Comparison of two electrical stimulation protocols on quadriceps muscle after anterior cruciate ligament surgery. Feasability study]

OBJECTIVES: To evaluate the feasibility of a study comparing the effects of two protocols of electrical stimulation of the quadriceps femoris after anterior cruciate ligament surgery. MATERIAL: Seven sportsmen with a mean age of 26 yrs were randomly grouped in two: a 20 Hz stimulated group (4 patients) and a 80 Hz stimulated group (3 patients). After surgery all patients received electrical stimulation of the quadriceps femoris, five days a week, for 12 weeks, and had a standard program of voluntary contractions. The main outcome assessed before and three months after surgery were: quadriceps and hamstring peak torque at 90, 180 and 240 degrees /second, maximal isometric quadriceps at 75 degrees of flexion and muscle and subcutaneous fat volumes of the thigh using MRI. RESULTS: After 12 weeks of rehabilitation, the thigh muscle volume deficit of the operated limb was between 3 and 9% in the 20 Hz stimulated group and between 1 and 2% in the 80 Hz stimulated group. Quadriceps peak torque deficit was less than 30% except for two patients in the 20 Hz stimulated group. Maximal isometric quadriceps deficit of the operated limb was higher than 30% except for two patients in the 20 Hz stimulated group. CONCLUSION: The study showed that comparison of two protocols of electrical stimulation of the quadriceps femoris after anterior cruciate ligament surgery is possible if stimulation period is not more than four weeks.