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Date of Award
Capstone Project (On-Campus Access Only)
Master of Science in Physical Therapy
Richard A. Rutt, PhD, PT
Kenneth W. Bush, PhD, PT
It has been shown that electrical stimulation is effective for the strengthening of quadriceps femoris muscles in healthy and injured populations. Research has demonstrated significant strength gains with a variety of duty cycles, but there is no conclusive evidence regarding the best duty cycle for strengthening. Therefore, the purpose of this research was to compare quadriceps femoris isometric strength gains produced by a 1: 1 and 1:5 duty cycle with all other variables being equal. Subjects, were randomly divided into two groups that trained three times per week for four weeks using the Electrostim 180-2i. Group A trained following a regimen of 10 contractions of 10 seconds duration with a 50 second rest between each contraction. Group B followed the same protocol with the exception of a 10 second rest between contractions. For Group A the mean pre-test force was 504.2 +/- 153.5 N and the mean post-test force was 569.9 +/- 156.7 N. For Group B the mean pre-test force was 592.7 +/- 192.6 N and the mean post-test froce was 652.6 +/- 224.0 N. The results of a repeated measures ANOVA demonstrated both groups achieved significant strength gains (p < .001), however, there was no significant difference in strength gains between the two groups.
Nelson, Benjamin E. and Cowling, Adam E., "Effect of Duty Cycle on Quadriceps Femoris Muscle Isometric Strength Gains with Electrical Stimulation" (1999). School of Physical Therapy. 176.