Transcutaneous magnetic stimulation of the quadriceps via the femoral nerve.

We investigated the efficacy of different frequencies and intensities of magnetic stimulation for activating the quadriceps muscles; a painless method for stimulating the quadriceps would be useful in the rehabilitation of patients who have difficulty in voluntarily activating their muscles after injury or surgery. Eleven subjects underwent magnetic stimulation of the femoral nerve over a range of frequencies and intensities using a MagStim Rapid magnetic stimulator. Magnetic stimulation at 30 Hz at 80% of the power output of the stimulator used was capable of generating 72% of quadriceps maximal voluntary contraction torque. Subjects reported little or no pain during the procedure. Magnetic stimulation of the femoral nerve is a well-tolerated way to activate the quadriceps muscles.