This study aimed to compare the immediate effects of 3 running technique modifications on the ankle, knee, hip and trunk kinematics and on the perceived comfort in healthy runners. The modifications were: forefoot striking pattern (FFOOT); increasing 10% of step rate (10% SR); and increasing forward trunk lean (FTL). 31 healthy runners participated. 3-dimensional lower limb and trunk kinematics were quantified while performing each condition on a treadmill. At initial contact, the FFOOT showed an increase in plantar flexion and knee external rotation, and reduction in knee flexion and adduction. During the stance phase, this condition showed greater peak knee external rotation and less mean and peak dorsiflexion and knee flexion. The 10% SR resulted in less hip flexion at initial contact. During the stance phase this technique showed less mean and peak knee flexion, peak reduction for dorsiflexion, knee abduction, hip flexion and hip adduction. At initial contact and during the stance phase, the FTL caused greater knee adduction and hip flexion. The usual running was the most comfortable technique.
The techniques showed different lower limb kinematic modifications; which could potentially reduce knee injury risk. This knowledge is clinically relevant as it can be used to better prescribe techniques in prevention and rehabilitation programs.