Association Between Dorsal Scapular Artery Blood Flow and Shoulder Internal Rotation Range of Motion in Patients with Symptomatic Rotator Cuff Tears: An Exploratory Analysis of Infraspinatus Muscle Cross-Sectional Area
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background The association between local circulatory dynamics and shoulder function in patients with rotator cuff tears (RCTs) has recently attracted attention. Although dorsal scapular artery (DSA) blood flow is associated with muscle morphology and shoulder function, its relationship with internal rotation (IR) range of motion remains unclear. Methods This cross-sectional study included 26 patients with symptomatic RCTs. The peak systolic velocity of the DSA (DSA-PSV) was measured using Doppler ultrasonography. IR was assessed using the hand-behind-back IR (HBB-IR) and IR at 90° abduction. The cross-sectional area of the infraspinatus muscle (ISP-CSA) was assessed using magnetic resonance imaging. Associations between DSA-PSV and IR were examined using Spearman rank correlation and multiple linear regression adjusted for movement-related pain. Furthermore, exploratory mediation analysis assessed whether ISP-CSA accounted for part of this association. Results DSA-PSV negatively correlated with HBB-IR (r = −0.39, p=0.049) and IR at 90° abduction (r = −0.49, p=0.012). In the adjusted model, a significant negative association of moderate magnitude remained for IR at 90° abduction (adjusted R 2 = 0.41, p=0.001) but not for HBB-IR. Exploratory mediation analysis revealed no significant indirect association of ISP-CSA with either HBB-IR or IR at 90° abduction. The direct association was significant for HBB-IR (p = 0.033), whereas the total association was not significant (p = 0.050). For IR at 90° abduction, direct and total associations were significant (p = 0.010 and p=0.003, respectively). Conclusion Higher DSA-PSV was moderately associated with reduced active IR at 90° abduction in patients with symptomatic RCTs. The association with HBB-IR was less consistent, and exploratory mediation analysis showed no significant indirect association through ISP-CSA. These findings should be interpreted with caution because of the small sample size and cross-sectional design. Level of Evidence Level IV, Cross-sectional observational study
Source: JSES International
Authors: Keita Kawabuchi, Masatoshi Nakamura
Institutions: Tottori Prefectural Central Hospital, Nishikyushu University
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $1,250
OpenAlex ID: W7220449331