Differences in the total hip rotation range of motion between sides in healthy young Japanese adults

[Purpose] To investigate the difference by degrees in total hip rotation range of motion (ROM) between sides and with regard to gender in healthy young Japanese adults. [Participants and Methods] Data from previously published studies were used. We utilized the left and right hip rotation ROM of 205 Japanese participants aged 18 to 25 years, who satisfied the inclusion criteria and were randomly measured three times in the prone position by the double-blind method. The average value of the three measurements was used to calculate the left–right difference of the hip total rotation ROM in the hip joints, which is the sum of the hip internal and external rotation ROM. We investigated the distribution of the total hip rotation considering the flexibility factor and its relationship with gender. [Results] We confirmed that there were seven participants with 2 SD or more and two with 3 SD or more. No significant difference was found in the left–right difference in the total hip rotation ROM, regardless of gender. [Conclusion] The distribution of left–right differences in the total hip rotation ROM in healthy young adults showed the existence of a significant left–right difference of 2 SD or more.