The Effects of Forefoot Striking, Increasing Step Rate, and Forward Trunk Lean Running on Trunk and Lower Limb Kinematics and Comfort.

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.

Hip and knee kinematics are associated with pain and self-reported functional status in males and females with patellofemoral pain.

Altered hip and knee kinematics in the frontal and transverse planes may increase patellofemoral joint stress and contribute to the development of patellofemoral pain. The purpose of this cross-sectional study was to evaluate the association among hip and knee kinematics, pain, and self-reported functional status in males and females with patellofemoral pain. 20 males and 20 females with patellofemoral pain participated in this study. 3-dimensional hip and knee kinematics were quantified while performing a step-down task. A visual analogue scale was used to evaluate usual knee pain. The anterior knee pain scale was used to evaluate the knee functional score. For both groups combined, greater usual pain was associated with greater peak hip adduction, hip internal rotation and knee abduction (r=0.54-0.57, P<0.001). Also, modest to low correlations (r=-0.48 to - 0.37, P=0.03-0.08) were found among hip and knee kinematics and functional score. Stepwise regression revealed that peak hip internal rotation and hip adduction were significant predictors of pain, while peak hip adduction was the only predictor of function. Greater hip adduction, hip internal rotation and knee abduction are associated with higher levels of pain and reduced function in males and females with patellofemoral pain.