Changes in quadriceps femoris muscle strength using isometric exercise versus electrical stimulation.

Reports in the literature appear to support the effectiveness of electrical stimulation as a means of increasing strength in normal muscles. The objective of this study was to measure and compare quadriceps muscle torque, isometrically and isokinetically, in three groups: 1) control group subjects (N = 9) did not alter their daily activities for 5 weeks, 2) isometric exercise group subjects (N = 10) exercised their quadriceps femoris muscle using maximum voluntary isometric exercises 3 times per week for 5 weeks, and 3) electrical stimulation group subjects (N = 10) who had 10 quadriceps femoris muscle contractions produced by electrical stimulation, 3 times per week for 5 weeks. No strength changes were noted in the control group; ANOVA revealed significant strength increases (P < 0.05) for both the electrical stimulation and isometric exercise groups. J Orthop Sports Phys Ther 1987;8(11):537-541.