Introduction: This study determines cross-sectional changes in transverse plane hip range of motion (ROM) in teenager soccer athletes and non-athletes and correlates these measures with changes in frontal plane leg alignment (varus-valgus alignment).
Evidence acquisition: This was a comparative cross-sectional study with non-random convenience sampling.
Evidence synthesis: Participants were recruited from a major professional soccer club and two local state-run schools in southern Brazil. A total of 396 male participants aged 9-18 years were assessed, 183 soccer players (athlete group; mean age, 13.3 ± 2.7 years) and 213 students (non-athlete group; mean age 14.4 ± 2.5 years). Hip internal rotation (IR) and external rotation (ER) and frontal plane leg alignment were measured in all participants. Changes in transverse plane hip ROM and frontal plane leg alignment were determined. Mean IR was 20.7° ± 5.8° in athletes versus 32.8° ± 2.9° in non-athletes, and mean ER was 36.5° ± 7.4° in athletes versus 46.7° ± 4.8° in non-athletes. Overall, IR was decreased in the athlete group compared to the non-athlete group (P < 0.001). Mean IR and ER were significantly lower in older athletes (P < 0.001), while only ER was significantly lower in older non-athletes (P < 0.001). Varus leg alignment was prevalent at all ages in the athlete group (71.0%, P = 0.153). In the non-athlete group, the occurrence of varus leg alignment was higher in older participants (P = 0.001). Lower mean IR was correlated with more severe varus leg alignment in the athlete group (rs = 0.19; P = 0.009).
Conclusions: We found a lower hip ROM, particularly in IR, in teenager soccer players according to the enhancement age group from the sample. But varus alignment of the leg was also prevalent in this group and comes before hip abnormalities started to be detected.
Keywords: Anterior cruciate ligament; Hip; Knee; Range of motion.