Pressure ulcers significantly contribute to the diminished quality of life and substantial disability in people with spinal cord injury (SCI). A broad consensus among clinicians and researchers has been reached that the best approach to reducing this burden is to implement an effective preventive treatment that would greatly reduce the incidence. The preventative intervention should eliminate/diminish causative factors and pathways involved with pressure ulcer development. The objective of this thesis is to explore the relationship between sacral skin blood flow and transcutaneous oxygenation in response to causative factors of pressure ulcers (i.e. thermal stress, mechanical stress, and sympathetic modulations) in five neurologically intact subjects. Two tests were performed to analyze the relationship between sacral skin blood flow and transcutaneous oxygenation. In test 1, skin blood flow and transcutaneous oxygenation were measured while subjects underwent orthostatic stimulation. Results from test 1 showed that both the level of heat used and the location of testing effects how skin blood flow and transcutaneous oxygenation respond to orthostatic stimulation. In test 2, skin blood flow and transcutaneous oxygenation were measured while external pressure was applied. Results from test 2 showed that a significant increase in peak skin blood flow and TcPO2 (p<0.05) occurred on average 588 and 298 seconds, respectively, following removal of occluding pressure when the skin is heated to 44 degrees C; however, at 37 degrees C, skin blood flow and transcutaneous oxygenation showed a significant peak increase (p<0.05) following removal of occluding pressure at 28 and 404 seconds, respectively.

The purpose of the first study was to investigate the effect of manual and power wheelchairs on the frequency of community activities of individuals with varying levels of spinal cord injury (SCI). One hundred and five individuals with SCI who use wheelchairs for mobility provided participated in the final analysis. A written survey that recorded assistive technology (AT) usage in daily activities, called Participation Survey/Mobility (PARTS/M), was distributed among clients from Pittsburgh and Saint Louis. Results showed that individuals who use power wheelchairs visit their friends and dine out much less than individuals who use manual wheelchairs. In addition, individuals with tetraplegia reported going to the doctors office less frequently than individuals with paraplegia. Therefore, individuals with SCI with varied level of injury and different mobility devices, experience different types of frequencies of public places and community participation. The purpose of the second study was to investigate the effect of wheelchairs, the physical and social barriers on community participation among individuals with SCI. One hundred and five individuals with SCI who use wheelchairs for mobility participated in the data analyses. A written survey, called Facilitators and Barriers Survey/Mobility (FABS/M) was distributed among clients from Pittsburgh and Saint Louis. Results showed that a greater number of individuals with tetraplegia who use power wheelchairs (TP) reported that lack of personal assistance as a perceived social barrier that limits their participation in their place of employment ASSESSING THE INFLUENCE OF WHEELCHAIR ON INDIVIDUALS WITH SPINAL CORD INJURY USING A MEASURE OF PARTICIPATION Eliana C. Ferretti, PhD University of Pittsburgh, 2007 when compared to those individuals with paraplegia who use manual wheelchairs (PM), individuals with paraplegia who use power wheelchairs (PP) and individuals with tetraplegia who use manual wheelchairs (TM). A greater number of individuals with TM and PM reported that the place of employment does not limit them compared to those PP and TP. In addition, a greater number of individuals with PP and TP indicated that lack of personal assistance as a perceived social barrier that limits their participation in the grocery store when compared to those with PM and TM. Furthermore, the perceived influence of the physical environment on participation in activities within the home and community was also demonstrated. The purpose of the third study was to investigate if the acquisition of new manual and power wheelchairs delivered by specialized AT clinic will change the frequency of participating in activities within the community of individuals with SCI and reduce the number of perceived limitations to participation over time. No significant difference between participants who received new wheelchairs delivered by specialized AT clinic and those who have received new equipment from a non-specialized AT clinic on the perception of frequency of community activities, satisfaction of community activities and number of physical and social barriers were found. The process of wheelchair service delivery has been shown to play an essential role in wheelchair related outcomes. However, the wheelchair service delivery may just be one of the factors that affect the individuals community participation. The purpose of the fourth study was to investigate if there is a correlation between mobility characteristics (distance traveled, speed, number of starts and stops and drive time) and the frequency of community activities of individuals with SCI as measured by the PARTS/M and data logger device. A significant negative correlation (r=-.783, p=.013) was found between number of start and stops during week days and community participation scores, indicating that individuals who use power wheelchairs who have less number of starts and stops have higher level of community participation. A significant positive correlation (r=.772, p=.015) was found between daily drive minutes during week days and community participation scores, indicating that individuals who use power wheelchairs who drive their wheelchair more have higher level of community participation. In addition, in the manual wheelchair group, a significant positive correlation was found between speed during week days (r=.760, p=.047) and community participation, indicating that individuals who travel at a higher speed have higher levels of community participation.

Purpose: The purpose of our study is to identify impairments in fine motor control in individuals with Parkinsons disease(PD) during a force-tracking task using force sensors and comparing that to the fine motor control in age-matched controls. We also observed differences in fine motor coordination across a spectrum of patients with varying severity of disease Methods: 30 subjects with Parkinsons disease and 30 age-matched controls participated. Commercially available six-axes force sensors were used to provide an interface for interaction between the subject and the force-tracking task. Subjects tracked a moving sine wave on a computer screen by controlling the amount of force exerted between their index finger and thumb. The two digits were attached to the force sensors that are capable of recording the amounts of force exerted by the subject. During a part of the task, a simultaneous mental activity was introduced and the effect of this distraction was evaluated. Performance of the task was also evaluated using a pseudorandom wave for another three minutes including the distraction components. Results: We compared results between subjects and controls using univariate analysis of variance. Association between the motor score of the Unified Parkinsons disease Rating Scale (UPDRS) and the force tracking variables as well as that between the force tracking variables and chronicity of the disease was evaluated using multiple regression analyses. Individuals with PD showed greater amounts of error, lesser coordination and greater amounts of lag compared to controls. Distraction significantly affected individuals with PD to a greater extent compared to controls. The test showed no association with chronicity of the disease and showed a moderate association to function based on the UPDRS. Clinical Relevance: Deficient hand function in activities that involve fine motor coordination is one of the chief complaints of individuals with Parkinsons disease. The ability to perform activities that involve precision grip depends on the capacity to make fine adjustments to forces in response to the demands placed by complex environments with a number of distractions. Individuals with PD performed with greater deficits on our test especially during the distraction component of the task.

Distance running performance is dependent on the integration of the complex mechanisms of neuromuscular control, central and peripheral cardiovascular performance, and fatigue resistance. The end result of these interactions is movement, as defined by running mechanics. During high-intensity running, specific muscles may demonstrate signs of neuromuscular fatigue, which may alter running local and whole-body running mechanics. There are few published studies specific to running which describe neuromuscular fatigue of torso and arm muscles, how fatigue affects the kinematics of the upper body, and how neuromuscular fatigue relates to kinematic changes. Fifteen trained male distance runners were recruited to participate in this study. Each subject performed an exhaustive run at an intensity approximating 95% of maximal oxygen consumption. Electromyographic data were collected from thirteen muscles unilaterally and kinematic data were collected from key joints of the upper and lower body during the exhaustive run. Increased motor unit recruitment was observed in nearly all muscles studied, many demonstrating statistically significant linear trends. Torso muscles demonstrated similar levels of recruitment to the leg muscles. Statistically significant models of neuromuscular fatigue were observed during the exhaustive run for two leg muscles and one torso muscle. None of the arm muscles demonstrated statistically significant changes indicative of fatigue. A number of statistically significant kinematic changes were observed throughout the run for all regions of the body. Some kinematic changes were significantly correlated to changes in motor unit recruitment patterns or neuromuscular fatigue. These results confirm that runners develop neuromuscular fatigue during high intensity running and this may limit performance. Based on these results, general recommendations for muscle-specific training programs may be made for groups of athletes similar to the population studied. However, there are many individual differences within this population and therefore personalized training recommendations require a thorough neuromuscular and kinematic evaluation. Groups of runners with different demographics may also show different trends in fatigue patterns. Therefore, further research is needed to investigate the effect of exhaustive running on various populations. Additionally, research is needed to validate training programs which aim to delay or prevent neuromuscular fatigue as a means of enhancing running performance.

Compared to individuals with spinal cord injury (SCI), propulsion by older adults is poorly defined. The goal of this project is to examine the impact of wheelchair, surface, and user characteristics on propulsion mechanics in older adults and individuals with SCI. All participants self-propelled over a series of surfaces at a self-selected velocity and kinetic data collection were provided by the SmartWheel. We described a standard clinical protocol (SCP) for objective assessment of manual wheelchair propulsion and defined reference values for individuals with SCI based this protocol (N=128). The SCP requires self-propulsion over tile, low pile carpet, and up an ADA ramp. In addition we provided a decision framework based on graphical reference data; guiding clinicians through an objective assessment of propulsion, identifying opportunities for intervention and follow-up. We then compared propulsion of individuals with paraplegia (IP, N=54) and older adults (OA, N=53). OA propelled slower than IP; used a greater push frequency and minimum Mz, shorter stroke length, and similar resultant force. When surface difficulty increased, the IP group responded with increased work. This may indicate a lack of capacity in OA to respond to increased resistance. For our cohort of older adults we defined the impact of surface type, wheelchair weight, and rear axle position (N=53). As surface difficulty or chair weight increased, velocity decreased. Controlling for velocity, push frequency, resultant and tangential force increased as surface difficulty increased; heavier chairs had decreased stroke length and increased resultant and tangential force; and posterior axle positions had increased velocity. Controlling for velocity, posterior axle positions had increased forces. Finally, we examined the impact of strength and gender. Body-weight normalized grip strength was collected. Stronger individuals propel faster than weaker individuals. On low pile carpet, both genders decreased velocity versus tile, but women decreased push frequency while men increased. Surface type has a substantial impact on propulsion velocity and force; magnifying any differences between users and wheelchair configurations. Wheelchair weight and axle position independently affect propulsion mechanics. Gender and strength appear to influence propulsion. Older adults are marginal self-propellers at best; powered mobility may be a more appropriate mobility solution.

A model is presented depicting the driving forces (Web industry, consumers, U.S. federal government, and technology) promoting an accessible Web and potential solutions within those forces. This project examines two distinct solutions, lawsuits (a consumer-driven solution) and AcceSS 2.1 transcoder (a technology-driven solution) to provide more information on two under-researched methods that could have far-reaching impacts on Web accessibility for the blind. First, an evaluation of the intraclass correlation (ICC) between homepage Web Accessibility Barrier (WAB) scores and WAB scores of levels 1-3 found that the homepage is not sufficient to detect the accessibility of the website. ICC of the homepage and average of levels 1-3 is 0.250 (p=0.062) and ICC of levels 1, 2, & 3 is 0.784 (p < 0.0001). Evaluating the homepage and first-level pages gives more accurate results of entire site accessibility. Second, an evaluation of the WAB scores of the homepage and first-level pages of websites of five companies sued for alleged inaccessible websites found mixed results: lawsuits worked in two cases, but didnt in three. This is seen through an examination of accessibility and complexity of the websites for years surrounding the lawsuits. Each sued website is compared to a control website within the same industry and to a random group of websites representing the general Web. Third, a usability study of the AcceSS 2.1 transcoding intermediary found that technology can increase users efficiency, effectiveness, and satisfaction in Web interaction, regardless of universal design. The study entails a within-subject cross-over design wherein 15 users performed tasks on three websites: one universally designed, one non-universally designed, and one reference site. Paired t-tests examine the effect of AcceSS 2.1 on time, errors, and subjective satisfaction and mixed-model analysis examines the effect of study design on outcomes. Results show that users perform tasks faster, with fewer errors, and with greater satisfaction when accessing pages via AcceSS 2.1, but users where less satisfied with the universally designed website and significant differences were found in the universally designed website and not the non-universally designed website. Website usability and ease of navigation are more important to users than simple accessibility.

Behavioral treatments performed in patients with dysphagia are designed to produce immediate or short-term outcomes that eliminate physiologic or biomechanical impairments of oropharyngeal swallowing. These short-term outcomes are expected to reduce aspiration of swallowed food into the respiratory system, and improve delivery of swallowed material into the digestive system. In the long-term these interventions are justified by expectations that they will reduce patient risk for dysphagia-related consequences such as pneumonia, malnutrition, and death. Two distinct investigations were performed in this dissertation. The first, a meta-analysis, was performed to evaluate available evidence regarding the efficacy of individually administered dysphagia interventions in neurogenic dysphagia, and the effectiveness of systematic, institutional dysphagia protocols at mitigating public health risks associated with dysphagia. The second investigation, an experimental study, was executed to evaluate whether the addition of surface electromyographic biofeedback to traditional training of the Mendelsohn maneuver, a common individually administered dysphagia intervention, altered the initial (first training session) efficacy of volitional prolongation of muscle activity responsible for upper esophageal sphincter opening during the swallow. The meta-analysis revealed that well designed investigations of individually administered treatments for short-term elimination of biomechanical impairments demonstrated small to large effect sizes (r = .13 - .45) for these treatments, all but one of which were statistically significant, and that overall, their combined effect size was small to medium (r = .29) and significant (p = .03). However studies of institutionally deployed dysphagia protocols demonstrated moderate effect sizes (Odds Ratio = .44 - .79) which, combined, were not statistically significant (p = .08). Overall, few published investigations of sufficiently robust evidence quality were found to justify their inclusion in the meta-analysis, suggesting that more research of this type is needed. The experiment revealed that training of the Mendelsohn maneuver with and without surface electromyographic biofeedback, produced significantly increased duration (p < .01) and average amplitude (p = .02) of swallowing myoelectric activity. There were no significant differences between treatment groups in swallow duration or amplitude, however a trend toward increased preparatory myoelectric consistency was observed for the biofeedback trained group (p = .052) compared to the non-biofeedback trained group.

Stroke is one of the leading causes of disability. Using an understandable measure to describe subsequent disabilities, namely, activities of daily living (ADL), is important for clinical practice. The three studies in this dissertation describe ADL task disability of stroke survivors at 3 months post-stroke, from multiple perspectives. The first study compared the constructs of five commonly used ADL measurement tools which used different scoring systems and assessment methods. Rasch analysis, using the partial credit model, confirmed that the performance-based and task-specific (criterion-referenced) ADL assessment, Performance Assessment of Self-Care Skills (PASS), had excellent unidimensionality for measuring independence in stroke survivors. It was also more valid and reliable than the other informant-based, and global non-summative (Glasgow Outcome Scale, 5-point [GOS5], Glasgow Outcome Scale, 5-point [GOS8], Modified Rankin Scale [mRS]) and global summative (Barthel Index [BI]) measures. The second study went on to develop an item difficulty hierarchy with the combined items from the PASS and the BI, and establish the person abilities of the stroke survivors. Rasch analysis and common person equating method revealed that the PASS was more difficult for the stroke survivors than the BI, and the participants had the greatest difficulty performing PASS instrumental ADL (IADL). The third study further delineated the independence of the stroke survivors with left and right hemispheric stroke (LHS and RHS) at the overall, domain, and task levels of the PASS. Rasch analysis, differential group functioning, and differential item functioning showed that the LHS group performed significantly more independently than the RHS group in the functional mobility domain, and better, but not significantly better on the overall PASS, and the personal care, physical IADL, and cognitive IADL domains. The findings of clinically significant differences in specific tasks between the two stroke groups (side of lesion, gender, and age) will advance the knowledge related to specific disabilities of stroke survivors, especially for IADL tasks. Further studies were recommended to explore the independence of the stroke survivors in performing ADL subtasks, with more homogeneous samples and at multiple time points.

Autism is a life-long neurodevelopment disorder affecting 1 in every 150 children in the United States. Along with the three major hallmarks of autism; impairments in social interaction, impairments in communication, and repetitive and restricted stereotypes of behavior, individuals with autism face a variety of impairments that affect their everyday functioning. These impairments include, but are not limited to, impairments in motor skills, impairments in sensory-perceptual skills, and impairments in executive functioning (EF) skills. This dissertation explored these aforementioned impairments in individuals with high-functioning autism (IHFA) in three studies. The first study explored simple and complex motor and simple and complex sensory-perceptual skills differences between IHFA and typically-developing individuals (TDI) for different age groups extending from childhood to early adulthood. The study found IHFA to be impaired compared to TDI on simple and complex motor skills across the continuum of age. However, for sensory-perceptual skills IHFA impairments were found only for complex sensory-perceptual skills for an older group of IHFA. The second study explored factors that were associated with good and poor complex fine-motor skills for IHFA and TDI. Two models were generated utilizing Exhaustive Chi-Square Automatic Interaction Detection (CHAID). In this study, we found different factors to be associated with complex fine-motor skills for IHFA versus TDI. The patterns of association for IHFA were also different from TDI. In the third study, we explored the factors that were associated with good and poor EF skills by generating two models, one for IHFA and one for TDI, utilizing Exhaustive CHAID. In this study, we found similar factors to be associated with EF skills for both IHFA and TDI, however, the factors held different levels of association with EF in each group. Findings from the first study suggest the importance of early assessment and continuous re-assessment of simple and complex motor skills and complex sensory-perceptual skills for IHFA. Findings from the second and third study offer models that have the potential to establish priorities for assessment and intervention for IHFA.

With the growing number of elderly long-term care residents in the United States, pressure ulcers (PU) represent a significant healthcare problem. The National Pressure Ulcer Advisory Panel (NPUAP) reported in 2001 that the incidence rates of PU in long-term care residents ranged from 2.2% to 23.9% and the prevalence from 2.3% to 28%. Multiple risk factors for the development of PU have been suggested, and can be divided into extrinsic factors and intrinsic factors. The aims of this study were to: (1) conduct a focused literature review of intrinsic and extrinsic factors related to PU development in elderly long-term care residents; (2) conduct a secondary analysis of demographic and clinical data from Randomized Clinical Trial on Preventing Pressure Ulcers with Seat Cushions (RCT-SC), to identify risk factors associated with acquiring/not acquiring a PU in elderly long-term care residents. Three different methods were used to analyze the data: (a) stepwise logistic regression, (b) odds ratios, and (c) Exhaustive Chi-Square Automatic Interaction Detection (CHAID); and generate a decision-making tree for the prescription of wheelchairs and seat cushions by rehabilitation practitioners for elderly long-term care wheelchair users. Inter-rater and intra-rater reliability of the rehabilitation team decisions were also established. As a result of this study it was concluded that:(a) the focused literature review provided useful information about intrinsic, extrinsic and combinations of these risk factors in PU acquisition,(b) the stepwise logistic regression, odds ratios, and CHAID analyses confirmed known risk factors and added new risk factors that predict PU development,(c) the decision-making tree can be a starting point for rehabilitation practitioners that are new to the field of seating and mobility, and (d) the decision making tree showed that the use of a pressure mapping system is a good tool if used in combination with clinical judgment.