Alterations in lower extremity muscular activation and joint angle patterns during gait in patients with type-2 diabetes mellitus with and without polyneuropathy

Aim: The aim of this study was to determine Type 2 Diabetes Mellitus (DM) and Diabetic Polyneuropathy (DPN) related lower extremity muscle activation and joint angle alterations independently from the gait speed. Material and Methods: 10 Type 2 DM, 8 DPN and 10 healthy age-matched subjects were evaluated at a comfortable and a test speed of 1.4 m/s. Gait characteristics, muscular activation characteristics and joint angle characteristics for the ankle, knee and hip joints were determined. Results: It has been determined that gait speed is lower (p=0.374) and relative duration of stance phase is higher (p=0.433) in DPN group subjects. It has been found out that m. tibialis anterior off time is delayed (p=0.022), m.vastus medialis activation amplitude is lower (p=0.045), activation duration is longer (p=0.028) in DPN group subjects at test gait speed. Knee joint range of motion (p=0.048) and maximum knee joint extension angle is smaller (p=0.076) in DM and DPN group subjects. Conclusion: Our study has shown that when the gait speed has been standardized, lower extremity muscular activation changes at the ankle and knee joint levels in DPN, and the joint angle differences at the knee joint level in relation to DM and DPN emerge during the early period of the stance phase. It is obvious that these changes will cause some impairments in braking force capacity while transfering the body weight from the heel to the forefoot gradually during gait.