Principal Component Analyses of Joint Angle Curves to Examine Lifting Technique

dc.contributor.authorSadler, Erinen
dc.contributor.departmentKinesiology and Health Studiesen
dc.contributor.supervisorStevenson, Joan M.en
dc.date2010-08-18 09:35:19.142's University at Kingstonen
dc.descriptionThesis (Master, Kinesiology & Health Studies) -- Queen's University, 2010-08-18 09:35:19.142en
dc.description.abstractThe objectives of the present body of work were 1) to evaluate the Personal Lift-Assist Device (PLAD) in terms of its effect on lifting technique, interjoint coordination, and whether sex modulates these effects and 2) to explore the use of principal component analysis (PCA) as a method to investigate lifting waveforms. Thirty participants (15M, 15F) completed a freestyle, symmetrical lifting protocol during which three-dimensional kinematics of the ankle, knee, hip, and lumbar and thoracic spine were collected using a two-camera Optotrak 3020 system. There were four testing conditions: a) with and b) without wearing the PLAD; and c) 0% load and d) 10% of maximum back strength load. All data were evaluated using PCA. In the first analysis, the relationship between the PLAD and lifting technique under a loaded condition was explored. Results showed that 8 PCs were significantly different between the PLAD/No PLAD conditions yet there were no significant effects of sex on any of the PCs. It was concluded that wearing the PLAD encourages a lifting technique that is reflective of a squat lift, independent of sex. In the second analysis, the PLAD’s effect on interjoint coordination patterns under both loaded and unloaded conditions was examined using the relative phase angle (RPA). It was found that there were no significant differences between device, sex, or load conditions on any of the PCs retained in the model. A novel approach to enhance interpretability of PCs was developed during this study. Finally, when the PLAD was not worn, male and female differences were further investigated under loaded and unloaded conditions. It was determined that when the load is individualized to personal strength characteristics, sex differences in lifting technique are negligible. This is a contradictory finding from previous research. Overall, the major contributions of this research are: support for the use of the PLAD in industry; the recommendation that load be selected based on individual strength characteristics for lifting research experimental design; the use of PCA as a method to effectively evaluate lifting waveforms; and the development of a novel approach to aid in the interpretation of principal components.en
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectLifting Kinematicsen
dc.subjectPrincipal Component Analysisen
dc.subjectPersonal Lift-Assist Deviceen
dc.titlePrincipal Component Analyses of Joint Angle Curves to Examine Lifting Techniqueen
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
3.09 MB
Adobe Portable Document Format
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
1.73 KB
Item-specific license agreed upon to submission