Walking and running are essential tasks people take for granted every day. However, these are highly complex tasks that require significant neural control. This is complicated by the inherent redundancy of the nervous system and by physiological noise. Humans may adopt different control strategies to achieve different goals (environmental or task specific). More specifically, walking/running on a treadmill only requires that one not walk off the treadmill. Of the many possible strategies that can achieve this goal, humans attempt to maintain a constant speed from each stride to the next (Dingwell, John et al. 2010). However, how humans alter the stride-to-stride regulation of their gait when the task goals change (e.g., by maintaining stride length and/or time, during running, or during a predicted walk to run transition speed) has not yet been demonstrated. In the first two of three experiments conducted, healthy adults either walked or ran on a motorized treadmill at a comfortable speed under the following conditions: constant speed, constant speed with the stride length goal (targets on the treadmill), constant speed with the stride time goal (metronome), or constant speed with both stride length and stride time goals. In a third experiment, subjects walked and/or ran at a comfortable speed and also at their predicted theoretical walk to run transition speed. Goal functions derived from the task specifications yielded new variables that defined fluctuations either directly relevant to, or irrelevant to, achieving each goal. The magnitude of the variability, as well as the stride-to-stride temporal fluctuations in these variables, were calculated. During walking, subjects exploited different redundancy relationships in different ways to prioritize certain task goals (maintain stride speed) over others (maintain stride length or stride time) in each different context. In general, subjects made rapid corrections of those stride-to-stride deviations that were most directly relevant to the different task goals adopted in each walking condition. Thus, the central nervous system readily adapts to achieve multiple goals simultaneously. During running, subjects exhibited similar adaptations to walking, but over-corrected to prioritize maintaining stride speed even more strongly. This suggests that stepping control strategies adapt to the level of perceived risk. This purposeful adaptability of these stride-to-stride control strategies could be exploited to developing more effective rehabilitation interventions for patients with locomotor impairments. During the predicted walk-to-run speeds, subjects were able to largely exploit the redundancy within task goal, and effectively operated at “uncomfortable” speeds. These results suggest that the stride speed control is robust even with additional novel tasks and uncomfortable, abnormal speeds of locomotion. / text

There has been a growing interest in promoting active transportation as an effective route to address the issues caused by the heavy reliance on motorized modes. Walking, as a unique form among all types of active transportation mode, is highly accessible and easy to be incorporated into every trip. A number of distinct benefits of walking deserve special mention. Among the whole transport system, walking is a fundamental and integral part linking various elements of trip together, irrespective of public or private modes. Besides, walking offers people an opportunity for regular physical activity that contributes to substantial health benefits. In order to identify how built and social environmental attributes influence on walking, four communities in Hong Kong with different physical and/or social characteristics were selected as case study. First hand data was collected by on-site questionnaire survey, together with objective assessments towards neighborhood walkability and condition of socio-economic disadvantage, the influences of physical and social factors on the level of walking were examined. For the study on walking intensity, individual characteristics including gender and income were found to be better predictors for the level of walking intensity. Among environmental determinants, the perceptions of pedestrians towards neighborhood walkability might be particularly important to predict one’s intensity of walking activity. Besides, positive association was observed between health condition and the level of walking activity. In terms of the study exploring the concordance between perceived and objective walkability, a moderate concordance between dual environmental measurements was found. The results of the study revealed that pedestrians’ perceptions towards neighborhood walkability might be crucial influencing one’s propensity and intensity. / published_or_final_version / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

Problem: Walking cadence (steps/minute) is used to prescribe walking intensity. For healthy adults, the recommended cadence is generally 100 steps per minute to reach moderate intensity. However, the required walking cadence to reach that intensity for people having risk factors for cardiovascular diseases (CVD) is unknown. Methods: Ninety-one people presenting risk factors for CVD completed a graded exercise test to assess maximum oxygen consumption. In a separate session, when participants reached moderate intensity based on their maximum oxygen consumption, walking cadence was recorded. Results: Mean walking cadence to reach moderate intensity was 115.8 ± 10.3 steps per minute. Using linear regression analysis, only body weight (ß=0.24; P=0.018) significantly predicted the walking cadence required to reach moderate intensity. Conclusions: The walking cadence needed for people presenting risk factors for CVD to reach moderate intensity is about 116 steps per minute. Body weight influences the walking cadence needed to reach moderate intensity. / October 2015

The components and alignment of a prosthesis have a large influence on the gait of an above knee amputee. The present criteria for determining the optimum alignment are mainly subjective, based on visual observation of the amputee's gait and by considering his/her comments. These comments however, are not always helpful. It has been reported that a range of alignments is acceptable to the patient and to the prosthetist, and it is believed that the optimum alignment can be selected from the range of acceptable alignments using biomechanical analysis. The socket is an important component in an above knee prosthesis and can affect the gait of the amputee. While the conventional socket is the quadrilateral, several problems have been reported with this type of socket. These include instability in the coronal plane, discomfort and restriction of the stump muscles causing limitations in the function of the prosthesis. In an attempt to overcome these problems the ischial containment (IC) socket was introduced in 1985. The biomechanical characteristics of the IC socket have, however, not been objectively assessed and compared with those of the quadrilateral socket. In this study, the effect of alignment adjustments on the gait variables for eight above knee amputees wearing quadrilateral sockets was investigated. Three of these amputees were also tested wearing IC sockets. The alignment of the prosthesis was systematically changed at the ankle, knee and socket. The primary aim of this project was therefore, to systematically vary the alignment of the prosthesis and to study the effects on the gait, and to compare the performance of amputees wearing IC and quadrilateral sockets. The ultimate goal of this research work is to provide a method for the determination of the optimum alignment from a range of acceptable alignments. A socket axis locator and a coordinate measuring system were used for measuring the prosthetic alignment accurately. Three TV cameras and two Kistler force plates were operated simultaneously and synchronously at a rate I of 50 Hz to acquire the displacements of the body segments and the ground reaction forces. All angular movements at the joints, moments and the temporal-distance parameters were calculated for both the prosthetic and the sound legs of the amputees, and for the right and left legs of ten normal subjects. The movement of the upper body was also recorded. Computer programs were developed to calculate and graphically present the above parameters in three dimensions. It was found that alignment changes affected the gait parameters of the whole body. At the prosthetic joints, certain changes in the alignment of the prosthesis resulted in specific alterations in the gait pattern. These effects were repeatable. The anterior-posterior (AP) joints moments and the fore-and-aft ground reaction force were found to be the most sensitive variables to alignment changes. The trunk rotations in the AP and medio-lateral planes, and the torso rotation in the transverse plane were also found to be sensitive to alignment changes, and the trunk was the main compensating element for any misalignment. At the sound side, the alignment changes resulted in noticeable changes in the AP joints moments and fore-and-aft ground reaction force. In the coronal and transverse planes, changes in the gait patterns that were analysed were not always consistent. These changes mainly depend on the method of compensation which is adopted by the patient. The IC socket showed improvements in the patient's performance in terms of higher speed of walking, comfort, improved symmetry in the two legs and the gait parameters are more comparable with those of normals.

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Imagine the anatomy of architecture as a complex system, where the form is the result of generative processes, the material properties of the components, and their patterns of assembly. Within this paradigm, surface is that part of the system which exchanges energy, information, and materials with the local environment. How does human occupation of a space offer energy, information, or material to the system-building, and how can the surface best vector these exchanges? Walking could represent human occupation in this context. I choose my walker’s lineage and declare my interest, as an architect, in empathetic space. I explore the history of bipedalism, of the path as an architectural object, and of the sciences, philosophies and poetries of walkers. And I browse through contemporary architectural discourse pertaining to emergent design methodologies. Along the way, I test my proposal in two experiments: one complete, and one in progress...

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Though the biomechanics of level walking have been studied extensively, the adaptations required for cross-slope locomotion are still largely unknown despite being a common terrain characteristic. The goals of this thesis were to determine (1) ground reaction forces (GRF) and moments (GRM), (2) lower-limb kinematics, and (3) lower-limb joint reaction forces (JRF) and moments (JRM) during level and cross-slope walking. Statistical analyses were made across limbs (down-slope (DS) and up-slope (US)) and across slope condition (level (0°) and cross-slope (6°)) (2X2 ANOVA). Ten healthy male volunteers performed several barefoot walking trials. The lower-limbs responded asymmetrically to the cross-slope condition by substantially changing (1) the medio-lateral GRF, (2) the sagittal and frontal plane kinematics as well as step-width, and (3) the medio-lateral JRF and frontal plane JRM. The modest cross-slope induced important asymmetrical changes in locomotor patterns and may represent a substantial physical obstacle to populations with restricted mobility.

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