EMG signals in co-activations of lower limb muscles for knee joint analysis

Integrity analysis of knee joint involves a detail study of several anatomical parts such as bones, cartilage, tendons etc. The disorderness or damage of these anatomical parts causes several knee diseases, like osteoarthritis (OA), which is generally found in an increasing tendency particularly, in an aged society. Although, the reasoning of OA in knee joint does not concentrated to the present paper, however, the influences of related muscular co-activities with knee flexor-extensor actions are figured out in the present research. Particularly, the muscle reflection action of two major skeletal muscles at knee are investigated with aging functions of participants. EMG signals have been collected from the Vastus lateralis and the Gastrocnemius for the dynamic movements (standing and sitting) of knee joint. Aged participants (around 60 years old) and young participants (around 20 years old) joined the experiments. Data have been collected from both legs, however, analysis is shown only for left leg in this paper. EMG sensors and the related devices for this sensing technique have been installed based on the instructions of Biometric Co. Ltd. The result shows that the voltage amplitudes of EMG signals vary largely with increasing ages and thus, the result focuses the postural effectiveness of muscular activities in the stability challenges of knee joint movements.