UBC Theses and Dissertations
The effect of electrical stimulation and isokinetic exercise on muscular power of the quadriceps Nobbs, Leslie Ann
Power and strength training, using conventional techniques, has been studied by several researchers. Investigations into the use of different training methods and their effect on power and strength development are continually being studied and re-assessed. Recently, the use of faradic or electrical stimulation has become an interesting alternative method, although much controversy surrounds this technique. It has been reported by Johnson et al. (1977) and Kots (1977) that faradic stimulation is used with success as part of a strengthening program by elite Soviet athletes. The combined effects of a program consisting of exercise as well as electrical stimulation was undertaken to determine the muscular power and strength potentials. The main objective of this study was to compare power and strength changes between equated groups employing the following training techniques: electrical stimulation plus isokinetic exercise, isokinetic exercise and electrical stimulation, respectively. Twenty-seven, moderately trained, female subjects, nine per group, were tested on three separate occasions. During the first session, height, weight, left and right quadriceps power evaluation, time to peak tension of the muscle contraction at the four velocities :(30, 100, 180 and 0 degrees per second) and two thigh girth measurements were determined. The three groups were equated for power after the pretest was conducted. The second and third testing sessions assessed the power and time to peak tension of the non-dominant leg at the four velocities and patellar and gluteal thigh girths. A significant difference for power was found between the pre and post tests and the pre and mid tests for the combined groups during the six week period of training. Although no difference was found between each of the three groups, the results indicated that programs involving electrical stimulation and isokinetic exercise, isokinetic exercise and electrical stimulation only, are potentially effective in improving muscular power and strength in normal subjects. The study revealed that one method was not superior to another after six weeks of training. There was significant power differences between the pre and post tests and pre and mid tests at the slow isokinetic speeds of 30° and 0° per second. Since the training was conducted at the speeds of 30° and 0° (isometric) per second, the slow testing speeds reflected neural adaptation and muscular recruitment when the specificity of training theory is considered. These findings imply that power and strength training benefits are limited to speeds used during training. During the six week training period, time to peak maximal torque and hypertrophy of the quadriceps muscle group did not alter significantly when examining the means of all three groups.
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