The central nervous system coordinates the contraction of many muscles during human motion. A hypothesis currently accepted by the scientific community is that CNS does not control each muscle separately during a motor task (e.g. walking), but groups together the muscles which perform similar functions during the task. The complexity of the motor control is thus reduced through the selection of an adequate number of motor modules, called muscle synergies. Muscle synergies are studied using factorization techniques applied to the sEMG signals sampled from the muscles involved in the motor task. Usually, muscle activation is assessed using a bipolar sEMG detection using a pair of electrodes for each muscle.