No description available.

No description available.

The progression of knee osteoarthritis (OA), the most common cause of physical disability in older adults, is influenced by muscular and biomechanical factors. Reliability of muscular and biomechanical measures, including knee muscle strength and limb alignment, is critical. Furthermore, conservative interventions that slow the course of OA disease progression and prevent disability are urgently needed. The objectives of this thesis were to: 1) investigate the reliability of measures of knee muscle strength and alignment in persons with knee OA, and 2) determine the influence of an exercise intervention targeting hip muscles on knee joint loading in those with medial knee OA. In the first study reliability of knee muscle strength measures was evaluated within one testing session in 40 persons with knee OA. Isometric and isokinetic peak torque values for the quadriceps and hamstring muscles demonstrated high degrees of intra-session reliability. Reliability of lower limb alignment measures was determined following a bone landmark-based approach with use of a computer program. Excellent reliability coefficients were found which compared favorably with reliability of manual measures from schematics of limb deformities drawn with AutoCAD® software. When the computer method was applied to 100 full-limb radiographs of persons with or at risk for knee OA, alignment measures demonstrated high inter- and intra-reader reliability. Hip muscle weakness may influence loading of the medial knee compartment. Hip abductor strength was evaluated in 40 individuals with medial compartment knee OA in comparison to a control group of 40 healthy older adults. The effect of an 8-week home-based hip abductor strengthening program on the knee adduction moment was also assessed in this group with knee OA, compared with the control group which received no intervention. Following the exercise program the OA group demonstrated improvements in hip abductor strength and functional performance on a sit-to-stand task. There were no changes in the knee adduction moment. Thus, hip muscle strengthening did not influence joint loading, but may improve function in persons with knee OA. Results from this thesis provide increased understanding of knee OA, from muscular and biomechanical perspectives, in the areas of measurement reliability and exercise intervention. / Thesis (Ph.D, Rehabilitation Science) -- Queen's University, 2008-09-25 01:29:13.675

No description available.

No description available.

No description available.

No description available.

Thesis (M.Tech.: Chiropractic)- Dept. of Chiropractic, Durban University of Technology, 2008. x, 52 leaves, Appendices A-E, [25] leaves. / To determine whether a relationship exists between core stability and bowling speed in Action Cricket bowlers. Methods: Thirty asymptomatic indoor Action Cricket fast and fast-medium bowlers were divided into two groups of 15 each, with Group A having well-developed core stability and group B having poorly-developed core stability. The concept of matched pairs was used for age and cricket experience in order to maintain homogeneity between the groups. The core stability and bowling speed of each participant was measured using a pressure biofeedback unit (PBU) and speed sports radar respectively. SPSS version 15.0 was used to analyse the data.

Dissertation submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic at the Durban University of Technology, 2009 / Objectives: When we consider the body position of a field hockey player, the lumbar spine is always in a flexed position, which combined with rotational movements during various hitting and pushing techniques, increases the strain upon the spine and surrounding muscles, thus leading to low back pain. To determine the relationship between core strength and trunk extensor endurance relating to the incidence of acute low back pain in field hockey players. Project Design: The research project was in the form of a quantitative cross-sectional study, using human subjects. Setting: The research project occurred during the field hockey season (2008) with players who had acute low back pain. The players were clinically assessed and subdivided into necessary groups at the Chiropractic Day Clinic at the Durban Institute of Technology. Subjects: Adult, male patients, aged between 18 and 30 years of age, playing premier field hockey. Out of the thirty players, 12 players have played in the National u/21 squad, 7 players have played in a Junior National team and 11 players have played senior provincial field hockey. Outcome measure: This included three tests. Firstly, the absolute difference of pressure from the reference value of 70mmHg (prone) and 40mmHg (supine) was used as the outcome measure on a Pressure Biofeedback Unit and length of time (in seconds), a correct contraction of the core stability muscles was maintained. Secondly, the length of time (in seconds) for Trunk Extensor Endurance. Thirdly, repeated measures for NRS-101 and Quebec Back Pain Disability Scale for the duration of the research period. v Results: It was found that there was no statistical evidence or convincing trend to show that the training programmes (core stability and trunk extensor endurance) increased the subjects’ core strength or trunk extensor endurance in the time allocated, although there seemed to be a placebo effect in the Trunk Extensor Group, which showed improvement in some of the core stability outcomes. There was statistical evidence that the intervention (training programmes) reduced pain, according to the Quebec Back Pain Disability Scale (Quebec) score over time, and a non-significant trend suggested this according to the Numerical Rating Scale-101 (NRS). Since both groups’ NRS and Quebec scores were not significantly different at baseline, the difference can be attributed to the effect of the intervention. Conclusions: The results of this study found that the Trunk Extensor Endurance Group, that performed the trunk extensor endurance training programme, yielded better results in core stability and trunk extensor endurance. However, the Core Stability Group, that performed the core stability training programme, showed a quicker reduction in pain levels during the three week intervention period. Therefore, by combining both training programmes, future rehabilitation of athletes suffering from acute low back pain will be more successful. Sport performance of the athletes (field hockey players), through the proponents of swiss ball training, will also improve.

Scientists are constantly seeking new and convenient non-destructive damage assessment techniques. In fact, a global market has developed for structural health monitoring products. Many of the currently available techniques are expensive and difficult to implement. An inexpensive alternative is technology based on strain memory alloys. These materials encompass a vast array of alloys, from austenitic stainless steels through to the extremely high strength TRIP steels. All, however, have in common the transformation from paramagnetic austenite to ferromagnetic martensite upon application of strain. The degree of ferromagnetism can be directly correlated to the peak strain undergone by the material. Strain memory alloys are not as expensive to manufacture as some smart materials, and in addition are capable of bearing significant load, and it is therefore possible to manufacture entire components from these alloys, thereby producing what is known as a smart component, i.e. one that is capable of doing the job of an ordinary component while at the same time assessing its own peak damage levels. A possible application of this technology is that of wing bolts for the Hercules e130 aircraft. The material usually used to manufacture the aircraft wing bolts is HSLA steel (AISI 4340). A strain memory alloy was therefore developed to match the mechanical properties of 4340 steel, while also having the requisite properties to perform the self damage-assessment. Ultra high strength TRIP steels were identified as possible candidates, and four alloys selected for investigation. These alloys were melted and then thermo-mechanically processed using a rolling operation. All alloys were tensile tested and magnetic susceptibility monitored. The final material selected possesses an ultimate tensile strength (UTS) of between 1270 and 1500 MPa with 10 to 12% elongation. The stress / strain induced transformation begins to occur before the yield point, which is important because bolts must be replaced before they fail. Compression tests were also performed, and yielded similar results to those of the tensile tests, with martensitic transformation again beginning before plastic yield. The strain induced phase transformation was confirmed not only by magnetic susceptibility measurements, but also by metallographic inspection before and after testing. A subscale Smart bolt was designed, manufactured and tested for magnetic sensitivity using a smart washer. / Thesis (Ph.D.)-University of KwaZulu-Natal, 2005.