Sternocleidomastoid Muscle Morphology and Neck Function in Athletes and Para-Athletes

BackgroundNeck functional capacity is clinically relevant in sports medicine for performance support, screening, and injury prevention in sports characterized by acceleration, contact, and sustained precision demands. Ultrasound can quantify local muscle morphology and may improve interpretation of neck performance beyond crude anthropometry and global strength indicators.

ObjectiveTo determine whether sternocleidomastoid (SCM) cross-sectional area (CSA) and neck anthropometry are associated with neck function (strength, endurance, range of motion), and whether SCM morphology explains function beyond age, BMI, general strength (handgrip), and sport-domain context in a male cohort of athletes, para-athletes, and physically active controls.

MethodsCross-sectional comparative study (n=195 men) including athletes across sport domains, para-athletes, and controls. Outcomes were isometric neck strength (flexor and extensor), neck flexor endurance, and active neck range of motion. SCM CSA was assessed by standardized musculoskeletal ultrasound; neck girth served as an anthropometric comparator. Analyses included Pearson correlations and adjusted linear regression models controlling for age and BMI. Explanatory value beyond general strength was evaluated by adding handgrip strength, and independence from sport-domain context by adding sport domain as a covariate.

ResultsSCM CSA correlated positively with flexor strength (r=0.34, p=0.001), and neck girth was not significantly associated with neck function. Adjusted linear regression models revealed that SCM CSA explained neck function beyond age, BMI, and handgrip strength. The authors found no significant association between SCM morphology and neck function in the context of sport domain.