Analysis of gait parameters and muscle activity in Parkinson’s disease patients

Parkinson's disease (PD) patients suffer gait disturbances, which are a major cause of disability, falls, reduced mobility, and quality of life. Gait assessment is important in the diagnosis and monitoring of the disease. Gait is one of the measures observed in the Unified Parkinson's disease rating scale part III (UPDRS III) and is scored by clinical observations to determine the severity of disease and efficacy of treatment. However, this is a subjective test and there is a need for quantifiable gait analysis to study the PD patients.<br><br> Walking patterns such as turning are affected in the early stages of the PD patients. The main consequence of turns in PD are falls or triggers freezing of gait (FOG), which can result in severe immobility and reduced quality of life. Thus, it is very important to evaluate the turning ability in PD and to investigate the effect of gait intervals across different turns. During the Unified Parkinson's disease rating scale (UPDRS) screening, neurologists observe their patients during the turn phase of their walks, but this is subjective and has not been quantified.<br><br> As the first objective, a series of experiments were performed on 72 participants: 24 with PD, 24 age-matched controls, and 24 young controls. The data recording was performed using a wireless inertial measurement unit (IMU), which can record acceleration, rotation, and surface electromyogram (sEMG) signals. The experimental protocol required the participants to walk in different turns and straight walking, designed in such a way that resembled the activities of daily living.<br><br> This research has investigated the effects of gait and muscle parameters based on the severity of disease and during turning. The study has proposed that variance and fraction of the gait sub-intervals can be used to estimate the severity of the disease. The study also shows that the variability of gait sub-interval, irrespective of the walking pattern, straight-line walking or turning, is suitable for the evaluation of PD patients, and differentiating from control. Finally, investigating the muscle characteristics of Tibialis anterior (TA) and Medial gastrocnemius muscle (MG), it was observed that there is an increase in co-activation, reduction in TA modulation, and increase in TA and MG lateral asymmetry among PD patients when compared to the control.<br><br> This research output has the potential to be used for the population-based screening for early diagnosis of disease while the patient performs simple walking and there is no need to perform the complicated task for evaluating PD. The research also highlights the importance of the sub-intervals of gait, which can be used for monitoring the progression of the disease and differentiating between PD and the control group. This method offers an alternative to the subjective measures used by clinicians. Additionally, the muscle characteristics can help clinicians better understand the neuromuscular activation underlying muscle contraction and altered muscle activation, resulting in gait impairment.