No-vision walking is supported in the central nervous system (CNS) by a spatial updating process. This process involves the iterative updating of a mental representation of the environment using estimates of distance traveled gleaned from locomotive kinematic activity. An effective means of examining the online regulation of this process is a continuous pointing task, which requires performers to walk along a straight-line forward trajectory while keeping their right arm straight and index finger fixated on a stationary ground-level target beside the walking path. In the current thesis, no-vision continuous pointing was examined in typically calibrated and recalibrated perceptual-motor states. Shoulder and trunk joint angles provided the basis for perceptual measures that reflected spatial updating performance and kinematic measures that reflected its underlying CNS online regulation. In the typically calibrated conditions, no-vision walking demonstrated a slight perceptual underestimation of distance traveled (Study 1). In the recalibrated conditions, no-vision walking demonstrated: a) perceptual underestimation and overestimation following adaptation periods involving walking with low and high visual gains, respectively (Study 2); and b) partial recalibration following exposures to vision and arm gains (Study 3). The latter was suggested as being impacted by task specific changes in CNS multisensory integration resulting from the development of a robust task prior and/or the altering of sensory cue weights. Importantly, this thesis used a novel trajectory parsing procedure to quantify discrete CNS perceptual updating units in the shoulder plane of elevation trajectory. The starts and ends of these updating units were consistently timed to the late left-to-early right foot swing phase of the step-cycle, regardless of perceptual-motor state. This was suggested to reflect perceptual units that were purposely timed, but indirectly mapped, to this kinematic event. The perceptual differences in Studies 1 and 2 were at least partially reflected in these units. / Thesis / Doctor of Philosophy (PhD) / It is well understood that humans can effectively walk without vision to environmental locations up to 15 metres away. However, less is known about how these walking movements are controlled during the course of forward progression. This thesis fills this knowledge gap using a task that requires participants to walk forward along a straight path while keeping their right index finger pointed toward a ground-level target beside the walking path. The patterns of arm movements performed during this task are indicative of the control strategies used by the performer to mentally update their positions in space. One of the key contributions of this work is showing that humans perform this mental updating in a repetitive manner, and that these repetitions are consistently linked to early forward movements of the right leg. This pattern is maintained when walking without vision is performed in a variety of different contexts.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第25283号 / 工博第5242号 / 新制||工||1998(附属図書館) / 京都大学大学院工学研究科航空宇宙工学専攻 / (主査)教授 藤本 健治, 准教授 丸田 一郎, 教授 大塚 敏之, 教授 青井 伸也(大阪大学) / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Bipedal locomotion in humanoid robots is a very challenging problem within the field of robot locomotion. In this thesis, we propose and demonstrate an omni-directional walking engine that achieves stable walking using feedback from an inertial measurement unit. Our walking engine generates gaits for which the zero moment point is on the center of the supporting foot. The mechanical structure of CHARLI-L, a humanoid robot used as our test platform in this thesis, is first introduced by describing the inverse kinematics of its legs. The principles of the omni-directional gait generator that creates walking motions and overcomes the robot's mechanical deficiencies is discussed. We develop and implement two kinds of feedback controllers; one is the gait feedback controller and the other is the joint feedback controller. Both feedback controllers use proportional-derivative of the angle of the pelvis from an inertial measurement unit. The results of the experiments are presented the efficacy of our proposed walking engine. / Master of Science

No description available.

Thesis (MScPhysio)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: BACKGROUND: A functional gait forms an integral part of life, allowing individuals to function within their environment and participate in activities of daily living. The evaluation of gait forms an essential part of a physical examination and can help screen for physical impairments. To the researchers‟ knowledge no 3D gait analysis studies of this nature have been conducted in South Africa. South African gait analysis laboratory protocols and procedures may differ from laboratories in other countries; therefore a South African data base of normative values is required to make a valid assessment of South African children‟s gait. OBJECTIVE: The aim of this study is to describe kinematics and spatiotemporal parameters of gait of typically developed children between the ages of 6-10 years in the Cape Metropole of the Western Cape, South Africa. METHODOLOGY: A descriptive study was conducted. Twenty-eight typically developed children were conveniently sampled from aftercare facilities and schools were performed in the Cape Metropole in the Western Cape, South Africa. The three-dimensional (3D) lower limb kinematics and spatiotemporal parameters of gait were analyzed. For data capture, the lower limb Plug-in-Gait (PIG) marker placement was used. Participants were asked to walk bare footed at self-selected speed. Due to a small sample size, children were also sub-divided into two groups (Group A: 6-8 years and Group B: 9-10 years) for comparison. Means and standard deviations (SD) were calculated for all outcomes, followed by statistical tests to determine significant differences between the two sub-groups for spatiotemporal parameters and kinematics. RESULTS: There was a significant difference between the sub-groups for all the non-normalized spatiotemporal parameters. A statistical significant difference between the sub-groups for the mean hip rotation minimum values (p=0.036) was found. There was no significant difference between the sub-groups for any other kinematic parameter or when comparing the normalized spatiotemporal parameters. CONCLUSION: This study provides descriptive gait parameters that can be used for comparison or gait analysis purposes. Our results suggest that normalized spatiotemporal parameters showed no significant difference between the age groups and are consistent with international children‟s spatiotemporal parameters. Kinematic values showed significant changes with hip rotation. Older children had more external rotation at their hips. KEYWORDS: 3D gait analysis, walking, children, spatiotemporal parameters, kinematics. / AFRIKAANSE OPSOMMING: INLEIDING: „n Funksionele stap is „n essensiële deel van die lewe wat mens toelaat om in jou omgewing te funksioneer en om deel te neem aan daaglikse aktiwiteite. Evaluasie van stap is „n belangrike deel van die fisiese evaluasie en kan help om te sif vir fisiese verswakking of abnormaliteite. So ver hierdie navorsers weet, is hierdie die eerste loop analise studie van sy soort wat in Suid-Afrika onderneem is. Suid-Afrikaanse stap-evaluasie-labrotorium protokols en prosedures mag ook dalk verskil van die in ander lande. Dus is „n Suid-Afrikaanse databasis vir normale waardes van loop nodig om „n gegronde evaluasie van Suid-Afrikaanse kinders se loopgang te kan maak. DOELWIT: Die doel van hierdie studie is om die kinematika en spatiotemporale parameters van loop te omskryf in tipies ontwikkelde kinders tussen die ouderdom van 6-10 jaar in die Kaapse Metropool en om die bevindinge tussen die twee ouderdomsgroepe te vergelyk. METODE: „n Beskrywende studie is uitgevoer. Ag-en-twintig tipies ontwikkelde kinders is van skole en nasorgfasiliteite in die Kaapse Metropool in die Wes-Kaap, Suid-Afrika gewerf. Die drie-dimensionele (3D) onderste ledemaat se kinematika en spatiotemporale parameters van loop is geanaliseer. Vir data insameling is die onderste ledemaat Plug-in-Gait (PIG) merker-plasing gebruik. Deelnemers is gevra om kaalvoet teen hulle eie spoed te stap. Die kinders is in die verskeie ouderdomsgroepe verdeel, maar as gevolg van klein toetsgroepgetalle, is hulle sub-verdeel in twee groepe (Groep A: 6-8 jaar en Groep B: 9-10 jaar). Beskrywende statistiese tegnieke is gebruik vir alle uitkoms maatreëls. Gemiddeldes en standaardafwykings (SA) was bereken, om beduidende verskille tussen die ouderdomsgroepe en sub-groepe te bepaal. RESULTATE: Daar is „n beduidende verskil tussen die jonger en ouer kinders vir nie-genormaliseerde spatiotemporale parameters, asook „n beduidende verskil tussen die sub-groepe vir die gemiddelde heuprotasie minimum waardes (p=0.036). Daar was geen beduidende verskil tussen die twee groepe met die ander kinematiese parameters of met genormaliseerde spatiotemporale parameters van die sub-groepe nie. GEVOLGTREKKING: Hierdie studie verskaf beskrywende statistiese data van stap-parameters wat gebruik kan word vir vergelyking met ander kinders van dieselfde ouderdomme of loop-analise doeleindes. Ons bevindinge stel voor dat genormaliseerde spatiotemporale parameters geen beduidende bevindings aandui tussen die verskeie ouderdomsgroepe nie. Dit is ook konsekwent met internasionale kinders se spatiotemporale parameterwaardes. Kinematisie waardes het beduidende verskille in heuprotatsie getoon. Ouer kinders het meer eksterne rotasie in hulle heupe in vergelyking met jonger kinders. Soos die kinders ontwikkel, verminder die heup-anteversie en die heup beweeg vanaf interne rotasie na „n relatiewe eksterne rotasie.

published_or_final_version / Human Performance / Master / Master of Philosophy

published_or_final_version / Nursing Studies / Master / Master of Nursing

Dynamic stability is commonly defined as the ability to maintain balance through center of mass control during locomotion. Patients with locomotor impairments are especially challenged when walking over uneven surfaces (Richardson 2004). We studied dynamic stability margins in young healthy adults and in adults with unilateral traumatic trans-tibial amputations (TTA). To date, studies have not controlled for walking speed over an uneven surface in a patient population. We hypothesized that: 1) DSMs would increase over the uneven rocky surface (URS) for both groups, 2) DSMs would be greater on the involved side at faster walking speeds for subjects with TTA and, 3) DSMs would increase more for the involved limb when on the URS. 17 (4 females, 13 males) young healthy military service members (22.8 ± 6.4 years) and 12 (1 female, 11 males) service members (27.2 ± 4.7 years) with traumatic unilateral trans-tibial amputations participated in two study designs. A 15-segment model was used to estimate whole body COM motions. All subjects walked at 5 dimensionless speeds over a flat level surface (FLS) and an URS. Subjects completed 6-10 trials over each surface at each speed. Minimum frontal plane DSM values were extracted for each stride for statistical analyses. For young healthy subjects a two factor (speed x surface) ANOVA was used to test significance (p<.05). The DSMs were not greater over the URS (p=.307), but a main effect due to speed was found (p<.001) for young healthy subjects. In contrast, DSMs were significantly larger when subjects with TTA walked on the URS compared to the FLS (p = 0.011). For subjects with unilateral TTA, a three-factor ANCOVA ((amputation) side x speed x surface) with residual limb length (p=.029) and time in prosthesis (p=.741) as covariates was used for hypothesis testing. When limb length and time in prosthesis were accounted for there was no significant within subjects effect due to speed (p=.656). There were no significant differences between involved and uninvolved limbs (p = 0.211). There were no significant interaction effects. In conclusion, there was a difference in DSMs due to speed in unimpaired subjects and due to surface and residual limb length in subjects with unilateral TTAs. In subjects with unilateral TTA side-to-side symmetry was found for DSM measures, which was in contrast to an earlier study of subjects with unilateral trans-femoral amputations (Hof 2006). It appears that symmetry and dynamic stability are reasonable expectations for young adults with isolated TTAs. / text

Background: Treadmill walking should closely simulate overground walking for research validation and optimal skill transfer. Traditional fixed-speed treadmill (FS) walking may not simulate natural walking because of the fixed belt speed and lack of visual cues. Self-paced (SP) treadmill walking, especially feedback controlled SP treadmill walking, enables close-to-real-time belt speed changes with users' speed changes. Different sensitivity levels of SP treadmill feedback determine how fast the treadmill respond to user's speed change. Few studies have examined the differences between FS and SP treadmill walking, or the difference between sensitivity levels of SP treadmills, and their methods were questionable because of averaging kinematics and kinetics parameters, and failing to examine directly treadmill and subjects' speed data. This study compared FS with two SP modes with variation of treadmill speed and user's speed as dependent variables. Method: Thirteen young healthy subjects participated. Subjects walked on a motorized split-belt treadmill under FS, high sensitivity SP (SP-H) and low sensitivity SP (SP-L) conditions at normal walking speed. Root mean square error (RMSE) for subject's pelvis global speed (Vpg), pelvis speed with respect to treadmill speed (Vpt), and treadmill speed (Vtg) data were collected for all trials. Results: Significant condition effects were found between FS and the two SP modes in all RMSE values (p < 0.001). The two sensitivity levels of SP had similar speed patterns. Large subject × condition interaction effects were found for all variables (p < 0.001). Only small subject effects were found. Conclusions: The results of the study reveal different walking patterns between FS and SP. However, the two sensitivity levels failed to differ much. More habituation time may be needed for subjects to learn to optimally respond to the SP algorithm. Future work should include training subjects for more natural responses, applying a feed-forward algorithm, and testing the effect of optic flow on FS and SP speed variation. / text

3 pp. / Pedometers are small devices worn at the hip to count the number of steps walked per day. Pedometers gained popularity as a tool for motivating and monitoring physical activity. The purpose of the publication was to provide basic mechanisms and functions of pedometers. Additionally, we provided information of new technology (cell phone and Google Maps) that are emerging as a tool for motivating physical activity.