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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Variability of vertical ground reaction forces in patients with chronic low back pain, before and after chiropractic care.

Russell, Brent S, Geil, Mark D, Wu, Jianhua, Hoiriis, Kathryn T 11 August 2011 (has links)
Introduction Many chiropractic articles and textbooks discuss gait, but there actually has been little research into the effects of chiropractic adjustment on gait. This pilot study used a quantitative method of gait evaluation before and after a series of chiropractic visits. Hypotheses: (1) adults with chronic low back pain (CLBP) would show increased variability in vertical ground reaction forces (VGRF) while walking, as compared to healthy control subjects, and (2) that, following chiropractic care, will show decreased variability. Methods VGRF data were collected for 6 controls and compared to 9 CLBP participants, who were also evaluated before and after the first visit of care and over 7 visits. Data were analyzed by Mean Standard Deviation (MSD), Mean Coefficient of Variation (MCV), and the Coefficient of Variation of loading rate. Chiropractic care consisted of “high velocity low amplitude” thrust type procedures, flexion-distraction, pelvic wedges, light mobilization, and stretching. Results CLBP participants had somewhat greater variability and became slightly less variable post-care; differences were not significant. Limitations: Some participants had no impairment of walking at baseline; MSD is an uncommon measure, and more research is needed; these results (small group seen by a single doctor) may not be generalizable. Conclusions Participants with CLBP had slightly more variability and had slight decreases in variability following chiropractic care. Differences were not statistically significant. With this small pilot study as a guide, more research should be done with larger groups and improved participant selection.
182

The Biomechanical Effects of an Externally Applied Orthosis on Medial Compartment Knee Osteoarthritis

Conrad, Janet 06 December 2011 (has links)
This thesis examined the immediate biomechanical effects of valgus unloader brace application in participants with moderate medial compartment knee osteoarthritis during gait. Thirty-three individuals were prescribed a valgus unloader brace. 3D knee moments and angles were calculated during walking with and without the brace. Principal Component Analysis identified amplitude and temporal changes of the moment and angle waveforms during gait. Three groups were identified based on the change in knee adduction moment magnitude with brace application. Two-Way ANOVA tested for differences among groups and conditions in principal component scores, as well as discrete varus thrust values. There existed three subgroups of participants identified by different gait adaptations to brace application. The brace had temporal and magnitude effects on 3D kinetics and kinematics for the participant group. This study showed that the brace does not provide a consistent change to knee joint mechanics. These results have implications for brace prescription.
183

The effects of botulinum toxin A (BTX-A) on gait in chronic stroke

Novak, Alison C 17 September 2007 (has links)
Excessive muscle tone or stiffness secondary to stroke frequently involves the ankle plantarflexors and has been associated with decreased mobility and reduced function. Although becoming more common in clinical practice, the effectiveness of botulinum toxin A (BTX-A) injected in the ankle plantarflexors on gait biomechanics is not well established. The primary objective of this study was to describe the kinematic and kinetic changes that occur during walking following BTX-A treatment of the hypertonic ankle plantarflexors. As well, the study explored whether there were clinical characteristics uniquely associated with subjects that exhibited biomechanical improvement. The study was a single group, open label trial with repeated measures, including multiple baseline and three post-intervention time points. Seven chronic hemiparetic stroke subjects with ankle hypertonicity were included in the study. Full lower limb bilateral gait analysis provided joint kinematic and kinetic information throughout stance. As well, clinical measures of ankle range of motion and spasticity were assessed pre and post treatment. Data were analyzed using paired samples t-tests and repeated measures ANOVA with Least Significant Difference adjustment for post-hoc analysis as necessary (significance level p≤0.05). Of the kinematic variables, significant improvements in peak dorsiflexion and plantarflexion and the ankle angle at initial contact were found 10 weeks post-injection relative to baseline. No significant kinetic changes were detected, however 2 subjects showed improved positive work at the ankle post-injection and 5 subjects demonstrated increased positive work at the hip post-treatment. Although subjects were classified as “responders” or “non-responders” based on clinical improvement observed 2 weeks post-injection, there was no observable association between those who responded clinically and those who demonstrated improved gait. The major findings suggest that BTX-A injection results in tone reduction and in some cases improves the biomechanical efficiency of gait. In cases where kinetic variables remained unchanged following treatment, perhaps the increased tone was not the limiting factor of reduced function. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2007-08-30 09:41:03.24
184

Reliability and validity of electronic measures of balance and gaze control in people with peripheral vestibular hypofunction

Wonneck, Elizabeth 13 August 2013 (has links)
The purpose of this study was to assess the reliability and validity of a new computerized method of assessing balance and gaze control under a broad range of physical and visual conditions in people with vestibular hypofunction. Test retest reliability for balance performance as measured by COP excursion was good in all conditions with ICCs ranging from .64 to .90 in the AP and ML directions. Closed loop visual tracking as measured by COD had high reliability on the sponge and treadmill (ICC=.71-.75) as compared to open loop tracking (ICC=.325-.463) which was poor. Convergent validity showed poor correlation between clinical tests and the electronic balance and gaze assessments. Construct validity demonstrated that as physical and visual loads increased, balance performance decreased significantly on the sponge as measured by an increase in COP excursion and visual tracking performance decreased significantly on the treadmill as measured by a decrease in COD.
185

Aging effects on balance, gait and cognition during treadmill walking

Sabapathy, Srikesavan 19 August 2014 (has links)
Background Limitations in mobility resulting from balance impairments contribute substantially to falls in older adults. Aging also has a detrimental effect on cognition which influences mobility and balance. A low cost treadmill rehabilitation platform (TRP) and a custom computer game that provided single and dual task challenges while standing and walking were used to evaluate standing balance, gait variables, visual tracking and cognition game performances in active young and older adults. Objectives The study objectives were, 1) to determine the differences in performance-based measures of standing balance, treadmill walking, visual tracking and executive cognitive function between young and older adults and 2) to examine the effect of age and dual tasks on performance-based measures of balance, gait, visual tracking and cognition in both groups. Methods Thirty active young adults (Mean age: 26.7± 2 years) and thirty older adults (Mean age 61.4± 4.4 years) performed visual tracking and cognitive game tasks on three different physical and cognitive loads on the TRP. The treadmill was instrumented with a force sense array (FSA) pressure mat to record the centre of foot pressure excursions. A motion sense air mouse (Gyration Elite) mounted on a custom made helmet was used to interact with the on screen cursor of the computer screen to perform visual tracking and cognitive game tasks. Participants were also evaluated for balance using clinical tests. Results During single tasks, younger adults performed better than older adults in the AP direction while older adults demonstrated better balance in the ML direction. Single task walking did not demonstrate a difference between the two groups. During single task cognition, there was no difference during both cognitive games while young adults did better during the closed loop visual tracking task. During the dual tasks, both groups demonstrated a dual task effect in balance, walking and cognitive tasks. Younger adults performed better than older adults in all the physical and cognitive load conditions. Conclusion The study findings provided evidence for discussion on the effects of single and dual tasking conditions in young and older adults. Understanding the effects of dual tasks has important clinical implications because older adults engage themselves in a wide variety of activities that require cognitive, mobility and balance skills simultaneously. Identifying the age at which there is a compromise on the above and providing appropriate interventions would be very useful to prevent falls.
186

Reliability and validity of electronic measures of balance and gaze control in people with peripheral vestibular hypofunction

Wonneck, Elizabeth 13 August 2013 (has links)
The purpose of this study was to assess the reliability and validity of a new computerized method of assessing balance and gaze control under a broad range of physical and visual conditions in people with vestibular hypofunction. Test retest reliability for balance performance as measured by COP excursion was good in all conditions with ICCs ranging from .64 to .90 in the AP and ML directions. Closed loop visual tracking as measured by COD had high reliability on the sponge and treadmill (ICC=.71-.75) as compared to open loop tracking (ICC=.325-.463) which was poor. Convergent validity showed poor correlation between clinical tests and the electronic balance and gaze assessments. Construct validity demonstrated that as physical and visual loads increased, balance performance decreased significantly on the sponge as measured by an increase in COP excursion and visual tracking performance decreased significantly on the treadmill as measured by a decrease in COD.
187

Combined Effects of High-heeled Shoes and Load Carriage on Gait and Posture in Young Healthy Women

Lee, Soul 10 February 2011 (has links)
The aim of this study was to determine the combined effects of high-heeled shoes and load carriage on gait and posture adaptation. Furthermore, the adaptation of gait and posture to the combined two conditions was examined by a comparison of the measured parameters between experienced and novice groups. 30 participants underwent a quantitative measurement of temporospatial, kinematic, and kinetic parameters of hip, knee, and ankle on both loaded and unloaded limbs using 3D motion analysis. Double support time and stride length increased during high-heeled gait and the magnitude of alteration was greater with a load. Increased plantarflexion was main cause of raised heel. Ankle plantarflexor moment increased with high-heeled but decreased with load carriage. As a result, plantarflexor moment diminished, in addition knee extensor moment exaggerated further. Hip extensor moment increased with heel height but not with load weight, however, hip angle was affected only by the load.
188

Effects of a supervised walking program on the cognitive function, gait, fitness, and behaviour of inactive older adults

Kowalski, Kristina Anne 03 September 2014 (has links)
Background & Objectives: Participation in cognitive, social and physical activity (PA) may play a role in prevention of cognitive decline in older adults. Literature supporting the benefits of healthy lifestyle behaviours, especially PA, on cognition continues to accumulate. Moreover, a strong association between gait and cognitive health is increasingly being recognized. Yet, a firm understanding of the individual differences and between-person effects of PA on cognition and gait of older adults is lacking. Thus, the primary objective of the main study was to distinguish the within- and between-person sources of variation in PA on cognition in a group of inactive older adults. Study 2 examined the within- and between-person effects of a) PA on gait and b) gait on cognition. Study 3 examined the social cognitive predictors of walking. Methods: The between- and within-person of PA on cognition were examined in a single-group longitudinal design. Participants (n=159) were enrolled in a four-month supervised walking program and provided with materials and coaching to promote the adoption of behaviours to enhance and maintain their cognitive health. Group participants walked at least 3 times per week at a brisk intensity and were encouraged to get 150 minutes of moderate-to-vigorous PA per week. At baseline, participants completed measures of social cognitive predictors of walking. Assessments of cognition, diet, fitness, gait, PA and other health behaviours occurred at baseline, and at 6, 9, 12, and 16 weeks follow-up. Results and Discussion: Multilevel models revealed significant: 1) within-person effects of PA on select measures of executive functioning and 2) consistent between-group effects of cognitive activity, but not other lifestyle behaviours, on cognition. Study 2 revealed consistent significant 1) within-person effects of PA on gait velocity and stride time variability during dual task walking, 2) between-person effects of PA on gait velocity during both dual task and normal walking, and 3) between-person effects of gait velocity and stride time variability on cognition during both normal and dual task walking. Significant within-person effects of gait on cognition were limited. In study 3, self-monitoring emerged as a significant predictor of change in walking. Conclusion: Distinct patterns of within- and between-person effects on the PA, cognition and gait were observed. Further work will need to continue to clearly elucidate the within- and between-person sources of variation in relations between PA, gait and cognition using well-designed longitudinal and experimental designs. / Graduate / 0633 / 0623 / kkowalsk@uvic.ca
189

Time and frequency domain applications in biomechanics

Giakas, Giannis K. January 1998 (has links)
No description available.
190

Aspects of voluntary motor performance in patients with Chronic Fatigue Syndrome

Paul, Lorna January 1999 (has links)
No description available.

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