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Application of Jerk Analysis to a Repetitive Lifting Task in Patients with Chronic Lower Back Pain

Slaboda, Jill (2004) Application of Jerk Analysis to a Repetitive Lifting Task in Patients with Chronic Lower Back Pain. Master's Thesis, University of Pittsburgh. (Unpublished)

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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. Woltring's 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.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Slaboda, Jilljcsst46@pitt.eduJCSST46
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairBoston, J Robertboston@engr.pitt.eduBBN
Committee MemberMiller,
Committee MemberRedfern, Markredfern@pitt.eduREDFERN
Committee MemberRudy,
Date: 13 September 2004
Date Type: Completion
Defense Date: 3 May 2004
Approval Date: 13 September 2004
Submission Date: 8 May 2004
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Institution: University of Pittsburgh
Schools and Programs: Swanson School of Engineering > Bioengineering
Degree: MSBeng - Master of Science in Bioengineering
Thesis Type: Master's Thesis
Refereed: Yes
Uncontrolled Keywords: lifting biomechanics; splines; chronic lower back pain; jerk; residual analysis
Other ID:, etd-05082004-123720
Date Deposited: 10 Nov 2011 19:44
Last Modified: 15 Nov 2016 13:43


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