**2.2. Equipment and electrode placement**

Surface electromyography activity was collected by an eight-channel unit (EMG System do Brazil Ltda®) consisting of a band pass filter of 20–500Hz, an amplifier gain of 1000, and a common rejection mode ratio >100dB. All data were acquired and processed using a 16-bit analog to digital converter (EMG System do Brazil Ltda®), with a sampling frequency 1024 Hz. A channel of the acquisition system was enabled for the utilization of the load cell (SF01 - EMG System do Brazil Ltda®) having an output between 0 and 20mV and a range up to 5kN.

The biosignals from the *semitendinosus* (ST), *semimembranosus* (SM) and *biceps femoris caput longum* (BFCL) muscles were recorded with pairs of bipolar silver–silver chloride surface electrodes (10 mm electrode diameter, fixed inter-electrode distance of 20 mm). Following skin abrasion with an alcohol soaked cotton pad, electrodes were placed with the recommendation of Marson [6].
