<p><p><strong>Abstract</strong></p><p><strong>Aim: </strong>The aim was to evaluate height measurements made with the single view metrology method and to investigate the influence of standing position and different phases of gait and running on vertical height.</p><p><strong>Method: </strong>Ten healthy men were recorded simultaneously by a 2D web camera and a 3D motion analysis system. They performed six trials, three standing and three during gait and running. The vertical height was measured with the single view metrology method and in Qualisys Track Manager. The results were compared for evaluation. The vertical height in the different postures was compared to the actual height.</p><p><strong>Results: </strong>The measurements made with the single view metrology method were significantly higher than the measurements made with Qualisys Track Manager (p<0.001). The vertical height in the two standing positions was significantly lower than the actual height (p<0.05). The vertical height in midstance was significantly lower than actual height in the walking trials (p<0.05). No significant difference was found between maximum vertical height and actual height during running (p>0.05).</p><p><strong>Conclusion: </strong>The single view metrology method measured vertical heights with a mean error of +2.30 cm. Posture influence vertical body height. Midstance in walking is the position where vertical height corresponds best with actual height, in running it is the non-support phase.</p><p> </p></p><p> </p>

Thèse de doctorat : Biomécanique : Paris 12 : 2006. / Titre provenant de l'écran-titre. Pagination : 244 p. Bibliogr. p. 196-209.

Thèse de doctorat : Santé Publique et Epidémiologie : Nancy 1 : 2008. / Titre provenant de l'écran-titre.

Thèse doctorat : Neurosciences : Nancy 1 : 2005. / Titre provenant de l'écran-titre.

Travel time has generally been regarded as an unproductive period, representing a means-to-an-end in order to engage in activities at specific destinations. Rapid developments in mobile technology have provided people with innovative ways to multi-task and engage in meaningful activities while travelling. Rail transportation specifically, offers passengers advantages over other means of transportation as there is no need to focus on driving tasks. Due to the increase in passenger numbers and limited seating availability in train carriages, over one third of rail passengers are required to stand while travelling (DfT, 2013). The vibration to which rail passengers are exposed has been shown to interfere with the performance of activities and for standing passengers, it is often necessary to use postural supports such as holding on to grab rails or leaning on walls in order to maintain stability. The overall aim of the research is to evaluate the influence of whole-body vibration (WBV) exposure and standing posture on the performance of manual control tasks and the associated subjective workloads experienced by rail passengers. The use of supports, such as a backrest in seated postures, has been found to influence the response of the human body to WBV exposure, yet no reported studies have investigated the effects of postural supports on the response of the body in standing postures. Understanding how the body is affected in these conditions would increase the current state of knowledge on the biomechanical responses of the human body to vibration exposure and provide improved representation of standing postures within vibration standards (for example, ISO2631-4 (2001)) and guidelines for device interface design. A field study, using direct observation, was conducted to assess the behaviour of standing rail passengers and determine the characteristics of typical vibration exposures. This information provided the basis for the design of four subsequent laboratory studies. The main investigations of the laboratory studies were the influence of WBV exposure on objective performance measures, such as task completion time and error rate, and subjective workloads (for example, NASA TLX) for a range of manual control tasks. One of these laboratory studies evaluated the influence of various postural supports (for example, backrests) on the biomechanical responses of standing individuals. Measurements obtained during the field investigation indicated that the vibration exposures did not exceed the EU Physical Agents Exposure Action Value (EAV) and therefore posed little risk of injury. Vibration magnitudes in the horizontal directions (x- and y-axes) were higher than in the vertical direction (z-axis) and it was necessary for standing passengers to alter behaviours and use supports in order to maintain stability while travelling. The results of the laboratory studies indicated that in conditions where decrements in task performance occurred, the extent to which performance was degraded increased progressively with increases in vibration magnitude. There were conditions (for example, in the continuous control task and the Overhead Handle supported posture in the serial control task) where vibration exposure showed no significant influence on performance measures. This suggested that individuals were able to adapt and compensate for the added stress of vibration exposure in order to maintain performance levels however, this occurred at the expense of mental workload. The workload experienced by the participants increased with corresponding increases in magnitude. Vibration frequency-dependent effects in performance and workload were found to match the biomechanical responses (apparent mass and transmissibility) of the human body and resemble the frequency weightings described in the standards (ISO2631-1 (1997)). During the serial control task, the postures which demonstrated the greatest decrements to performance (for example, Lean Shoulder and Lean Back ) corresponded to the same postures that showed the greatest influence on the biomechanical responses of the body. It was concluded therefore, that measurements of the biomechanical responses to WBV could be used to offer predictions for the likelihood of activity interference. Consideration should however, be given to the applicability of this research before these results can be generalised to wider contexts. Further validation is recommended for future work to include different conditions in order to substantiate the findings of this research.

published_or_final_version / Paediatrics / Master / Master of Philosophy

Recorded on July 27, 2007 by Eugene Barsky, Physiotherapy Outreach Librarian, UBC / N/A

Correct posture is the basis for normal development and function of chest box, extremities and internal organs. Irregular posture is one of the most widespread disorders of musculoskeletal system, which might be caused by the low level of culture and lack of education. It has an influence on children‘s health, physical and psychological well-being. Lack of assessment and delay of treatment might worsen situation and progress into complicated forms of disorders. Aim of the work: to evaluate posture of 11–12 years old children in sagittal and frontal planes and effects of physical therapy. Contingent: 96 11–12 years old children were participated in the first assessment: 59 girls and 37 boys. 64 children were participated in the second assessment: 33 girls and 31 boys. Methods: inspection, palpation, cirtometry, scoliometry, SPSS software. Results: Distribution of curves of column in frontal and sagittal planes after physical therapy were the same among boys and girls as well as children of 1’st and 2’nd group. Analyzing data of first and second assessments we can say, that physical therapy had no influence on boy’s kyphosis and lordosis, but it had a statistically significant positive effects on girl’s parameters of kyphosis and lordosis. Conclusions: posture disorders in frontal and sagittal planes are still widespread among schoolchildren. Physical therapy is very important for the correction of schoolchildren’s posture. Special physical exercises had to be used under... [to full text]

Tree-planters are likely to suffer from musculoskeletal injuries during their short work season. The objective of this research is to identify the biomechanical mechanisms that contribute to these injuries with an overall goal of reducing injury frequency and severity. Pre- and post-season discomfort questionnaires were administered to workers in two tree-planting camps to identify areas of the body most prone to injury. Musculoskeletal pain and discomfort were significantly higher post season. Greatest pain and discomfort were reported in the feet, wrists and back, while the highest frequency of pain was reported in the back. Upper body and trunk postures were recorded during the tree-planting task in the field using digital video and inclinometers. Results indicated that deep trunk flexion occurred over 2600 times per day and workers spent at least half of their workday in trunk flexion greater than 45 degrees. Although results provide useful insight into injury mechanisms, postural data were two dimensional. Inertial motion sensors were used in a second field study the following season to examine differences in three-dimensional upper limb and trunk relative joint angles during commonly used tree seedling unloading methods. Results showed trunk rotation up to 50 degrees combined with deep trunk flexion during parts of the task. Trunk flexion and rotation were significantly less when the tree seedling load was distributed asymmetrically as compared to symmetrically. Joint reaction forces in the lower body and trunk during the same unloading methods was examined during a simulated planting task in a lab environment. Greatest joint reaction forces and non-neutral postures occurred when the tree was inserted into the ground. Right-loaded planting bags resulted in more substantial differences in posture and joint reaction forces than either left-loaded or even-loaded bags. Axial forces were greater in the right leg than the left throughout the task, regardless of loading condition. In conclusion, underlying biomechanical mechanisms for injury during tree-planting seem to be a combination of awkward postures (particularly the trunk), repetitive motions, and carrying of heavy loads. Different seedling unloading strategies did not result in substantial overall differences in posture or joint reaction forces. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2010-04-14 10:02:32.385

Exercise-induced hypoxemia is a common observation in endurance-trained athletes. The present study examined the kinetics of oxyhemoglobin saturation during upright (UP) maximal cycling exercise in 84 healthy, untrained subjects between 8 and 26 years old. The prevalence of oxyhemoglobin desaturation (DS: SaO$ sb2 $ 0.05). A subgroup of children (n = 6) repeated the maximal exercise protocol in the supine (SU) position. In NDS values of SaO$ sb2$ were not affected by posture (UP: 95.3 $ pm$ 2.3 vs SU: 94.1 $ pm$ 0.9) for similar VO$ sb{ rm 2max}$ (UP: 3.7 $ pm$ 0.36 vs SU: 3.43 $ pm$ 0.36) (p $>$ 0.05). These observations suggest that exercise-induced DS is independent of age or training status. Differences due to posture may be related to variations in ventilatory and/or pulmonary perfusion parameters.