Ultrasound evaluation of the subacromial space in healthy subjects performing three different positions of shoulder abduction in both loaded and unloaded conditions. (January 2017)

• Record Type: Journal Article
• Authors: Longo, Stefano; Corradi, Alberto; Michielon, Giovanni; Sardanelli, Francesco; Sconfienza, Luca Maria
• Is Part Of: Physical therapy in sport. Volume 23(2017)
• Page Start: 105
• Page End: 112
• Publication Date: 2017-01
• Subjects: Subacromial space -- Lateral rise -- Upright row -- Ultrasound; Sports physical therapy -- Periodicals; Sports injuries -- Patients -- Rehabilitation -- Periodicals; Athletic Injuries -- diagnosis -- Periodicals; Athletic Injuries -- therapy -- Periodicals; Physical Therapy -- Periodicals; Sports Medicine -- Periodicals; 615.82088796
• DOI: 10.1016/j.ptsp.2016.08.007
• Languages: English
• ISSNs: 1466-853X

Abstract

Abstract: Background: Subacromial space (SS) narrowing may result in unsafe contact of rotator cuff tendons and bursa with the acromion, possibly promoting rotator cuff pathologies and pain. We measured SS in asymptomatic subjects after three movements employed for shoulder muscles' training. Participants and main outcome measures: Twenty-five males (age 24±5years; stature 175±8 cm; body mass 74±12 kg) underwent SS ultrasound evaluation while executing with (WL) and without (NL) 4-kg load: 90° shoulder abduction (SA) without humerus rotation (90°neutral ); 90° SA maximal humeral external rotation (90°er ); maximum SA (above 90°) during upright row (UR). For inter-operator reliability analysis, a subset of 12 subjects was assessed by two operators. Results: Intra/inter-operator reliability coefficients were high (ICC>0.87; standard error of measurement range: 0.23–0.51 mm; minimum detectable change range: 0.61–1.79 mm). ANOVA revealed significant differences between loads (p = 0.003, η 2 = 0.37) and angles (p < 0.001, η 2 = 0.72), and interaction (p = 0.004, η 2 = 0.45). Normalized SS values WL were higher at 90°er vs. 90°neutral and UR (p < 0.001 for both). Differences in NL were found between 90°neutral and both 90°er (p = 0.002) and UR (p = 0.009). Conclusions: When holding a 4-kg load, SS is larger at 90°er than at 90°neutral and UR shoulder abduction positions. In unloaded condition, SS at 90°neutral is reduced compared to 90°er and UR. Highlights: Shoulder abduction leads to a reduction of subacromial space (SS). SS reduction may be related to shoulder problems. SS for lateral rise (with/without external rotation) and upright row were assessed. At 90° external rotation SS was larger compared to no rotation and upright row. Type of movement influences SS when exercising shoulder muscles.