Altering a Runner’s Foot strike using a Modified Elliptical Trainer

One possible solution to common running related injuries is to transition runners from a rearfoot strike during initial contact to a midfoot strike. Natural rearfoot strike runners were studied to see if a modified elliptical trainer could be used to alter their running pattern to that of a midfoot strike runner. Their results were compared to subjects who ran on a non-modified elliptical trainer. After training on the modified elliptical trainer, subjects demonstrated a decrease in foot angle at initial contact when attempting to run with a midfoot strike. Training did not affect all kinetic metrics or stride frequency. However, the kinematic change suggests that there may be an impact on running energetics. Training on the modified elliptical trainer resulted in improved midfoot strike kinematics in natural rearstrike runners when they attempted run in a midfoot strike pattern

Vibrotactile Sensory Augmentation and Machine Learning Based Approaches for Balance Rehabilitation

Vestibular disorders and aging can negatively impact balance performance. Currently, the most effective approach for improving balance is exercise-based balance rehabilitation. Despite its effectiveness, balance rehabilitation does not always result in a full recovery of balance function. In this dissertation, vibrotactile sensory augmentation (SA) and machine learning (ML) were studied as approaches for further improving balance rehabilitation outcomes. Vibrotactile SA provides a form of haptic cues to complement and/or replace sensory information from the somatosensory, visual and vestibular sensory systems. Previous studies have shown that people can reduce their body sway when vibrotactile SA is provided; however, limited controlled studies have investigated the retention of balance improvements after training with SA has ceased. The primary aim of this research was to examine the effects of supervised balance rehabilitation with vibrotactile SA. Two studies were conducted among people with unilateral vestibular disorders and healthy older adults to explore the use of vibrotactile SA for therapeutic and preventative purposes, respectively. The study among people with unilateral vestibular disorders provided six weeks of supervised in-clinic balance training. The findings indicated that training with vibrotactile SA led to additional body sway reduction for balance exercises with head movements, and the improvements were retained for up to six months. Training with vibrotactile SA did not lead to significant additional improvements in the majority of the clinical outcomes except for the Activities-specific Balance Confidence scale. The study among older adults provided semi-supervised in-home balance rehabilitation training using a novel smartphone balance trainer. After completing eight weeks of balance training, participants who trained with vibrotactile SA showed significantly greater improvements in standing-related clinical outcomes, but not in gait-related clinical outcomes, compared with those who trained without SA. In addition to investigating the effects of long-term balance training with SA, we sought to study the effects of vibrotactile display design on people’s reaction times to vibrational cues. Among the various factors tested, the vibration frequency and tactor type had relatively small effects on reaction times, while stimulus location and secondary cognitive task had relatively large effects. Factors affected young and older adults’ reaction times in a similar manner, but with different magnitudes. Lastly, we explored the potential for ML to inform balance exercise progression for future applications of unsupervised balance training. We mapped body motion data measured by wearable inertial measurement units to balance assessment ratings provided by physical therapists. By training a multi-class classifier using the leave-one-participant-out cross-validation method, we found approximately 82% agreement among trained classifier and physical therapist assessments. The findings of this dissertation suggest that vibrotactile SA can be used as a rehabilitation tool to further improve a subset of clinical outcomes resulting from supervised balance rehabilitation training. Specifically, individuals who train with a SA device may have additional confidence in performing balance activities and greater postural stability, which could decrease their fear of falling and fall risk, and subsequently increase their quality of life. This research provides preliminary support for the hypothesized mechanism that SA promotes the central nervous system to reweight sensory inputs. The preliminary outcomes of this research also provide novel insights for unsupervised balance training that leverage wearable technology and ML techniques. By providing both SA and ML-based balance assessment ratings, the smart wearable device has the potential to improve individuals’ compliance and motivation for in-home balance training.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/143901/1/baotian_1.pd

Towards better assessment and training of kinematics in post-stroke gait therapy

Gait impairment is common following neurological injury such as stroke. Therapists train patients based on restoring healthy motions, or kinematics, but evidence for training proper kinematics is not well-established. Because the dosage of therapy has not been well quantified, it is unclear what aspects of gait therapy are important, but simply that more therapy is likely better. However, cost restrictions prevent such intensive therapy, incentivizing value-based care. Robotic gait trainers that repetitively train a specific kinematic walking motions can potentially ease the burden on therapists and allow greater patient throughput, improving the value of therapy. Still, the cost of these trainers is only affordable to the wealthiest clinics, leaving them unavailable to the vast majority of stroke survivors. The overall goal of my research is twofold: to show the role of kinematics in gait recovery following stroke, and how these kinematics can be trained in an economical manner. My first aim focuses on design of an affordable robotic gait trainer that can adapt to an individual’s healthy gait pattern. Such a device could make robotic gait training more accessible to new markets including resource-limited hospitals and even patients’ homes. My second aim presents development of an online algorithm for producing speed-dependent reference joint trajectories that can be used for general robotic gait training applications. The goals of my third and fourth aims investigate the importance of gait kinematics using a novel longitudinal cohort approach in subacute stroke patients. I quantified the dosage of therapy using a wearable motion capture to find correlates of functional recovery, defined as gait speed. I then questioned whether gait speed was sufficient to define gait recovery, taking an innovative look at how gait quality during this subacute period changes as gait function improves. I expect these aims will justify the importance of kinematics and suggest that wearable sensors can become a valuable tool for monitoring detailed kinematic motion, providing insight for more effective therapy regimens.Mechanical Engineerin

Understanding Movement and its Influence on Tribology of the Human Hip

Total hip arthroplasty is one of the most successful and innovative medical procedures developed during the 20th century. Success post-op has been shown to decrease for younger, more active patients when compared to those who are older and less active, raising concerns surrounding the reasons behind the increased risk of prosthesis failure for some individuals. Sliding distance, cross-shear, load and edge loading are important factors when determining potential wear rates at the hip. Global and local hip biomechanics were calculated for eighteen healthy subjects, completing thirteen common daily activities. Results showed variation in cross-shear motion and hip reaction forces between individuals and across activities. Variation in motion paths and loading, between and within activities, suggested variation in the fluid film thickness and corresponding lubrication regimes at the joint. Walking tasks showed high levels of cross-shear and the potential for excessive wear both at initial contact and heel-off. More linear activities, such as sitting and standing, showed low cross-shear alongside a potential risk of posterior edge loading. Tribological discrepancies were shown between hip simulator input data (ISO) and measured walking data, with the ISO cycle potentially underestimating cross-shear wear at initial contact, during walking. Results provide detailed data that may facilitate improvements in the reliability of pre-clinical testing for hip prostheses and tissue engineered cartilage substitution. The data indicates that durability testing standards should consider incorporating a range of activities, rather than just walking, and aim to represent the variability shown between individuals. Results also provide evidence for determining the appropriateness of specific activities/ rehabilitation for post-operative total hip replacement patients

Design and Development of a Lower Limb Rehabilitation Device for Spinal Cord Injury Patients

Introduction: Spinal cord injuries (SCI) are seen commonly in Southern Africa and can completely change the course of the affected's life. Lower limb disability is a common complication from this injury, but a patient can be rehabilitated in some cases. Research and clinical observations suggest that early mobilisation and rehabilitation leads to shorter hospital stays and better clinical outcomes. Relieving the time dedication placed onto the rehabilitation team could mean that patients receive a higher standard of care. Methods: A cyclic movement device has been designed to mimic the gait cycle that a patient is attempting to recover. The device was intended towards providing a ground reaction force simulation at the correct points of the gait cycle. The device was tested in-silico with validated skeletal models to determine joint torques and angles. In-silico testing was also utilised to determine the loads placed onto the patient by the device through its use. The force data could then be used to predict possible ground reaction forces. Results: The device allows for a gait similar trace path of the ankle, comparable to that found in the literature. The ankle has a range of motion of 3 1° as the device completes a full cycle in which the crank rotates 360 °. The hip has a range of motion of 28° and the knee 35° in this same movement. The shape of the displacements of the joints of the lower limb is comparable to that seen in researched gait patterns. However, the timing of the knee and hip joints' movements are not synchronous with that of the gait patterns. The device is validated to be sufficiently stable to use, and the motor and power components can provide the 7259N.mm of torque needed to move the model. Conclusion: The results suggest that the device has potentia l as an adjunct to rehabilitation schemes. In-silico testing showed that the device is able to simulate some of the kinetic and kinematic parameters seen in normal gait. Further work is needed to prototype the device to physically and clinically validate the device

An investigation into the effects of traditional neuromuscular training Vs rider specific training on novice rider position

The equine industry and within it, the competition rider community, is increasingly acknowledging that rider strength and fitness is vital in achieving the best results in competition. The sport of horse riding is described as unique in its posture and motion patterns and cannot be easily be compared to the actions of any other athletic endeavour. There are several factors that cause a horse to not move correctly, the most common being an unbalanced rider. Other sporting disciplines are more aware of the potential of the utilisation of additional methods to improve performance, for example Pilates is commonly used to develop optimal strength and balance in modern dance and ballet. In the absence of published work on the benefits of additional dismounted exercise on rider posture, this study aimed to determine a quantifiable measure to assess progress in the development of a novice mounted rider’s position using two different dismounted treatments to determine the key factors in promoting the benefits of a fitness programme. Students at Duchy College (n=16) were divided into two treatment groups, Rider Specific training (n=7) and Traditional Neuromuscular training (n=9) and completed the allocated training regime for 8 weeks and 5 weeks respectively between 26th January 2012 to 23rd March 2012. Measurements were taken whilst subjects were mounted on horseback before any additional training treatment was administered, riding in walk, sitting trot and rising trot as well as on a weekly basis until the fitness programmes had been completed. A final data collection session was filmed upon conclusion of the additional fitness treatments. In addition to the mounted measurements, fitness data were collected using the 20m shuttle run, resting heart rate and the sit and reach test before and after additional dismounted exercise. Each rider had 3D spherical markers attached at specific anatomical landmarks; top of hat, shoulder, hip and heel. Using Quintic Sports Biomechanics Video Analysis Software package a vertical line was drawn through the hip marker and the deviation of each marker from this line was recorded. Leg length data were collected by measuring the distance between the hip and heel marker before and after the treatment sessions. All data were collated using MS Excel software and tested for normality of distribution using an Anderson Darling test in the Minitab™ v16 statistical analysis package. If a normal distribution was present a paired t test was used to determine the extent of differences in all fitness tests and leg length pre- and post- fitness treatments. The deviations from the ear, shoulder, hip and heel (ESHH) alignment were not normally distributed. The deviation of the marker in relation to time, marker placement; gait and repeat stride were tested using a Friedman test. The comparison between rider (subject) and marker (factor) were analysed using a Kruskal Wallis test. For all statistical tests a probability of P<0.05 alpha was used. Engagement in additional dismounted exercise, either traditional neuromuscular training or rider specific training methods did not result in a significant difference in Resting Heart Rate (RHR) (t7=3.18; p>0.05) or Bleep Test (BT) (t1=2.0; p>0.05) in the rider specific training group in comparison to the traditional neuromuscular training group that showed significant difference in the (RHR) and (BT) (t5=6.15; p0.05) in the traditional neuromuscular training (6.3 ± 1.5 (cm).Both Rider Specific training showed significant improvement in rider position (P<0.005) as well improvements in the Traditional Neuromuscular training treatment (P<0.005). Each gait had a significant effect on the deviation from the ESHH alignment (N=16, H2=221.53; P<0.001). Both treatment groups demonstrated a similar significant effect (n=7, H2=133.25; P<0.001, n=9, H2=101.75; P<0.001) respectively. The deviation of markers in the rider specific training (n=7, H2=351.38; P<0.001) displayed a significant difference of each markers deviation in line with the findings of the ball sports (n=9, H2=377.48; P<0.001). Both treatments had a significant impact on mounted leg length, treatment group one, rider specific training (t6= -7.91; p=0.001) and treatment group two (t2=3.77; p<0.05) traditional neuromuscular training. This study demonstrated that additional dismounted exercise significantly (p<0.05) improves mounted rider position. It is reasonable to assume that the relationship between the treatment and decrease in deviation from the ESHH alignment is due to the general implementation of an additional exercise regime. However, the traditional neuromuscular training treatment group showed improvements at a quicker rate over the rider specific training group. The impact of personal participation was identified as a major contributing factor in using dismounted exercise in improving novice rider position and therefore assists in our understanding the role of exercise that could be most beneficial to further education equine students. Even though this study was undertaken on a relatively small sample of Further Education students, these findings suggest a role for additional team exercises in promoting fitness and improvement of mounted rider position in novice equine athletes.Thank you to the European Social Fund (ESF) for the funding to undertake the Research Masters Degree