Title: Fylogenetic aspects of human locomotion Objectives: To find fylogenetic connection between human locomotion and animal locomotion as animal are considered to be our predecessors. Methods: Study and analysis of accessible literary sources. The results gained in the research will be generalized and used to find the fylogenetic connection of human and animal locomotion. Results: Similar locomotive principles happened to be found in connection with first vertebrates, amphibians, birds, mammals and humans. The need for presence of punctum fixum was also found to implement the crossed motion model. There were summarized necessary adaptations to bipedal human locomotion. Key words: punctum fixum, kvadrupedal crossed model, human locomotion, motion, development

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A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy / This thesis is a study of quantifiable variation in the geometric shape of the superior articular surface of the talus of higher primates, with special reference to fossil tali of Plio- Pleistocene hominids. (Abbreviation abstract ) / AC2017

本論文以表面肌電（Surface Electromypgraphy, SEMG）信號中動態信號能被獲取為前提，把被處理過的表面肌電信號轉變成步態參數 (gait parameters). 我們利用一些便攜式步態測量裝置，如加速度計，陀螺儀和腳踏開關和表面肌電圖測量裝置去採集步態參數。信號的處理和生物信息（身體的動態特性）轉換都加以討論和解釋，如濾波和預測肌肉的收縮等。 / 我們利用被採集步態參數作步態分析，並發現表面肌電信號內的動態信號的頻率特性能夠代表運動過程中的非恆久步態參數，如行走時的足部擺動的期間 (period of swing phase)、行走時的足部站立的期間 (period of stance phase) 和行走時的步幅期間 (period of stride)。 / 最後，我們發現可以利用線性預測 (linear prediction) 和閾值分析 (threshold analysis) 處理表面肌電信號以便獲得三種非恆久步態參數。根據我們的觀察，行走時足部擺動的期間可以被股直肌（rectus femoris, RF）的表面肌電信號捕獲，行走時的步幅期間可以被二頭肌股（bicep femoris, BF）的表面肌電信號捕獲，而行走時的足部站立的期間則可由BF和RF輸出的結果的平均值所捕獲。因此，表面肌電信號是可以作為一種獲取非恆久步態參數的工具。 / Electromyography (EMG) signal is an important quantity for describing the muscle’s activities and provides additional information in describing movement and locomotion in gait analysis. Surface electromyography (SEMG) measurement is a non-vivo technology for acquiring EMG signal. During the measurement of SEMG signals, the motion artifact is captured. Filters are applied to eliminate the frequency characteristics of motion artifact. However, this unwanted signal could be useful for obtaining the temporal gait parameters during the movement, such as the period of swing phase, the period of stance phase, and the period of stride of free walking. / In this study, accelerometers, gyroscopes and foot switches are used for the acquisition of kinematics and surface electromyography is used for measuring muscle’s activities. These measurement devices are evaluated in a gait study on lower extremity. The signal processing and conversion of bio-information (the dynamic characteristics of body) are discussed, such as filtering, and the prediction of muscle’s contraction. / Lastly, temporal gait parameters could be captured by SEMG measurement with the linear prediction process and threshold analysis. From the results, it is observed that the swing period can be captured through the SEMG measurement for rectus femoris (RF), the stride period can be captured by the SEMG measurement for bicep femoris (BF), and the stance period can be captured by the averaged result of the outputs of BF and RF. Thus, SEMG measurement could be a tool for capturing temporal gait parameters. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chan, Chi Chong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 67-69). / Abstracts also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Literature Review --- p.1 / Chapter 1.2 --- Objectives --- p.5 / Chapter 1.3 --- Thesis Description --- p.5 / Chapter 2 --- Description for Wearable Gait Measurement --- p.7 / Chapter 2.1 --- Wearable Sensors --- p.8 / Chapter 2.2 --- Surface Electromyography (SEMG) --- p.12 / Chapter 2.3 --- Processing Unit --- p.15 / Chapter 2.4 --- Hardware Connection and Communication --- p.16 / Chapter 2.5 --- Summary --- p.20 / Chapter 3 --- Gait Analysis for Lower Extremity during Walking --- p.21 / Chapter 3.1 --- Gait Parameters Captured by Wearable Sensors --- p.21 / Chapter 3.1.1 --- Foot Switch: Walking Phase Detection --- p.22 / Chapter 3.1.2 --- Gyroscope: Frequency Response of Lower Limbs during Walking --- p.24 / Chapter 3.1.3 --- Accelerometer: Knee Joint Angle Estimation during Walking --- p.30 / Chapter 3.2 --- Analysis of Muscle Activities by SEMG signals --- p.36 / Chapter 3.3 --- Summary --- p.42 / Chapter 4 --- Temporal Gait Parameters during Walking by SEMG Measurement --- p.43 / Chapter 4.1 --- Motion Event and SEMG Signals --- p.43 / Chapter 4.2 --- Walking Phase Detection by SEMG Signals --- p.49 / Chapter 4.3 --- Temporal Gait Parameters --- p.53 / Chapter 4.4 --- Summary --- p.62 / Chapter 5 --- Conclusions, Contributions and Future Work --- p.63 / Chapter 5.1 --- Conclusions --- p.63 / Chapter 5.2 --- Contributions --- p.64 / Chapter 5.3 --- Future Work --- p.65 / Bibliography --- p.67

La marche humaine nécessite la génération de force propulsive ainsi que des forces antigravitaires pour maintenir l’équilibre. Pour cela, le système nerveux central est requis d’orchestrer la contraction des muscles des membres inférieurs, notamment les fléchisseurs plantaire de la cheville qui interface entre le sol et le corps humain. Durant la première phase de simple appui, le triceps sural (TS) est en contraction excentrique et son activation aide à soutenir le corps en résistant à la rotation du tibia sur le Tarsus. Par contre, la phase finale de simple appui est marquée par une augmentation des forces de réactions au sol « Push-off », du couple articulaire de la cheville et de l’activité électromyographique du TS. Le rôle du TS durant la phase finale de simple appui est l’objet de débat dans la littérature, où certains lui attribut le rôle de propulseurs et d’autre de soutien du corps. Dans ce travail, nous postulons que l’augmentation de l’activité du TS en phase finale de simple d’appui sert uniquement à décélérer la chute du centre de masse. En outre, nous postulons que la modulation temporelle de l’activité du TS permet de contrôler la cinématique (cadence et longueur de pas) et la cinétique de la marche. Deux études ont été mises en places pour tester les hypothèses de travail. Des données biomécaniques mesurées à partir d’une plateforme de force et l’activité EMG du soléaire et des gastrocnémiens latéral et médial de la jambe d’appui ont été collecté pour les deux études. Dans la première études des volontaires ont initié la marche sans et avec un ajout de poids de 20 kg attaché au niveau de la ceinture abdominale. L’ajout du poids augmente les forces de propulsion. Une augmentation de l’activité EMG du triceps permettrait de comprendre si le triceps participe à la génération de force propulsive. La deuxième étude est composée de deux expérimentations. Dans la première expérimentations des volontaires ont accompli 3 conditions de initiation de marche à vitesse variée tout en maintenant la longueur de pas constante. Dans la deuxième expérimentation, les sujets ont été incliné et instruit de récupérer leur équilibre en exécutant un pas de longueur différente. Les résultats ont montré que : 1) le triceps ne participe pas au push-off mais freine la chute du centre de masse en phase finale de simple appui. 2) L'amplification d’activité électromyographique durant la marche rapide est due à l’augmentation de demande de support de corps causé par la croissance des forces inertiels du corps. 3) La durée de contraction du TS permet de déterminer la cadence et la longueur de pas, donc la cinématique de la marche. La durée d’activité du TS permet aussi de déterminer la position du centre de masse par rapport au centre de pression au moment du contact avec le sol. 4) Ceci permet au TS de moduler le couple de déséquilibre responsable des forces propulsives, donc la cinétique de la marche. / Human gait necessitates the generation of both propulsive force to propel the body forward and anti-gravitational force to maintain dynamic postural equilibrium. This requires the central nervous system to orchestrate lower limb muscles. Notably the CNS has to control ankle plantar flexors activity as the whole body rotates around the ankle, which in turn interfaces with the external environment. From early to middle stance, triceps surae (TS) contracts eccentrically thus resisting tibial rotation around the tarsus. However, late stance is marked by an increase in ground reaction forces, commonly known as « Push-off », in ankle torque and electromyographic activity of TS. The role of triceps surae during late stance is object of debate in the literature. Some believe it is responsible for the push-off other insist it is sole role is to maintain dynamic postural equilibrium. In this work, we postulate that the increase in TS activity in late stance is to decelerate vertically the fall of the centre of mass. We further hypothesise that temporal modulation of TS activity determines global gait kinematics (cadence and step length) and kinetics. Two studies have been conducted to test the work hypotheses. Ground reaction force data gathered from a large force platform and EMG activity of soleus, medial and lateral gastrocnemius of stance was measured using surface electrodes. In the first study, subjects initiated gait with and without an added mass of 20 kg attached around the waist. Adding the weight increases propulsive force. If TS activity increases as well than it is responsible for generating propulsive force. The second study is composed of two experiments. In the first volunteers performed gait initiation at three different walking velocity conditions while maintain step length constant. In the second experiment, subjects were inclined and asked to recuperate their equilibrium by performing a step. They were asked to perform three step lengths. Results showed that: 1) Triceps does not participate in push-off but brakes the fall of the centre of mass during late single stance. 2) Increasing TS EMG activity in late stance is due to an increase in the requirement of maintaining dynamic postural equilibrium. 3) Control over the duration of TS activity determines cadence and step length and thus the kinematics of gait. Temporal modulation of TS also sets the position of centre of mass with respect to centre of pressure at the moment of foot-contact. 4) By controlling the distance between the two, the CNS modulates the disequilibrium torque that is responsible for propulsive force and thus the kinetics of gait.

One of the difficulties of human figure tracking is that humans move their bodies in complex, non-linear ways. An effective computational model of human motion could therefore be of great benefit in figure tracking. We are interested in the use of a class of dynamic models called switching linear dynamic systems for figure tracking. This thesis makes two contributions. First, we present an empirical analysis of some of the technical issues involved with applying linear dynamic systems to figure tracking. The lack of high-level theory in this area makes this type of empirical study valuable and necessary. We show that sensitivity of these models to perturbations in input is a central issue in their application to figure tracking. We also compare different types of LDS models and identification algorithms. Second, we describe 2-DAFT, a flexible software framework we have created for figure tracking. 2-DAFT encapsulates data and code involved in different parts of the tracking problem in a number of modules. This architecture leads to flexibility and makes it easy to implement new tracking algorithms.

Motor control of any movement task involves the integration of neural, muscular and skeletal systems. This integration must occur throughout the sensorimotor system and focus its efforts on controlling the system endpoint, e.g. the foot during locomotion. A person with a uni-lateral trans-tibial amputation has lost the foot, ankle joint, and muscles crossing those joints, hence the residuum becomes the new terminus of the motor system. The amputee must now adjust to the additional challenges of utilizing a compromised motor system as well as the challenges of controlling an external device, i.e. prosthesis, through the mechanical interface between the residuum and prosthetic socket. The obvious physical and physiologic asymmetries between the sound and amputated limbs are also involved in strategies for locomotion involving kinematic and kinetic asymmetries (Winter&Sienko, 1988). There are many questions as to why these asymmetric locomotor strategies are selected and what factors may be influencing that strategy. Factors influencing a change in locomotor strategy could be related to 1) the central nervous system accounting for the loss of sensorimotor feedback, 2) the altered mechanics of this new human/prosthetic system, or some combination of these factors. Understanding how the human motor system adjusts to the amputation and to the addition of an external mechanical device can provide useful insight into how robust the human control system may be and to adaptations in human motor control. This research uses a group of individuals with a uni-lateral trans-tibial amputation and a group of intact individuals using an Ankle Foot Orthosis (AFO) performing a cycling task to understand the "motor adjustments" necessary to utilize an external device for locomotion. Results of these experiments suggest 1) the motor system does account for the activation-contraction dynamics when coordinating muscle activity post amputation, 2) the motor system also changes joint kinetics and muscle activity, 3) these changes are related to control of the interface between the limb and the external device, and 4) the motor system does not alter kinetic asymmetries when kinematic asymmetries are minimized, contrary to a common practice in rehabilitation (Kapp, 2004). Results suggest that control of the external device, i.e. prosthesis or AFO, via the interface between the limb and the device reflect "motor adjustments" made by the nervous system and may be viewed in the context of tool use. Clinical goals in rehabilitation currently focus on minimizing gait deviations whereas the clinical application of these results suggest these deviations from normal locomotion are motor adjustments necessary to control a tool, i.e. prosthesis, by the motor system. Examining amputee locomotion in the context of tool use changes the clinical paradigm from one designed to minimize deviations to one intended to understand this behavior as related to interface control of the device thereby shifting the focus to improving function of the limb/prosthesis system. Kapp SL. (2004) Atlas amp limb def: surg pros rehab princ. 3rd ed: 385 - 394. Winter&Sienko. (1988) J Biomech, 21: 361 - 367.

Title: Kinesiological analysis of the rowing stroke on a single scull and on a rowing ergometer Concept 2 comparison Purposes: The purpose of the present study was to determine a specific structure in timing of selected muscles during two movement patterns - rowing on a single scull and rowing on an ergometer Concept 2. Methods: By surface electromyography we recorded muscular activity, synergies and involvement throughout mean cycle of the rowing stroke. Results: The mutual correlations of mean EMG curves of all measured muscles showed, that there were not found any differences in inter-locomotive synchronization of selected muscles. Established values of correlation (r) showed higher level of dynamic balance (performance similarity between both measured activities. Determination of the muscular activity timing considering onsets and cessations, was in the percentual results explication of the movement cycle inter-locomotive different. Conclusion: Results showed a great similarity in synergies organizing the muscular coordination in between both measured physical activities. But timing of the movement was different in the moments of muscular activity onsets during rowing and during ergometer rowing. This may be attributed to the specificity of on-water locomotion. Key words: Rowing, Concept 2,...

Title: Kinesiological analysis of the rowing stroke on a single scull and on a rowing ergometer Concept 2 comparison Purposes: The purpose of the present study was to determine a specific structure in timing of selected muscles during two movement patterns - rowing on a single scull and rowing on an ergometer Concept 2. Methods: By surface electromyography we recorded muscular activity, synergies and involvement throughout mean cycle of the rowing stroke. Results: The mutual correlations of mean EMG curves of all measured muscles showed, that there were not found any differences in inter-locomotive synchronization of selected muscles. Established values of correlation (r) showed higher level of dynamic balance (performance similarity between both measured activities. Determination of the muscular activity timing considering onsets and cessations, was in the percentual results explication of the movement cycle inter-locomotive different. Conclusion: Results showed a great similarity in synergies organizing the muscular coordination in between both measured physical activities. But timing of the movement was different in the moments of muscular activity onsets during rowing and during ergometer rowing. This may be attributed to the specificity of on-water locomotion. Key words: Rowing, Concept 2,...