Distal Radioulnar Joint Kinematics Evaluated Using Ultrasonography During Handstanding in Female Gymnasts

Background: Wrist pain prevalence is significantly higher in female gymnasts than in male gymnasts, and the pathological site varies depending on patient age. However, the differences between age groups have not been elucidated with a focus on changes in the kinematics of the distal radioulnar joint (DRUJ). Purpose: To analyze the effect of wrist weightbearing during a handstand on the kinematics of the DRUJ using ultrasonography in female elementary school (ES), junior high school (JH), and high school (HS) gymnasts, and to determine whether wrist pain affects the kinematic measurements in female gymnasts. Study Design: Descriptive laboratory study. Methods: A total of 66 wrist joints in 33 female gymnasts (5 ES, 9 JH, and 19 HS students) were included. Ultrasound examinations were performed in neutral extension, nonweightbearing (NENWB); full extension, nonweightbearing; and full extension, weightbearing (FEWB). The radioulnar joint kinematics were evaluated by measuring the radioulnar separation and dorsivolar shift. The change in distance in the FEWB condition was determined as a reference for those in the NENWB condition and for comparison between the 3 school groups. Also, the change in distance was compared between the gymnasts with and without wrist pain. Results: The radioulnar separation increased from the NENWB to the FEWB condition in all 3 groups, and a significantly larger change in distance was observed in HS students compared with ES students ( P = .008). The dorsivolar shift decreased from the NENWB to the FEWB condition in ES and JH students; it was almost unchanged in HS students. There was a significant difference in change in dorsivolar shift from the NENWB to the FEWB condition between ES and JH students ( P = .023). There were 2 ES, 2 JH, and 10 HS students with wrist pain. The change in radioulnar separation was significantly greater separation in gymnasts with wrist pain compared with those without wrist pain ( P < .001). Conclusion: The radioulnar joint kinematics during the FEWB condition varied with school age in female gymnasts. The larger increase in the radioulnar separation from the NENWB condition to the FEWB condition might be associated with a biomechanical mechanism of wrist pain in female gymnasts. Clinical Relevance: Repetitive tensile loads put female gymnasts at risk of wrist pain and overuse injury.