A Comparative Investigation of Strength Gained in the Right Knee Extensor Muscles Utilizing Isotonic Exercises with the Delorme Boot and the Qem Machine
Authors:   , Hazlett Jack 
Published: February 2023

The purpose of this study was to compare the strength gained in the right knee extensor muscles using the DeLorme Boot with the strength gained in the right knee extensor muscles using the QEM Machine. Sixty- three male college students enrolled at Fort Hays Kansas State College during the spring semester of 1965 were employed as subjects for this study. The subjects were those volunteers from the Fundamentals of Sports physical education classes who could meet with the investigator during the designated daily time for the required number of days. A cable tensiometer and associated equipment were utilized for the measurement of the strength of the right knee extensor muscles at 135 degrees extension. On Monday at the beginning of the exercise program the subjects were given a pre-test to obtain the initial strength of the right knee extensor muscles. Before the pre-test the subjects were assigned by alphabetical order to the DeLorme group, the QEM group, and the control group. During the seven-week exercise program the DeLorme group performed isotonic exercises with the DeLorme Boot, the QEM group performed isotonic exercises with the QEM Machine, and the control group performed no exercises. The exercise program consisted of ten repetitions, utilizing fifty per cent maximum, of the right knee extensor muscles. The range of movement in each repetition was from ninety degrees flexion to full extension. Each repetition was held at complete extension for six seconds and then returned to the original ninety-degree starting position. There was a ten second rest period between each of the repetitions. The exercise program lasted seven weeks. Exercise bouts were held on Monday, Wednesday and Friday of each week, with the exception of Friday of the final week. This day was spent taking the final strength test with the cable tensiometer. At the beginning and the end of the exercise program, the DeLorme group, the QEM group, and the control group were tested with the cable tensiometer. During this study, the control group was not tested at any other time with the cable tensiometer. However, the DeLorme group and the QEM group were tested with the cable tensiometer on Monday of each week in order to determine the amount of weight to use in the exercise bouts. The statistical technique of analysis of variance, analysis of covariance, and the t-test were used to analyze the data compiled in this study. The results of the t-test showed that the DeLorme group's strength increases and the QEM group's strength increases were both significant at the one percent level of significance. It was found that the QEM group showed significantly larger strength gains than did the DeLorme group. The DeLorme group and the QEM group showed significant gains in strength throughout the exercise program, but the control group lost strength during the exercise program. However, this loss of strength in the control group was not significant to warrant consideration in this study. In the light of the preceding data and discussions and within the limitations of this study, the following conclusions seem warranted: 1. Ten isotonic contractions of the knee extensor muscles, with the DeLorme Boot or the QEM Machine and weight attachments, three times weekly for a seven-week period, are sufficient to produce significant gains in strength in the right knee extensor muscles. 2. Measuring the strength of the right knee extensor muscles at 135 degrees extension is satisfactory for determining the fifty per cent maximum used in regulating the weight load for ten repetitions. 3. The subjects performing exercises with the DeLorme Boot showed significant gains in strength. 4. The subjects performing exercises with the QEM Machine showed significant gains in strength, which were significantly greater than the strength gains in the DeLorme group. 5. The subjects in the control group did not show significant gains in strength which indicates that performing no exercises resulted in no strength gain. 6. Subjects performing exercises with the QEM Machine and weight attachments did not experience the pain between repetitions that occurred during the use of the DeLorme Boot and weight attachments.