Running footstrike pattern effect on lower extremity work in an individual with transtibial amputation

Asymmetrical loading favoring the intact limb during running has been associated with increased prevalence of reported knee pain and potential risk factors of knee osteoarthritis in that limb for patients with amputation. Footstrike pattern alterations have been suggested to help alleviate some overloading of the knee, but little is known about how it affects the rest of the limb. The purpose of this case study was to evaluate the effect of footstrike pattern on the distribution of loading throughout the lower extremities during submaximal running of an individual with transtibial amputation (TTA). This study compared loading distribution among the lower extremity joints in a male patient who sustained a TTA and ran using both a rearfoot (RFS) and forefoot strike (FFS) pattern. The results of this case demonstrated that altering footstrike pattern minimally alters the total mechanical work being done by the lower extremities but more so affects the relative amount of work contributed by the individual joints. In the intact limb, the ankle contributes the most to power absorption using a FFS pattern while the knee has a larger role using a RFS pattern. This case suggests that the footstrike pattern affects lower extremity loading distribution at the joint level, and adopting a FFS pattern may alleviate overloading the knee, whereas a RFS pattern may reduce loading at the ankle in individuals with TTA.