Typescript (Photocopy) Includes paper co-authored by the author as attachment. Bibliography: leaves 133-140.

During pregnancy the female body must accommodate the enlarging gravid uterus and increased mass. Therefore the maternal musculoskeletal system is required to adapt in both morphology and functional workload. After childbirth there is a rapid change in both mass and dimensions, requiring further adaptations. The objectives of the study were to investigate seated and standing upper body posture, the kinematics of seated and standing trunk motion, and the three dimensional kinematics and kinetics during rising to stand from a chair, as pregnancy progressed and in the early post-birth period. Nine maternal subjects (aged 28 to 40 years) were tested at less than 16 weeks, 24 weeks, 30 weeks, 38 weeks gestation and at 8 weeks postbirth. The subjects, fitted with 37 retroreflective markers, were filmed during upright sitting, quiet standing, and four trials each of maximum seated and standing trunk forward flexion, side to side flexion and during maximum seated axial rotation. Three trials each of constrained and free rising to stand from a height adjustable stool and with each foot placed on a forceplate were also recorded. An eight-camera motion analysis system was used to record movements of the body segments and synchronised force plate variables in three dimensions. Motion of the ankle, knee and hip joints, pelvic, thoracic and head segments and the thoracolumbar and cervicothoracic spines and shoulder joints were investigated. Twelve nulliparous subjects (aged 21 to 35 years) were used as controls to provide standard descriptive data and to investigate the consistency of the selected biomechanical variables with repeated testing. A repeated measures ANOVA was used to investigate the possibility of linear and quadratic trends showing systematic changes within the maternal group, over the four test sessions during pregnancy for each variable. Two tailed Student t-tests were used to compare the maternal postbirth variable results with the control group. There was no significant effect of pregnancy on the upper body posture during upright sitting and quiet standing. Postbirth, the pelvic segment had a smaller anterior orientation and the thoracolumbar spine was less extended, indicating a flatter spinal curve. The maternal subjects were similar to the control subjects in early pregnancy and postbirth for trunk segment motions during seated and standing forward flexion and side to side flexion and seated axial rotation. Strategies, such as increasing the width of the base of support and reducing obstruction to movements from other body parts, were used in late pregnancy in attempts to minimise the effects of increased trunk mass and circumference. For seated and standing side to side flexion, the strategies were successful and no significant decreases in range of motion were seen. For seated and standing forward flexion and seated axial rotation, motion of the thoracic segment and the thoracolumbar spine were significantly reduced, although movement of the pelvis was less affected. In early pregnancy and postbirth the kinematics and kinetics of the lower limbs and upper body segment kinematics during constrained and free rising were generally similar to the control subjects. As pregnancy progressed there were increases in mass and dimensions of body segments. The effect of increased mass was seen in increased ground reaction forces and sagittal plane lower limb joint external moments. An increased base of support width was found in association with an increased lateral ground reaction force and ankle inversion moment from each foot, which would move the body centre of mass medially. There was little change in the three dimensional kinematics of the thoracolumbar and cervicothoracic spine, although the contribution of the upper body segments differed for each rise condition. There were also few significant changes in the displacement of the ankle, knee and hip, and the angular velocity of ankle and knee joints. The maternal subjects were thus able to flex the upper body forward, raise the body and maintain stability as pregnancy progressed, regardless of whether the rise to stand was performed in a natural manner or under constrained conditions. The overall results show that, contrary to expectations as pregnancy progressed, maternal subjects minimised propulsion rather than increasing it to overcome the increased mass and possibly limited trunk flexion. A fear of postural instability may have made the subjects more cautious and as they were able to adequately flex the trunk forward, propulsion was minimised in favour of maintaining upright terminal balance.

Prehension is a fundamental skill usually performed as part of a complex action sequence in everyday tasks. Using an information processing framework, these studies examined the effects of task complexity, defined by the number of component movement elements (MEs), on performance of prehension tasks. Of interest was how motor control and organisation might be influenced by age and/or motor competence. Three studies and two longitudinal case studies examined kinematic characteristics of prehension tasks involving one-, two- and three-MEs: reach and grasp (low-complexity); reach, grasp and object placement (moderate-complexity); and reach, grasp and double placement of object (high-complexity). A pilot study established the suitability of tasks and procedures for children aged 5-, 8- and 11-years and showed that responses to task complexity and object size manipulations were sensitive to developmental changes, with increasing age associated with faster movements. Study 2 explored complexity and age effects further for children aged 6- and 11-years and adults. Increasing age was associated with shorter and less variable movement times (MTs) and proportional deceleration phases (%DTs) across all MEs. Task complexity had no effect on simple reaction time (SRT), suggesting that there may be little preprogramming of movements beyond the first ME. In addition, MT was longer and more on-line corrections were evident for the high- compared to the moderate-complexity task for ME1. Task complexity had a greater influence on movements in ME2 and ME3 than ME1. Adults, but not children, showed task specific adaptations in ME2. Study 3 examined performance of children with different levels of motor competence aged between 5- and 10-years. Increasing age was associated with shorter SRTs, and MTs for ME1 only. A decrease in motor competence was associated with greater difficulty in planning and controlling movements as indicated by longer SRTs, higher %DTs and more on-line corrections, especially in ME2. Task complexity affected movements in all MEs, with a greater influence on ME1 compared to Study 2. Findings also indicated that performance in MEs following prehension may be especially sensitive to motor competence effects on movement characteristics. Case studies for two children at risk of Developmental Coordination Disorder (DCD) revealed two different patterns of performance change over a 16-17 month period, highlighting the heterogeneous nature of DCD. Overall, findings highlighted age-related differences, and the role of motor competence, in the ability to adapt movements to task specific requirements. Results are useful in guiding movement education programmes for children with both age-appropriate and lower levels of motor competence.

"July 2004" / Bibliography: leaves 215-230. / viii, 230 leaves : ill., maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Chemistry and Physics, Discipline of Physics, 2004

Impairments of upper limb function can negatively impact an individual???s ability to carry out everyday tasks. Children with cerebral palsy can have limitations of upper limb movement due to physiological and structural changes in their body. Current treatment regimes for children with upper limb involvement of cerebral palsy are assessed using a variety of qualitative assessment tools. These measures rely on subjective input from the assessor, and can be insensitive to significant functional improvements. Research methods in upper limb motion analysis are developing towards use as clinical tools. To date, there is a paucity of knowledge on the quantitative measures of range of motion (ROM) and function of upper limbs in healthy children. There is also lack of agreement on repeatable functional tasks of the upper limb for 3D measurement. The identification of a repeatable task in healthy children would facilitate the use of upper limb 3D motion analysis to guide clinical practice and improve patient outcomes. This thesis aims to describe upper limb joint range of movement in each degree of freedom and present normative three dimensional kinematic data of upper limb movement in healthy children during a repeatable upper limb functional task. This will provide a basis for comparison to children with movement disorders for future research and clinical practice. The UNSW kinematic upper limb model was found to successfully measure three dimensional upper limb anatomical and functional movements in healthy children. Normative kinematic data are reported for anatomical movements and two functional tasks. The results of the studies undertaken showed that differences in dominant and non-dominant limbs were present during anatomical and functional movements. Joint angles measured were found to be repeatable in healthy children. The results suggest that methods used were reliable for investigating upper limb kinematics. Functional movement time-series data were found to be repeatable for the group with the exception of wrist flexion/extension during the hand to mouth movement for both the dominant and non-dominant limbs. These findings improve current knowledge on upper limb kinematics in healthy children. This knowledge can assist the investigation of movement disorders in children to facilitate clinical decision making.

Impairments of upper limb function can negatively impact an individual???s ability to carry out everyday tasks. Children with cerebral palsy can have limitations of upper limb movement due to physiological and structural changes in their body. Current treatment regimes for children with upper limb involvement of cerebral palsy are assessed using a variety of qualitative assessment tools. These measures rely on subjective input from the assessor, and can be insensitive to significant functional improvements. Research methods in upper limb motion analysis are developing towards use as clinical tools. To date, there is a paucity of knowledge on the quantitative measures of range of motion (ROM) and function of upper limbs in healthy children. There is also lack of agreement on repeatable functional tasks of the upper limb for 3D measurement. The identification of a repeatable task in healthy children would facilitate the use of upper limb 3D motion analysis to guide clinical practice and improve patient outcomes. This thesis aims to describe upper limb joint range of movement in each degree of freedom and present normative three dimensional kinematic data of upper limb movement in healthy children during a repeatable upper limb functional task. This will provide a basis for comparison to children with movement disorders for future research and clinical practice. The UNSW kinematic upper limb model was found to successfully measure three dimensional upper limb anatomical and functional movements in healthy children. Normative kinematic data are reported for anatomical movements and two functional tasks. The results of the studies undertaken showed that differences in dominant and non-dominant limbs were present during anatomical and functional movements. Joint angles measured were found to be repeatable in healthy children. The results suggest that methods used were reliable for investigating upper limb kinematics. Functional movement time-series data were found to be repeatable for the group with the exception of wrist flexion/extension during the hand to mouth movement for both the dominant and non-dominant limbs. These findings improve current knowledge on upper limb kinematics in healthy children. This knowledge can assist the investigation of movement disorders in children to facilitate clinical decision making.

Impairments of upper limb function can negatively impact an individual???s ability to carry out everyday tasks. Children with cerebral palsy can have limitations of upper limb movement due to physiological and structural changes in their body. Current treatment regimes for children with upper limb involvement of cerebral palsy are assessed using a variety of qualitative assessment tools. These measures rely on subjective input from the assessor, and can be insensitive to significant functional improvements. Research methods in upper limb motion analysis are developing towards use as clinical tools. To date, there is a paucity of knowledge on the quantitative measures of range of motion (ROM) and function of upper limbs in healthy children. There is also lack of agreement on repeatable functional tasks of the upper limb for 3D measurement. The identification of a repeatable task in healthy children would facilitate the use of upper limb 3D motion analysis to guide clinical practice and improve patient outcomes. This thesis aims to describe upper limb joint range of movement in each degree of freedom and present normative three dimensional kinematic data of upper limb movement in healthy children during a repeatable upper limb functional task. This will provide a basis for comparison to children with movement disorders for future research and clinical practice. The UNSW kinematic upper limb model was found to successfully measure three dimensional upper limb anatomical and functional movements in healthy children. Normative kinematic data are reported for anatomical movements and two functional tasks. The results of the studies undertaken showed that differences in dominant and non-dominant limbs were present during anatomical and functional movements. Joint angles measured were found to be repeatable in healthy children. The results suggest that methods used were reliable for investigating upper limb kinematics. Functional movement time-series data were found to be repeatable for the group with the exception of wrist flexion/extension during the hand to mouth movement for both the dominant and non-dominant limbs. These findings improve current knowledge on upper limb kinematics in healthy children. This knowledge can assist the investigation of movement disorders in children to facilitate clinical decision making.

There has been much interest in the area of model-based reasoning within the Artificial Intelligence community, particularly in its application to diagnosis and troubleshooting. The core issue in this thesis, simply put, is, model-based reasoning is fine, but whence the model? Where do the models come from? How do we know we have the right models? What does the right model mean anyway? Our work has three major components. The first component deals with how we determine whether a piece of information is relevant to solving a problem. We have three ways of determining relevance: derivational, situational and an order-of-magnitude reasoning process. The second component deals with the defining and building of models for solving problems. We identify these models, determine what we need to know about them, and importantly, determine when they are appropriate. Currently, the system has a collection of four basic models and two hybrid models. This collection of models has been successfully tested on a set of fifteen simple kinematics problems. The third major component of our work deals with how the models are selected.

Thesis (M.S.)--University of Montana, 2006. / Title from PDF t.p. (viewed on July 2, 2007). Includes bibliographical references.

Qualitative studies investigating the sexual activity of people with low back pain found a substantial reduction in the frequency of coitus and have shown that pain during coitus due to mechanical factors (i.e., movements and postures) are the primary reason for this decreased frequency. However, a biomechanical analysis of coitus has never been done. The main objective of this study was to describe male and female lumbar spine and hip motion and muscle activation patterns during coitus and compare these motions and muscle activity across five common coital positions. Specifically, lumbar spine and hip motion in the sagittal plane and electromyography signal amplitudes of selected trunk, hip, and thigh muscles were described and compared. A secondary objective was to determine if simulated coitus could be used in place of real coitus for future coitus biomechanics research. Ten healthy males (29.3 ± 6.9 years, 176.5 ± 8.6 centimeters, 84.9 ± 14.5 kilograms) and ten healthy females (29.8 ± 8.0 years, 164.9 ± 3.0 centimeters, 64.2 ± 7.2 kilograms) were included for analysis in this study. These couples had approximately 4.7 ± 3.9 years of sexual experience with each other. This study was a repeated-measures design, where the independent variables, coital position and condition, were varied five (i.e., QUADRUPED1, QUADRUPED2, MISSIONARY1, MISSIONARY2, and SIDELYING) and two (i.e., real and simulated) times, respectively. Recruited participants engaged in coitus in five pre-selected positions (presented in random order) for 20 seconds per position first in a simulated condition, and again in a real condition. Three-dimensional (3D) lumbar spine and hip kinematic data were continuously collected for the duration of each trial by optoelectronic and electromagnetic motion capture systems. Electromyography (EMG) signals were also continuously collected for the duration of each trial. The kinematic data and EMG signals were collected simultaneously for both participants. Five sexual positions were chosen for this study based on the findings of previous literature and a biomechanical rationale. QUADRUPED – rear-entry, female quadruped, male kneeling behind – had two variations; in QUADRUPED1 the female was supporting her upper body with her elbows and in QUADRUPED2 the female was supporting her upper body with her hands. MISSIONARY – front-entry, female supine, male prone on top – also had two variations; in MISSIONARY1 the female was not flexing her hips or knees and the male was supporting his upper body with his hands, but in MISSIONARY2, the female was flexing her hips and knees and the male was supporting his upper body with his elbows. SIDELYING – rear-entry, female side-lying on her left side, male side-lying behind – did not have any variations. To determine if each coital position had distinct spine and hip kinematic and muscle activation profiles, separate univariate general linear models (GLM) (factor: coital position = five levels, α=0.05) followed by Tukey’s honestly significant difference (HSD) post hoc analysis were used. To determine if simulated coitus was representative of real coitus across all spine and hip kinematic and muscle activation outcome variables, paired-sample t-tests (α=0.05) were performed on all outcome variables for the real condition and their respective simulated values. In general, the coital positions studied showed that, for both males and females, coitus is mainly a flexion-extension movement of the lumbar spine and hips. Males used a greater range of their spine and hip motion in comparison to females. As expected, differences were found between coital positions for males and females and simulated coitus was not representative of real coitus, in particular the spine and hip kinematic profiles. The results found in this biomechanical analysis of common coital positions may be useful in a clinical context. It is recommended that during the acute stage of a low back injury resulting in flexion-, extension-, or motion-intolerance that coitus be avoided. If the LBP is a more chronic issue, particular common coital positions should be avoided. For the flexion-intolerant male patient, avoid SIDELYING and MISSIONARY2 as they were shown to require the most flexion. Both variations of QUADRUPED are the more spine-sparing of coital positions followed by, MISSIONARY1. Coaching the male patient on proper hip-hinging technique while thrusting – an easy technique to incorporate in both variations of QUADRUPED – will likely decrease spine movement and increase the spine-sparing quality of QUADRUPED. For the flexion-intolerant female patient, avoid both variations of MISSIONARY, especially with hip and knee flexion, as they were shown to elicit the most spine flexion. QUADRUPED2 and SIDELYING are the more spine-sparing coital positions, followed by QUADRUPED1. Subtle posture changes for a coital position should not be considered lightly; seemingly subtle differences in posture can change the spine kinematic profile significantly, resulting in a coital position that was considered spine-sparing becoming a position that should be avoided. Thus, spine-sparing coitus appears to be possible for the flexion-, extension-, and motion-intolerant patient. Health care practitioners may recommend appropriate coital positions and coach coital movement patterns, such as speed control and hip-hinging. With respect to future research in the area of sex biomechanics, using simulated coitus in replace of real coitus is not justifiable according to the data of this study. However, including a simulated condition did prove beneficial for increasing the comfort level of the couples and allowing time to practice the experimental protocol. Future directions may address female-centric positions (e.g., ‘reverse missionary’ with male supine and female seated on top), and back-pained patients with and without an intervention (e.g., movement pattern coaching or aides, such as a lumbar support).