The foot seems to demonstrate considerable power absorption and generation characteristics during running. These have been mainly accounted to the mechanics of the ankle joint, however, evidence suggests that joint kinetics have been overestimated by single-segment foot models. The scope of the present study was to estimate the energetics of the ankle-, chopart-, lisfranc- and hallux joint during heel-strike running. Power absorption and generation occuring at different segments of the foot of seven asymptomatic adults was modelled using a four-segment kinetic foot model. Participants ran barefoot with an average running speed 3.5 m/s along a 10 meter walkway. The peak power generation of the ankle, chopart, lisfranc, and hallux joint reached respectively an average of 13.9, 4.12, 1.08 and 0.32 Watt/kg. The Lisfranc joint showed poor power absorption compared to the other three joints. It was further demonstrated that the Ankle and Chopart joints seem to have both receptive and propulsive characteristics. The behavior of the Lisfranc joint complied almost exclusively with propulsive characteristics. Finally, it can be concluded that the midfoot accounts for approximately 25% of the total power absorption occuring at the foot joints and not 50% as initially hypothesized.
There is an ongoing debate regarding the advantages and harms of different running striking patterns. The purpose of this study was to explore the kinematic differences between running with a midfoot- and rearfoot striking (RFS) pattern. Multi-segment foot kinematics of 12 students were assessed while running barefoot at 3.3 m/s (±10%) using a passive optoelectronic motion analysis system. Participants performed multiple running trials while landing on the rearfoot and midfoot. Comparison of the kinematic waveforms was performed using one-dimensional statistical parametric mapping (1DSPM) (paired t-test). The inter-segment angle between the shank and calcaneus was found to be significantly more plantar-flexed, more inverted and more adducted in the midfoot striking (MFS) condition compared to the RFS pattern. The calcaneus-midfoot inter-segment angle was found to be more plantar-flexed in the MFS condition. The downward angulation of the metatarsals and the medial longitudinal arch angle in the late swing phase was found to be more pronounced during MFS. Differences between midfoot and RFS patterns occur in the first sub-phase of stance (0–50% of the stance phase). These findings may be of interest for the kinesiopathological or pathokinesiological reasoning processes when facing foot- and lower limb-related running injuries.