A COMPARISON OF LOADING FORCES INCURRED DURING EXERCISE

Abstract

The market for home exercise equipment has proliferated in the last ten years. Advertisements regularly bombard the American public, extolling the virtues of the equipment while lauding the health benefits gained through regular exercise. Some of this equipment has been manufactured to meet the needs of the home exercise market as well as to provide closed kinetic chain exercise in a clinical setting. Providing an aerobic workout which will not exacerbate a preexisting condition for individuals who exercise at home, as well as for patients in a rehabilitation setting, may very well depend on the amount of weight the client/patient can support throughout the exercise bout. The purpose of this study was to quantify the amount of loading force applied by the feet during exercise on five home exercise ergometers. In addition, loading symmetries were also investigated. Twelve volunteers (6 males, BM=73.3 kg; and 6 females, BM=59.6 kg) ages 20-25 years were utilized as subjects. Each subject attended a minimum of three practice sessions to become familiar with each exercise ergometer. The five exercise ergometers consisted of the following: curvilinear shuffle skier (CSS), pedal type stair stepper (S), rectilinear shuffle skier (RSS), non-motorized treadmill 0, and motorized treadmill (MT). Vertical force data were collected with in-shoe pressure sensors (TEKSCAN, Inc.) operating at 60 Hz for 6 seconds during each condition. Peak vertical forces were obtained from the left (LF) and right feet (RF) simultaneously for three consecutive gait cycles during each condition. Data were normalized and converted to a percentage of BM (100% = BM). Loading forces expressed as a percentage of body mass (BM) are listed below: A repeated measures ANOVA was used to analyze the data. There were no significant differences between forces for the left and right feet and no interactions for gender x condition. There was a significant pc0.05 main effect between conditions. Tukey's post hoc test showed significant differences between both CSS and RSS and the other three ergometers.