The effect of induced joint restriction on plantar pressure during gait - a pilot study

Abstract

Background: The aim of this study was to analyse the effect of induced lower limb joint restriction on plantar pressures during gait. Focusing on restricting a single joint, without the effect of other co-morbidities, would provide better understanding as to the resultant plantar loadings during gait, which would be especially beneficial in patients requiring offloading procedures.

Research question: Does induced lower limb joint restriction affect plantar pressure distribution during gait?

Methods: A prospective, quasi-experimental study was conducted, recruiting ten healthy, adult participants who were instructed to walk barefoot over a Tekscan HR Mat™. This procedure was repeated after separately inducing restriction of the hip, knee and ankle joints. Mean peak plantar pressure (MPP) and pressure-time integral (PTI) data were analysed to compare between unrestricted and restricted data.

Results: Significant plantar pressure changes were observed in the heel and first metatarsal regions. Rearfoot PTIs were increased with restriction of the contralateral hip (left p <0.001) (right p =0.02) and knee joints (left p =0.01) (right p =0.04). Both MPPs (left p =0.01; right p =0.01) and PTIs (left p =0.004; right p =0.03) were increased in the first metatarsal when restricting the hip joint of the same limb. MPP was decreased in the left first metatarsal with induced knee (left p =0.01; right p =0.04) and ankle (left and right p <0.001) joint restriction. Finally, MPP was decreased in the right first metatarsal with knee (left and right p =0.01) and ankle (left p =0.04; right p =0.01) joint restriction.

Significance: Limited joint mobility may have a direct effect on plantar pressure, particularly with restriction in the hip and knee joints, hence careful attention should be given especially in patients with conditions involving plantar loadings. Results in this study also show that PTI changes during gait should be equally evaluated clinically along with peak plantar pressure analysis.

Keywords: Diabetic foot ulceration; Joint restriction; Mean peak plantar pressure; Offloading devices; Pressure-time integral.