In this work we discuss the design and implementation of a computer program to simulate the wear on knee implants over a standardized gait cycle. The contact problems during the gait cycle are formulated using linear elasticity with a linear non-penetration condition. Archard's wear law is used to estimate long-term wear. The algebraic problem after discretization is solved using the Truncated Nonsmooth Newton Multigrid (TNNMG) algorithm. The linear correction step of the algorithm leads to indefinite systems in our application for which we describe a novel heuristic damping algorithm. Our problem sizes allow using a direct solver for these systems and with some modifications we are able to reuse the Cholesky factorization of the system matrix over multiple iterations of the TNNMG algorithm. For our application we are able to significantly improve over the performance of IPopt, a state-of-the-art solver using penalty-based methods. The program is then used for in-silico simulations of wear of two different total knee implant models for which in-vitro results are also available. Both wear volume and spatial distribution of wear that are computed compare well with the experimental results.

Osteoarthritis (OA) of the knee, a musculoskeletal disease characterized by degenerations in multiple joint tissues including the articular cartilage and subchondral bone, is a major clinical challenge worldwide that currently has no cure. Traumatic knee injuries such as anterior cruciate ligament (ACL) tear predispose subjects to early onset of post-traumatic OA (PTOA), necessitating the development of effective disease modifying therapies as total knee replacement surgeries have a limited lifetime. Significant knowledge gap remains in the pathogenesis of OA, while recent evidence suggests the important role of subchondral bone microstructure and mechanics in OA development. Subchondral bone is composed of the subchondral bone plate, a thin layer of cortical lamella, and the subchondral trabecular bone, composed of individual plate-like and rod-like trabeculae. These trabecular plates and rods determine the microstructure and mechanics of trabecular bone entirely and can be quantitatively analyzed using individual trabecula segmentation (ITS). Recent application of ITS showed that changes in the plate-and-rod microstructure of subchondral trabecular bone precede cartilage damage and are implicated to play a role in disease pathogenesis. Studies presented in this thesis aim to provide a deeper understanding of subchondral bone in knee OA scientifically and clinically, which may ultimately be used to improve diagnosis, prevention and treatment of this prevalent and disabling disease. In the first study, we comprehensively quantified microstructural and tissue biomechanical properties of the subchondral bone and articular cartilage in human knee specimens with advanced OA and control knees without OA. We found reduced tissue modulus in trabecular plates and rods in regions with moderate OA, where cartilage is still intact, that persisted in severe OA regions, where cartilage is severely damaged. These observations suggest that tissue biomechanical changes in the subchondral trabecular bone may precede cartilage damage in OA development. Furthermore, we found strong correlations between structural and mechanical parameters of the cartilage and subchondral bone in CT knees, suggesting cross-talk at the tissue level. This coupling persisted in moderate OA regions but disappeared in severe OA regions, suggesting that loss of tissue crosstalk may be an additional indicator of disease progression. In the second study, we quantified subchondral bone microstructural changes after ACL tear in vivo in human subjects using the second-generation high resolution peripheral quantitative computed tomography (HR-pQCT). We examined short-term longitudinal changes during the acute phase (~18 days to ~141 days) after injury, as well as long-term adaptations (~5 years post injury) in the injured knee relative to the contralateral knee in a cross-sectional cohort. We found subchondral bone loss within 1 month from injury that primarily targeted trabecular rods, especially at the distal femur. We also found increased spatial heterogeneity in subchondral trabecular microstructure within the injured knees compared to the contralateral knees in the long-term after injury. These findings indicate that ACL tear results in both short-term and long-term microstructural adaptations in the subchondral bone. ITS based on HR-pQCT knee scans may be a valuable tool to monitor disease progression in vivo. Finally, we quantified subchondral bone microstructural changes after ACL-transection in a canine model of PTOA and investigated the effects of bisphosphonate and NSAID treatment on subchondral bone changes and OA progression. Studies were conducted in skeletally-mature and juvenile animals to investigate the effect of injury age. We found that subchondral bone adaptations after surgery and treatment effects depended on skeletal maturity of animals. In mature animals, changes in the microstructure of trabecular plates and rods occurred 1-month post-op and persisted until 8-months post-op. Bisphosphonate treatment attenuated these microstructural changes and cartilage degeneration while NSAID treatment did not. In juvenile animals that have not reached skeletal maturity, transient changes in trabecular plate and rod microstructure occurred at 3-months post-op but disappeared by 9-months post-op. Neither bisphosphonate nor NSAID treatment attenuated bone microstructural changes or cartilage damages. These findings suggest that age and skeletal maturity at time of injury may need to be considered as additional factors in studying PTOA progression and developing preventative treatments. Taken together, these studies highlight the importance of microstructural and tissue biomechanical changes of subchondral bone in the development of OA. In vivo quantification of subchondral bone using advanced imaging modalities enable longitudinal monitoring of disease progression. Therapeutic agents targeting subchondral bone changes after traumatic injury may be effective preventative strategies for PTOA.

Modern advances in technology have allowed for an increase in the precision with which we are able to measure, record, and affect behavior. These developments suggest that the domains in which behavior analysis might contribute are considerably broader than previously appreciated, for instance the area of behavioral medicine. One way the field of behavior analysis can begin to address problems in behavioral medicine is with biosensor technology, like surface electromyography (sEMG). For sEMG technology to be useful in behavioral medicine, specifically recovery from total knee arthroplasty, a reference value (the maximum voluntary individual contraction-MVIC) must be established. The MVIC value allows for the comparison of data across days and may allow the programming of contingencies. However, current MVIC methods fall short. Study 1 compares MVIC values produced by a participant given the typical instruction only method with two alternative methods: instruction + feedback, and instruction + feedback in a game context. Across 10 participants both feedback conditions lead to higher MVIC values then the instruction only condition. Study 2 applies the MVIC techniques developed during Study 1 to an exercise procedure. Using an MVIC value as the criteria for feedback Study 2 compares the same three conditions, however this time assessing for the conditions under which exercise performance is optimal. Across all 9 participants the instruction + feedback in a game context lead to the participant ‘working harder' and 8 out of 9 participants exceeded the MVIC value more often during this condition then in the other two conditions.

Knee osteoarthritis affects approximately 25 million adults. In severe cases, total knee arthroplasty (TKA) is the most common solution. TKA is effective at addressing pain and reducing continued degeneration of articular cartilage. However, effective physical therapy (PT) following TKA is vital for a full functional recovery. Despite the importance of PT, half of patients never achieve a full functional recovery. Decreases in proprioceptive feedback, severe atrophy, and pain inhibition all likely contribute to the variability in effectiveness. Surface electromyography-based biofeedback (sEMGBF) may allow clinicians to address some of these barriers by supplementing proprioceptive feedback and targeting small muscle contractions before eventually increasing the contraction requirement. Using a between group design, we compare the effectiveness of sEMGBF (7) to neuromuscular stimulation (NMES) (6), and a control group (6) in recovery following TKA. Effectiveness was evaluated across 4 metrics (quadriceps strength, range of motion, functional improvement, and quality of life) in a pre-test/post-test fashion. At the statistical level this study suggest that sEMGBF leads to greater improvements in quadriceps strength relative to the NMES and control group. Additionally, visual analysis suggests that sEMGBF may also lead to greater improvements in range of motion, and functional improvement relative to the NMES and control group. The results for quality of life are mixed. Overall, the study provides initial clinical support for the utility of sEMGBF following TKA.

Thesis (Ph. D.)--University of Missouri--Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 162-175). Also available on the Internet.

High quality health services are often difficult to access in rural and remote areas of Australia. This is due to a shortage of health care professionals and specialists, inadequate and poorly distributed resources, and the tyranny of distance. The result is a reduced level of health and a higher mortality rate than seen in urban communities. Telemedicine, which is the use of various technologies to deliver a range of health care services over a distance, has the potential to increase equity and access to health care in rural and remote areas. To date there has been a poor uptake of telemedicine technology within the profession of physiotherapy. This undoubtedly stems from the perceived, and indeed, real difficulty of performing what is traditionally ‘hands on’ therapy, via an electronic medium. Added to this is a paucity of rigorous clinical outcome studies to demonstrate the efficacy of performing successful treatment via this delivery method. The aim of this thesis was to establish the efficacy of telemedicine as a clinical tool for physiotherapists. To achieve this, the first major undertaking was the development of a telemedicine system to meet the unique needs of clinical physiotherapists and their patients. A series of studies was then performed to calibrate the system and establish its validity and reliability as a clinical assessment tool. Finally, a randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The telemedicine system was constructed using a human systems development approach, with close consultation with senior clinical physiotherapists and potential users of the system. The personal computer-based system was designed to connect patients in their home with physiotherapists in the hospital, via low-speed and low-cost communications. The system incorporated real-time videoconferencing and physical measurement tools to enable the remote assessment of patients. The validity and reliability of the telemedicine physical measurement tools were established through a series of five studies. The results demonstrated these measurements to be accurate and reliable, under various measurement conditions, when compared to reference instruments. A prospective randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The research model chosen for this study was the rehabilitation of subjects who had undergone total knee replacement surgery. Block randomisation was used to assign 65 participants to either a traditional face-to-face therapy group or a telemedicine rehabilitation group. Participants in both groups received treatment over a six week period. Data analysis focussed on comparing physical and functional rehabilitation outcomes achieved in each treatment group. The results of this study demonstrated that the rehabilitation outcomes produced via the telemedicine system were similar to those achieved in the traditional manner. Additionally, the telemedicine therapy was found to produce greater improvements in a number of functional outcome measurements. A high level of satisfaction was expressed by participants who received treatment via the telemedicine method. This thesis provides evidence of the efficacy of telemedicine as a clinical tool for physiotherapists. Furthermore, the work detailed in this thesis represents one of the first randomised control trials in telerehabilitation and makes a significant contribution towards the knowledge of low-bandwidth telemedicine in general. This thesis provides a framework upon which further research and telemedicine applications may be developed, with the ultimate goal of improving equity and access to high quality health services in rural and remote areas.

High quality health services are often difficult to access in rural and remote areas of Australia. This is due to a shortage of health care professionals and specialists, inadequate and poorly distributed resources, and the tyranny of distance. The result is a reduced level of health and a higher mortality rate than seen in urban communities. Telemedicine, which is the use of various technologies to deliver a range of health care services over a distance, has the potential to increase equity and access to health care in rural and remote areas. To date there has been a poor uptake of telemedicine technology within the profession of physiotherapy. This undoubtedly stems from the perceived, and indeed, real difficulty of performing what is traditionally ‘hands on’ therapy, via an electronic medium. Added to this is a paucity of rigorous clinical outcome studies to demonstrate the efficacy of performing successful treatment via this delivery method. The aim of this thesis was to establish the efficacy of telemedicine as a clinical tool for physiotherapists. To achieve this, the first major undertaking was the development of a telemedicine system to meet the unique needs of clinical physiotherapists and their patients. A series of studies was then performed to calibrate the system and establish its validity and reliability as a clinical assessment tool. Finally, a randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The telemedicine system was constructed using a human systems development approach, with close consultation with senior clinical physiotherapists and potential users of the system. The personal computer-based system was designed to connect patients in their home with physiotherapists in the hospital, via low-speed and low-cost communications. The system incorporated real-time videoconferencing and physical measurement tools to enable the remote assessment of patients. The validity and reliability of the telemedicine physical measurement tools were established through a series of five studies. The results demonstrated these measurements to be accurate and reliable, under various measurement conditions, when compared to reference instruments. A prospective randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The research model chosen for this study was the rehabilitation of subjects who had undergone total knee replacement surgery. Block randomisation was used to assign 65 participants to either a traditional face-to-face therapy group or a telemedicine rehabilitation group. Participants in both groups received treatment over a six week period. Data analysis focussed on comparing physical and functional rehabilitation outcomes achieved in each treatment group. The results of this study demonstrated that the rehabilitation outcomes produced via the telemedicine system were similar to those achieved in the traditional manner. Additionally, the telemedicine therapy was found to produce greater improvements in a number of functional outcome measurements. A high level of satisfaction was expressed by participants who received treatment via the telemedicine method. This thesis provides evidence of the efficacy of telemedicine as a clinical tool for physiotherapists. Furthermore, the work detailed in this thesis represents one of the first randomised control trials in telerehabilitation and makes a significant contribution towards the knowledge of low-bandwidth telemedicine in general. This thesis provides a framework upon which further research and telemedicine applications may be developed, with the ultimate goal of improving equity and access to high quality health services in rural and remote areas.

High quality health services are often difficult to access in rural and remote areas of Australia. This is due to a shortage of health care professionals and specialists, inadequate and poorly distributed resources, and the tyranny of distance. The result is a reduced level of health and a higher mortality rate than seen in urban communities. Telemedicine, which is the use of various technologies to deliver a range of health care services over a distance, has the potential to increase equity and access to health care in rural and remote areas. To date there has been a poor uptake of telemedicine technology within the profession of physiotherapy. This undoubtedly stems from the perceived, and indeed, real difficulty of performing what is traditionally ‘hands on’ therapy, via an electronic medium. Added to this is a paucity of rigorous clinical outcome studies to demonstrate the efficacy of performing successful treatment via this delivery method. The aim of this thesis was to establish the efficacy of telemedicine as a clinical tool for physiotherapists. To achieve this, the first major undertaking was the development of a telemedicine system to meet the unique needs of clinical physiotherapists and their patients. A series of studies was then performed to calibrate the system and establish its validity and reliability as a clinical assessment tool. Finally, a randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The telemedicine system was constructed using a human systems development approach, with close consultation with senior clinical physiotherapists and potential users of the system. The personal computer-based system was designed to connect patients in their home with physiotherapists in the hospital, via low-speed and low-cost communications. The system incorporated real-time videoconferencing and physical measurement tools to enable the remote assessment of patients. The validity and reliability of the telemedicine physical measurement tools were established through a series of five studies. The results demonstrated these measurements to be accurate and reliable, under various measurement conditions, when compared to reference instruments. A prospective randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The research model chosen for this study was the rehabilitation of subjects who had undergone total knee replacement surgery. Block randomisation was used to assign 65 participants to either a traditional face-to-face therapy group or a telemedicine rehabilitation group. Participants in both groups received treatment over a six week period. Data analysis focussed on comparing physical and functional rehabilitation outcomes achieved in each treatment group. The results of this study demonstrated that the rehabilitation outcomes produced via the telemedicine system were similar to those achieved in the traditional manner. Additionally, the telemedicine therapy was found to produce greater improvements in a number of functional outcome measurements. A high level of satisfaction was expressed by participants who received treatment via the telemedicine method. This thesis provides evidence of the efficacy of telemedicine as a clinical tool for physiotherapists. Furthermore, the work detailed in this thesis represents one of the first randomised control trials in telerehabilitation and makes a significant contribution towards the knowledge of low-bandwidth telemedicine in general. This thesis provides a framework upon which further research and telemedicine applications may be developed, with the ultimate goal of improving equity and access to high quality health services in rural and remote areas.

High quality health services are often difficult to access in rural and remote areas of Australia. This is due to a shortage of health care professionals and specialists, inadequate and poorly distributed resources, and the tyranny of distance. The result is a reduced level of health and a higher mortality rate than seen in urban communities. Telemedicine, which is the use of various technologies to deliver a range of health care services over a distance, has the potential to increase equity and access to health care in rural and remote areas. To date there has been a poor uptake of telemedicine technology within the profession of physiotherapy. This undoubtedly stems from the perceived, and indeed, real difficulty of performing what is traditionally ‘hands on’ therapy, via an electronic medium. Added to this is a paucity of rigorous clinical outcome studies to demonstrate the efficacy of performing successful treatment via this delivery method. The aim of this thesis was to establish the efficacy of telemedicine as a clinical tool for physiotherapists. To achieve this, the first major undertaking was the development of a telemedicine system to meet the unique needs of clinical physiotherapists and their patients. A series of studies was then performed to calibrate the system and establish its validity and reliability as a clinical assessment tool. Finally, a randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The telemedicine system was constructed using a human systems development approach, with close consultation with senior clinical physiotherapists and potential users of the system. The personal computer-based system was designed to connect patients in their home with physiotherapists in the hospital, via low-speed and low-cost communications. The system incorporated real-time videoconferencing and physical measurement tools to enable the remote assessment of patients. The validity and reliability of the telemedicine physical measurement tools were established through a series of five studies. The results demonstrated these measurements to be accurate and reliable, under various measurement conditions, when compared to reference instruments. A prospective randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The research model chosen for this study was the rehabilitation of subjects who had undergone total knee replacement surgery. Block randomisation was used to assign 65 participants to either a traditional face-to-face therapy group or a telemedicine rehabilitation group. Participants in both groups received treatment over a six week period. Data analysis focussed on comparing physical and functional rehabilitation outcomes achieved in each treatment group. The results of this study demonstrated that the rehabilitation outcomes produced via the telemedicine system were similar to those achieved in the traditional manner. Additionally, the telemedicine therapy was found to produce greater improvements in a number of functional outcome measurements. A high level of satisfaction was expressed by participants who received treatment via the telemedicine method. This thesis provides evidence of the efficacy of telemedicine as a clinical tool for physiotherapists. Furthermore, the work detailed in this thesis represents one of the first randomised control trials in telerehabilitation and makes a significant contribution towards the knowledge of low-bandwidth telemedicine in general. This thesis provides a framework upon which further research and telemedicine applications may be developed, with the ultimate goal of improving equity and access to high quality health services in rural and remote areas.

High quality health services are often difficult to access in rural and remote areas of Australia. This is due to a shortage of health care professionals and specialists, inadequate and poorly distributed resources, and the tyranny of distance. The result is a reduced level of health and a higher mortality rate than seen in urban communities. Telemedicine, which is the use of various technologies to deliver a range of health care services over a distance, has the potential to increase equity and access to health care in rural and remote areas. To date there has been a poor uptake of telemedicine technology within the profession of physiotherapy. This undoubtedly stems from the perceived, and indeed, real difficulty of performing what is traditionally ‘hands on’ therapy, via an electronic medium. Added to this is a paucity of rigorous clinical outcome studies to demonstrate the efficacy of performing successful treatment via this delivery method. The aim of this thesis was to establish the efficacy of telemedicine as a clinical tool for physiotherapists. To achieve this, the first major undertaking was the development of a telemedicine system to meet the unique needs of clinical physiotherapists and their patients. A series of studies was then performed to calibrate the system and establish its validity and reliability as a clinical assessment tool. Finally, a randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The telemedicine system was constructed using a human systems development approach, with close consultation with senior clinical physiotherapists and potential users of the system. The personal computer-based system was designed to connect patients in their home with physiotherapists in the hospital, via low-speed and low-cost communications. The system incorporated real-time videoconferencing and physical measurement tools to enable the remote assessment of patients. The validity and reliability of the telemedicine physical measurement tools were established through a series of five studies. The results demonstrated these measurements to be accurate and reliable, under various measurement conditions, when compared to reference instruments. A prospective randomised controlled trial was conducted to assess the treatment efficacy of the telemedicine system. The research model chosen for this study was the rehabilitation of subjects who had undergone total knee replacement surgery. Block randomisation was used to assign 65 participants to either a traditional face-to-face therapy group or a telemedicine rehabilitation group. Participants in both groups received treatment over a six week period. Data analysis focussed on comparing physical and functional rehabilitation outcomes achieved in each treatment group. The results of this study demonstrated that the rehabilitation outcomes produced via the telemedicine system were similar to those achieved in the traditional manner. Additionally, the telemedicine therapy was found to produce greater improvements in a number of functional outcome measurements. A high level of satisfaction was expressed by participants who received treatment via the telemedicine method. This thesis provides evidence of the efficacy of telemedicine as a clinical tool for physiotherapists. Furthermore, the work detailed in this thesis represents one of the first randomised control trials in telerehabilitation and makes a significant contribution towards the knowledge of low-bandwidth telemedicine in general. This thesis provides a framework upon which further research and telemedicine applications may be developed, with the ultimate goal of improving equity and access to high quality health services in rural and remote areas.