Purpose: The purpose of this dissertation was to determine the effects of chronic plantar fasciitis on intrinsic foot structures with respect to biomechanics, muscle atrophy and muscle energetics. This was accomplished in three parts. Methods: In Part I, a three-dimensional motion capture system with a synchronized force platform quantified multi-segment foot model kinematics and ground reaction forces associated with walking. Healthy individuals were compared to individuals with chronic plantar fasciitis feet. Typical kinematic variables, measures of coupling, phase and variability were examined in rearfoot, forefoot and hallux segments. In Part II, foot and leg magnetic resonance images were taken in subjects with unilateral plantar fasciitis so that within each subject, the healthy limb could be compared to the plantar fasciitis limb. Cross sectional areas (CSA) of the plantar intrinsic foot muscles (PIFM) and tibialis posterior muscle were computed from user-digitized images. In Part III, the metabolic demands of the PIFM were evaluated using phosphorous magnetic resonance spectroscopy at rest and after barefoot walking. Muscle pH and the ratio of inorganic phosphate to phosphocreatine (Pi/PCr) were compared in healthy and plantar fasciitis feet. Results: In comparison to healthy feet, plantar fasciitis feet exhibited significantly (p < 0.05): 1) greater rearfoot motion, 2) greater sagittal plane forefoot motion, 3) fewer rearfoot-forefoot frontal anti-phase movements, 4) reduced rearfoot-forefoot transverse coordinative variability, 5) greater first metatarsophalangeal (FMPJ) joint dorsiflexion, 6) greater FMPJ-medial longitudinal arch (MLA) coupling variability, and 7) decreased vertical ground reaction forces at propulsion. Also, plantar fasciitis feet had 5.2% smaller PIFM CSA at the forefoot compared to contralateral healthy feet. No CSA differences were seen in the rearfoot PIFM or at the tibialis posterior muscle. The PIFM of healthy and PF feet were not significantly different in resting intracellular levels of pH or Pi/PCr, and there were no significant differences in the increase of Pi/PCr from rest to postwalking. Conclusions: In Part I, it was concluded that plantar fasciitis feet exhibit kinematics which are consistent with theoretical causation of the plantar fasciitis injury, that is, the plantar fasciitis foot exhibits excessive motion. Fewer number of anti-phase movements exhibited by plantar fasciitis feet may be an indication of pathology. The ground reaction force results suggested a compensatory pain response. In Part II, it was concluded that atrophy of the forefoot PIFM may destabilize the medial longitudinal arch and prolong the healing process. Lastly in Part III, it was concluded that resting energetics were consistent with muscle free of systemic disease or neuromuscular pathology. The presence of plantar fasciitis did not elicit systematic asymmetries in the metabolic response in comparison to healthy feet. Clinical Relevance: These kinematic results provided some evidence to support the clinical assertion that excessive motion is related to plantar fasciitis. These results also support treatment modalities which clinicians currently use to reduce rearfoot eversion, flattening of the medial longitudinal arch and dorsiflexion of the FMPJ (e.g. foot orthoses, insoles, taping, rocker soles). When treating plantar fasciitis patients, clinicians should assess for PIFM and tibialis posterior muscle atrophy and prescribe targeted exercises when appropriate.

The foot/ankle complex (particularly the hindfoot) is frequently injured in a wide array of debilitating events, such as car crashes. Numerical models have been used to assess injury risk, but most are minimally validated and do not account for variations in ankle posture that frequently occur during these events. The purpose of this study was to develop an accurate finite element (FE) model of the foot and ankle that accounts for these positional changes. The bone positions and load path in the foot and ankle were quantified throughout its natural range of motion. CT scans were taken of a male cadaveric leg in five postures in which fractures are commonly reported, while strains were recorded by strain gauges attached to the hindfoot bones in response to quasi-static, sub-failure loading. Substantial variations in bone displacements, rotations and strains were observed for all postures tested, highlighting the need for an FE model that accounts for these positional changes. The CT scans were used as the basis of an FE model of the foot and ankle that was developed using TrueGrid® and LS-Dyna® software. The model met rigorous mesh quality criteria, and its properties were optimized to best represent the experimental plantar tissue compression and surface strains. The model was evaluated by comparing its bone position and strain responses to the experimental results in each posture. The fracture thresholds and locations in each posture were estimated and were similar to those reported in the literature. The least vulnerable posture was neutral, and the talus and calcaneus exhibited the lowest fracture thresholds in all postures. This work will be useful in developing improved injury limits for the ankle and postural guidelines to minimize injury. The model can be used to evaluate new protective systems to reduce the occurrence of lower leg injuries. / Thesis / Master of Applied Science (MASc) / Ankle fractures are common occurrences that can lead to severe disability. Safety evaluations of the lower leg are often performed using computer models in a neutral ankle posture, which may underestimate the fracture tolerance in altered postures. The purpose of this study was to develop a computer model of the ankle that accounts for these changes. A cadaveric leg was used to determine how the locations of and strains in the bones of the foot and ankle varied as ankle posture was adjusted. A computer model of the lower leg and ankle was developed, and its accuracy was evaluated by comparison with the experimental results. The least vulnerable posture was neutral, and the hindfoot bones were the most likely to experience fracture in all postures. This model can be used in the future to evaluate new protective systems and develop comprehensive injury criteria for these altered postures.

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Foot posture is an important characteristic that can affect kinematics, plantar loading, and injury risk. Arch height is one common aspect of foot posture, and it is estimated that about 60% of the population has normal arches while 40% of the population is either pes planus or pes cavus. It is important to be able to accurately and reliably assess foot posture characteristics in order to propose interventions that could prevent injuries due to abnormal foot alignment. However, despite multiple classification metrics, many of the devices that are commonly used for foot posture measurements are not economically feasible for smaller clinics or research labs. Therefore, the first purpose of this study was to develop an affordable device to measure different foot posture characteristics. The Foot Posture Measurement System was developed and can measure total foot length, truncated foot length, foot width, dorsum height, and navicular height. This system was shown to have good to excellent validity (ICC = 0.908-0.994) and repeatability (ICC = 0.867-0.996) when compared to a 3D scanner. This device was then used in the second portion of this study, which evaluated the effects of ankle braces on plantar loading patterns in individuals with different foot postures. Contact area, peak force, force-time integral, and center of pressure were evaluated during a walk, run, and cut while the participant was unbraced, wearing a lace-up stabilizer brace, and wearing a semi-rigid brace. It was demonstrated that arch height did affect the maximum plantar forces during all tasks (p=0.001-0.047), as hypothesized based on previous studies. Additionally, this study found that ankle braces affected contact area (p=0.001-0.0014), maximum force (p<0.001 – p=0.043), and force-time integral (p<0.001 – p=0.015) during the walk, run, and cut. This is a novel finding and points to the potential for an impact of ankle braces on plantar loading during athletic activities, independent of foot type. / Master of Science / Foot posture is an important characteristic that can affect daily life and contribute to the risk of injury. Arch height is one common aspect of foot posture, and it is estimated that about 60% of the population has normal arches while 40% of the population is either high arched or low arched/flat footed. It is important to be able to accurately and reliably assess foot posture characteristics in order to propose interventions that could prevent injuries due to abnormal foot alignment. However, despite multiple classification metrics, many of the devices that are commonly used for foot posture measurements are not economically feasible for smaller clinics or research labs. Therefore, the first purpose of this study was to develop an affordable device to measure different foot posture characteristics. The Foot Posture Measurement System was developed and can measure five different length, width, and height characteristics of the foot. This system was shown to be valid when compared to a 3D scanner and repeatable between days. This device was then used in the second portion of this study, which evaluated the effects of ankle braces on individuals with different foot postures. Four different force and pressure variables were examined within the foot during a walk, run, and cut while the participant was unbraced, wearing a lace-up stabilizer brace, and wearing a semi-rigid brace. It was shown that arch height did alter plantar loading measures during all tasks, as hypothesized based on previous studies. Additionally, this study found that ankle braces affected all variables during the walk, run, and cut. This is a novel finding and points to the potential for an impact of ankle braces on plantar loading during athletic activities, independent of foot type.

Foot placement prediction can be important for exoskeleton and prosthesis controllers, human-robot interaction, or body-worn systems to prevent slips or trips. Previous studies investigating foot placement prediction have been limited to predicting foot placement during the swing phase, and do not fully consider contextual information such as the preceding step or the stance phase before push-off. In this study, a deep learning-based foot placement prediction approach was proposed, where the deep learning models were designed to sequentially process data from three IMU sensors mounted on pelvis and feet. The raw sensor data are pre-processed to generate multi-variable time-series data for training two deep learning models, where the first model estimates the gait progression and the second model subsequently predicts the next foot placement. The ground truth gait phase data and foot placement data are acquired from a motion capture system. Ten healthy subjects were invited to walk naturally at different speeds on a treadmill. In cross-subject learning, the trained models had a mean distance error of 5.93 cm for foot placement prediction. In single-subject learning, the prediction accuracy improved with additional training data, and a mean distance error of 2.60 cm was achieved by fine-tuning the cross-subject validated models with the target subject data. Even from 25-81% in the gait cycle, mean distance errors were only 6.99 cm and 3.22 cm for cross-subject learning and single-subject learning, respectively / Master of Science / This study proposes a new approach for predicting where a person's foot will land during walking, which could be useful in controlling robots and wearable devices that work with humans to prevent events such as slips and falls and allow for more smooth human-robot interactions. Although foot placement prediction has great potential in various domains, current works in this area are limited in terms of practicality and accuracy. The proposed approach uses data from inertial sensors attached to the pelvis and feet, and two deep learning models are trained to estimate the person's walking pattern and predict their next foot placement. The approach was tested on ten healthy individuals walking at different speeds on a treadmill, and achieved state-of-the-arts results. The results suggest that this approach could be a promising method when sufficient data from multiple people are available.

A retrospective study was performed to determine the prevalence of foot pathologies of horses subjected to magnetic resonance imaging for foot lameness and to determine the long-term outcome of horses after medical treatment. The MR studies of 95 horses were interpreted retrospectively by a boarded certified radiologist. Follow-up information was obtained from medical records, owners and referring veterinarians via telephone questionnaires. Long term response to treatment (minimum of 12 months) was recorded. Horses were divided in two different groups based on the diagnosis and on the treatment using intrasynovial antiinflammatory drugs or not. Logistic regression analysis was performed to compare the outcome between the two groups. The null hypothesis was that the proportion of horses treated successfully between treatment protocols was similar. A diagnosis based on magnetic resonance imaging was made in all horses. Approximately 30% of horses had ≥ 4 lesions, which were determined to be responsible for the lameness and 70% of horses had navicular bone abnormalities. Treatment was determined by individual clinician judgment. No significant difference was found in the long-term outcome between treatment groups. This result suggests that intrasynovial antiinflammatory drugs may not provide additional benefit over corrective shoeing, rest followed by controlled exercise in horses with lesions of structures associated with the navicular apparatus or the distal interphalangeal joint. / Master of Science

This paper has been undertaken, first, to contribute several more cases of various congenital anomalies to the literature on human genetics, and, second, by an analysis of the genealogies, to determine the possible modes of transmission of these anomalies.

Yes / Purpose: Clubfoot is a common disabling condition that is prevalent across all populations. Approximately, one out of 750 children globally suffers from clubfoot, and around 150,000 to 200,000 children are born with clubfoot every year with 80% of the cases occurring in developing countries. Clubfoot can result in mobility impairments when not properly managed and researchers have argued that understanding knowledge and perceptions are key components to early identification and effective management of clubfoot. The study explored the barriers to clubfoot management from the perspectives of caregivers and healthcare providers in Duayaw Nkwanta, Ghana. Methods: A total of 26 participants made up of 22 caregivers of children with clubfoot and six healthcare providers were purposively sampled for the study guided by a set of inclusion and exclusion criteria. Qualitative data were collected using a semi-structured interview guide through in-depth face-to-face interviews. Interviews were transcribed and analyzed thematically and presented as findings. Results: High cost of treatment, long travel distance, long hours spent at the treatment facility, non-availability of clubfoot treatment services, late reporting of clients for treatment, and non-compliance of parents/caregivers with treatment protocols were identified as the barriers to effective management of clubfoot. Conclusion: These findings have substantial implications for current interventions to effectively manage clubfoot in Ghana.

Yes / Background: When trans-tibial amputees cross obstacles leading with their prosthesis, foot clearance is achieved using compensatory swing-phase kinematics. Such compensation would suggest able-bodied individuals normally use swing-phase ankle dorsiflexion to attain adequate obstacle clearance, however, direct evidence of such contribution is equivocal. The present study determined the contribution of sagittal plane ankle motion in achieving lead-limb clearance during obstacle negotiation. Methods: 12 male able-bodied individuals (ages 18-30) completed obstacle crossing trials while walking on a flat surface. Lead-limb (right) ankle motion was manipulated using a knee-ankle-foot orthosis. Trials were completed with the ankle restricted at a neutral angle or unrestricted (allowing ~ ±15  plantar/dorsiflexion). Findings: Restricted ankle motion caused significant increase in trail-limb foot placement distance before the obstacle (p=0.005); significant decrease in vertical toe clearance (p<0.003), vertical heel clearance (p=0.045) and lead-limb foot placement distance after the obstacle (p=0.045); but no significant changes in knee angle at instant of crossing or in average walking speed. Interpretation: The shifts in foot placements altered the part of swing that the lead-limb was in when the foot crossed the obstacle, which led to a decrease in clearance. These adaptations may have been due to being unable to dorsiflex the ankle to ‘lift’ the toes in mid-swing or to being unable to plantarflex the ankle during initial contact following crossing, which changed how the lead-limb was to be loaded. These findings suggest individuals using ankle bracing or those with ankle arthrodesis, will have reduced gait safety when negotiating obstacles.