The development, preliminary validation and clinical utility of a shoe model to quantify foot and footwear kinematics in 3-D

Functional electrical stimulation (FES) applied to the common peroneal nerve is commonly prescribed to correct both equinus and excessive foot inversion in swing and initial contact. This paper presents the development of a simple shoemodel, to allow quantification of 3-D shoe (foot and footwear) kinematics in clinical situations when footwear is required, e.g. with FES systems requiring footswitches. To preliminarily validate the shoemodel, barefoot ‘normal’ adult data (n = 11) processed using validated 3-D footmodels, were reprocessed with the shoemodel. Outputs were compared through calculation of waveform similarity and correlation. Clinicalutility of the shoemodel is demonstrated through the presentation of 3-D shoe kinematics, calculated from a cohort of existing unilateral common peroneal FES users (n = 16), both with and without FES. A trend of reduced inversion at mid-swing and initial contact was seen, although this was not found to be statistically significant (p ≤ 0.0125). The shoemodel was found to be practical to use in aclinical environment, and has potential to contribute to the evidence base for interventions such as common peroneal FES.