The effects of age and sex on active and passive hip range of motion in individuals with alkaptonuria

Purpose: To report active and passive hip range of motion (ROM) data for individuals with alkaptonuria (AKU), with consideration for age, sex, and non-AKU comparative data. Materials and Methods: Using a cross-sectional study design, 123 patients who had baseline ROM assessed in a previous international, multi-centre clinical trial were included. Data was compared between age groups, sexes, and with existing data from individuals without AKU. Data was analysed using a one-way ANOVA, paired t-test, and one-sample t-test, with results interpreted using partial eta squared and standardised mean differences (SMD). Results: Differences were observed across the age groups for active and passive flexion (F = 3.815, p = 0.006, eta(2)(p) = 0.115) and active hip abduction (F = 1.941, p = 0.108, eta(2)(p) = 0.062). Differences between sexes ranged from trivial-to-large (SMD = 0.03 to 1.90), with variability evident across the age groups. Individuals with AKU were within the lower range of scores observed for healthy adults in flexion (t = -8.545 to -3.166, p = 0.010 to <0.001) and abduction (t = -20.830 to -0.737, p = 0.478 to <0.001). Conclusions: Our results provide insight into the clinical value of ROM with consideration for age, sex and normative data as a determinant of disease progression and functional ability within individuals with AKU.