Objectives To investigate the effectiveness of electrical stimulation on quadriceps and hamstring muscle performance in patients with patellofemoral pain.
Methods Twenty-one patients participated in the 4-week exercise program and were randomly assigned to either closed kinetic chain exercises or closed kinetic chain exercises combined with electrical stimulation of bilateral quadriceps and hamstring muscles. Quadriceps and hamstring muscle peak torques were measured at baseline and at 4 weeks with an isokinetic dynamometer at 60°/sec and 180°/sec angular velocities.
Results After the 4-week exercise program the mean torque values for quadriceps and hamstring at both angular velocities were higher in both groups. There was a significant difference in the left hamstring peak torque values at 60°/sec and 180°/sec angular velocities and in the left quadriceps peak torque at 180°/sec angular velocity in the electrical stimulation group (p < 0.01). In the other group the peak torque differences in the left hamstring and quadriceps muscles at 60°/sec angular velocity and in the left hamstring muscle at 180°/sec angular velocity were statistically significant (p < 0.05).
Conclusion Although it seems that electrical stimulation does not provide an additional effect on muscle performance, it can be used with closed kinetic chain exercises to accelerate the rehabilitation program.