Posterior shoulder tightness can be a risk factor of scapular malposition: a cadaveric biomechanical study

Acute Effects of Handheld Vibration Massage on Posterior Shoulder Soft Tissues

Background

Interventions using vibration stimulation have been recognized for their potential for increasing range of motion (ROM) without compromising muscle strength. Handheld vibration massagers can efficiently deliver vibration therapy to the shoulder joint and may be a potential treatment.

Purpose

To evaluate the effects of vibration massage using a handheld device on the soft tissues of the posterior shoulder joint, particularly on internal rotation (IR) passive ROM and external rotation (ER) muscle strength.

Study Design

Crossover study design.

Methods

A crossover study with a 5-min vibration massage and passive control condition was conducted in healthy male volunteers (mean age 20.5 ± 1.7 years). Vibration massage was applied to the posterior shoulder soft tissues of the dominant arm, with no intervention under control conditions. IR-ROM (vertebral level and in abduction) and strength of the external rotators (isometric and isokinetic) were measured before and immediately after the intervention. Vertebral levels were calculated as a ratio of lengths (ratio decreases with increased mobility). IR-ROM in abduction, the angle was measured. Statistical analysis was performed with two-way repeated measures ANOVA and paired t-test (Bonferroni correction).

Results

Vibration application decreased (improved) vertebral level IR ROM by -4.1% (p < 0.01, d = 0.445) and increased abduction position IR ROM by 11.4° (p < 0.01, d = 0.694). These changes exceeded the 95% confidence interval for the minimum detectable change. By contrast, the control condition produced no changes. IR-ROM (vertebral level and abduction) immediately after the intervention showed significant differences between the control and vibration conditions (p = 0.036, d = 0.273; p = 0.048, d = 0.483, respectively). Muscle strength did not show any interaction, time, or between-condition effects.

Conclusions

A massage using a handheld vibration massager applied to the posterior shoulder soft tissues increased IR-ROM without negatively affecting muscle strength, suggesting its potential use as a means of warming up.

Level of Evidence

Level 3.

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.

Comparison of scapular position in elite tennis players with and without shoulder impingement: A case-control study

BACKGROUND

To maximize the ball velocity in the tennis sever, the shoulder plays a key role in the kinetic chain. But shoulder inefficiency leads to shoulder injuries such as shoulder impingement syndrome (SIS). Thus, to verify the scapular movements during the tennis serve could help prevent shoulder injury in tennis players.

OBJECTIVE

This case-control study aimed to verify the scapular movements during flat first serve for elite tennis players with shoulder impingement syndrome compared to those without it.

METHODS

Eight elite tennis players (4 males and 4 females) with SIS and 8 elite healthy players (4 males and 4 females) performed flat first serves, and the three-dimensional scapular kinematic data was recorded using the Qualisys motion capture system through spherical reflective markers including the acromion marker cluster.

RESULTS

The scapula was more internally rotated (median difference: 10.40∘) in the male players with SIS than in those without it at the maximally externally rotated humerothoracic joint during flat first serve, and female players with SIS (median difference: 7.16∘ and 11.28∘, respectively) had more internally rotated scapula at the maximally externally rotated humerothoracic joint and ball impact.

CONCLUSION

Increased scapular internal rotation may be something that affects shoulder injuries in the overhead sports, and it may help to prevent and rehabilitate overhead injuries including SIS.

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.