Thesis (doctoral)--Göteborgs Universitet.

Thesis (doctoral)--Göteborgs Universitet.

Numerous mathematical models have been developed to investigate the high incidence of low back pain associated with lifting activities. These mainly consider the muscle forces required to support the spine, and few have considered the additional role of curvature. One previous model which represented the spine as an arch (Aspden 1987) indicated the curvature to have a significant effect on both loading and stability of the spine. However this model included collective loading patterns for body weight and muscle forces, and only partial representation of the spine. On the basis that the level of anatomic detail of a model affects the accuracy of its predictions (McGill and Norman, 1987), this thesis describes the development of a model which provides greater detail for investigating spinal stability in the sagittal plane. The curvature of the whole spine, a distributed loading pattern for body weight, and the activity of individual spinal muscle groups have been considered. Comparison with the previous arch model has shown these to be necessary features for determining the loading and stability associated with a given posture. In particular, application of individual muscle forces provide greater control of stability at each vertebral level. By considering the force requirements of the individual muscle groups and the consequent loads at each intervertebral joint, possible areas of tissue over load can be identified.

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While a substantial number of studies exist in the medical and mental health fields reflecting the physical and psychological implications for couples with chronic back pain, studies thus far have focused on the independent perceptions of each partner. Research investigating how couples jointly perceive the impact of chronic back pain on their relationship is absent. This qualitative study explored eight couples' joint perceptions of how chronic back pain has impacted their relationship. Using thematic analysis, dominant themes to emerge included (1) relationship changes, (2) influential relationship factors, and (3) making sense of pain. Limitations of the study as well as future research and clinical implications are also discussed. / Master of Science

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Standing at a workbench is required for manual work including sorting and assembly. When work heights and reach distances are not matched to stature or arm length, the trunk assumes a partially bent position, which increases the postural effort required to stand or to reach to far distances. As a result, the biomechanical load on the lumbar spine is raised, which contributes to a higher risk for back pain. In ergonomics, assistive devices are being developed to counter this effect. A new leaning device was tested in the laboratory with forward-bent standing and reaching where the trunk was bent forward and twisted to reach to a far target 45° from the center. This device supported the trunk at the upper chest. With leaning, back muscle activity decreased by ~ 60% with forward-bent standing and ~ 23-30% with the off-center reach, depending on reach height. Because leaning changed how standing remained balanced, ~12° less bending was required to reach the target. Therefore, upper-trunk support may be helpful for benchworkers when ergonomic design is not possible; some product development and testing is still needed to provide the right amount of support at the right time and to ensure there is no rib joint irritation. An interesting outcome from these previous studies was related to workers’ posture when they leaned against a workbench that was adjusted for heavier work (hip height). Low back muscle activity was unchanged with forward-bent standing, but decreased by ~ 23-30% with the off-center reach. This reduction was accompanied by greater twist at the mid back as a way of compensating for a loss of hip rotation. Three different heights for bench leaning were compared in a third study: elbow height, hip height and below hip height. The results showed that leaning at elbow height lowered the work demand by ~16-24% for far reach, partially due to changed motions consistent with greater mid back movement and coincided with ~ 8% increase in work demands at the mid-back and greater scapular recruitment. Therefore, more research is needed to establish work height guidelines for use when leaning against a workbench. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2013-01-29 14:32:19.696

Objective: To develop modular software to assess angular impulse and to determine the effect of a reduced dataset on the net angular impulse acting at the L5/S1 joint. Background. With the prevalence and incidence of lower back pain increasing annually, accurate assessment of physical job demands is needed. Many lab based approaches exist to measure the moments acting on the lower back, but require advanced and sensitive testing equipment. Of the methodologies currently used in industrial settings, most require significant contributions of time or money to be implemented. There is a need for cost and time effective methods to record a worker’s kinematic data over their whole shift. Methods: Twelve participants performed 12 consecutive lifts under five lifting conditions: SQ00 (squat 0kg); SQ04 (squat 4kg); SQ10 (squat 10kg); FP04 (fast squat 4kg); ST04 (stoop 4kg). Kinematic data of the upper limbs, head, and trunk was recorded with external load data and kinetic analysis was performed by implementing an extension of the Hof (1992) method called the lined-segment engine (LSE) to calculate the angular impulse (N•m•s) acting on the L5/S1 joint. Results: The LSE was sensitive to changes in load, lifting speed, and lifting posture (p < 0.05). There was no difference in dynamic, quasi-static, or static models when calculating angular impulse, but there was a difference in the L5/S1 angular impulse when the upper limbs were removed from the dynamic LSE model (p < 0.05). Conclusion: The LSE requires further refinement, but could be a generic approach to kinetic calculations. A scaled no-arms model for calculating the angular impulse acting on the low back could be used to assess field based lifting studies with 5.8% error. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2013-08-03 15:05:03.257

ABSTRACT Aim: The aim of this study was to determine the most effective exercise program for the management of occupational lower back pain. Background: Occupational lower back pain accounts for 25% of workdays lost. The annual occurrence of occupational related lower back pain among blue collar workers in South Africa has shown to be between 55,7% and 63,9%. Methodology: Primary studies were searched with the use of the Entrez-cross-database search tool. Methodologies were assessed and critiqued. Data which included exercise detail, outcome measures of lower back pain intensity, painful episodes, sick leave and physical measures with statistical p-values was then extracted. Results: Nine primary studies, which included 11 exercise groups, complied to the inclusion and exclusion criteria. These studies proved to be of high methodology quality with quality scoring 70% on the quality assessment checklist. Exercise regimes, which included stretching, strengthening, endurance exercises and the combination use of stretching, strengthening and endurance exercises were identified and grouped according to the corresponding outcome measures. No meta-analysis could be done as no similar exercises with similar outcome measures could be found. Discussion: The limitations in the nine selected studies methodological quality were the lack of blinding of the assessors and subjects, and in six of the nine studies the lack of adequate participation rate among the intervention subjects. The validation process is acknowledged as a weakness within this study. Stretching, dynamic strengthening and endurance exercises were not statistically significant. Isometric exercise was statistically significant for lower back pain relief when the control group (p<0,0001) was compared to the experimental group. Isometric exercise however had no significant effect on abdominal strength at 9 months follow up period. Functionalexercises were statistically significant when the exercise group was compared to the control group with lower back pain intensity relief (p<0,018), painful episodes (p<0,018), sick leave (p< 0,0044). Functional exercises also had a long-term statistically significant effect on back muscle strength. A meta analysis could not be done due to insufficient similar studies. Conclusion: Although the methodology quality of the nine primary studies showed to be of high quality the validation process was a weakness within this study. Functional strengthening exercises were the most effective type of exercise for the management of occupational lower back pain among blue-collar workers. Future similar randomized control trials on exercise as an intervention to occupational lower back pain are needed to conduct a meta analysis. A meta analysis will be able to provide more evidence to establish which exercise regime is most effective for the management of occupational lower back pain.

ABSTRACT Pain is a subjective sensation and is difficult to measure. It is important to quantify pain as benefits are obtained from its quantification. The validity and reliability of pain outcome measures have been extensively researched in Europe, America and Asia. In Africa on the other hand, very few studies have been done. This study was a cross-sectional study to validate and test the reliability of pain scales.The aim of this study was to establish the validity and reliability of the Tswana translations of three pain scales, namely, the Visual Analogue scale (two versions), the Verbal Rating Scale and the Wong-Baker Faces Pain Measure. The validity of the study was determined by the face validity,criterion validity and construct validity.The statistical analysis of the results showed several significant p values (p< 0.05).However, none of the correlations illustrated a strong relationship as there were no r values in excess of 0.5 indicating a moderate correlation or greater than 0.7 indicating a good correlation. The statistical significance only indicated that the observed values were not due to chance.From the statistical analysis of the results, it became apparent that the subjects tested did not have an understanding of any of the three scales .This was seen in all the age groups and education levels selected for the purpose of this study. It is our recommendation therefore, that suitable, new scales be developed for our local population. The scales which have been used up until now are not being understood and hence are not being interpreted or used correctly in the South African context amongst Tswana speaking individuals. Future research needs to be done in developing entirely different scales for the South African scenario. More relevant and better understood scales should be developed for our local population to include persons of different languages and different education levels. This will assist in a better understanding of the health care process and will by so doing, improve their health care and management.