High tibial shock (TS), during running has been linked to an increased risk for developing tibial stress fractures. However, gait retraining using real time feedback has been shown to reduce TS during running up to 25%. Although it is unclear what kinematic strategies are used, midfoot strike (MFS) and forefoot strike (FFS) patterns have been reported to reduce load rates in running. Therefore, we predict that runners will adopt more of an anterior strike pattern, subsequently reducing dorsiflexion (DF) and increasing knee flexion (KF) at foot strike (FS).PURPOSE:To determine the kinematic strategies runners use to reduce TS following gait retraining.
METHODS: To date, 15 rearfoot strike (RFS) runners (age: 28 ± 8 yr, 16.7 ± 10.8 mpw, TS: 11.4 ± 2.9 g) have participated in this ongoing study. The gait retraining protocol consisted of 8 retraining sessions with real time visual feedback aimed at reducing TS. Motion, ground reaction force, and accelerometry data were collected during running pre- and post gait retraining. Variables of interest can be found in Table 1.
RESULTS: Of the 15 runners, 13 were able to decrease their TS. 7 of these adopted more of MFS or FFS pattern. These runners increased their strike index (SI), and increased their KF while decreasing their DF at FS, as hypothesized (Table 1). The remaining 6 runners used an ankle strategy landing with greater dorsiflexion and decreased KF at FS (Table 1). Interestingly, this group also exhibited lower approach accelerations.
CONCLUSIONS:Two distinct kinematic strategies were exhibited by runners who reduced TS after participating in gait retraining; a MFS or FFS strategy or an ankle strategy.