(E. Kellis, Quantification of quadriceps and hamstring antagonist activity, Sports Med. 26 (1998) 37–62)
the (mathematical) approach is time consuming and difficult to apply in practice. Furthermore, the outcomes of such an approach often demonstrate several limitations and assumptions, thus making their practical application difficult. This leads most researchers and clinicians to rely on EMG measurements to express co-activation
Muscle co-activation has been examined by comparing the EMGs of the involved muscles expressed as percentages of reference EMG values[7,9,18,21,27,30,31]
2. Methods
2.1. Subjects
in normal gait speed , twelve healthy subjects (age = ± years, ) volunteered to take part in the study after signing informed consent forms. The subjects had a training background of 6.4 ± 0.5 years and had no health problems. The study was approved by the local University Ethics Committee
2.4. Co-contraction index
The EMG raw data were full-wave rectified and low pass filtered related with the cadence of patient at (4- 6 Hz), yielding the linear envelopes of BF , RF and VL muscle EMG. The EMG of this muscles was then expressed as a percentage of the EMG value during the MVC.
3. Results
4. Discussion