A descriptive comparison of postural, functional, and electromyographic characteristics in asymptomatic female overhead athletes with and without scapular dyskinesis

Scapular dyskinesis is commonly observed in overhead athletes, including those without shoulder symptoms. However, postural, functional, and neuromuscular characteristics have rarely been examined concurrently within the same population. This study compared these characteristics between asymptomatic female overhead athletes classified as having obvious scapular dyskinesis and those with normal scapular movement. This exploratory cross-sectional study included 50 asymptomatic female overhead athletes (25 dyskinesis, 25 control) participating in volleyball, handball, or badminton. Participants were classified using the Scapular Dyskinesis Test. Postural, functional, strength, range-of-motion, and surface electromyographic variables were assessed during a standardized laboratory session. Between-group differences were evaluated using independent-samples tests selected according to data distribution, with effect sizes and 95% confidence intervals reported. The Benjamini–Hochberg procedure was additionally used as a false-discovery-rate sensitivity analysis. The dyskinesis group showed significantly greater forward shoulder angle (d = 1.52), scapular asymmetry (d = 1.48), and acromion asymmetry ( r = 0.41); shorter pectoralis minor length (PMI: 7.17 vs. 8.22, d = 1.08); lower Y-balance scores (d = 1.26); and reduced flexion (d = 0.95), abduction (d = 0.85), and external rotation (d = 1.31) range of motion and strength (d = 0.99, 0.73, and 1.09, respectively; all P < 0.05). No significant differences were observed for extension or internal rotation. The dyskinesis group also exhibited higher upper trapezius activity (d = 1.34) and lower lower trapezius (d = 1.38) and serratus anterior (d = 1.22) activity (all P < 0.001). The largest effect sizes were observed for postural and neuromuscular variables (d = 1.38–1.52). Asymptomatic female overhead athletes classified with obvious scapular dyskinesis showed differences across postural, functional, and neuromuscular measures. The findings provide a multidomain descriptive profile rather than evidence of causal relationships or clinically established impairment and may help generate hypotheses for future prospective research.