Novel methods to quantify gait rehabilitation following ankle-foot fractures

Lower limb fragility fractures included a break in bone from the pelvis to the foot. Weight-bearing and walking stability stand as key performance indicators to quantify fracture restoration. Normally, progress in fracture rehabilitation is observed through clinical assessments and patients' responses, and modern research also presents instrumented gait analysis. There exists a gap to statistically compute the regaining in patients' weight-bearing ability and walking stability following fractures. This study introduces methods to advance the analysis of instrumented signals and evaluate walking stability in fracture-healing patients. The centre of pressure (CoP) signals were captured for four conditions: tibia/fibula/talus fracture near the ankle (AF), lower-leg shaft fracture (LF), calcaneus fractures (CF), and normal ankle (NA). The time derivative for CoP signals showed impulsive responses during the loading and unloading transitions which were then modelled and transformed to the frequency domain. The developed models were further analysed by applying Nyquist and Bode methods and margins of stability were calculated for the fractured and healthy subjects. Results showed a substantial decline (Kruskal-Wallis's test, <i>p</i> < 0.001) in the intralimb stability of all three fractures. Also, there was a strong interlimb dependency (<i>p</i> < 0.001) observed between fractured and intact limbs applying Spearman's correlation during double limb support periods. Overall, the calcaneus fracture (CF) exhibited minimum intralimb stability and increased interlimb dependency. These methods stand clinically important in monitoring patients' rehabilitation and in decision-making about alternative treatment plans.