Differences in shoulder range of motion among tennis athletes by age and sex

Investigating shoulder range of motion (ROM) among junior tennis athletes may help in developing injury prevention programs; however, few studies have examined the shoulder function of Chinese tennis athletes. Therefore, this study compared the shoulder ROM among tennis athletes by age and sex. A convenience sample of 123 healthy tennis athletes (aged 918 years) was included and categorized into primary school (9–12 years), junior high school (13–15 years), and senior high school (16–18 years) groups. Shoulder abduction, internal rotation (IR), external rotation (ER), and total range of motion (TROM) were assessed using a digital goniometer. Between-group and between-side differences were analyzed using mixed-effects linear models, with other comparisons analyzed using parametric or non-parametric tests as appropriate; post hoc comparisons were adjusted using the Benjamini-Hochberg false discovery rate (FDR) procedure. Significant effects of side were found for shoulder abduction, IR, and ER ROM ( P = 0.007, P = 0.007, and P = 0.004, respectively). The non-dominant side showed greater abduction and IR ROM, whereas the dominant side showed greater ER ROM (all P < 0.001). Significant age effects were observed for ER ROM ( P = 0.004) and TROM ( P = 0.007). ER was greater in the elementary school group than the junior high and high school groups (both P = 0.002), and in the junior high school than the high school ( P = 0.002). TROM was greater in the elementary and junior high school groups than in the high school group ( P = 0.003 and P = 0.017, respectively). A significant sex × age interaction was found for shoulder abduction ROM ( P = 0.042); in males, abduction ROM was greater in the elementary and junior high school groups than in the high school group ( P = 0.026 and P = 0.003, respectively). Chinese tennis players aged 9–18 years showed side-related differences in shoulder abduction, IR and ER, and age-related differences in ER and TROM, with a sex × age interaction for shoulder abduction observed mainly in males. These findings may provide descriptive data on shoulder ROM in healthy tennis athletes aged 9–18 years.