Age, sex and physical activity differences in the knee joint loadings during walking-a cross-sectional study

The aim of this cross-sectional cohort study was to assess differences in internal knee joint loading during walking in relation to age, sex, and physical activity level.

Kinematic and dynamic data obtained from experimental investigations were analysed and used to develop a mathematical model of walking within the AnyBody Modeling System. Statistical Parametric Mapping (SPM) was used to assess the associations between individual parameters and the resultant knee joint reaction force.

The results demonstrated that age-, sex-, and physical activity-related differences in knee joint loading varied across phases of the walking gait cycle. A statistically significant association with physical activity (p < 0.05) was observed in the youngest group of women (18-25 years) and in the 46-65-year age groups in both sexes, with physically inactive individuals exhibiting higher force values during the mid-phase of the walking gait cycle (30%-50%). Sex-related differences were equivocal, with higher resultant knee joint reaction force in men identified only in selected age groups (18-25 and 56-65 years) and during the early stance phase (10%-22%). Comparison between younger and older groups revealed an age-related shift in peak loading towards the early phase of foot-ground contact, which may reflect compensatory changes in locomotor strategy.

The findings indicate that age, sex, and physical activity are significant factors that should be taken into account in the analysis of knee joint biomechanics, both in the context of preventing degenerative changes and in the planning of individualised training programmes.