Methodical maintenance and renewal of infrastructure systems is critical due to the rapid deterioration of infrastructure assets under increasing loads and environmental effects and the scarcity of resources allocated for their preservation. A crucial step in pavement management is the formation and prioritization of maintenance and rehabilitation (M&R) projects that compete for limited funding for inclusion in the agency’s multiyear pavement management plan (PMPs). In general, many highway agencies perform this task subjectively, and thus a more rational and objective approach is desired to produce sound and justifiable PMPs. Specifically, such methodology should take into account the multiple factors that are considered by engineers in prioritizing M&R projects. This research addresses this need by developing a methodology for use by the Texas Department of Transportation (TxDOT) in preparing their four-year PMPs. Several key decision factors were considered and TxDOT decision makers were surveyed to weigh these factors as to their influence on prioritizing M&R projects. These were then used to develop a priority score for each candidate M&R project. Since TxDOT collects and stores data for individual 0.5-mile pavement sections, these sections must be grouped in a logical scheme to form realistic candidate M&R projects. The incremental benefit-cost analysis was performed on the candidate M&R projects to identify a set of M&R projects that maximizes network’s priority score under budgetary constraint. Future pavement condition was projected using performance prediction models and the process is repeated throughout the planning horizon to produce a multi-year pavement management plan. Data from Bryan district, which consists of 7,075 lane-miles of roadway, were used to develop and validate the PMP methodology. Comparison with the actual PMP (produced by TxDOT) shows some disagreements with the PMP generated by the methodology though the latter was shown to produce more cost-effective and defendable pavement management plans. Since the methodology is founded on TxDOT engineers’ decision criteria and preferences, they can be assured that the PMPs produced by this methodology are in line with their goals and priorities.

The ability to safely and efficiently negotiate stairs is an essential skill for independent ambulation. To date, basic research to identify biomechanical and physical costs is limited in older adults. In persons with stroke, this aspect of mobility is virtually unexplored. The main objective of this thesis was to investigate biomechanical alterations during stair negotiation and to evaluate the physical costs of the task in older adults and persons with stroke. This was approached by conducting four studies. The first study identified age-related alterations in joint kinetics during stair negotiation. The results showed age-related differences in moment magnitudes, an exaggerated net support moment and sustained abductor moments through stance. To gain insight into these adaptive changes with respect to mechanical efficiency, the second study evaluated age-related changes in mechanical energy transfers during stair negotiation. During ascent, older adults achieve similar efficiencies as young adults by slowing their cadence. During descent, age-related differences in mechanical energy expenditures and related variances in mechanical energy compensation coefficients reflect a loss in mechanical efficiency. The impact was likely the provision of enhanced extensor support and stability. The results also highlight a functional role for concentric energy expenditures during descent. The third study provided a detailed biomechanical description of stair negotiation in people with stroke, revealing important differences in how stroke survivors manage stairs and how handrail use modifies the magnitudes of lower limb joint moments. The fourth study evaluated the strength and aerobic requirement of stair ambulation in persons with stroke. The findings reveal increased costs of the task, primarily due to reduced neuromuscular and aerobic capacities and serve to identify factors that may be limiting during stair negotiation. This thesis provides new information regarding movement control in older adults during stair negotiation, providing a normative benchmark of age-related alterations in movement patterns. In persons with stroke, this work is the first to quantify the biomechanical patterns and physical requirements of stair negotiation. Future work may extend these findings to explore mobility challenges in persons with greater levels of impairment as well as guide the development of targeted and task oriented rehabilitation programs. / Thesis (Ph.D, Rehabilitation Science) -- Queen's University, 2011-08-25 09:24:26.106

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This study investigated the effects of providing body weight support (BWS) on the gait pattern of 15 incomplete spinal cord lesioned subjects. Electromyographic (EMG), joint angular displacement and temporal distance parameters were simultaneously recorded as subjects walked on a treadmill while 0% and 40% of their body weight was mechanically supported by an overhead harness. The effects of 0% and 40% BWS while walking with and without parallel bars and at different treadmill speeds was further investigated in a subgroup of 8 subjects. / In general, 40% BWS led to a decrease in prolonged EMG activity of proximal muscles, a decrease in premature activation of distal muscles as well as a decrease in clonus. Such changes in EMG activity were evident especially during more demanding external conditions such as walking without parallel bars or at faster treadmill speeds. A general decrease in EMG mean burst amplitude for lower limb muscles was also noted. Sagittal angular displacement profiles revealed a straighter trunk and knee alignment during initial and midstance. Forty percent BWS appeared to facilitate gait by allowing subjects to walk for longer periods and to walk at faster treadmill speeds. Increases in stride length, single limb support time and decreases in total double support time were also noted with 40% BWS at comparable treadmill speeds. The results this study suggest that BWS facilitates the expression of a more normal gait pattern.

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Background. Evidence-based practice aims to improve patient care and service delivery, particularly in the management of individuals with low back pain, the largest client group seen by out-patient physiotherapists. Objective: This study determined the prevalence of use of interventions with evidence of effectiveness in the management of acute non-specific low back pain by physiotherapists. Methods. A multi-centered cross-sectional study was conducted on 100 physiotherapists working with low back pain patients. Using a telephone-administered interview, therapists described their current and desired treatment practices for a typical case of low back pain. Each intervention reported was coded according to its evidence of effectiveness (strong, moderate, limited or none) as per Van Tulder's rating system. Information on clinician, workplace and client characteristics was also obtained. Results. The prevalence of use of interventions with strong or moderate evidence of effectiveness was 68%. Almost all therapists use interventions with limited or no evidence of effectiveness or moderate evidence of ineffectiveness. Users of interventions with high evidence of effectiveness, as compared to non-users, had graduated more recently (p = 0.0098) and had taken a higher number of post-graduate clinical courses (p = 0.0091). Conclusion. Although most therapists use interventions with high evidence of effectiveness, much of their treatment programs consist of interventions that are not well studied in the literature.

A study was conducted to investigate the effects of age on functional recovery following a median and/or ulnar nerve repair. A group of 17 children was compared to a group of 17 adults with nerve injuries of similar severity and site. Motor and sensory function, tactile gnosis, manual dexterity, pain and perception of disability were assessed by an independent examiner. The results indicate a better qualitative and quantitative recovery in children than in adults, with respect to two-point discrimination, grip strength, tactile gnosis, manual dexterity and self-report of performance in daily activities. In conclusion, age at the time of injury was found to influence the extent of functional recovery following peripheral nerve injuries. Other factors, such as cortical plasticity, rate and extent of nerve regeneration, attitudes and psychological adjustment to disability, may further explain the differences observed between the two groups.

A new clinical measure of postural adaptation, the Advanced Mobility and Balance Scale (AMBS), was developed to assess balance capacities of stroke patients in standing and walking. In the first pilot study, involving 12 stroke patients and 6 healthy subjects, we found excellent interrater reliability and reasonable discriminative capacity of the AMBS. However, high-level functioning stroke subjects could not be differentiated from healthy subjects. / In order to refine the scoring of the AMBS for better discrimination, we conducted a kinematic analysis of head turning while walking in 10 stroke patients and 5 age-matched healthy subjects. Results showed that stroke patients manifested disrupted head-trunk-pelvis coordination and increased footpath deviation during head turns towards the paretic side. These abnormal patterns are likely due to compensations and altered sensorimotor integration processes.

The objectives of this study are to contribute evidence for construct validity of a self-administered questionnaire of physical activities (CHAMPS) as an indicator of the process of surgical recovery. / The surgical population is unique, as it comprises people diverse in age and functioning. The data for this study were obtained from a randomized control trial (RCT) evaluating the impact of a presurgical period of physical conditioning on surgical recovery following scheduled colonic resection, termed rehabilitation. Patients were randomized into two groups, Exercise and Control. Cross-sectional and longitudinal analyses were conducted at entry into the study, at one-day pre-surgery, and at one- and two-months post-surgery. A sample of 62 subjects participated in this study. The Short Form Health Survey (SF-36) Physical Functioning Scale (PF) and Physical Component Summary Score (PCS), VO2max and 6MWT were low to moderately correlated with the CHAMPS questionnaire at the same time points. For the Exercise group, energy expenditure as estimated using the CHAMPS questionnaire, increased significantly from 2653 to 3957 kcal.wk-1 (p<0.05). Physical activity levels dropped significantly (p<0.001) from pre-surgery (4103 kcal.wk-1) to one month post-surgery (1547 kcal.wk-1); and they were still lower (2396 kcal.wk-1) at two months post-surgery (p<0.01). Older age (>65), cancer diagnosis and female gender were associated with higher drop in physical activity levels at one-month post surgery. Evidence has been provided towards construct known groups, longitudinal (sensitivity to change and responsiveness) and convergent validity of physical activity questionnaire (CHAMPS) as an indicator of the process of surgical recovery. The information obtained from the questionnaire will allow health professionals to better plan care and develop programs to best manage the patients.