Sensitivity of loading to the timing of joint kinematic strategies in simulated forefoot impact landings

The impact loads experienced in landing may be influenced by the joint kinematic strategy used. This study aimed to enhance the understanding of the sensitivity of impact loading to the timing of joint kinematic strategies in simulated forefoot landings. Coordinate and force data of drop landings were used to initiate, drive, and evaluate a wobbling mass model. Ankle, knee, and hip joint angle profile timings were modified in the simulated motions. Changes to the timing of the ankle and knee joint angle profiles were associated with substantial changes in the peak vertical ground reaction force (GFz _max) of up to 3.9 bodyweights (BW) and 1.5 BW, respectively, whereas loading was less sensitive to temporal changes in the hip joint strategy. Accentuated impact loads incurred by a modified knee flexion action may be explained by the need to maintain an ordered and controlled load attenuation strategy. Individual strategies and external and joint reaction forces should be considered for developing insight into loading in impact landings.