Muscle stimulation is an electric therapeutic modality that physiotherapists can use to help strengthen the muscles around the knee.
Relationship Between Intensity of Quadriceps Muscle Neuromuscular Electrical Stimulation and Strength Recovery After Total Knee Arthroplasty. Stevens-Lapsley JE, Balter JE, Wolfe P, Eckhoff DG, Schwartz RS, Schenkman M and Kohrt WM. Phys Ther. 2012 Sep; 92(9): 1187–1196.