Does the increase in body weight change the knee and ankle joint loading in walking and running?

Abstract

Previous obese studies showed that there is a correlation of weight to joint load in the knee joint during walking. In load-carrying studies, there are several studies but no consistent findings in the knee joint loads in walking and running.

Our aim was to investigate how the joint load changes in body weight gaining, using added vest that was 10% of the body weight to mimic the conditions. We used Vicon eight-camera system and five force platforms with inverse dynamics to calculate the peak ground reaction forces(GRFs), joint angle, joint moments, and patellofemoral contact forces(PFCF), patellafemoral stress(PFS), peak patellofemoral tendon force(PTF) and peak Achilles tendon force (ATF).

The results showed that in walking, there were significant increases in joint loadings in both knee and ankle as the weight increased. There were significant increases in PFCF, PFS, PTF and ATF (p<0.001). This may be due to the significant increases in knee flexion ROM, ankle dorsiflexion ROM maximum (P<0.05) and added weight. The relationship between the weight increase and PFCF was 1:1, in PTF 1:2, in peakATF 1:3 and in PFS 1:0.05. During running, the relationship between body weight increase and PFCF change is 1:4, in peakPTF 1:4, in peakATF 1:2 and in PFS 1:0.1. Our results indicated that the knee joint loading increased proportionally with increased weight and in running, the loading increased in double, suggesting the speed also affected the loadings. This implies that as human gains weight, there might be a higher risk of getting knee osteoarthritis, especially with one that has major recreational sports in running. Our study also suggests that weight reduction is crucial for those that are overweight to prevent osteoarthritis since weight is directly correlated to joint loads.