Posterior shoulder tightness; an intersession reliability study of 3 clinical tests

Morphologic changes in the posterior glenoid rim is independently associated with rotator cuff impingement in baseball players

Background

The morphological changes in the posterior glenoid rim are unknown in relation to the area of rotator cuff tendons pinched within the glenohumeral joint in the throwing shoulders of baseball players. Therefore, this study aimed to clarify whether these changes are associated with the area of impingement in baseball players.

Methods

Overall, 25 asymptomatic male college baseball players (average age19.8 years, 11.6 years of competing, and 50 shoulders) participated in this study. The area of impingement (AOI, mm2) and posterior glenohumeral distance (PGHD, mm) were measured using magnetic resonance imaging to quantitatively assess the impingement area of the rotator cuff tendon within the glenohumeral joint and the morphologic change in the posterior glenoid rim. These magnetic resonance imaging assessments were measured at 90° shoulder abduction with 90° and 100° external rotation. Multiple linear regression analysis was performed to determine whether AOI is predicted by PGHD.

Findings

Multiple linear regression analysis showed that the PGHD was a predictor of the AOI at external rotation 90° (β-coefficient = 0.738, R2 = 0.77, P < 0.001) and external rotation 100° position (β-coefficient = 0.879, R2 = 0.76, P < 0.001).

Interpretation

This study found that the area of impingement was associated with posterior glenohumeral distance. Therefore, these findings may indicate that complex shoulder joint morphologic changes result in a disabled throwing shoulder.

An evidence-informed rehabilitation management framework for posterior shoulder tightness: A scoping review

Objective

To systematically scope the literature on posterior shoulder tightness (PST) and define a therapist-instructed and therapist-administered management framework.

Design

Scoping review.

Literature search

We searched MEDLINE, EMBASE, CINAHL, Scopus and Google Scholar from inception to December 2021.

Study selection criteria

Peer-reviewed studies written in English, French, Greek, Japanese or Tamil, with extractable pre- and post-intervention data. Physiotherapy interventions amenable for posterior shoulder structural (muscle, capsule) causes of PST within an adult population.

Data synthesis

Arksey and O'Malley's framework was implemented and the PRISMA extension for scoping reviews directed our data synthesis. The data charted from each study included authors, title, study year, location, study design; participant number, age, sex; PST intervention and parameters; patient-reported outcomes; and results. Themes were organized into therapist-instructed and therapist-administered rehabilitation strategies, as well as combined treatment methods.

Results

Of 2777 articles identified from our search strategy, 21 articles were included. Therapist-instructed interventions included cross-body stretch (CBS), sleeper stretch (SS), a combination of the two and general stretching. Therapist-administered interventions included CBS, SS, instrument-assisted soft tissue mobilization (IASTM), muscle energy techniques, dry needling and Fauls protocol (12 therapist-assisted stretches). Combined interventions of tape with self-stretching and IASTM and stretching were also identified.

Conclusion

Based on the current evidence, CBS and SS are the most researched treatments for PST and seem to be effective at improving PST. Furthermore, stabilization of the scapula while performing these stretches optimized the stretch targeted to the PST and ROM benefits for horizontal adduction.

The Contribution of Posterior Capsule Hypertrophy to Soft Tissue Glenohumeral Internal Rotation Deficit in Healthy Pitchers

BACKGROUND

The relationship between posterior capsule adaptations and soft tissue glenohumeral internal rotation deficit (GIRD) in healthy pitchers remains unclear.

PURPOSE/HYPOTHESIS

This study aimed to identify if posterior capsule thickness (PCT) was associated with soft tissue GIRD in healthy pitchers. We hypothesized that there would be a positive relationship between soft tissue GIRD and PCT in the dominant arm, no relationship between soft tissue GIRD and PCT in the nondominant arm, and a strong positive relationship between soft tissue GIRD and the bilateral difference in PCT (posterior capsule hypertrophy [PCH]).

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 45 healthy collegiate and professional pitchers were included. Glenohumeral internal rotation and external rotation range of motion, humeral retroversion, and PCT were measured bilaterally. PCT was determined for unilateral posterior capsule measurements, and PCH of the throwing shoulder was calculated as the bilateral difference in PCT. Soft tissue GIRD was calculated as the sum of clinical GIRD and the bilateral difference in humeral retroversion. Pearson correlation coefficients were determined to evaluate the relationships between dominant arm PCT, nondominant arm PCT, and PCH and soft tissue GIRD.

RESULTS

Pearson correlations showed that both dominant arm PCT (R = -0.13; P = .378) and nondominant arm PCT (R = 0.21; P = .165) were not related to soft tissue GIRD. However, Pearson correlations did show that the amount of PCH was moderately related to soft tissue GIRD (R = 0.40; P = .007). Therefore, as the posterior capsule hypertrophied, soft tissue GIRD moderately increased.

CONCLUSION

Increased PCH was associated with an increase in soft tissue GIRD in healthy pitchers. If PCT measurements are feasible, clinicians should consider performing bilateral ultrasound assessments to isolate posterior capsule adaptations (ie, PCH). This will allow clinicians to identify pitchers with potentially maladaptive structural adaptations and optimize management strategies throughout the season to counteract them.

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.