 ATP and WTA tournaments.

MAIN VARIABLES STUDIED

long head of biceps (LHB) tenderness and synovitis; glenohumeral internal rotation deficit (GIRD), total range of motion (TRM), external rotation (ER) and scapular dyskinesis (DK). Secondary variables: shoulder dominance, gender, age, training hours, ranking, type of backhand. LHB tenderness and synovitis were assessed by clinical and ultrasound examination, TRM with goniometer and DK by dynamic observation.

RESULTS

LHB tenderness of the dominant shoulder was present in 35% of all players, being more prevalent in women (47.4%) than men (26.9%) p = 0.023. LHB synovitis of the dominant shoulder was present in 20.2% of all players without difference between genders (n.s). High prevalence of GIRD was found in both dominant (87.4%) and non-dominant (56.3%) shoulders, being more prevalent in the dominant shoulder p = 0.00005. TRM was decreased in both dominant (144.5° ± 20.2°) and non-dominant shoulders (161.2° ± 18.9°) p = 0.00005. ER was normal in dominant (93.8° + /9.3°) and non-dominant shoulders (93.4° + /8.4°) (n.s). DK was present in 57.7% of dominant and 45.9% of non-dominant shoulders (n.s). The combination of LHB alterations, GIRD and DK in the dominant shoulder was present in 13.3% of the participants. There were no significant differences between younger (< 22 years) vs older players (≥ 22 years).

CONCLUSION

Professional tennis players actively playing suffer a high prevalence of LHB inflammation, GIRD, scapular dyskinesis and decreased TRM in their dominant and non-dominant shoulders. The LHB is a significant cause for anterior shoulder pain in this population. Women suffer more LHB tenderness than men. Young players are as affected as older players.

LEVEL OF EVIDENCE

Level IV.

The Epidemiology of Youth Sport-Related Shoulder Injuries: A Systematic Review

Background

Youth around the globe place their shoulders at risk for injury when participating in sports. Shoulder injuries may vary in severity, produce the potential for time-loss from sport, and result in functional disability. We sought to explore sport-related shoulder injuries in youth by identifying injury rates, risk factors, injury mechanisms, and injury prevention strategies.

Methods

All relevant full-text articles were identified by searching MEDLINE, EMBASE, CINAHL, Sport Discus, and the Cochrane Controlled Trials Registry. No date restrictions were used. All full-text studies reporting original research describing sport-related shoulder injury among female and/or male youth from 5 to 18 years old were included.

Results

Of 3,889 studies screened, 97 described shoulder injury in youth sports. Shoulder injuries were identified in 24 unique sports. The median seasonal prevalence of shoulder injury was 10.9% (range 1.2-28.2%). The most common injury mechanisms identified were contacted with another player, contact with the playing environment, and falling to the ground. Risk factors for shoulder injury identified were side-to-side strength imbalances, weak external rotator muscles, and scapular dyskinesia. One study evaluated a successful training strategy to prevent shoulder injuries, but two other interventions demonstrated no effect.

Conclusions

Sport-related shoulder injuries are prevalent among youth athletes. Injury risk factors identified included modifiable intrinsic factors such as strength, range of motion, and training load. The most common injury mechanism was direct contact with either another person or an object in the playing environment. Innovative shoulder-specific strategies are needed to reduce shoulder injuries in this population. Trial Registration: PROSPERO ID: CRD42020189142.

Flexibility, Position, and Strength of the Shoulder Complex in Pediatric and Adult Amateur Tennis Athletes

CONTEXT

Understanding the musculoskeletal adaptations in the shoulder complex of varying ages of tennis athletes may suggest preventive protocols and conditioning and rehabilitation programs to this population. This study aimed to generate a bilateral descriptive profile of shoulder flexibility, scapular and clavicular position, and muscle strength in pediatric and adult amateur tennis athletes. The outcome measures were compared between groups and sides. The number and percentage of athletes "at risk" according to cutoff values for shoulder range of motion (ROM) were also analyzed.

DESIGN

Cross-sectional study.

METHODS

36 pediatric and 28 adult amateur tennis athletes were tested. Outcome measures were ROM of shoulder flexion, abduction, internal and external rotation, posterior capsule tightness, pectoralis minor index (PMI), scapular upward rotation, clavicular elevation, and strength of the external rotators, serratus anterior, and lower trapezius of the dominant/nondominant sides.

RESULTS

Pediatric athletes had greater dominant side external rotation (P = .01) and total ROM (P = .04), increased Low Flexion test (P = .01), and decreased PMI (P = .01) compared with the adults. Bilaterally, the pediatric athletes had greater dominant side external rotation ROM (P < .01) and decreased PMI (P = .002) as compared with their nondominant side, whereas the adults displayed lower values on posterior capsule tightness (P = .01) and decreased PMI (P = .02) on their dominant side compared with their nondominant side. For the remaining outcomes, no interaction effects were observed. The cutoff values for shoulder ROM showed that several athletes were "at risk" of shoulder problems.

CONCLUSION

Upper extremity adaptations at the shoulder are present in both pediatric and adult tennis athletes. These data can assist clinicians in better understanding the biomechanical adaptations in the shoulder of amateur tennis athletes in different age groups.

Effect of Forearm Position on Glenohumeral External Rotation Measurements in Baseball Players

BACKGROUND

Alterations in glenohumeral internal rotation (GIR), glenohumeral external rotation (GER), and the total arc of motion (TAM) have been linked with increased injury risk in the shoulder and elbow. These motions have been routinely measured with the forearm in neutral rotation (GIRN, GERN, TAMN). GER capacity appears to be especially important. The throwing motion, however, requires forearm pronation as GER occurs to achieve optimal cocking (GERP). No previous studies have evaluated GERP to determine GER capacity or pronated TAM (TAMP) values.

HYPOTHESIS

There would be significant differences between GERN and TAMN and between GERP and TAMP.

STUDY DESIGN

Cross-sectional.

LEVEL OF EVIDENCE

Level 3.

METHODS

Sixty asymptomatic male Minor League Baseball players (32 pitchers, 28 position players) participated in the study and were tested on the first day of spring training. Passive range of motion measurements were recorded using a long-arm bubble goniometer for GIRN, GERN, and GERP on both arms. TAM was calculated separately as the sum of internal and external rotational measurements under neutral and pronated conditions.

RESULTS

Within pitchers and position players, all measurements were statistically reduced for the throwing arm (P ≤ 0.03) except for GERN of the pitchers. GERP measures were significantly less than GERN for both arms of each group (P < 0.01): pitchers throwing arm +11.8°/nonthrowing arm +4.8°, position players throwing arm = +8.6°/nonthrowing arm +4.0°.

CONCLUSION

The forearm position of pronation, which appears to be mediated by tightness of the biceps, decreases GER capacity and TAM. GER and TAM should be calculated in neutral and pronated positions, considering that 80% of the players have a demonstrated difference between 8° and 12°.

CLINICAL RELEVANCE

Measurement of GERP more accurately reflects the GER required in throwing, allows better quantification of the motion capacity necessary to withstand the loads in throwing, and may suggest interventions for at risk athletes.