The immediate effects of a shoulder brace on muscle activity and scapular kinematics in subjects with shoulder impingement syndrome and rounded shoulder posture: A randomized crossover design.

BACKGROUND: Round shoulder posture (RSP) is one of the potential risks for shoulder impingement syndrome (SIS) due to alignment deviation of the scapula. Evidence on how the characteristics of a shoulder brace affecting the degree of RSP, shoulder kinematics, and associated muscle activity during movements is limited. RESEARCH QUESTION: The purposes of this study were (1) to compare the effects of a shoulder brace on clinical RSP measurements, muscle activities and scapular kinematics during arm movements in subjects with shoulder impingement syndrome (SIS) and RSP; and (2) to compare the effects of two configurations (parallel and diagonal) and two tensions (comfortable and forced tension) of the brace straps on muscle activities and scapular kinematics during arm movements in subjects with SIS and RSP. METHODS: Twenty-four participants (12 males; 12 females) with SIS and RSP were randomly assigned into 2 groups (comfortable then forced, and forced then comfortable) with 2 strap configurations in each tension condition. The pectoralis minor index (PMI), acromial distance (AD) and shoulder angle (SA) were used to assess the degree of RSP. Three-dimensional electromagnetic motion analysis and electromyography were used to record the scapular kinematics and muscle activity during arm movements. RESULTS: All clinical measurements with the brace were significantly improved (p < 0.05). Under forced tension, muscle activities were higher with the diagonal configuration than with the parallel configuration in the lower trapezius (LT) (1.2-2.3% MVIC, p < 0.05) and serratus anterior (SA) (2.3% MVIC, p = 0.015). For upward rotation and posterior tilting of the scapula, the diagonal configuration was larger than the parallel configuration (1.5°, p = 0.038; 0.4°-0.5°, p < 0.05, respectively). SIGNIFICANCE: Different characteristics of the straps of the shoulder brace could alter muscle activity and scapular kinematics at different angles during arm movement. Based on the clinical treatment preference, the application of a shoulder brace with a diagonal configuration and forced tension is suggested for SIS and RSP subjects.

Single-Session Video and Electromyography Feedback in Overhead Athletes With Scapular Dyskinesis and Impingement Syndrome.

CONTEXT: Subacromial impingement syndrome (SIS) is associated with scapular dyskinesis, or imbalanced scapular muscle activity. Evidence has shown that feedback can improve scapular control in patients with SIS. However, it is unknown whether real-time video feedback or electromyography (EMG) biofeedback is optimal for improving scapular kinematics and muscle activity during a functional task. OBJECTIVE: To compare the effects of video and EMG feedback sessions on absolute muscle activity (upper trapezius [UT], lower trapezius [LT], serratus anterior), muscle balance ratios (UT/LT, UT/serratus anterior), and scapular kinematics (anterior-posterior tilt, external-internal rotation, upward rotation) in SIS participants during arm elevation and lowering. DESIGN: Randomized controlled clinical trial. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Overhead athletes who were diagnosed with SIS and who also exhibited scapular dyskinesis (N = 41). MAIN OUTCOME MEASURE(S): Three-dimensional kinematics and EMG were recorded before and after feedback training. RESULTS: Lower trapezius muscle activity increased (4.2%-18%, P < .011) and UT/LT decreased (0.56-1.17, P < .013) in the EMG biofeedback training group as compared with those in the video feedback training group. Scapular upward rotation during arm elevation was higher in the video group than in the EMG group after feedback training (2.3°, P = .024). CONCLUSIONS: The EMG biofeedback improved muscle control and video feedback improved the correction of scapular upward rotation in patients with SIS. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT03252444.

Kinesiology taping with exercise does not provide additional improvement in round shoulder subjects with impingement syndrome: A single-blinded randomized controlled trial.

OBJECTIVE: Round shoulder posture (RSP) may exaggerate symptoms of subacromial impingement. The effects of kinesiology taping with exercise on posture, pain, and functional performance were investigated in subjects with impingement and RSP. DESIGN: This study was a single-blinded randomized controlled trial. SETTING: An outpatient rehabilitation clinic in a university hospital. PARTICIPANTS: Thirty-four subjects with subacromial impingement and RSP. INTERVENTIONS: Kinesiology taping with and without tension was applied 2 times per week for 4 weeks. Both groups also performed strengthening and stretching exercises 3 times per week for 4 weeks. MAIN OUTCOME MEASUREMENTS: The pain level, shoulder angle and self-reported score were evaluated at pre-intervention, 2-week post-intervention and 4-week post-intervention time points. RESULTS: Functional performance improved after intervention in both groups (p = 0.027). A greater decrease in pain level was related to better functional performance of the shoulder in both groups (r = -0.760 and -0.674; p < 0.010). Moderate correlations were found for posture and functional performance of the shoulder in the intervention group (0.48). CONCLUSION: Four weeks of strengthening and stretching exercises with or without kinesiology taping improved functional performance in subjects with impingement and RSP. Improvement in clinical symptoms was related to better performance of posture.