A patient of mine tore his pectoral muscle quite badly while doing some Brazilian Jiu Jitsu. Initially we used the Electrical Muscle Stimulation machine (EMS) to help pump the swelling and inflammation away from the area.
A few weeks later we are now using the device to elicit a stronger muscle contraction to help rebuild the strength. At the start of the rehab process this guy was only able to chest press a 2kg dumbbell (most men will be pressing a minimum of 14kg), so you can how much strength has been lost!