Kinematic, kinetic and electromyography patterns of standing up in Parkinson's disease

Standing up is an usual task in the life daily activities, and it can be limited in Parkinson?s disease patients with postural control deficits. The aim of the study was to explore the electromyography, kinetics and kinematics patterns during standing in healthy individuals and in Parkinson?s disease patients. Sixteen patients (8 healthy individuals and 8 Parkinson?s disease patients) participated in this study, standing, as fast as possible from a chair. The linear and angular displacement of involved segments, the electromyography activity of tibialis anterior, soleus, vastus medialis oblique, biceps femoris, erector spinae were collected. The data, including knee and ankle torque, were calculated within Matlab software. Although some results indicated similar patterns in both groups, Parkinson?s disease subjects did not performed the standing up as healthy subjects. They showed increased knee torque values (p<0.05), their knee angle were more fleted than healthy subjects (p<0.05) and they also produced smaller linear displacement in sagittal plane (p<0.05). Such behaviour can be explained by the typical flexed posture observed in the presence of Parkinson?s disease. Another aspect is the rigid posture which contributed to muscle retraction. These factors give rise to a flexed knee and then, the knee torque increased in the final movement phases. Trying to decrease this knee torque, the soleus activity changed in the parkinsonian (p<0.05). It?s seems to compensate the vastus medialis oblique function. All data suggest that the parkinsonian with moderate envolviment, use different pattern to perform the standing up, determined by the structural postural changes.