Electrical stimulation and strength training to improve quadriceps strength in people with incomplete spinal cord injuries

The experimental intervention will be based on the principles of progressive-resistance training. The intervention will be delivered to one leg, 3 times a week, over an 8-week period. Participants will perform two sets of 6 X 10 leg extension exercises against a weighted resistance. The first set of 6 X 10 leg extension exercises will require participants to voluntarily and maximally contract their quadriceps muscles with ES superimposed. The second set of 6 X 10 leg extension exercises will not require participants to voluntarily contract their quadriceps muscles. Instead this set will be done with ES alone. During both sets participants will extend the knee against resistance equivalent to 10 repetitions maximum (10 RM). There will be a 3 minute rest after each 10 lifts. The resistance will be applied through a device specifically designed for the purpose. Briefly, the device will consist of a wheel attached to a leg bar. A weight will be hung from a rope which wraps around the wheel and attaches to the leg bar. The participant will be required to extend the knee against the leg bar. This will necessitate lifting the weight suspended from the wheel. Training of experimental lower limb increased according to the principles of progressive resistance training. That is, if participants could lift the weight more than 10 times per set, the weight was too light and increased. In the experimental lower limb this progression also involved increasing stimulation intensity as tolerated up to 100 mA