In response to the potential benefits of task specific training in rehabilitation of gait after stroke and the need for affordable, simple ways to implement it, our group designed the elliptically based robotic gait trainer (EBRGT). A design review of the EBRGT, covering the design goals, an overview of the mechanical and electrical design, and a discussion of the novelty of the device and why it may be beneficial for individuals with hemiparesis secondary to stroke is discussed (Chapter 2). To characterize the new device, a study was performed to determine if the EBRGT produced a gait pattern that mimicked level surface walking in healthy adults (chapter 3). Sagittal plane kinematic analysis suggested the EBRGT produced joint movement patterns that are similar to level surface walking at the hip and knee with less similarity between activities at the ankle. Electromyography (EMG) revealed that the EBRGT induced a cyclic muscle firing pattern that had some similarities when compared to level surface walking. We also examined the feasibility of ambulatory individuals after stroke to use the EBRGT and if their movement patterns were similar to healthy adults walking on the same device (Chapter 4). All six participants were able to walk on the device with minimal assistance. These participants had joint kinematics and EMG similar to healthy adults, suggesting that individuals with hemiparesis perform a gait like movement when using the EBRGT. Lastly, a study was performed to determine if the EBRGT could improve gait parameters and function in ambulatory individuals with hemiparesis after stroke (chapter 5). Four participants walked on the EBRGT 3x/week for 4 or 8 weeks. After the intervention, all 4 participants increased their preferred gait speed. One participant had an improvement in gait speed that indicated functional gains. The results of this research suggest that the EBRGT can produce a gait pattern that has some similarities to level surface walking and that it is feasible for ambulatory individuals with hemiparesis to use the device. The device may also improve gait parameters in ambulatory individuals after stroke, but future studies with a control group need to be performed.

The intent of the following research is to utilize task-specific, constraint-induced therapies and apply towards dynamic training for symmetrical balance. Modifications to an elliptical trainer were made to both measure weight distributions during dynamic stance as well as provide kinetic biofeedback through a man-machine interface. Following a review of the background, which includes research from several decades that are seminal to current studies, a design review is discussed to cover the design of the modified elliptical (Chapter 2). An initial study was conducted in a healthy sample population in order to determine the best visual biofeedback representation by comparing different man-machine interfaces (Chapter 3). Index of gait symmetry measures indicated that one display interface optimized participant performance during activity with the modified elliptical trainer. A second study was designed to determine the effects of manipulating the gain of the signal to encourage increased distribution towards the non-dominant weight bearing limb. The purpose of the second study was to better understand the threshold value of gain manipulation in a healthy sample set. Results analyzing percentage error as a measure of performance show that a range between 5-10% allows for a suitable threshold value to be applied for participants who have suffered a stroke. A final study was conducted to apply results/knowledge from the previous two studies to a stroke cohort to determine short-term carryover following training with the modified elliptical trainer. Data taken from force measurements on the elliptical trainer suggest that there was carryover with decreased error from pre to post training. For one participant GaitRite® data show a significant difference from pre to post measurements in single limb support. The results of the research suggest that visual biofeedback can improve symmetrical performance during dynamic patterns. For a better understanding of visual biofeedback delivery, one display representation proved to be beneficial compared to the others which resulted in improved performance. Results show that healthy human participants can minimize error with visual biofeedback and continue minimizing error until a threshold value of 10%. Finally, results have shown promise towards applying such a system for kinetic gait rehabilitation.

京都大学 / 新制・論文博士 / 博士(人間健康科学) / 乙第13484号 / 論人健博第10号 / 新制||人健||7(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 黒木 裕士, 教授 青山 朋樹, 教授 髙橋 良輔 / 学位規則第4条第2項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM

Decreased gait symmetry has been correlated with an increased fall risk, abnormal joint loading and decreased functional outcomes. Therefore, symmetry is focused on in the rehabilitation of many patient populations. Currently, load based symmetry is collected using expensive and immobile devices that are not clinically accessible, but there is a clinical need for an objective measure of loading symmetry during daily tasks like walking. Therefore, the purpose of this dissertation was to 1) assess the validity and reliability of the loadsol® to capture ground reaction force data, 2) use the loadsol® to determine the differences in symmetry between adults with a TKA and their healthy peers and 3) explore the potential of a commercially available biofeedback system to acutely improve gait symmetry in adults. The results of this work indicate that the loadsol® is a valid and reliable method of collecting loading measures during walking in both young and older adults. TKA patients who are 12-24 months post-TKA have lower symmetry in the weight acceptance peak force, propulsive peak force and impulse when compared to their healthy peers. Finally, a case study with four asymmetric adults demonstrated that a 10-minute biofeedback intervention with the loadsol® resulted in an acute improvement in symmetry. Future work is needed to determine the potential of this intervention to improve symmetry in patient populations and to determine whether the acute response is retained following the completion of the intervention. / Doctor of Philosophy / Symmetry during walking is a valuable attribute as asymmetry has been correlated with an increased fall risk and decreased mobility. Currently, load based symmetry is collected using expensive and immobile devices that are not clinically accessible. As a result, there is a critical need for a system that can objectively measure load and loading symmetry during rehabilitation and everyday tasks in a variety of settings. A new device has been developed (loadsol®) that could potentially fill this need. Before it can be used to assess and treat patients, the loadsol® needed to be assessed for accuracy and reliability in both older and younger adults and at various speeds. Then we needed to determine if the loadsol® can be used to look at the levels of symmetry in patients who have had a knee replacement compared to their healthy peers. Finally, we tested a visual biofeedback intervention with the loadsol® to see if this intervention was able to improve symmetry. We found that the loadsol® is accurate and reliable. Patients with a knee replacement were less symmetric than their age matched peers. Finally, in a small study, the visual biofeedback intervention improved symmetry during walking in a group of people with less than 90% symmetry. Future work is needed to explore the potential of this biofeedback intervention to improve symmetry in various patient populations and to determine the extent to which patients are able to retain these improvements.

Clinicians working on motor skill learning interventions often find that improvements observed during training are not sustained and do not transfer to very similar tasks. Research suggests that strategies such as real-time biofeedback and learner's focus of attention seem to facilitate motor skill learning. However, research on the implications of these strategies in rehabilitation is limited and has not been investigated in healthy individuals. The motor learning effects of these strategies need to be assessed as they offer the possibility of enhancing rehabilitation regimens. The purpose of this study was to investigate the generalizability of real-time biofeedback and learner's focus of attention to a treadmill gait retraining program aimed at correcting knee hyperextension insidious gait patterns in healthy young women. Assessing the acquisition, retention, and transfer of kinematic improvements was the focus of this study. 1.Knee sagittal plane kinematics could be influenced with dynamic gait training using real-time biofeedback. Gained proficiency in controlling knee hyperextension during treadmill training was evident during overground walking immediately and 1 month after training. 2.The effectiveness of real-time biofeedback in improving performance does not seem to be influenced by the focus of attention, internal or external, induced during treadmill training. Participants in both intervention groups improved in a similar way as a consequence of practice. However, there were trends in the data that pointed that the external focus of attention group had better long-term retention. It is not known if participants actively switched to an external focus of attention despite the instructions provided during training. Tests to ensure instructional compliance should be used. 3.A treadmill gait retraining program using learner's focus of attention indicated that that there were not differences in learning acquisition, short and long-term retention, and transfer to overground walking and obstacle crossing between intervention groups. It is not known if these changes persist beyond the 4-month follow-up included in this study. The results of this study will help to reduce knee hyperextension gait patterns in women. Future studies may also use the methodology used in this study to further investigate the implications of learner's focus of attention in rehabilitation. Similarly, the findings of this study could offer an additional strategy for rehabilitation regimens.

Title: Neuro Biomechanical principles in robot-assisted gait training for pediatric patients Background: There is a lack of data on how robot-assisted gait training (RAGT) contributes to gait changes in children with cerebral palsy (CP). Methods: This research study investigated efficacy of a 4-week RAGT intervention in twelve ambulatory spastic diparesis children with CP (10.8±2.6 years old; 2 girls and 10 boys; Gross Motor Function Classification System I-III) by using computerized gait analysis (CGA); passive joint range of motion (PROM); selective control assessment of lower limbs evaluation (SCALE), and the six-minute walk test (6MWT). Pre-post RAGT intervention data of children with CP was compared with the normative data curves of typically developing children by cross-correlation, and further statistically evaluated by a Wilcoxon test. Results: Significant pre-post RAGT intervention differences (p<0.05) that indicate more physiological gait comparing to the normative data curves were found. Biceps femoris, rectus femoris, and tibialis anterior decreased activity almost across all gait cycle phases. Medial gastrocnemius decreased activity mainly in terminal stance, mid-swing, and terminal swing phases. Internal hip rotations and foot progress angles decreased almost across all gait cycle...