The influence of peripheral arterial disease on lower limb surface myoelectric signals in patients living with type II diabetes mellitus

Abstract

Background: The aim of this study was to evaluate whether there are any significant differences in muscle activity between individuals living with type II diabetes mellitus (T2DM) and individuals living with T2DM and peripheral arterial disease (PAD), during gait at a self-selected speed. The influence of different stages of PAD on muscle activity during gait was also assessed with the use of surface electromyography (EMG).

Research question: Does PAD affect lower limb muscle activity during gait in the presence of T2DM?

Methods: This quantitative study involves a prospective, comparative, non-experimental subject design. Ninety participants were divided into three groups namely Group A (thirty participants living with T2DM), Group B(i) (thirty participants living with T2DM and mild PAD) and Group B(ii) (thirty participants living with T2DM and severe PAD). Surface electrode sensors were placed according to SENIAM guidelines, on six main lower limb muscles on both limbs. Muscle activity was recorded using a wireless system, where participants were instructed to walk at a self-selected speed on a 10-m walkway. Average Burst RMS was performed and the amplitude (mV) and the duration of muscle activation (s) was analysed.

Results: There was a significant increase in muscle amplitude and duration of activation in the presence of lower limb ischaemia during gait. The largest significant difference (p= <0.05) in EMG amplitude and duration of activation when looking at the twelve muscles in general was found between participants living with T2DM and participants living with T2DM and severe PAD.

Significance: The increase in muscle activity indicates that there are musculoskeletal and biomechanical changes in the lower limb musculature with increasing severity of PAD. Higher muscle exertion demands are required during gait which may result in earlier fatigue. EMG tests would be beneficial for detecting muscle dysfunction objectively and non-invasively in T2DM and PAD.