Patients with chronic lower back pain (CLBP) typically demonstrate different biomechanics than healthy controls during a lifting task. Motion differences in a repetitive lifting task have been described previously using differences in the timing of body angles changes during the lift. These timing changes rely on small differences of motion and are difficult to measure and to interpret. The purpose of this study is to evaluate shoulder jerk (rate of change of acceleration) in a repetitive lifting task as a parameter to detect differences of motion between controls and CLBP patients and to measure the impact of a rehabilitation program on jerk. The jerk calculation proved to be a noisy measure since jerk is the third derivative of position, and a simulation study was performed to evaluate smoothing methods to provide the best estimates of the third derivative. Woltrings generalized cross-validation spline produced the best estimates and was fit to subject data. Derivatives were calculated using differentiation of the spline coefficients, and root-means-square (rms) amplitude of jerk was used for comparison. Lifts were divided into phases of early, middle or late based on the number of repetitions completed by the subject. Average values of rms jerk during a lift were computed at each of the task phases. Significant group differences were found for rms jerk. CLBP patients were found to perform lifts with lower jerk values than controls and as the task progressed, rms jerk increased for both groups. A group-by-phase interaction was significant. After completion of a rehabilitation program, CLBP patients performed lifts with greater rms jerk. In general, patients performed lifts with lower jerk values than controls, suggesting that pain impacts lifting style.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-05082004-123720 |
| Date | 13 September 2004 |
| Creators | Slaboda, Jill |
| Contributors | Dr. Mark Miller, Dr. Mark Redfern, Dr. Thomas Rudy, Dr. J.Robert Boston |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-05082004-123720/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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