Following this, the researcher will attach 40 retro-reflective markers to the skin of the lower limb on both legs and attach surface electromyographic electrodes to four muscles as in figure 4 on both legs. The electrode placement will be performed according to the SENIAM guidelines. Suface EMG (sEMG) data will be collected of vastus medialis, vastus lateralis, biceps femoris and semitendinosus will be synchronised with the motion capture system on Qualisys.