Muscle activation during gait in Parkinson’s Disease compared to healthy controls: a preliminary analysis

Background: Gait disorders are frequently reported in individuals with Parkinson's disease (PD). Despite extensive research, the specific gait features affected by PD are still not clearly defined. Objective: To investigate muscle activation patterns during single and dual task gait in individuals with PD compared to healthy controls (HC). Materials and methods: Participants with idiopathic PD and HC were analyzed and compared in two conditions: simple and dual task walking. Subjects were instructed to walk along a 10m straight path at comfortable speed, with the addition of a cognitive task (counting backwards) during the dual task condition. Data were collected using 3D Motion capture and surface electromyography (sEMG) to record muscle activity of both lower limbs i.e., gluteus maximus, biceps femoris, rectus femoris, vastus medialis, gastrocnemius medialis, soleus and tibialis anterior. Qualisys Track Manager (QTM), Visual3D and MATLAB, were used to analyze data. Comparisons were performed to study the effect of task (simple vs dual) and the effect of group (PD vs HC). After normalization of the sEMG signals and the gait cycle, Statistical Parametric Mapping (SPM) was used to perform statistical analysis. Results:12 PD (age 63.2± 6.1 yrs old; H&Y 2 ± 0.62; disease duration 8.20 ± 7.8) and 6 matched HC (age 60.8± 9.4 yrs old) were analyzed. The sEMG of PD showed an increase in the activation of gluteus maximus, biceps femoris and rectus femoris, throughout the gait cycle with differences being significant during early to mid-stance and in late swing, both in single and dual-task gait. A decreased activation of medial gastrocnemius and soleus muscles during the push-off phase was found, which however was not found to be significant. Conclusion: We highlighted an increase in muscle activation in PD during early stance, associated with a reduced activity of the medial gastrocnemius and soleus during the push off phase.