Moment-angle Relationship of Hip Musculature
Open Access
- Author:
- Kindel, Curtis
- Graduate Program:
- Kinesiology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- December 17, 2014
- Committee Members:
- John Henry Challis, Dissertation Advisor/Co-Advisor
Jinger Gottschall, Committee Chair/Co-Chair
Sayers John Miller Iii, Committee Member
Andris Freivalds, Special Member - Keywords:
- Biomechanics
hip
patellofemoral-syndrome
moment-angle relationship
joint moment fluctuations - Abstract:
- In the rehabilitation field, developing effective and efficient treatments for individuals with knee pathologies, specifically, patellofemoral syndrome, is very important. While the muscles crossing the knee joint have been widely accepted as having a role to play in knee pathology, muscles of the hip joint have also been associated with knee pathologies such as patellofemoral syndrome. However, research is inconclusive as to whether these hip muscles lack strength, neuromuscular control, or both in subjects with patellofemoral syndrome. Additional research is needed regarding the characteristics and properties of hip musculature in order to comprehensively understand this relationship. This dissertation consisted of three studies designed to analyze the isometric moment-angle relationships of the hip abductors and hip extensors in healthy subjects as well as those with patellofemoral syndrome. The moment-angle relationships were then analyzed in multiple facets: the peak joint moment at pre-determined positions throughout an arc of motion, the gradient of the aforementioned peak moments across the arc of motion, and the joint moment fluctuations at each hip position. In the first study, measurements of peak isometric joint moments at various positions in hip abduction (-15°, 0°, 15°, 30°) and hip extension (-45°, -30°, -15°, 0°) were gathered and then analyzed to determine the moment angle relationship in normal healthy subjects. The position of the knee was either in flexion or extension throughout the hip joint moment assessments. Results showed a descending moment-angle curve for both hip abduction and hip extension. These results demonstrate that joint strength decreases throughout hip abduction and hip extension. These findings have implications for clinicians for prescribing exercises for this musculature. The second study analyzed the peak hip joint moments of hip abduction and hip extension in individuals with current complaints of patellofemoral syndrome, and compared them with age and size matched control subjects. The results demonstrated that individuals with patellofemoral syndrome had a decreased joint moment of hip extension with the knee flexed, but not with the knee extended. This suggests a deficit of strength of the uniarticular gluteus maximus, or increased strength of the biarticular hamstring musculature, in subjects with patellofemoral syndrome. Contrary to previous literature, there were no statistically significant differences in hip abductor strength between the two groups. The third study examined joint moment fluctuations of subjects with patellofemoral syndrome and healthy controls, during maximal isometric moments produced during hip abduction and hip extension. The fluctuations in joint moment data were quantified using statistical techniques (signal coefficient of variation) in addition to methods from statistical physics (e.g., signal complexity and signal fractal properties). Results showed increased coefficient of variation, indicating greater signal noise and therefore poorer muscle control, of the hip extension moment with the knee flexed for the group of subjects with patellofemoral syndrome. This suggests the weakness of the uniarticular musculature in subjects with patellofemoral syndrome is, at least in part, due to different neuromuscular control. No differences were found in signal complexity between subjects with patellofemoral syndrome and healthy controls. These studies demonstrated that subjects with patellofemoral syndrome were found to be deficient in strength and neuromuscular control for hip extension joint moment, especially when the knee was flexed. Therefore, the hip extensor musculature should be strengthened when rehabilitating individuals with patellofemoral syndrome. The hip extensor muscle group should also be trained to facilitate neuromuscular control, such as controlled eccentric exercise and static isometric holds, at various joint angles of hip extension.