Identifier

etd-11182005-094704

Degree

Master of Science (MS)

Department

Kinesiology

Document Type

Thesis

Abstract

The purpose of the study was to determine if the body weight support system (BWSS) maintains the targeted percentage of the subject's body weight support (BWS) during walking and to explore the relationship between unloading and ground reaction force. Sixteen healthy college students (mean age: 22 years old) were recruited as subjects. Tests were conducted using an instrumented treadmill with a BWSS. The BWSS harness was secured around the lower abdomen and pelvis of each subject for effective body weight support. Vertical ground reaction force was measured by force platforms embedded in the treadmill. A force sensor was attached to the top of the harness to measure the actual amount of support force being exerted by the BWSS while the subject walked on the treadmill. The subject's body weight was supported at targeted levels of 0%, 15%, 30%, and 45%. Subjects walked at speeds of 0.447, 0.671, 0.894, and 1.117 meters per second for each level of targeted body weight support (TBWS). As speed increased, the maximum support force (SFmax) increased while the minimum support force (SFmin) decreased. As the levels of TBWS increased, the SFmax as well as the SFmin increased. The maximum support force was affected by the different body weight support levels and fluctuated from 5.08% to 11.22% above the TBWS. The minimum support force fluctuated from 0.40% below to 13.05% above the targeted body weight support. The fluctuations were also affected by walking speed. SFmax deviation ranged from 6.12% to 10.03% above TBWS across speeds while the SFmin deviated from 7.06 to 8.58% above TBWS across speeds. As speed increased, maximum ground reaction force also increased. As the levels of BWS increased, the maximum ground reaction force decreased. The BWSS did not sustain the targeted percentage of BWS and actually supported a lesser percentage of the subject's body weight throughout the trials. Vertical ground reaction forces were reduced with the use of the BWSS but were disproportional to the TBWS levels. These findings are important in providing both safe and efficient treatment for future patients in producing maximum benefits in therapy.

Date

2005

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Li Li

Included in

Kinesiology Commons

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