Walking groups are increasingly being set up to increase physical activity in sedentary population groups, but little is known about whether they are effective at doing so and how they work. The present thesis aims to build an evidence base of whether walking groups are effective at promoting public health and what factors account for their effectiveness. Methods: Four studies were conducted to address the overall aim. Study One: a systematic literature review with meta-analysis investigated whether interventions to promote walking in groups are effective at promoting physical activity. Study 2: a multi-perspective thematic analysis of interviews with walkers, walk leaders and walk co-ordinators, includingfollow up interviews with walkers, explored whether the needs and expectations of people who participated in walking groups were satisfied. The sample was gained from walking schemes run by Coventry City Council. Study Three: awalk-along interview study with walk leaders explored what and how environmental factors are seen to affect walking behaviours in groups. Study Four: a prospective cohort survey explored what theoretical constructspredict maintenance of attendance at walking groups in the Midlands. Results: Study One:interventions to promote walking in groups were found to be effective at promoting physical activity within efficacy studies targeting adults (d=0.42). Study Two: walkers reported that they joined walking groups to gain social and health benefits. Three months later the same walkers reported that they continued attending walking groups when their initial needs were satisfied by the other people in the group. Walk leaders and walk coordinators often acknowledged the same reasons but expressed lack of confidence to effectively address them. Study Three: walk leaders describedenvironmental factors that were important facilitators for behaviours within walking places. Lap walking places were reported to facilitate physical activity, park walking places were reported to facilitate social interactions and city centre walking places were reported to facilitate time efficient behaviours. Study Four: recovery self-efficacy and satisfaction with outcome expectancies and overall experiences within the groups were found to predict maintenance of attendance at walking groups. ix Conclusions:The results of this thesis suggest that walking groups increase physical activity. Furthermore, successful walking groups should include theory based techniques to promote behaviour change and social integration within participants. The outcomes of this thesiscan be used as an evidence base for developing, implementing and evaluating effective walking groups within the community.

Research has highlighted that adolescent girls are insufficiently active which has serious implications for their current and future health. Walking is recognised as an effective way of implementing regular, health enhancing physical activity (PA) into the daily routine of the general population and in an adolescent population walking is a convenient alternative to active play and sports participation. However it is currently difficult to promote walking and walking initiatives with adolescent girls due to lack of well-established evidence regarding both the quantity and quality of walking that might be advocated to promote PA and health. Therefore the aim of this thesis was to provide step based guidelines with regard to both the quantity and quality of walking required for health and thus inform walking interventions in adolescent girls. In order to achieve this aim four studies were undertaken. Study one explored the most appropriate way to assess walking activity, specifically whether walking on a treadmill accurately replicates walking overground in adolescent girls. Treadmill walking was found to overestimate the metabolic cost of walking in this population. This indicated that studies with the aim of exploring or promoting moderate intensity walking should focus on overground walking. Study 2 explored the quality of walking (steps·min-¹) required to achieve moderate intensity physical activity (MPA) overground. The influence of different anthropometric measures on step rate (steps·min-¹) equating to MVPA were also compared. Results suggest that a generic step rate of 120 steps·min-¹ and 7200 steps in 60 minutes may be advocated to achieve MPA in adolescent girls. However inter-individual variation in step rate associated intensity was observed and it was suggested that a step rate range based on the girl’s body mass may be beneficial for use with adolescent girls. Study 3 considered the most appropriate step measurement instrument to assess free-living walking. Five commercially available instruments (activPAL™ and pedometers; Omron HJ-720-ITC, Omron HJ-304-E, New Lifestyles NL-1000, Yamax CW-701) were compared to direct observation hand-tally step counts, during continuous (study 3a) and incidental (study 3b) walking overground. The New lifestyles NL-1000 was most consistently accurate in quantifying steps and ‘activity time’ during continuous walking, but not during incidental walking. However due to the ease of use and additional youth friendly design features, the New Lifestyles NL- 1000 was utilised in study 4. Study 4 explored the quantity of walking (steps·day-¹) required for health in adolescent girls. The results indicated that in terms of walking activity, ‘healthy’ adolescent girls do not walk significantly more in term of steps∙day⁻¹ or time spent in activity than girls classified as at ‘health risk’. Therefore specific thresholds for quantity and quality of walking required for health could not be defined for this population. Overall findings of this thesis highlight, that walking should be assessed overground with an appropriate measurement instrument. A step rate of 120 steps·min-¹ and 7200 steps in 60 minutes may be advocated to achieve MPA in adolescent girls. However further research is required to explore the relationship between walking and health in this population before we can promote an appropriate threshold of walking that is conducive to good health in adolescent girls.

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This thesis addresses modeling and simulation of the human lower extremities in order to track walking motion and estimate walking distance. The lower extremities are modeled as an articulated object, which consists of rigid bars connected to each other by joints. This model is tested by using both synthetic and real data. The synthetic data is created based on the main principles of biomechanics. The real data is obtained from the MARG sensors and is processed by the Factored Quaternion algorithm. Next, it is implemented in a simulation program written in Matlab. The program utilizes a mathematical model that represents the human gait-cycle and is based on the theory of forward kinematics as well as on the theory of manipulator kinematics. The simulation program is able to track the motion of the limbs that represent the lower extremities and estimate the traveled distance. Extensive laboratory tests verified the validity of the configuration.

No description available.

Since its first measurement in 1679, the usefulness of the location of whole body centre of mass (COM) data has progressed from having largely theoretical value into being an instrument with several diagnostic and applied scientific uses. This thesis describes first the biomechanical and measurement theory foundation of COM research and then details the historical development of methods to measure COM location and the various applied uses of this variable. Original research data presented in this thesis then go on to provide the first direct measurements of COM movement in walking humans. A second study quantifies the accuracy of the most commonly used current technique to quantify COM location (the kinematic segmental method) by determining the limits of agreement between it and a direct measurement method (the reaction-board), in lying and running subjects. In the latter studies a novel reaction-board measurement method is developed making use of life-sized projections of subjects in various stride positions and used to place runners into recumbent static running positions. These data demonstrate that reaction-board and segmental methods report COM locations with a mean difference of 1.6cm and agree to within limits of 6.0cm for the location of COM in recumbent individuals. The final study described in this thesis compares single COM measurements made using two kinematic segmental methods (models) to a direct suspension technique of measuring COM location. The suspension technique used is adapted from the original method of determining COM location upon which kinematic segmental methods derive their origin. The data show that both cadaver-derived kinematic models of COM, and kinematic models derived from live human data, differ from a direct COM suspension method, and that cadaver based estimates display greater accuracy (agreement with the direct suspension method). This study also uniquely provides information on the effect of whole body mass, body fat or body water on the accuracy of segmental models in male subjects.

In the field of exercise science there exists no single best method, or tool, for the measurement of physical activity, in particular, activity in everyday free-living conditions. The pedometer, a tool for recording the number of steps taken by an individual, could potentially measure this important component of free-living physical activity. To establish the reliability and validity of the pedometer, 40 subjects wore two pedometers (same brand) in two consecutive I 0-minute trials during normal daily activity. Both trials were videotaped. Each videotape segment was replayed, the number of steps were counted and this count served as the criterion measure of steps. In order to evaluate the reliability of the criterion measure the researcher recounted ten of the forty trials a second time and performed an intraclass reliability estimate and follow-up ANOVA comparing the two separate counts. This yielded an intra-observer reliability estimate of R=0.99 (F=l .36, p=.27). Data analyses included trial-to-trial comparisons of pedometer recordings, left-toright comparisons of pedometer recordings, and comparisons of pedometer recordings to the established criterion scores. Results of trial-to-trial comparisons yielded intraclass reliability estimates of R=0.87 (F=l .51, p=.23) for the left side pedometer and R=0.90 (F=.97, p=.33) for the right side pedometer; no significant differences were found. Estimates of pedometer consistency (left versus right pedometer) yielded a correlation ofR=0.96, with follow-up ANOVA (F=6.46 and p=.02) indicating significant differences between left and right side pedometers. Comparisons of pedometers to the established criterion scores (validity) yielded correlations ofR=0.84 (F=l .85, p=.18) for the left pedometer and R=O. 79 (F=S. 71, p=.02) for the right pedometer. Follow-up ANOVA indicated a significant difference between pedometer and criterion scores for the right pedometer but not the left. Under the conditions of this study, the pedometer worn at the waist level directly above the left leg provided reliable and valid measures of walking steps taken during typical everyday activities. The pedometer worn on the right side of the body underestimated the number of steps taken. Further research on the influence of leg dominance, surface, shoe type, pedometer brand, and gait is needed.

There is no abstract available for this thesis. / School of Physical Education