Effects of Aging and Activity on the Hamstring: Quadriceps Ratio

Indianapolis, IN

The purpose of this study was to determine the impact of exercise on the maintenance of strength with age using the hamstring (H) to quadriceps (Q) ratio (H: Q). It was hypothesized that as one ages and continues to exercise, one can maintain muscular strength. It also was hypothesized that the relative strength among muscle groups, as determined by the H: Q ratio, will remain intact with age. Forty subjects male and female,were equally distributed in the college-aged group and the older group (over the age of thirty). The subjects were also equally distributed based on activity level being sedentary or active. All subjects completed three experimental trials on the Cybex isokinetic dynamometer. Two protocols measured the true H: Q ratio. That is, the maximal strength of the H muscles divided by the maximal strength of the Q muscles. In one protocol the concentric strength was determined, while in another the eccentric strength was determined. An acceptable H: Q ratio for concentric and eccentric strength is 0.5-0.8. The third trial estimated fiber type. In the procedure to assess the H: Q ratio, subjects completed five maximum concentric and eccentric repetitions at 60° per second for the H and the Q muscles on the left and right leg. To estimate fiber type, 50 sub-maximal concentric repetitions at 180° per second were performed by the left and right H and Q muscles. Data collection is ongoing. Pilot data suggests that the H: Q ratio remains intact with age and activity level.