BIOMECHANICAL COMPARISON OF RUNNING IN LAND AND WATER MEDIA

Abstract

The purpose of this study was to investigate the effects of media on running performance at various training intensities, The comparisons were based upon Borg Rate of Perceived Exertion (RPE). The treadmill was used for the land condition while running in the deep water was performed with use of a buoyant device located above the W. Two subjects, both skilled swimmers and runners, who had a good understanding of RPE were tested. Evaluation of joint angles involved sagittal and rear view video with the former reported here. The joints evaluated included the shoulder elbow, wrist, hip, knee, and ankle. Heart rate was monitored for evaluation of intensities and immersion effects with a Polar Accurex monitor. Five trials were performed and videotaped in both suspended deep water and land conditions at 13 and 18/19 WE. Data were manually digitized using the Arid Performance Analysis System for both land and water at 60 and 30 Hz respectively. The 30 Hz data were interpolated to 60 Hz and smoothed using a ninth order polynomial and derivatives were calculated. Within subjects statistical procedures (p<0.05) were performed. Results identified significant differences between media conditions for both subjects. In the water, 18 RPE had a higher percentage of significant changes across joints (89%) thin 13 RPE. Joint Range of Motion (ROM), minimum, and maximum values produced 83.03. a d 100% significant differences across subjects for 18 RPE. Similar comparative values for 13 RPE in the water were 83.67. and 83%,respcctively, In contrast, 13 RPE on land had a higher percentage of significant changes across joints (83%) than 18 RPE. The greatest changes we observed between land and water (83%) at 18 RPE. Results suggest that when a subject attempts to increase RPE in the warter they increase the ROM in the upper extremity joints. Perhaps the lower extremities ROM did not increase in water due to use of the buoyant device, which increased resistance at the lower extremities making running more difficult. The water media clearly magnifies individual differences (13 RPE = 78% and 1 R RPR = 89%). These differences were further magnified with an increase in RPE, suggesting that water may be used as a diagnostic tool.