Contents lists available at ScienceDirect Gait & Posture journal homepage: www.elsevier.com/locate/gaitpost Full length article The influence of peripheral arterial disease on lower limb surface myoelectric signals in patients living with type II diabetes mellitus Erica Bartolo a, ⁎ , Claire Saliba Thorne a , Alfred Gatt b , Cynthia Formosa b a Faculty of Health Sciences, Univeristy of Malta, Msida, Malta b Faculty of Health Sciences, University of Malta, Msida, Malta ARTICLE INFO Keywords: Peripheral arterial disease Type II diabetes mellitus Surface electromyography Muscle amplitude Muscle duration of activation 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. 1. Background Peripheral arterial disease (PAD), also known as peripheral vascular disease or peripheral obliterative artheriopathy, is defined as a partial or complete obstruction of arteries due to atherosclerotic occlusion of the lower extremities [1]. It has been estimated that, globally, there are more than 202 million individuals living with PAD, with 70% of af- fected people living in countries having a low to moderate financial status [1]. PAD presents a high health, social and human impact [2]. As a re- sult, early identification and prevention of disease is of great sig- nificance to reduce the severity of PAD and the risk of amputation. Preventative measures through diabetic, vascular, neurological and musculoskeletal screening are more cost effective than the need for surgical interventions and rehabilitation for advanced PAD [2,3]. Fur- thermore, preservation of an individual’s independence through im- proving mobility and prevention of pain and risk of ulceration, could significantly improve one’s quality of life and provide a better prognosis [4]. Examination and monitoring of individuals living with PAD is more focused on the vascular aspect rather than the effect of PAD on the biomechanical and neurological status of the individual. The role of the treating clinician should be to determine the presence / absence and severity of PAD in the lower limbs, whilst also linking any neurological or musculoskeletal problems to the reduction in blood supply [5]. Literature shows that lower limb ischaemia may result in abnormal gait patterns, thus better evaluation of the effect on muscle activity would enhance our understanding in gait impairment and may lead to https://doi.org/10.1016/j.gaitpost.2019.07.254 Received 12 June 2018; Received in revised form 25 June 2019; Accepted 19 July 2019 ⁎ Corresponding author. E-mail address: erica.bartolo.08@um.edu.mt (E. Bartolo). Gait & Posture 73 (2019) 228–232 0966-6362/ © 2019 Elsevier B.V. All rights reserved. T