Date of Award


Degree Type


Degree Name

Master of Science (MS)


Health, Physical Education, and Recreation

First Advisor

Eadric Bressel


The purpose of this study was to examine the acute effects of underwater treadmill (UTM), body weight supported (BWS), and land treadmill (LTM) exercise on oxygen consumption (VO2), ratings of perceived exertion (RPE), and two-dimensional kinematics of the lower extremities during. Seventeen healthy and physically active male participants between the ages of 21 and 40 years performed an exercise bout for each mode of exercise. Each exercise bout lasted 7 min, consisting of 5 min of walking and 2 min of running and using the same self-selected treadmill walking and running speeds throughout all three conditions. The VO2, RPE, and kinematic data were collected during each exercise bout. The participants were submerged to the xiphoid process during the UTM exercise session and 20% of their body weight was unloaded using a Pneumax body weight support unloader for the BWS session. An ANOVA with follow-up multiple comparisons were used to determine significance differences (alpha = 0.05) among modes of exercise. Results revealed that VO2 values for LTM and BWS were 10% and 6% less (p < .02), respectively than UTM walking exercise. During running, there were no significant differences between the LTM and UTM. The VO2 values were 9% less (p < .01) during BWS than LTM exercise. There were no differences between RPE levels for any of the conditions. Plantar flexion joint angular displacement values were greater accompanied by decreased velocities for UTM exercise in comparison to LTM and BWS for both walking and running. Knee extension values were greater for walking and running during LTM and BWS than UTM exercise at 5% and 4% respectively (p < 0.001). These findings suggest that VO2 values are greater during UTM than LTM exercise during self-selected walking speeds and comparable during selfselected running speeds. However, kinematically there are differences in the ankle and knee joints during UTM exercise in comparison to the other two exercise modes, whereas similar lower extremity joint angular displacements and velocities occur during BWS and LTM exercise for both walking and running. These findings would indicate that based on what a clinician’s goal for their patient is, a BWS unloader may be best for a patient doing gait retraining to obtain similar gait techniques as they would find on a LTM and an UTM may be best for a patient wanting to keep their VO2 responses at the same level as seen on land, but with a decreased concern of providing similar gait techniques as those obtained by a LTM.


This work made publicly available electronically on April 11, 2011.