Posterior capsular contracture of the shoulder

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.

Effects of modified sleeper stretch and modified cross-body stretch on upper limb functions and shoulder ROM in tennis players: a randomized trial

Tennis players often experience posterior shoulder pain due to restricted internal rotation (IR) range of motion (ROM) of the glenohumeral joint. No research has compared the effects of modified sleeper stretch (MSS) versus modified cross-body stretch (MCBS) on tennis players' upper limb functions and IR ROM. The study aimed to compare the efficacy of modified sleeper and cross-body adduction stretch in improving shoulder IR ROM and upper limb functions in tennis players. Thirty male lawn tennis players (aged 20 to 35 years) with more than 15° glenohumeral IR deficiency on the dominant side compared to the non-dominant side were recruited and divided into two groups: Modified sleeper stretch group (MSSG) and modified cross-body stretch group (MCBSG). MSSG received MSS, and MCBSG received MCBS, 3-5 repetitions once daily for 4 weeks. Upper limb functions were measured using the Disability of the Arm, Shoulder, and Hand (DASH) scale, and the IR ROM of the shoulder joint was measured using a universal goniometer. Both groups observed significant (p < 0.05) DASH scores and IR ROM improvements. DASH scores decreased by 85% in MSSG and 79.60% in MCBSG. IR ROM increased by 94.64% in MSSG and 89.52% in MCBSG. No significant differences (p > 0.05) were found in post-intervention DASH scores and IR ROM values between both groups. MSS and MCBS improved upper limb functions and IR ROM of the shoulder joint in the selected sample population of lawn tennis players. No difference was observed between both stretching techniques in improving upper limb functions and IR ROM of the shoulder joint.

Shoulder stretching versus shoulder muscle strength training for the prevention of baseball-related arm injuries: a randomized, active-controlled, open-label, non-inferiority study

Glenohumeral internal rotation deficit (GIRD) and weakness in prone external rotation are risk factors for shoulder and elbow injuries in high school baseball pitchers. While a shoulder-stretching prevention program to improve GIRD decreases the injury rate, the effects of external rotation strength remain unclear. This non-inferiority (NI) study investigates the hypothesis that external rotation strength training is not inferior to sleeper stretching for shoulder and elbow injury prevention in high school baseball pitchers. Participants were randomly allocated to the stretching (n = 62; active control group) and muscle-training (n = 51) groups. Specific exercises were performed each night. Elbow and shoulder injuries were monitored for 150 days. Kaplan-Meier survival curves were generated, and the hazard ratios (HRs) for injury occurrence were calculated using multivariate Cox regression. The log-rank test was used to compare the injury-free time. A one-sided NI test using a fixed NI margin was performed (significance level, P = 0.025). The injury rates were 22.6% (n = 14) in the stretching group and 9.8% (n = 5) in the muscle-training group. The muscle-training group had a lower injury rate (P < 0.001) and a lower risk of injury than the stretching group (HR = 0.489). Therefore, external rotation muscle strength training is not inferior to stretching for preventing baseball-related arm injuries.

The Relationship between Scapular Upward Rotation and Shoulder Internal and External Rotation Isokinetic Strength in Professional Baseball Pitchers

This study aims to assess the relationship between scapular upward rotation (SUR) across varying humeral-elevation angles (HEAs) and shoulder isokinetic strength and ratio in professional baseball pitchers. The subjects were professional baseball pitchers (n = 16) without a history of shoulder injury in the last six months. The subject’s SUR angles were measured with the humerus elevated at HEAs of 0° (at rest), 60°, 90°, and 120° to the scapular plane. Shoulder isokinetic strength was evaluated for shoulder internal rotation (IR) and external rotation (ER) strength (PT%BW and TW%BW), and the ER/IR strength ratios were determined at 60, 120 and 180°/s using an isokinetic dynamometer. The SUR angle at an HEA of 0° was positively correlated with IR strength at 120°/s (r = 0.535) and 180°/s (r = 0.522). The SUR angle at an HEA of 60° was negatively correlated with the ER/IR strength ratios at 60°/s (r = −0.505) and 120°/s (r = −0.500). The SUR angle at an HEA of 90° was negatively correlated with the ER/IR strength ratios at 60°/s (r = −0.574; r = −0.554) and 120°/s (r = −0.521; r = −0.589) as well as with ER strength at 180°/s (r = −0.591, r = −0.556). The SUR angle at an HEA of 120° was negatively correlated with ER strength at 60°/s (r = −0.558), 120°/s (r = −0.504; r = −0.524), and 180°/s (r = −0.543) and the ER/IR strength ratio at 60°/s (r = −0.517). In this study, we found that the ratio of isokinetic strength between ER and IR became closer to the normal range on increasing the SUR angle. In particular, an HEA of 90°, which resembles the pitching motion, showed a clear relationship between SUR, shoulder ER, and the ratio of ER/IR isokinetic strength in professional baseball pitchers.

Comparison of specific and non-specific treatment approaches for individuals with posterior capsule tightness and shoulder impingement symptoms: A randomized controlled trial

BACKGROUND

Posterior capsule tightness (PCT) is associated with shoulder pain and altered shoulder kinematics, range of motion (ROM), external rotation (ER) strength, and pain sensitization.

OBJECTIVE

To assess the effects of two interventions on shoulder kinematics, Shoulder Pain and Disability Index (SPADI) scores, ROM, strength, and pressure pain threshold (PPT) in individuals with PCT and shoulder impingement symptoms.

METHODS

In this prospectively registered randomized controlled trial 59 individuals were randomized to either an Experimental Intervention Group (EIG, n=31) or a Control Intervention Group (CIG, n=28). The low flexion (LF) test was used to determine the presence of PCT. Shoulder kinematics, SPADI scores, internal rotation (IR) and ER ROM, ER strength, and PPT were measured pre- and post-treatment. Those in the EIG received an intervention specific to pain and PCT and those in the CIG received a non-specific intervention, both 4 weeks in duration.

RESULTS

Individuals in the EIG demonstrated more scapular upward rotation (P=.03; mean difference (MD)=3.3°; 95% Confidence Interval (CI)=1.3°, 4.9°) and improved value on the LF test (P=.02; MD=4.6°; 95%CI=0.7°, 8.6°) than those in the CIG after treatment. Both groups presented less anterior (P<.01; MD=-0.7mm; 95%CI=-1.3mm, -0.2mm) and superior (P<.01; MD=-0.5mm; 95%CI=-0.9mm, -0.2mm) humeral translations, decreased SPADI score (P<.01; MD=-23.6; 95%CI=-28.7, -18.4), increased IR ROM (P<.01; MD=4.6°; 95%CI=1.8°, 7.8°) and PPTs for upper trapezius (P<.01; MD=60.1kPa; 95%CI=29.3kPa, 90.9kPa), infraspinatus (P=.04; MD=47.3kPa; 95%CI=2.1kPa, 92.5kPa), supraspinatus (P<.01; MD=63.7kPa; 95%CI=29.6kPa, 97.9kPa), and deltoid (P<.01; MD=40.9kPa; 95%CI=12.3kPa, 69.4kPa) after treatment.

CONCLUSION

The experimental intervention was more effective at improving PCT as measured through changes in the LF test. No benefit of the specific approach over the non-specific intervention was noted for the remaining variables.

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.

The position of sling immobilization influences the outcomes of anatomic total shoulder arthroplasty: a randomized, single-blind, prospective study

BACKGROUND

To date, no studies have been published that have assessed the optimal position of sling immobilization after anatomic total shoulder arthroplasty for glenohumeral osteoarthritis.

METHODS

Thirty-six patients undergoing anatomic total shoulder arthroplasty for osteoarthritis were randomized to a neutral rotation sling versus an internal rotation sling. The primary outcomes assessed included the Disabilities of the Arm, Shoulder and Hand score; Western Ontario Osteoarthritis of the Shoulder score; Single Assessment Numeric Evaluation score; visual analog scale (VAS) scores for pain and satisfaction; compliance ratings; and radiographic and range-of-motion measurements. Primary outcomes were assessed at baseline and postoperatively at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year.

RESULTS

All patient-determined outcome scores for both groups revealed statistically significant improvements (P < .0001) from enrollment to final follow-up. There were statistically significant advantages to the neutral rotation sling group compared with the internal rotation sling group when we evaluated the improvements in (1) active external rotation (42° vs 25°, P = .03), (2) passive external rotation (44° vs 26°, P = .02), (3) passive horizontal adduction (7.7 cm vs 3.7 cm, P = .05), and (4) pain relief with passive adduction (VAS score, 6.2 cm vs 3.5 cm; P = .002). There was a trend toward greater improvements in the neutral rotation sling group when we measured (1) active horizontal adduction (8.3 cm vs 2.9 cm, P = .06) and (2) active internal rotation behind the back (18 cm vs 11.1 cm, P = .09). At 2 weeks, the neutral rotation sling group had significantly less night pain than the internal rotation sling group (mean VAS score, 18 mm vs 34 mm; P = .047).

CONCLUSIONS

Neutral rotation sling use after anatomic total shoulder arthroplasty resulted in statistically significant improvements in external rotation and adduction, as well as decreased night pain, compared with an internal rotation sling.

Arthroscopic Management of the Stiff Shoulder

Shoulder stiffness affects a diverse population of patients suffering a decrease in function and shoulder pain. Arthroscopic management of this debilitating spectrum of pathology is a safe and effective course of action in cases recalcitrant to nonoperative therapy. Arthroscopic management of the stiff shoulder has been reported to be effective in the treatment of stiffness due to adhesive capsulitis, birth palsy, stiffness in the setting of rotator cuff tears, and osteoarthritis in the posttraumatic patient, in the postoperative patient, and in the throwing athlete. Arthroscopic management is most effective in treating the stiff shoulder in the setting of adhesive capsulitis recalcitrant to nonoperative therapy or posttraumatic stiffness. Results are more guarded in the treatment of postoperative stiffness. Excessive force and trauma to the shoulder, including fracture of the humerus, can be avoided with a 360[degrees] capsular release for shoulder stiffness rather than manipulation under anesthesia.

What is the reliability of clinical measurement tests for humeral head position? A systematic review

STUDY DESIGN

Systematic review.

INTRODUCTION

Physiotherapists routinely assess the position of the humeral head (HH) in patients with shoulder pain.

PURPOSE OF THE STUDY

To conduct a systematic review to determine the quality and content of studies that evaluated the reliability of clinical measurement methods for assessing the HH position.

METHODS

Five databases and gray literature were searched for studies fitting the eligibility criteria. After abstract and full-text review, the included studies were appraised using the Quality Appraisal of Reliability Studies checklist. Articles were considered of high quality if 8 was achieved on the checklist, and the overall quality of evidence was classified using prespecified criteria. Multiple raters extracted and performed quality ratings; a consensus process was used to finalize the reliability data that were synthesized and presented in a narrative synthesis. Reliability was classified as excellent if the intracorrelation coefficients or intercorrelation coefficients (ICCs) reported exceeded 0.75.

RESULTS

Fifteen studies on the reliability of ultrasound (US) and 3 studies on palpation were included. The methodologic quality was moderate in 17 of 18 studies. The intrarater reliability for all studies was excellent (ICC, 0.76-0.99) with the exception of the 90° abduction in internal rotation position (ICC, 0.48) for palpation. The inter-rater reliability tended to be lower (ICC, 0.48-0.68) for palpation and higher (ICC, 0.66-0.99) for US. Physiotherapists demonstrated excellent intrarater reliability across different levels of training in ultrasonography.

DISCUSSION

Our study found a moderate overall level of evidence to support the use of US for assessing HH position in symptomatic or asymptomatic subjects.

CONCLUSION

A moderate overall level of evidence exists for the use of US to reliably assess the HH position. Limited research supports the methods used for palpation within a clinical setting.

LEVEL OF EVIDENCE

2a.

Glenohumeral Internal Rotation Deficit and Injuries: A Systematic Review and Meta-analysis

Background:

There is an association between throwing activity and glenohumeral internal rotation deficit (GIRD). An 18° to 20° deficit has been adopted as the standard definition of pathological GIRD, but specific findings as to how GIRD relates to an injury are inconsistent.

Purpose:

To systematically review the literature to clarify the definition of GIRD diagnosis for adolescent and adult overhead athletes and to examine the association between GIRD and an increased risk of injuries in these athletes.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review of the literature was performed. Observational studies comparing glenohumeral internal rotation range of motion (ROM) in injured and uninjured overhead athletes were included for the meta-analysis. Studies of adolescent and adult athletes were analyzed separately. ROM was compared for the injured and uninjured groups, and a weighted mean GIRD was estimated. To account for potential heterogeneity across studies, both fixed- and random-effects models were used to calculate a standardized mean difference (SMD).

Results:

Nine studies of level 3 or 4 evidence were included. From these, 12 study groups (4 adolescent, 8 adult) comprising 819 overhead athletes (226 injured, 593 uninjured) were included in the meta-analysis. The estimated SMD in GIRD between the injured and uninjured groups was 0.46 (95% CI, 0.15-0.77; P < .01) for the overall sample. The between-group effect was larger for adults (SMD, 0.60 [95% CI, 0.18 to 1.02]; P < .01) than adolescents (SMD, 0.20 [95% CI, –0.24 to 0.63]; P = .13). The weighted mean GIRD for the injured and uninjured groups was 13.8° ± 5.6° and 9.6° ± 3.0°, respectively, which also differed by age group. Moderate study heterogeneity was observed (I² = 69.0%).

Conclusion:

Based on this systematic review, the current definition of pathological GIRD may be too conservative, and a distinct definition may be required for adolescent and adult athletes. While the results indicate a link between internal rotation deficits and upper extremity injuries in the overhead athlete, higher quality prospective research is needed to clarify the role that GIRD plays in future injuries to overhead athletes of various ages.

Glenohumeral internal rotation deficit in throwing athletes: current perspectives

Glenohumeral internal rotation deficit (GIRD) is an adaptive process in which the throwing shoulder experiences a loss of internal rotation (IR). GIRD has most commonly been defined by a loss of >20° of IR compared to the contralateral shoulder. Total rotational motion of the shoulder is the sum of internal and external rotation and may be more important than the absolute value of IR loss. Pathologic GIRD has been defined as a loss of IR combined with a loss of total rotational motion. The leading pathologic process in GIRD is posterior capsular and rotator-cuff tightness, due to the repetitive cocking that occurs with the overhead throwing motion. GIRD has been associated with numerous pathologic conditions, including posterior superior labral tears, partial articular-sided rotator-cuff tears, and superior labral anterior-to-posterior tears. The mainstay of treatment for patients with GIRD is posterior capsular stretching and strengthening to improve scapular mechanics. In patients who fail nonoperative therapy, shoulder arthroscopy can be performed. Arthroscopic surgery in the high-level throwing athlete should be to restore them to their functional baseline with the minimum amount of intervention possible.

Effectiveness of a Posterior Shoulder Stretching Program on University-Level Overhead Athletes: Randomized Controlled Trial

OBJECTIVE

To determine whether a posterior shoulder stretch was effective in increasing internal rotation (IR) and horizontal adduction (HAd) range of motion (ROM) in overhead athletes identified as having reduced mobility.

DESIGN

Randomized controlled trial (parallel design).

SETTING

University-based sports medicine clinic.

PARTICIPANTS

Thirty-seven university-level athletes in volleyball, swimming, and tennis, with IR ROM deficits ≥15°, were randomized into intervention or control groups. No subjects withdrew or were lost to follow-up.

INTERVENTION

The intervention group performed the "sleeper stretch" daily for 8 weeks, whereas the control group performed usual activities.

MAIN OUTCOME MEASURES

Independent t tests determined whether IR and HAd ROM differences between groups were significant at 8 weeks and 2-way repeated-measures analysis of variance tests measured the rate of shoulder ROM change. Subject-reported shoulder pain and function were obtained at each evaluation.

RESULTS

Significant differences were found between the intervention and control groups' IR and HAd ROM at 8 weeks (P < 0.001 and P = 0.003, respectively) compared with baseline (zero weeks) (P = 0.19 and P = 0.82, respectively). Significant improvements in IR were detected in the intervention group at 4 weeks (P < 0.001), whereas HAd demonstrated significant changes only at 8 weeks (P = 0.003). Reported shoulder function (P = 0.002) was different between study groups at 8 weeks.

CONCLUSION

Overhead, university-level athletes with an IR deficit ≥15° significantly increased their IR and HAd ROM after performing a posterior shoulder stretch for 8 weeks.

CLINICAL RELEVANCE

Effective management of posterior shoulder tightness through stretching may reduce the incidence of shoulder pathology in overhead athletes.

The influence of anatomic total shoulder arthroplasty using a subscapularis tenotomy on shoulder strength

BACKGROUND AND HYPOTHESIS

There is limited evidence describing the influence of total shoulder arthroplasty on strength. The hypothesis was that after total shoulder arthroplasty, strength would improve compared with the preoperative state but remain inferior to that of the nonoperative shoulder. An additional aim was to determine whether strength improvement was associated with improvements in outcome scores and motion.

MATERIALS AND METHODS

Thirty-six patients underwent total shoulder arthroplasty, with 31 patients (86%) having 1 year of follow-up for all outcomes. Patient-determined outcomes (Western Ontario Osteoarthritis of the Shoulder score; Disabilities of the Arm, Shoulder and Hand score; Single Assessment Numeric Evaluation rating; and shoulder activity level), range of motion, and strength were assessed. Isometric strength was determined for scaption and external rotation, as well as the liftoff test, belly-press test, and bear-hug test.

RESULTS

All strength measures improved, with significant increases in external rotation, the liftoff test, and the bear-hug test, but remained inferior to the nonoperative-side strength. Improved strength in the belly-press test was associated with greater improvement in Single Assessment Numeric Evaluation scores. Improvements in scaption and belly-press testing were associated with improvements in active flexion. Strength improvements in the liftoff test were associated with improved internal rotation in 90° of abduction. Patients with improvements in strength had improvements in their shoulder activity level from baseline to final follow-up, whereas patients without improved strength test findings did not have improved shoulder activity levels.

CONCLUSIONS

Total shoulder arthroplasty improved external rotation, liftoff, and bear-hug strength testing. Operative shoulder strength remained inferior to strength of the nonoperative shoulder. Patients with improvements in strength were more likely to have greater improvements in outcome scores and range of motion. Improvements in the shoulder activity level after anatomic total shoulder arthroplasty may be dependent on improvements in strength.

Effects of a stretching protocol for the pectoralis minor on muscle length, function, and scapular kinematics in individuals with and without shoulder pain

STUDY DESIGN

Parallel-group intervention with repeated measures.

INTRODUCTION

Shortening of the pectoralis minor (PM) may contribute to alterations in scapular kinematics.

PURPOSE OF THE STUDY

To evaluate the effects of a stretching protocol on function, muscle length, and scapular kinematics in subjects with and without shoulder pain.

METHODS

A sample of 25 patients with shoulder pain and 25 healthy subjects with PM tightness performed a daily stretching protocol for 6 weeks. Outcome measures included Disabilities of the Arm, Shoulder, and Hand questionnaire, PM length, and scapular kinematics.

RESULTS

Disabilities of the Arm, Shoulder, and Hand scores decreased (P < .05) in the patient group at post-intervention. No differences (P > .05) were found for PM length in both groups. Scapular anterior tilt increased (P < .05) at 90° of flexion in the healthy group.

DISCUSSION

This study demonstrated that a daily home stretching protocol significantly decreases pain and improves function in subjects with shoulder pain. The mechanism responsible for these improvements does not appear directly related to PM muscle length or scapula kinematics, suggesting that other neuromuscular mechanisms are involved.

CONCLUSION

The PM stretching protocol did not change the PM length or scapular kinematics in subjects with or without shoulder pain. However, pain and function of the upper limbs improved in patients with shoulder pain.

LEVEL OF EVIDENCE

2b.

Cam morphology and inguinal pathologies: is there a possible connection?

Background

To analyse the prevalences of the cam and pincer morphologies in a cohort of patients with groin pain syndrome caused by inguinal pathologies.

Materials and methods

Forty-four patients (40 men and 4 women) who suffered from groin pain syndrome were enrolled in the study. All the patients were radiographically and clinically evaluated following a standardised protocol established by the First Groin Pain Syndrome Italian Consensus Conference on Terminology, Clinical Evaluation and Imaging Assessment in Groin Pain in Athlete. Subsequently, all of the subjects underwent a laparoscopic repair of the posterior inguinal wall.

Results

The study demonstrated an association between the cam morphology and inguinal pathologies in 88.6% of the cases (39 subjects). This relationship may be explained by noting that the cam morphology leads to biomechanical stress at the posterior inguinal wall level.

Conclusions

Athletic subjects who present the cam morphology may be considered a population at risk of developing inguinal pathologies.

Level of evidence

Level IV, Observational cross-sectional study.

The presence and influence of posterior capsule tightness on different shoulder problems

BACKGROUND

In the literature it has been shown that posterior capsule flexibility is a precursor to shoulder problems. However, no study thus far has shown the influence of the flexibility of posterior capsule in different shoulder pathologies.

OBJECTIVE

This study set about to compare the role of posterior capsule tightness in different shoulder problems.

METHODS

One-hundred-twenty-five patients diagnosed with shoulder subacromial impingement syndrome (n= 52), partial rotator cuff tear (n= 31) or frozen shoulder (n= 42) and 30 asymptomatic peers participated in the study. Horizontal adduction was assessed in side-lying position for posterior capsule tightness. Pain was measured via the visual analogue scale and shoulder range of motion and active total elevation was assessed with goniometer. Hand behind the back (HBB) test was assessed the active internal rotation by measuring the distance between T5 and the thumb.

RESULTS

It was found that the affected side of the posterior capsules of the patients with subacromial impingement syndrome (p< 0.001), partial rotator cuff tear (p< 0.001) and frozen shoulder (p< 0.001) was stiffer than their healthy side. There were significant differences among groups in the level of tightness in the posterior capsule between the affected and the healthy sides (p< 0.001). All range of motion of the shoulder including HBB test and the posterior capsule tightness of the affected side are found to be correlated (p< 0.05).

CONCLUSIONS

This study emphasized that the posterior capsule's susceptibility to tightness is most evident in frozen shoulder among different shoulder problems.

Shoulder Stretching Intervention Reduces the Incidence of Shoulder and Elbow Injuries in High School Baseball Players: a Time-to-Event Analysis

We prospectively evaluated the effects of a prevention program on the incidence of shoulder and elbow injuries in high school baseball pitchers. Ninety-two pitchers participated in this study and were taught to perform stretching and strength exercises aimed at improving shoulder external rotation strength in the preseason. The pitchers freely chose to participate in one of four groups [SM-group: performed both exercises, S-group: performed stretching exercise only, M-group: performed strength training only, and N-group: performed neither intervention]. Injury was defined as inability to play for ≥8 days because of shoulder/elbow symptoms. Kaplan-Meier survival curves were generated and hazard ratios (HRs) for injury occurrence were calculated using multivariate Cox regression. Log-rank test was used for between-group comparisons of survival distributions. The injuries occurred in 25, 35, and 57% of participants and median times to injury were 89, 92, and 29.5 days in the S- (n = 32), SM- (n = 46), and N- (n = 14) group, respectively. Nobody chose M-group. HRs were 0.36 and 0.47 for the S- and SM-group, respectively, based on the N-group. The incidence of injury was significantly lower in the S-group than in the N-group (p = 0.04). Daily posterior shoulder stretching may reduce the incidence of the injuries in high school baseball pitchers.

Quantifying Range-of-Motion Changes Across 4 Simulated Measurements of the Glenohumeral Joint Posterior Capsule: An Exploratory Cadaver Study

Study Design Repeated-measures controlled laboratory cadaveric study. Background There is a lack of information about the most sensitive measure of glenohumeral joint posterior capsule length. Although maximum strains on the glenohumeral joint posterior capsule are observed in measurements combining glenohumeral joint flexion and internal rotation (IR), the range-of-motion (ROM) change after experimental contracture has never been compared across commonly used posterior capsular measurements. Objectives To evaluate the IR ROM change across 4 glenohumeral joint posterior capsule measurements after experimental capsule shrinkage using radiofrequency thermal energy. Methods Repeated measures of ROM across 4 test positions were compared after progressive experimental contracture of the posterior capsule in 12 cadaver shoulders. The ROM data were collected with a 3-D motion-capture device and evaluated using repeated-measures analysis of variance. Results Overall, ROM decreased after experimental capsular contracture. There was a significant interaction effect between test and condition (F = 4.26, P = .01). Two of the 4 tests, those that combined humeral flexion and IR, detected significant reductions in the ROM following experimental capsular contracture. Conclusion Greater ROM change was observed in tests combining flexion and IR of the glenohumeral joint after experimental posterior capsular contracture. These tests appear more responsive to capsular-length change. J Orthop Sports Phys Ther 2016;46(12):1080-1085. Epub 29 Oct 2016. doi:10.2519/jospt.2016.6440.

Does chondrolysis occur after corticosteroid-analgesic injections? An analysis of patients treated for adhesive capsulitis of the shoulder

BACKGROUND

Clinical studies using continuous infusions of local anesthetics and basic science studies that model injections of local anesthetics have shown chondrotoxicity. However, clinical studies do not exist that have assessed for the risk of chondrolysis in nonarthritic joints exposed to single or intermittent corticosteroid or analgesic injections. Currently, there are no data available to guide the clinician on the safety of using these injections in clinical practice.

MATERIALS AND METHODS

A retrospective review of patients treated for adhesive capsulitis of the shoulder with at least 1 intra-articular injection of a corticosteroid and anesthetic was performed. The inclusion criteria were a diagnosis of adhesive capsulitis and a minimum 2-year follow-up. Prospective follow-up was performed to obtain patient-determined outcome scores, range of motion, and radiographs to determine the presence of chondrolysis.

RESULTS

Fifty-six patients with a mean age of 52.5 ± 7.2 years were enrolled at a mean follow-up of 54 months. The mean number of injections performed was 1.5 ± 0.7 (range, 1-4). At final follow-up, the mean Western Ontario Osteoarthritis of the Shoulder score was 91.4% ± 14.2%; Disabilities of the Arm, Shoulder and Hand score, 6.7 ± 9.6; Shoulder Pain and Disability Index score, 7.4 ± 11.4; and Single Assessment Numeric Evaluation score, 92.7% ± 10.1%. The Shoulder Activity Score was 8.3 ± 4.7. Passive and active forward elevation, external rotation, internal rotation, and cross-body adduction showed no significant differences compared with the unaffected contralateral shoulder. There was no radiographic evidence of chondrolysis in any patient.

CONCLUSIONS

This study did not show chondrolysis in patients treated with an intra-articular corticosteroid and local anesthetic for adhesive capsulitis. The findings of this study do not support the cessation of using intra-articular analgesic-corticosteroid injections for the treatment of adhesive capsulitis.

LEVEL OF EVIDENCE

Level IV; Case Series; Treatment Study.

Evaluation of Hip Internal and External Rotation Range of Motion as an Injury Risk Factor for Hip, Abdominal and Groin Injuries in Professional Baseball Players

Normal hip range of motion (ROM) is essential in running and transfer of energy from lower to upper extremities during overhead throwing. Dysfunctional hip ROM may alter lower extremity kinematics and predispose athletes to hip and groin injuries. The purpose of this study is characterize hip internal/external ROM (Arc) and its effect on the risk of hip, hamstring, and groin injuries in professional baseball players. Bilateral hip internal and external ROM was measured on all baseball players (N=201) in one professional organization (major and minor league) during spring training. Players were organized according to their respective positions. All injuries were documented prospectively for an entire MLB season (2010 to 2011). Data was analyzed according to position and injuries during the season. Total number of players (N=201) with an average age of 24±3.6 (range=17-37). Both pitchers (N=93) and catchers (N=22) had significantly decreased mean hip internal rotation and overall hip arc of motion compared to the positional players (N=86). Players with hip, groin, and hamstring injury also had decreased hip rotation arc when compared to the normal group. Overall, there is a correlation between decreased hip internal rotation and total arc of motion with hip, hamstring, and groin injuries.

Glenohumeral range of motion (ROM) and isometric strength of professional team handball athletes, part III: changes over the playing season

INTRODUCTION

The aim of our study was to investigate the relation of workload on range of motion and isometric strength of team handball athletes' shoulders over a competitive season.

MATERIALS AND METHODS

31 Professional male handball athletes underwent clinical shoulder examinations. Athletes were examined subsequently during the complete playing season (week 0, 6, 22 and 40) to determine bilateral isometric shoulder rotational strength and active range of motion (ROM). In addition, relative (intraclass correlation coefficients (ICC) and absolute (standard error of measurement) reliability were calculated.

RESULTS

Intraobserver reliability was excellent (ICC 0.76-0.98) for isometric strength and flexibility measurements. Internal rotation (IR) and total arc ROM in the throwing shoulder (TS) decreased significantly (p < 0.05) in both sequences (week 22 to week 40, week 0 to week 40). External rotation (ER) ROM and isometric strength in IR and ER did not change significantly. Glenohumeral internal rotation deficit (GIRD) and external rotation gain (ERG) of the TS decreased significantly between week 22 and week 40, but both did not change overall (week 0 to week 40). There was significant influence on IR ROM (week 22 to week 40) and strength in ER (week 0 to week 40) in the non-throwing shoulder.

CONCLUSIONS

Several characteristics of handball players' shoulders changed significantly from the beginning to the end of a season. More specifically, the repetitive forces accumulated during the competitive season resulted in altered GIRD, ERG and isometric strength of the dominant glenohumeral joint.

Reliability of measuring the passive range of shoulder horizontal adduction using a smartphone in the supine versus the side-lying position

[Purpose] The purpose of this study was to compare the reliability of the measurement of the passive range of motion (PROM) of shoulder horizontal adduction (SHA) measurements using a smartphone for the assessment posterior shoulder tightness (PST) between the side-lying and supine test positions. [Subjects and Methods] Forty-seven subjects (mean ± age, 24.9 ± 3.5 years) without shoulder pathology were included in this study. Intra-rater and inter-rater reliabilities were determined using intraclass correlation coefficients. The SHA PROM of each subject's dominant shoulder was measured using a smartphone by two investigators in two positions: the standard supine position, and a side-lying position on the tested side. [Results] The intra-rater reliability of the supine measurements was fair to good (ICC3,1 = 0.72-0.89), and for the side-lying measurements was excellent (ICC3,1 = 0.95-0.97). The inter-rater reliability of the supine measurements was fair (ICC2,2 = 0.79) and for the side-lying measurements was excellent (ICC2,2 = 0.94). [Conclusion] These results suggest that for healthy subjects, measurements of SHA using smartphones in the side-lying position has superior intra-rater and inter-rater reliabilities compared to the standard supine position.

Range of motion and isometric strength of shoulder joints of team handball athletes during the playing season, Part II: changes after midseason

OBJECTIVE

Our objective was to investigate the influence of workload and consecutive changes on active range of motion and isometric strength of team handball athletes' throwing shoulders (TSs) because the available data are insufficient.

METHODS

In a longitudinal investigation, 31 professional male handball athletes underwent a clinical shoulder examination. Athletes were examined at the beginning (week 0), at the end (week 6) of the preseasonal training, and at the end of the half-season (week 22) on both shoulders to determine isometric rotational strength (hand held dynamometer) and active range of motion (goniometer).

RESULTS

This analysis demonstrates the results subsequently from week 6 to week 22 and from week 0 to week 22. The glenohumeral internal rotation (IR) deficit (GIRD), external rotation (ER) gain, and ER at the TS increased significantly (P < .05, η(2) > 0.10, d > 0.30) in the first sequence (week 6 to week 22) but not significantly from week 0 to week 22. The total range of motion remained stable, and IR changed but not significantly. There was no influence on IR, ER, and total range of motion at the non-TS. The isometric strength of the TS and non-TS IR did not change. The isometric strength in ER significantly increased bilaterally during the investigation period.

CONCLUSIONS

Our data verify changes and influences, such as an increasing GIRD, at the overhead TS joint in accordance with the workload during team handball season. ER gain did improve after the half-season period but did not fully compensate the GIRD at the TS.

Effect of scapular stabilization during horizontal adduction stretching on passive internal rotation and posterior shoulder tightness in young women volleyball athletes: a randomized controlled trial

OBJECTIVE

To evaluate the effect of scapular stabilization during horizontal adduction stretching (cross-body) on posterior shoulder tightness (PST) and passive internal rotation (IR).

DESIGN

Randomized controlled trial with single blinding.

SETTING

Athletic club.

PARTICIPANTS

Asymptomatic volleyball players who are women with glenohumeral internal rotation deficit (N=60).

INTERVENTIONS

Subjects were randomly assigned to either horizontal adduction stretching with manual scapular stabilization (n=30) or horizontal adduction stretching without stabilization (n=30). Passive stretching was performed for 3- to 30-second holds in both groups.

MAIN OUTCOME MEASURES

Range of motion measurements of PST and IR were performed on the athlete's dominant shoulder prior to and immediately after the intervention.

RESULTS

Baseline mean angular measurements of PST and IR for all athletes involved in the study were 62°±14° and 40°±10°, respectively, with no significant difference between groups (P=.598 and P=.734, respectively). Mean PST measurements were significantly different between groups after the horizontal adduction stretch, with a mean angle of 83°±17° among the scapular stabilization group and 65°±13° among the nonstabilization group (P<.001). Measurements of IR were also significantly different between groups, with a mean angle of 51°±14° among the scapular stabilization group and 43°±9° among the nonstabilization group (P=.006).

CONCLUSIONS

Horizontal adduction stretches performed with scapular stabilization produced significantly greater improvements in IR and PST than horizontal adduction stretching without scapular stabilization.

The evaluation and treatment of rotator cuff pathology

Rotator cuff pathology accounts for most presentations of shoulder pain to primary care clinics. History and physical examination are important for excluding other causes of shoulder pain, while imaging assists in confirming the diagnosis and defining the severity of the abnormality. Treatment options include nonsteroidal anti-inflammatory agents, subacromial corticosteroid injections, and exercise therapy. Surgical intervention is generally reserved for those failing nonoperative measures and/or healthy, young, and middle-aged adults with full-thickness rotator cuff tears. No surgical technique has proved to be superior. Despite surgery, about 20% of patients experience retears, more likely occurring in those with larger tears.

Imaging monitored loosening of dense fibrous tissues using high-intensity pulsed ultrasound

Pulsed high-intensity focused ultrasound (HIFU) is proposed as a new alternative treatment for contracture of dense fibrous tissue. It is hypothesized that the pulsed-HIFU can release the contracted tissues by attenuating tensile stiffness along the fiber axis, and that the stiffness reduction can be quantitatively monitored by change of B-mode images. Fresh porcine tendons and ligaments were adapted to an ex vivo model and insonated with pulsed-HIFU for durations ranging from 5 to 30 min. The pulse length was 91 µs with a repetition frequency of 500 Hz, and the peak rarefactional pressure was 6.36 MPa. The corresponding average intensities were kept around 1606 W cm(-2) for ISPPA and 72.3 W cm(-2) for ISPTA. B-mode images of the tissues were acquired before and after pulsed-HIFU exposure, and the changes in speckle intensity and organization were analyzed. The tensile stiffness of the HIFU-exposed tissues along the longitudinal axis was examined using a stretching machine. Histology examinations were performed by optical and transmission electron microscopy. Pulsed-HIFU exposure significantly decreased the tensile stiffness of the ligaments and tendons. The intensity and organization of tissue speckles in the exposed region were also decreased. The speckle changes correlated well with the degree of stiffness alteration. Histology examinations revealed that pulsed-HIFU exposure probably damages tissues via a cavitation-mediated mechanism. Our results suggest that pulsed-HIFU with a low duty factor is a promising tool for developing new treatment strategies for orthopedic disorders.

Glenohumeral range of motion in handball players with and without throwing-related shoulder pain

BACKGROUND

Overhead athletes are subject to adaptations in the shoulder including glenohumeral internal rotation deficit (GIRD). It has been documented that this alteration is more evident in overhead athletes with pain. Our objective was to compare glenohumeral rotation motion between symptomatic and asymptomatic handball players.

MATERIALS AND METHODS

Glenohumeral rotation range of motion, GIRD, external rotation gain (ERG), and total rotation motion were determined with a standard goniometer in 30 handball players with pain and 27 without pain. Differences between the throwing and non-throwing shoulder were determined in each group.

RESULTS

Handball players with pain had significantly greater GIRD (P = .002), ERG (P = .027), and external rotation in the throwing arm (P = .042) and lesser internal rotation in the throwing arm (P = .029) in comparison to the athletes without pain. Comparisons between limbs exhibited a significant difference in the 2 groups regarding internal and external rotation (P < .02), but differences within the group with pain were greater. Differences were not found in the total rotation motion between the 2 groups.

CONCLUSION

Handball players showed specific adaptations in the throwing shoulder; in particular, handball players with pain have greater GIRD, ERG, and external rotation and lesser internal rotation of the throwing shoulder.

The effect of glenohumeral internal rotation deficit due to posterior capsular contracture on passive glenohumeral joint motion

BACKGROUND

To date, no study has investigated the biomechanical consequences of glenohumeral internal rotation deficit (GIRD) at values seen in symptomatic athletes. Hypothesis/

PURPOSE

The purpose of this study was to determine the biomechanical changes that occur with a full spectrum of GIRD in a cadaveric model with passive loading. We hypothesized that there is a critical percentage of GIRD that will result in a decrease in posterior glenohumeral translation and shift of the humeral head apex at the extreme ranges of motion.

STUDY DESIGN

Controlled laboratory study.

METHODS

Six specimens were tested using the following conditions: (1) native state ("intact"); (2) after external rotation (ER) stretch ("stretched"); and (3) GIRD of 5%, 10%, 15%, and 20%. For each condition, maximum ER, maximum internal rotation (IR), and total range of motion were measured. Kinematic data were obtained to determine the position of the humeral head apex (HHA), the highest point on the articular surface of the humeral head, relative to the geometric center of the glenoid. The amount of translation was measured in the anterior, posterior, superior, and inferior directions.

RESULTS

External rotation significantly increased compared with the intact condition for the stretched and 5% GIRD states, and IR decreased significantly beginning with 5% GIRD. At maximum ER, the HHA shifted significantly in the superior direction compared with the intact condition for all GIRD states, and at maximum IR, the HHA shifted significantly in the inferior direction compared with the intact and stretched conditions starting at 10% GIRD. The amount of posterior translation decreased significantly starting at 10% GIRD, and the amount of inferior translation decreased significantly starting at 20% GIRD.

CONCLUSION

Biomechanical changes of passive glenohumeral joint motion occur in the glenohumeral joint with as little as 5% GIRD.

CLINICAL RELEVANCE

Biomechanical changes of passive glenohumeral joint motion are noted with as little as 5% GIRD in this cadaveric model, and as the amount of GIRD increases, more substantial effects are noted.

A randomized controlled single-blinded comparison of stretching versus stretching and joint mobilization for posterior shoulder tightness measured by internal rotation motion loss

BACKGROUND

Posterior shoulder tightness, as demonstrated by limited internal rotation range of motion, is a suggested factor in many shoulder pathologies. Methods to increase posterior shoulder mobility may be beneficial.

HYPOTHESIS

Shoulder internal rotation range of motion will not change with either of 2 interventions: cross-body stretch alone and cross-body stretch plus posterior capsule joint mobilization.

STUDY DESIGN

Randomized controlled single-blinded clinical trial.

METHODS

The study comprised 39 college-age asymptomatic participants (7 men, 32 women) who were randomly assigned to 1 of 2 groups: stretching only (n, 20) and stretching plus posterior joint mobilizations (n, 19). All had a between-shoulder difference of internal rotation of 10° or more. Shoulder internal and external rotation was measured before and after a 4-week intervention period and 4 weeks postintervention. Participants in the stretching-only group performed the cross-body stretch on the limited side. Those in the other group (cross-body stretch plus joint mobilization) were treated with posterior joint mobilization techniques on the limited side.

RESULTS

Overall means for internal rotation of the treated shoulders significantly increased over baseline at the end of the intervention period and at 4 weeks postintervention. External rotation in all shoulders remained unchanged. By the end of intervention, total motion increased significantly from baseline but decreased significantly from the end of intervention to 4 weeks postintervention. Although not statistically significant, the second group (cross-body stretch plus joint mobilization) had greater increases in internal rotation. At 4 weeks postintervention, the second group had maintained its internal rotation gains to a greater degree than those of the stretching-only group.

CONCLUSION

Internal rotation increased in both groups. Inclusion of joint mobilization in a rehabilitation program created trends toward increased shoulder internal rotation mobility.

CLINICAL RELEVANCE

Both methods-cross-body stretch and cross-body stretch plus joint mobilization-may be beneficial for those with limited internal rotation range of motion.

Massive rotator cuff tear in an adolescent athlete: a case report

Full-thickness rotator cuff tears in the young athlete are a rare injury. These injuries typically result from an acute traumatic event in a contact athlete, as opposed to overuse injuries more commonly seen in throwing athletes. Acute tears may be initially overlooked, with the symptoms attributed to other, more common causes, such as cuff contusion or brachial plexus neuropraxia (“stinger” or “burner”). If undiagnosed, the tear may progress to an irreparable state at the time of eventual diagnosis. Therefore, rotator cuff tear must be included in the differential for acute shoulder injuries in the young athlete. This article presents a case of an adolescent athlete with a traumatic, massive rotator cuff tear that was diagnosed and managed promptly with excellent outcome.

REASSESSMENT OF PAINFUL SHOULDERS AMONG BASEBALL PLAYERS AFTER CONSERVATIVE TREATMENT

OBJECTIVE

The objective of this study was to evaluate the rehabilitation results among baseball players who presented pain and medial rotation deficit in their shoulders.

METHODS

Out of 55 baseball players assessed between April and June 2009, it was observed that 20 presented pain at some instant during throwing movements. They were advised to undergo a rehabilitation program with exercises to stretch the posterior capsule and reinforce the muscles of the scapular belt, especially the lateral rotators. Eighteen patients followed the advice, while two were lost from the follow-up. The parameters evaluated were: pain, range of motion, strength before the program and strength after the end of the program.

RESULTS

Comparing the initial and final assessments, we observed mean increases as follows: 10° of elevation (p = 0.001); three vertebral levels of medial rotation (p < 0.001); 20° of medial rotation at 90° abduction (p < 0.001); and 26° of range of motion (p < 0.001). Regarding strength, elevation force increased by 3 kgf (p = 0.002) and lateral rotation force increased by 1 kgf (p = 0.020). Out of the 18 baseball players studied, the pain level improved in 16, while two continued to present pain and underwent magnetic resonance imaging, which showed lesions for surgical treatment.

CONCLUSION

The rehabilitation program conducted among the baseball players was effective and enabled increases in medial rotation, elevation, range of motion and strength of elevation and lateral rotation, consequently producing pain improvements in most of the players.

Published evidence relevant to the diagnosis of impingement syndrome of the shoulder

BACKGROUND

Acromioplasty for impingement syndrome of the shoulder is one of the most common orthopaedic surgical procedures. The rate with which this procedure is performed has increased dramatically. This investigation sought high levels of evidence in the published literature related to five hypotheses pertinent to the concept of the impingement syndrome and the rationale supporting acromioplasty in its treatment.

METHODS

We conducted a systematic review of articles relevant to the following hypotheses: (1) clinical signs and tests can reliably differentiate the so-called impingement syndrome from other conditions, (2) clinically common forms of rotator cuff abnormality are caused by contact with the coracoacromial arch, (3) contact between the coracoacromial arch and the rotator cuff does not occur in normal shoulders, (4) spurs seen on the anterior aspect of the acromion extend beyond the coracoacromial ligament and encroach on the underlying rotator cuff, and (5) successful treatment of the impingement syndrome requires surgical alteration of the acromion and/or coracoacromial arch. Three of the authors independently reviewed each article and determined the type of study, the level of evidence, and whether it supported the concept of the impingement syndrome. Articles with level-III or IV evidence were excluded from the final analysis.

RESULTS

These hypotheses were not supported by high levels of evidence.

CONCLUSIONS

The concept of impingement syndrome was originally introduced to cover the full range of rotator cuff disorders, as it was recognized that rotator cuff tendinosis, partial tears, and complete tears could not be reliably differentiated by clinical signs alone. The current availability of sonography, magnetic resonance imaging, and arthroscopy now enable these conditions to be accurately differentiated. Nonoperative and operative treatments are currently being used for the different rotator cuff abnormalities. Future clinical investigations can now focus on the indications for and the outcome of treatments for the specific rotator cuff diagnoses. It may be time to replace the nonspecific diagnosis of so-called impingement syndrome by using modern methods to differentiate tendinosis, partial tears, and complete tears of the rotator cuff.

The lateral Jobe test: A more reliable method of diagnosing rotator cuff tears

Purpose:

The most reliable clinical investigations to diagnose rotator cuff tears reported in the literature is a triad of weakness on resisted external rotation, pain on impingement, and weakness on supraspinatus testing, or a combination of two of the above in a patient over 60 years of age. We present a simple new clinical test “The lateral Jobe Test” and compare it to these combined tests. The lateral Jobe test is performed with the patient’s shoulder abducted 90° in the coronal plane and internally rotated so that with the elbows flexed 90° the fingers point inferiorly and thumbs medially. A positive test is pain or weakness on resisting an inferiorly directed force applied to the distal arms or an inability to perform the test.

Materials and Methods:

A consecutive series of 175 patients undergoing shoulder arthroscopy were reviewed prospectively and examined by two independent orthopedic surgeons blinded to the diagnosis. The results of the clinical tests were validated against arthroscopic findings.

Results:

The lateral Jobe test had a significantly higher sensitivity (81 vs. 58%) than the combined tests. The specificity of both was similar at 89 and 88%, respectively.

Conslusion:

The lateral Jobe test is a simple single test which can help in the clinical diagnosis of rotator cuff tears.

Level of Evidence:

Level IIb

Shoulder joint and muscle characteristics among healthy female recreational weight training participants

Shoulder disorders attributed to weight training are well documented in the literature, with prevalence rates exceeding that of the general population. Although researchers have identified both intrinsic and extrinsic risk factors among men who participate in weight training, a paucity of evidence-based research exists to describe risk factors inherent to participation among women. The purpose of this study was to investigate shoulder joint and muscle characteristics among healthy female recreational weight training (RWT) participants to determine specific risk-related adaptations that may occur from training. Eighty-eight women aged 18-55 (mean 26.8), including 57 who participated in upper extremity RWT and 31 controls with no record of RWT participation were recruited. Active range of motion (AROM), posterior shoulder tightness (PST), glenohumeral (GH) joint laxity, body weight-adjusted strength and strength ratios of force couples were compared between the RWT and control groups. Statistical analysis identified significant differences (p ≤ 0.004) between groups when analyzing shoulder internal rotation AROM, PST, and joint laxity. The RWT participants had decreased internal rotation AROM, greater PST, and anterior GH joint hyperlaxity when compared to the control group. No differences in strength ratios between groups were identified (p ≥ 0.109) implying the absence of weight training-induced muscle imbalances. The findings of this investigation suggest that female RWT participants are predisposed to mobility imbalances as a result of training. The imbalances identified in this investigation have been associated with shoulder disorders in both the general and athletic population thus may place weight training participants at risk for injury. Clinicians and strength and conditioning professionals should consider the biomechanical stresses and adaptations associated with RWT when prescribing exercises. Exercise prescription that mitigates mobility imbalances may serve to prevent injury in this population.

The effect of cyclic loading simulating oscillatory joint mobilization on the posterior capsule of the glenohumeral joint: a cadaveric study

STUDY DESIGN

Experimental laboratory design.

OBJECTIVES

To examine the effect of force and repetition during oscillatory joint mobilizations on the posterior capsule of the glenohumeral joint.

BACKGROUND

The optimal external force and frequency to be used during joint mobilization to elongate the posterior capsule of the glenohumeral joint has yet to be identified.

METHODS

Twenty-one posterior capsules were harvested from fresh-frozen shoulders. A cyclic loading test simulating oscillatory posterior joint mobilization on the shoulder specimens was performed with a material testing machine. The specimens were assigned to 3 different loading groups simulating joint mobilization in the toe (5 N), transition (20 N), and beginning of the linear regions (40 N) of the load displacement curve. Displacement of the humeral head at an applied load of 5 N was recorded at the 1st, 100th, 200th, 300th, 400th, 500th, and 600th cycles and at 1 hour after completion of the cyclic loading. Furthermore, stiffness was calculated after the 1st and 600th cycles and 1 hour after testing.

RESULTS

Humeral head displacement was significantly greater for the 100th to 600th cycle, compared to the 1st cycle, for all 3 loading groups. Significant increases in displacement and stiffness were observed between the 1st cycle and 1 hour after completion of the cyclic tests for both the 20-N and 40-N loading groups.

CONCLUSION

While oscillatory joint mobilization to a force of 5 N resulted in temporary elongation of the posterior capsule, mobilization to loads of 20 and 40 N resulted in sustained elongation of the capsule for up to 1 hour. Our findings also suggest that mobilization up to loads that represent the beginning of the linear region of the load displacement curve could be performed without serious damage to the posterior capsule.

EVALUATION OF PAINFUL SHOULDER IN BASEBALL PLAYERS

Objective: To assess the relationship between shoulder mobility and strength and the presence of pain among baseball players. Methods: Between April and July 2009, 55 baseball players were assessed by the Shoulder and Elbow Group of the School of Medical Sciences, Santa Casa de Misericórdia, São Paulo. They were all males, aged between 15 and 33 years (mean of 21); they attended an average of three training sessions per week and had been doing this sport for a mean of 10 years. Results: 14 of the 55 players evaluated were pitchers, and 20 reported pain during the pitching motion. The mean values for lateral and medial rotation and range of motion (ROM) in the dominant shoulder were, respectively, 110 °, 61 ° and 171 °, with a statistically significant difference in relation to the non-dominant limb. Pitchers had greater gains in lateral rotation and deficits in medial rotation than did non-pitchers. Pain presented a statistically significant correlation with diminished ROM, greater length of time playing the sport and situations of “shoulder at risk”. Conclusions: Statistically significant differences in dominant shoulder mobility were found, with increased lateral rotation, diminished medial rotation and smaller ROM, in relation to the contralateral limb. There was a statistically significant relationship between the pitcher's position and greater gain in lateral rotation and diminished medial rotation. There were statistically significant correlations between pain and diminished ROM, greater length of time playing the sport and situations of “shoulder at risk”. There was a statistical tendency suggesting that players with diminished medial rotation of the dominant shoulder presented a relationship with pain.

Quantifying strain on posterior shoulder tissues during 5 simulated clinical tests: a cadaver study

STUDY DESIGN

Controlled laboratory study using a repeated-measures approach.

OBJECTIVE

To quantify the amount of strain on cadaver posterior shoulder tissues during simulated clinical tests across different tissue conditions.

BACKGROUND

Several clinical tests are used to quantify posterior glenohumeral joint (GHJ) tissue tightness; however, the ability of these tests to directly assess the flexibility or tightness of the posterior capsule has not been evaluated.

METHODS

The middle and lower regions of the posterior shoulder tissues were instrumented with strain gauges on 8 cadaver shoulder specimens. Strain was quantified on the posterior shoulder muscles, on the native posterior GHJ capsule (baseline condition), and on the posterior GHJ capsule after it was experimentally contracted using thermal energy. Five simulated clinical tests were compared across each of the 3 conditions: humerus cross-body adduction, and GHJ internal rotation with the humerus positioned in 4 combinations of plane and elevation angle. Repeated-measures analyses of variance were used to compare strain measured during the 5 simulated clinical tests across the 3 conditions, and to evaluate the change in strain after contracting the posterior capsule.

RESULTS

There was a statistically significant interaction between tests and conditions for the middle region of the posterior shoulder. In the experimentally contracted condition, strain was greater when GHJ internal rotation was added to humerus flexion than when GHJ internal rotation was added to humerus abduction. There was a statistically significant main effect of tests at the lower region of the posterior shoulder, with internal rotation in abduction and internal rotation in the GHJ resting position demonstrating greater strain than cross-body adduction. The percent change in strain between the baseline and contracted capsule conditions did not reach statistical significance at either region.

CONCLUSION

Strain on an experimentally contracted posterior GHJ capsule is highest when tested with a combination of GHJ internal rotation and humerus flexion.

Infraspinatus strength assessment before and after scapular muscles rehabilitation in professional volleyball players with scapular dyskinesis

HYPOTHESIS

This study tested the hypothesis that infraspinatus strength in professional volleyball players can be assessed with the scapula free (infraspinatus strength test, IST) and with the scapula retracted (infraspinatus scapula retraction test, ISRT) before and after scapular musculature training.

MATERIALS AND METHODS

A prospective study was performed in 31 professional volleyball players. Isometric strength (kg) of the infraspinatus with IST and with ISRT was recorded by a handheld dynamometer and compared with the values found after 3 and 6 months of rehabilitation. Magnetic resonance imaging was performed to exclude articular and cuff pathology. Pain scores were assessed using a visual analog scale.

RESULTS

The mean increase in the force values of IST was statistically significant after 3 months (P < .01) and 6 months (P < .001) of rehabilitation. The mean difference between IST and ISRT decreased from 4.72 ± 0.007 before rehabilitation to 1.2 ± 0.26 at 3 months and to 0.4 ± 0.006 at 6 months. The mean score for pain was 2.4 ± 1.8 at 3 months and 2.6 ± 1.4 at 6 months.

DISCUSSION

Acquired scapular dyskinesis in overhead athletes can lead to the rotator cuff weakness. Inhibition due to pain and the negative biomechanic effect of scapular dyskinesis results in specific infraspinatus dysfunction that arise with the ISRT.

CONCLUSIONS

ISRT is practical and consistent to assess the infraspinatus strength in overhead athletes with scapular dyskinesis. A functional rehabilitation protocol, designed to restore scapular muscles balance and shoulder mobility, is essential in the training program to prevent shoulder dysfunction and improve sports performance.

Passive ranges of motion of the hips and their relationship with pitching biomechanics and ball velocity in professional baseball pitchers

BACKGROUND

Pelvis and trunk motions during baseball pitching are associated with ball velocity. Thus, limits in hip flexibility may adversely affect pitching biomechanics and the ability to generate ball velocity.

HYPOTHESES

Professional baseball pitchers will have less passive range of motion in the nondominant hip and the measured ranges of motion of both the nondominant and dominant hips will correlate with biomechanical parameters of the lower extremity among professional pitchers.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Nineteen healthy professional baseball pitchers volunteered for testing. Fluid goniometry was used to measure passive range of motion of adduction (ADD), abduction (ABD), internal rotation, external rotation, total arc of rotation, and total arc of ADD + ABD. Pitching biomechanical data were collected using an automated 3-dimensional motion analysis system while participants threw fastballs.

RESULTS

Pitchers possessed significantly less passive range of motion in the nondominant hip when compared with the dominant hip for all ranges. Total arc of rotation of the nondominant hip correlated with ball velocity (r = .50). Total arc of ADD + ABD in the nondominant hip and ABD in the nondominant hip were correlated with stride length (r = -.72 and .70, respectively). Dominant hip ABD (r = .63), total arc of rotation in the nondominant hip (r = -.45), and total arc of ADD + ABD of the dominant hip (r = .44) were correlated with trunk separation. Total arc of ADD + ABD of the nondominant hip (r = -.52) and total arc of rotation of the dominant hip (r = -.44) were correlated with pelvic orientation.

CONCLUSION

Passive range of motion is smaller in the nondominant hip than the dominant hip among professional pitchers. The measured disparity between the hips is significantly correlated with various pitching biomechanical parameters of the trunk and pelvis. Future research is required to investigate a causal relationship between less hip passive range of motion and both ball velocity and pitching biomechanics.

Internal impingement: a review on a common cause of shoulder pain in throwers

Internal impingement is a term used to describe the pathologic contact of the undersurface of the rotator cuff with the glenoid. It typically occurs in overhead athletes, particularly throwers. In these athletes, the bones and soft tissues adapt to allow these athletes to have a supraphysiologic range of motion. In many athletes, these changes may lead to symptoms of internal impingement. This article discusses the background, biomechanics, pathophysiology, clinical and radiographic assessment, treatments, and outcomes of this disorder.