Musculoskeletal (MSK) Knee Practice Test

Starting isometric and active exercise with NMES immediately after total knee arthroplasty is recommended because it helps counteract quadriceps inhibition and prevents rapid strength loss. After a knee replacement, swelling and pain cause the quadriceps to shut down its voluntary activation (arthrogenic inhibition), so initiating muscle activation early supports neural drive to the muscle, helps maintain knee extension, and reduces atrophy. NMES aids motor unit recruitment when voluntary effort is limited, so you can begin strengthening goals sooner without stressing the joint. This early start also supports range of motion and helps minimize stiffness as healing progresses. Practical safety matters: begin as soon as the surgeon approves and there are no contraindications (such as infection, skin irritation at the electrode sites, or devices that NMES would interfere with). Delaying activation—by weeks or months—can lead to greater weakness and stiffness, making rehabilitation more difficult later.