BONE-FRACTURE DURING ELECTRICAL-STIMULATION OF THE QUADRICEPS IN A SPINAL-CORD INJURED SUBJECT

We report a fracture through the lateral femoral condyle of a parapleg ic subject caused by electrical stimulation (ES). The subject was a 50 -year-old man who 4 years earlier had sustained a complete spinal cord injury (SCI) at level T6, The fracture occurred during ES-induced mea surement of maximal isometric torque of the quadriceps with the knee f lexed at an angle of 90 degrees. ES was delivered through surface elec trodes with biphasic square wave pulses from a constant current stimul ator. The torque was calculated to be 93Nm, corresponding to 20.8kg at the ankle. The regional bone mineral density of the entire lower extr emities was .83g/cm(2), corresponding to 60% of sex- and age-matched a ble-bodied reference values. Several factors are suspected to have con tributed to the fracture: maximal ES in combination with a muscle spas m, servere osteoporosis, increased muscular strength induced by regula r ES cycling (twice a week), and testing position with the knee locked in 90 degrees flexion. The risk of fracture as well as various precau tions are discussed and should be taken into consideration in future s tudies. (C) 1998 by the American Congress of Rehabilitation Medicine a nn the American Academy of Physical Medicine and Rehabilitation.