Thesis (M.S.)--Michigan State University, 2005. / Includes bibliographical references (leaves 53-55)

Thesis (M.S.)--Michigan State University, 2005. / Includes bibliographical references (leaves 53-55). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.M.E.)--University of Delaware, 2007. / Principal faculty advisor: Jill S. Higginson, Dept. of Mechanical Engineering. Includes bibliographical references.

A dissertation presented in partial compliance with the requirements for the Master's Degree in Technology: Chiropractic, Technikon Natal, 2001. / The purpose of this study was to evaluate the relative effectiveness of chiropractic manipulation alone compared to chiropractic manipulation in conjunction with gastrocnemius and soleus stretching in the treatment of subacute and chronic grade I and II ankle inversion sprains / M

No abstract Provided / Thesis / Master of Science (MSc)

Ankle sprains are one of the most common type of sports injury. They occur most frequently when the foot is in a supine or inverted position. Recovery from an ankle sprain can take from one and up to 26 weeks depending on the severity of the injury. During that period the individual will be unable to participate in any meaningful sports activity and as such it is important to be able to prevent the occurrence of such injuries. Prevention of ankle sprain injuries would require a better understanding of the risk factors of this injury. Several studies attempted to assess such risk actors by inducing foot inversion or supination however the platforms used in these studies were shown to be limited. Hence the main aim of this project is to develop a system that can be used to assess the effect of sudden foot and ankle inversion/supination on the musculoskeletal system of dynamic subjects (e.g. walking, running, jumping, etc.). For this purpose a three degrees of freedom (DOF) rotating platform has been designed, manufactured and installed in the Institute of Motion Analysis and Research (IMAR) Sports Laboratory. The platform rotates around 3 different axes allowing inversion or supination of the foot and ankle of dynamic subjects. The degree of rotation around each axis can easily be set by the researcher/operator. A strain gauge was used to detect foot strike to the platform. As a safety measure laser emitter/receivers check that the entire foot is on the footplate before the platform rotates. Optical encoders provide essential feedback of rotation angles, speed and acceleration. The necessary software and user interface for controlling the platform were also written and tested. The platform was synchronised with a bilateral four-channel EMG (electromyography) system and a 12 camera Vicon® MX-13 system thus allowing measurement of muscle activity and kinematic data during the supination of the foot. A set of software modules were written to allow automated management and processing of the data generated by the new system. The new system was then implemented in a study to validate it and to assess the role of shoes in ankle sprains. In this study, subjects would walk in three different foot conditions: barefoot, and with two different types of sports shoes, along the walkway of the Sports Laboratory where the platform was fitted. When a subject steps on the embedded platform, it rotates causing the subject's foot to supinate. At the same time, the EMG data from the peroneus longus, tibialis anterior, and lateral gastrocnemius muscles are recorded, along with the kinematics of the subject's whole body. The obtained results demonstrated the validity of the newly developed system. Data from the validation study also revealed increased muscle activity following induced foot supination in shod conditions compared to barefoot. Muscle activity of the rotating platform step was found to be significantly higher than the steps before and after. The platform rotation was also found to have an observable effect on body kinematics. The newly developed system is hoped to help provide a better understanding of the risk factors of ankle sprain injury and how to prevent this injury. The system can be used to help improve the design of current footwear and identify which footwear provides better protection against ankle sprain injury. The system can also be used to assess the effectiveness of different ankle injury rehabilitation schemes and different training programs that aim to reduce ankle sprain injuries. The new system can be utilised to identify individuals who are at risk of sustaining an ankle sprain injury. The system can also be utilised in studies outside the scope of ankle sprain injuries.

abstract: It has been repeatedly shown that females have lower stability and increased risk of ankle injury when compared to males participating in similar sports activities (e.g., basketball and soccer), yet sex differences in neuromuscular control of the ankle, including the modulation of ankle stiffness, and their contribution to stability remain unknown. To identify sex differences in human ankle stiffness, this study quantified 2- dimensional (2D) ankle stiffness in 20 young, healthy men and 20 young, healthy women during upright standing over a range of tasks, specifically, ankle muscle co-contraction tasks (4 levels up to 20% maximum voluntary co-contraction of ankle muscles), weight-bearing tasks (4 levels up to 90% of body weight), and ankle torque generation tasks accomplished by maintaining offset center-of-pressure (5 levels up to +6 cm to the center-of-pressure during quiet standing). A dual-axial robotic platform, capable of perturbing the ankle in both the sagittal and frontal planes and measuring the corresponding ankle torques, was used to reliably quantify the 2D ankle stiffness during upright standing. In all task conditions and in both planes of ankle motion, ankle stiffness in males was consistently greater than that in females. Among all 26 experimental conditions, all but 2 conditions in the frontal plane showed statistically significant sex differences. Further analysis on the normalized ankle stiffness scaled by weight times height suggests that while sex differences in ankle stiffness in the sagittal plane could be explained by sex differences in anthropometric factors as well as neuromuscular factors, the differences in the frontal plane could be mostly explained by anthropometric factors. This study also demonstrates that the sex differences in the sagittal plane were significantly higher as compared to those in the frontal plane. The results indicate that females have lower ankle stiffness during upright standing thereby providing the neuromuscular basis for further investigations on the correlation of ankle stiffness and the higher risk of ankle injury in females. / Dissertation/Thesis / Masters Thesis Biomedical Engineering 2020

Rocker profiles are one of the most commonly prescribed footwear modifications provided to individuals with impaired rollover. Impaired rollover is caused due to loss of neuromuscular function (i.e. stoke) or orthotic ankle constraint. When rollover is impaired, continued forward progression is interrupted and walking gait becomes less efficient (i.e. increased energy expenditure). Rocker profile footwear modifications are designed to mimic the functions of the anatomical ankle-foot rockers and provide its users with a smooth and efficient rollover. However, while there is theory governing the design of a rocker profile and subjective descriptions of rocker profile function, the extent to which a rocker profile footwear provides rollover has not yet been quantified. The aim of this study was to quantify effective and ineffective rollover and test whether our rocker profile provides effective rollover. We hypothesized that healthy subjects (n=4) walking with orthotic ankle constraint and the rocker profile (STOP) would have no change in rollover and energy expenditure outputs compared to walking with orthotic ankle free and rocker profile (FREE); but that healthy subjects (n=4) walking in STOP would have a change in rollover and energy expenditure outputs compared to walking with orthotic ankle constraint and no rocker profile (STOP-NR). To test this hypothesis, rollover was quantified as stance phase duration, cadence and radius of curvature and energy expenditure was quantified as heart rate and rating of perceived exertion. In addition to these outputs, we analyzed the ground reaction forces and duration of stance in early, middle and late stance period to determine the effects of the rocker profile footwear components. Through the rollover and energy expenditure outputs of the STOP, FREE and STOP-NR conditions, we quantified effective rollover as 0.29 (0.01) radius of curvature with a heart rate of 110.5(6.7) bpm and ineffective rollover as 0.69(0.12) radius of curvature with a heart rate of 131.5 (8.1) bpm. By creating this scale, we were able to determine that our rocker profile provided effective rollover (0.34[0.04] radius of curvature with a heart rate of 111.3[8.3] bpm). However, a future study with a greater sample size is needed to confirm these results.

A central concept in Evolutionary theory is the character trait. It provides a context in which to explore differences and similarities among taxa, both extant and extinct. It is expanded in scope in Evolutionary Developmental theory to functional units with a biological role, "evolutionarily stable configurations." The talo-crural joint is such a configuration, a highly canalized structural unit in primates forming the interface between organism, and foot and substrate. It is a microcosm in which to examine the relationship of shape with environment and function and the interplay of genetics, ontogeny, and use. Geometric Morphometric analysis of landmark data was employed in studying the articular surfaces of the talus in a diverse sample of adult specimens in nine catarrhine taxa. The influence of four factors on talar shape was examined: superfamily, a proxy for phylogeny; size and mass, a proxy for physical attributes; and substrate preference, a proxy for behavior. All significantly affected shape, and substrate preference was unrelated to the others. Appositional articular morphology, the shape of the subchondral bone surfaces of the talo-crural joints in an expanded sample of 12 taxa, showed a significant effect of the four proxies on the tibial and talar components, and substrate preference was weakly related to the other proxies in each. Singular Warp analysis of the cross-covariance matrices of the joints demonstrated sorting of taxa by substrate use and signals of convergent and divergent evolution among hominoids and cercopithecoids in joint shape. The ontogeny of the appositional articular shape was examined using adult and subadult specimens grouped by molar eruption. Singular Warp analysis demonstrated a genetic signal in the subadults, strongest in the slowly maturing African hominoids, and an epigenetic signal across taxa to substrate use in the adults. The talo-crural joint, a highly canalized, modular, and integrated "evolutionarily stable configuration," provides a model for the study of the evolution of shape. The epigenetic signal observed is consistent with plasticity or developmental plasticity in response to the interaction of the joint complex with the environment due to a behavioral effect, substrate use. This dissertation included previously unpublished, co-authored material.

No description available.