Hip adduction during running and knee-related symptoms – Sex differences and longitudinal associations in runners with a history of knee surgery: Two-year data from the TRAIL cohort

Background Increased peak hip adduction during running has been observed in runners with knee pain and is thought to increase knee joint loading and symptom development. This study aimed to explore: (i) sex differences in peak hip adduction during running and knee-related symptoms in runners with a history of knee surgery; and (ii) associations between baseline hip adduction and knee-related symptoms at baseline and two-year follow-up. Methods Runners with a history of knee surgery, who ran ≥3 times and ≥ 10 km per week, were recruited. Overground running biomechanics at baseline were recorded via three-dimensional motion capture and embedded force plates at both 3–3.5 m/s and 5–6 m/s. Surgical limb peak hip adduction during stance was extracted. Knee-related symptoms were assessed using the Knee injury and Osteoarthritis Outcome Score 4 and the patellofemoral subscale at baseline and two-year follow-up. Linear regressions explored sex differences in peak hip adduction while generalised linear models explored sex differences in knee-related symptoms and associations between hip adduction and symptoms cross-sectionally and longitudinally. Findings 108 runners with a history of knee surgery completed baseline testing (53 females; 55 males). Females demonstrated greater peak hip adduction (3.42° and 1.09°) and worse knee-related symptoms (−5.61 to −8.18) than males. No significant associations were found between hip adduction and symptoms (baseline or two-year follow up). Interpretation Female runners with a history of knee surgery demonstrated greater hip adduction and worse knee-related symptoms than males. Peak hip adduction was not significantly associated with knee-related symptoms at baseline or 2 years.