The majority of people with stroke regard walking in their community as very important (Lord et al 2004). Walking in the community is limited by slow walking speeds and poor walking capacity (Lord et al 2004; Patterson et al 2007). Slow walking speeds and poor walking capacity are identified sequela in people with stroke (Hill et al 1997). By the end of rehabilitation approximately 80% of people with stroke achieve independent walking (Dean & Mackay 1992; Hill et al 1997). However, less than 10 percent are able to easily walk in their community (Hill et al 1997). Optimal motor learning requires task-specific practice (Carr & Shepherd 2003). Treadmills offer the opportunity for repetitive practice of complete gait cycles (Shepherd & Carr 1999), potentially providing greater intensity and longer duration walking practice than usual physiotherapy rehabilitation. Recently there has been some suggestion that high-intensity interventions may improve walking in people with stroke (Moseley et al 2005). Low levels of cardiorespiratory fitness in people with stroke have been shown to impact on walking, in particular walking capacity (Kelly et al 2003). Treadmills, commonly used to retrain cardiorespiratory fitness in the healthy population, have been used to implement high-intensity interventions, improving cardiorespiratory fitness in people with chronic stroke (Macko et al 2005). Therefore it is possible that exercise aimed at improving cardiorespiratory fitness may improve walking in people with stroke. The aim of these four studies was to investigate in those following stroke if walking on a treadmill at high-intensity during inpatient rehabilitation could improve walking capacity without compromising pattern and quality. The first study determined, in an Australian setting, the duration and intensity of usual physiotherapy rehabilitation. Study 2 compared walking pattern immediately following overground and treadmill walking practice at the same intensity. Study 3 examined the effect of treadmill walking at intensities high enough to influence cardiorespiratory fitness on walking pattern and quality. The final study, investigated the feasibility of implementing a high-intensity treadmill intervention in addition to usual physiotherapy rehabilitation in people following stroke able to walk undergoing inpatient rehabilitation. Intensity in all studies was calculated using heart rate reserve or the Karvonen method. Heart rate is a valid, accurate and stable indicator of exercise intensity due to its relatively linear relationship with oxygen consumption (ACSM 2006). For those people taking beta-blocker medication, the heart rate-lowering effect of this type of medication was accommodated. A target intensity of 40% heart rate reserve was used; as this is the minimum required improve cardiorespiratory fitness (ACSM 2006). Walking pattern and quality were measured in Studies 2-4. Walking pattern was measured by linear kinematics using GAITRite (CIR Systems, Clifton, NJ, USA) and angular kinematics using a 2-dimensional webcam application. Walking quality was determined by observation of the webcam footage and scored using the Rivermead Visual Gait Assessment, Wisconsin Gait Scale and a vertical visual analogue scale by blinded assessor. The first study found that people with stroke spent an average of 21 (SD 11) minutes participating in standing and walking activities that are associated with reaching the target intensity during physiotherapy rehabilitation. Those who could walk spent longer in these activities (25 minutes, SD 12) compared to those would couldn’t walk (17 minutes, SD 9). However, the intensity of these activities was low; walkers reached a maximum of 30% heart rate reserve and non-walkers reached 35% heart rate reserve. Using the treadmill as a mode of task-specific physiotherapy rehabilitation, the second study in this thesis found that walking pattern was similar following 10 minutes of treadmill and overground walking practice at the same intensity. The third study found that during walking on the treadmill at intensities high enough to influence cardiorespiratory fitness (up to 60% heart rate reserve), many of the linear and angular kinematic parameters moved closer to a more normal pattern and walking quality was not compromised. The final study in this thesis, a randomised controlled trial, found that a 6-week high-intensity treadmill walking intervention was feasible in people with stroke able to walk who were undergoing rehabilitation. Participants attended 89% of the treadmill sessions, reaching an average duration of more than 20 minutes and an intensity of 40% heart rate reserve after two weeks. The intervention also appeared effective with significant improvements in walking speed and capacity following the treadmill walking intervention. Improvements in walking speed were maintained at 3 months. In summary, these studies found that usual physiotherapy in people with stroke was of low intensity. In addition, it was found that treadmill walking was safe and feasible as a means of increasing the intensity of physiotherapy rehabilitation, without compromising walking quality and pattern. Therefore, it may be possible to improve walking in people with stroke using high-intensity treadmill walking.

This paper describes a representation of the dynamics of human walking action for the purpose of person identification and classification by gait appearance. Our gait representation is based on simple features such as moments extracted from video silhouettes of human walking motion. We claim that our gait dynamics representation is rich enough for the task of recognition and classification. The use of our feature representation is demonstrated in the task of person recognition from video sequences of orthogonal views of people walking. We demonstrate the accuracy of recognition on gait video sequences collected over different days and times, and under varying lighting environments. In addition, preliminary results are shown on gender classification using our gait dynamics features.

This thesis describes a representation of gait appearance for the purpose of person identification and classification. This gait representation is based on simple localized image features such as moments extracted from orthogonal view video silhouettes of human walking motion. A suite of time-integration methods, spanning a range of coarseness of time aggregation and modeling of feature distributions, are applied to these image features to create a suite of gait sequence representations. Despite their simplicity, the resulting feature vectors contain enough information to perform well on human identification and gender classification tasks. We demonstrate the accuracy of recognition on gait video sequences collected over different days and times and under varying lighting environments. Each of the integration methods are investigated for their advantages and disadvantages. An improved gait representation is built based on our experiences with the initial set of gait representations. In addition, we show gender classification results using our gait appearance features, the effect of our heuristic feature selection method, and the significance of individual features.

Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Todd D. Royer, Dept. of Health, Nutrition, and Exercise Sciences. Includes bibliographical references.

Many studies have investigated the differences in gait patterns with increasing heel height. The purpose of this investigation is to study the differences in gait patterns when wearing stiletto and wedge type high-heeled shoes with different heel designs versus barefoot walking. A Vicon 512 Motion Analysis system and four Kistler force plates were used to record changes in lower-extremity joint kinetics and kinematics in three conventional planes of motion. Additionally, electromyography (EMG) was used to assess differences in the behavior of selected muscles under each condition. Results showed that wearing of the high-heeled shoes increased vertical ground reaction forces during both early and late stance. Ankle dorsiflexion moment was significantly greater in stiletto type high-heeled shoes compared to wedge and barefoot conditions. A reduction in ankle plantar flexor moment and ankle power was observed between high heeled shoe conditions and barefoot walking during late stance. An increase in the integrated EMG values of soleus and gastrocnemius lateralis muscles was noted during stance, while gastrocnemius medialis integrated EMG values decreased in both type of high heeled shoes. Integrated EMG of tibialis anterior was also decreased throughout swing phase due to more plantarflexed foot position. Knee extension moment during late stance increased significantly in both shoe conditions. Additionally, rotational hip moments were significantly different in high-heeled shoes compared to barefoot condition during both early and late stance. Peak plantar/dorsiflexion angles as well as maximum knee flexion angles differed significantly during stance phase of walking between all conditions. Quadriceps activity was increased and prolonged throughout stance and full gait cycle to control knee flexion. There was a trend towards more severe biomechanical changes occurring in stiletto type high-heeled shoes in majority of the dependent variables. Future research should focus on the biomechanics of female gait using different designs of high heeled shoes considering the weight, age, and experience of the wearer. Furthermore, utilizing multi-segmental foot models in order to assess kinematic changes occurring in the entire foot segment and recruitment of triceps surae muscle group will provide more insight to instability of high-heeled gait in different designs of high heeled shoes.

Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 102-109). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 113-119). Also available for download via the World Wide Web; free to University of Oregon users.

The purpose of this research is to imitate the motion of the crab, and to propose a new control strategy for hexapod robots. Referring to the proportion of a real crab, we construct a 12- actuator hexapod robot. Walking experiments are achieved by using a tripod gait, a metachronal gait and a paired metachronal gait. We observe the loading of actuators and compare the functionality of the gaits. A special feed-forward gait and the Zero Torque control strategy are added in the climbing experiment. A compressed rubber-wire carpet and wire dactyl claws are used to simulate the non-slip climbing condition. Our experiment results show that the loading condition of the pendulous tripod gait is better than conventional tripod gait, and the paired metachronal gait is better than metachronal gait. During climbing experiments, our robot walks on a vertical, an upside-down, and two transitional terrains.

This thesis describes the development of a tool to assist animators in doing walk cycles. In traditional animation, animators create expressive walk cycles with key poses. The process of generating walk cycles by hand is tedious and repetitive. To help animators, many researchers in computer graphics have worked on automating gait generation. However, almost all of them used methods that eliminate animator defined key poses. Although they produce realistic results, their methods are not suitable for expressive walk cycles that can be found in cartoons. The tool described in this thesis attempts to incorporate practices of traditional animators such as comparison of key poses and the use of arc into the program interface. With this tool, animators can concentrate only on setting key poses, which is the most creative task in animating expressive walk. The gait generation program can produce highly expressive walks like the double bounce walk and the sneak. With automated features of the developed tool, animators can save time and effort when animating expressive walk along a curved path.

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Lynn Snyder-Mackler, Dept. of Physical Therapy. Includes bibliographical references.