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. The objective of our study was to investigate the influence of femoral AVA and NSA on muscle forces and joint loads during walking. We conducted a comprehensive musculoskeletal modelling study based on three-dimensional motion capture data of a healthy person with a typical gait pattern. We created 25 musculoskeletal models with a variety of NSA (93°-153°) and AVA (-12°-48°). For each model we calculated moment arms, muscle forces, muscle moments, co-contraction indices and joint loads using OpenSim. Multiple regression analyses were used to predict muscle activations, muscle moments, co-contraction indices, and joint contact forces based on the femoral geometry. 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. Large AVA lead to increases in both knee and hip contact forces. Large NSA (153°) combined with large AVA (48°) led to increases in hip joint contact forces by five times body weight. Low NSA (108° and 93°) combined with large AVA (48°) led to two-fold increases in the second peak of the knee contact forces. Increased joint contact forces in models with increased AVA and NSA were linked to changes in hip muscle moment arms and compensatory increases in hip and knee muscle forces. Knowing the influence of femoral geometry on muscle forces and joint loads can help clinicians to improve treatment strategies in patients with femoral deformities.

A framework based on subject-specific musculoskeletal models and Monte Carlo simulations to personalize muscle coordination retraining

“…Modenese et al 14 showed that personalizing the femoral anteversion angle leads to more accurate estimations of knee joint contact forces. Furthermore, their study showed that joint loads increase with high anteversion angles, which is in agreement with our previous work 13 , 18 . Last but not least, joint loads depend on a person’s muscle coordination.…”

“…Prior research has indicated that even slight variations in walking velocity within this range can lead to an approximate alteration of hip and knee JCF by about one body weight 51 , 52 . Notably, despite the variation in walking velocities, JCF from our reference simulations were very similar among most participants (e.g., TD01, TD02, TD03, and TD04), underscoring the substantial influence of bony geometry on JCF 53 . While we observed large differences in the maximum reduction of JCF, even among participants with similar walking velocities (e.g., TD01 vs. TD05), we assume that walking velocity had a relatively minor impact on our analyses.…”

“…We personalized a generic musculoskeletal model by incorporating anatomical details derived from MRI images. As a result, our models accurately considered key anatomical features (e.g., femoral neck-shaft angle), known to significantly influence simulation outcomes 53 , while overlooking others (e.g., femoral shaft bending, variations in muscle attachment points among participants). While fully MRI-based models 17 , 55 , 56 theoretically offer a more precise representation of a participant's musculoskeletal geometry, they require defining muscle attachment points based on MRI images—a process fraught with challenges and uncertainties.…”

“…Although these findings are very promising, future research is needed to evaluate which muscles can be easily altered with gait retraining and which training modalities achieve the best results. Fourth, JCF were calculated based on rigid-body simulations in OpenSim, a common approach known to yield reasonable results 14 , 53 , 65 , but one that neglects soft tissue contact biomechanics. Modeling approaches that combine musculoskeletal dynamics and joint-level finite element analysis in a concurrent framework can provide insights into the interaction between muscle activation and joint tissue deformation 66 – 68 .…”