Elektromyografie
The muscular activities and their coordinated responses were detected using a 16-channel-telemetric system Trigno Wireless EMG system (Delsys, USA), which was checked prior to subject measurements to ensure there was no interference from the implant telemetry data transfer. The EMG dual surface electrodes are placed on the preselected muscles to detect the myoelectric signals throughout the motion tasks. The data recording was telemetrically sent to the workstation by means of a small transmission unit and synchronized with the kinematic measurements.
The electrodes were attached to the skin at eight predominant muscle sites on each lower limb. At the beginning of the test session, the EMG signals during maximal voluntary contractions (MVC) of each muscle were recorded. For this purpose, the following four motion tasks were performed for both legs:
Triceps surae: One legged standing together with lifting the heel to stand on tiptoe.
Quadriceps: With the subject sitting on a bench, with their lower legs hanging down, extension of the knee joint was performed against a load by means of a strap around the lower leg, just above the ankle.
Hamstrings: With the subject sitting on a bench, with their lower legs hanging down, flexion of the knee joint was performed against a load by means of a strap around the lower leg, just above the ankle.
Tibialis anterior: With the subject standing, dorsiflexion of the ankle was performed against a manual resistant force provided by the investigator.
