Influence of femoral anteversion angle and neck-shaft angle on muscle forces and joint loading during walking

Abstract

Femoral deformities, e.g. increased or decreased femoral anteversion (AVA) and neck-shaft angle (NSA), can lead to pathological gait patterns, altered joint loads, and degenerative joint diseases. The mechanism how femoral geometry influences muscle forces and joint load during walking is still not fully understood. Hence, we conducted a comprehensive musculoskeletal modelling study to investigate the influence of femoral AVA and NSA on muscle forces and joint loads during walking. We created 25 musculoskeletal models with a variety of NSA and AVA. For each model we calculated moment arms, muscle forces, muscle moments, and joint loads based on motion capture data of a healthy person with a typical gait pattern. We found a significant increase in co-contraction of hip and knee joint spanning muscles in models with increasing AVA and NSA, which led to a substantial increase in hip and knee joint contact forces. Decreased AVA and NSA had a minor impact on muscle and joint contact forces. Neglecting an individual’s femoral geometry when estimating joint contact forces can lead to errors above five times body weight. Knowing the influence of femoral geometry on muscle forces and joint loads can help clinicians to improve treatment strategies in patients with femoral deformities.

The gait pattern and not the femoral morphology is the main contributor to asymmetric hip joint loading

“…Asymmetric HJCF can alter growth plate loading [ 19 ] and therefore lead to asymmetric development of bones in length and shape resulting in altered biomechanics. Previous studies showed that not only the subject-specific gait pattern but also the femoral geometry has a big impact on the estimation of the HJCF [ 16 , 20 – 22 ].…”