The need for the development of a rigorous analytical model of the lumbar spine to clarify the role of mechanical factors in low-back disorders has long been recognized. In response to this need, a general three dimensional nonlinear finite element program has been developed as part of this work and has been applied to the analysis of a lumbar L(,2-3) joint including the posterior elements. The analysis accounts for both the material and geometric nonlinearities and is based on a representation of the nucleus as an incompressible inviscid fluid and of the annulus as a composite of collagenous fibres embedded in a matrix of ground substance. The facet articulation has been accounted for by treating it as a general moving contact problem. The ligaments have been modelled as a collection of nonlinear axial elements. The geometry of the finite element model is based on in-vitro measurements. / The response of the joint under single compression, single flexion, single extension and also under flexion or extension combined with compression and sagittal shear has been analyzed for both the normal and degenerated states of the nucleus. Validity of the model has then been established by a comparison of those predictions which are also amenable to direct measurements. The states of strain and stress in different components of the lumbar joint have been thoroughly studied under all the foregoing loading conditions. / Those elements of the joint predicted to be vulnerable to mechanical failure or damage under the above types of loading have been identified. These results have been correlated with the lumbar joint injuries reported clinically. Furthermore, some joint injury mechanisms and degeneration processes have been proposed and the supporting clinical evidences have been presented.

Thesis (M.Tech.: Chiropractic) -Dept. of Chiropractic, Technikon Natal, 2002 1 v. (various pagings) / The purpose of this study was to evaluate the effect of wearing a scuba diving cylinder on static lumbar spine posture, in terms of clinical objective findings, namely radiographic changes in the lumbar lordosis, lumbosacral angle, lumbosacral disc angle, and the lumbar gravity line, during upright standing on land.

Thesis (M.Tech.: Chiropractic)- Dept. of Chiropractic, Durban University of Technology, 2008. x, 52 leaves, Appendices A-E, [25] leaves. / To determine whether a relationship exists between core stability and bowling speed in Action Cricket bowlers. Methods: Thirty asymptomatic indoor Action Cricket fast and fast-medium bowlers were divided into two groups of 15 each, with Group A having well-developed core stability and group B having poorly-developed core stability. The concept of matched pairs was used for age and cricket experience in order to maintain homogeneity between the groups. The core stability and bowling speed of each participant was measured using a pressure biofeedback unit (PBU) and speed sports radar respectively. SPSS version 15.0 was used to analyse the data.

Background: In the clinical examination of patients with low back pain (LBP), musculoskeletal physiotherapists routinely assess lumbar spinal segmental motion by performing physical examination procedures such as observation of active range of motion and palpation of intervertebral motion. The validity of manual assessment of segmental motion, however, has not been adequately investigated. Methods: In this pragmatic, multi-centre, criterion-related validity study, 138 consecutive patients with LBP were recruited and examined by physiotherapists with postgraduate training in musculoskeletal manual therapy. Clinicians examined each patient�s spine for the presence of segmental motion abnormalities, described as lumbar segmental rigidity (LSR) and lumbar segmental instability (LSI), then referred the patients for flexion-extension (FE) radiographs. The physical examination procedures of interest were: 1) assessment of forward-bending (FB) active range of motion (AROM); 2) FB and backward-bending (BB) passive physiological intervertebral motion testing (PPIVMs) in the sagittal plane; and 3) central postero-anterior passive accessory intervertebral motion testing (PAIVMs). Sagittal displacement kinematics of the lumbar spinal segments were measured from the FE radiographs, and served as the criterion standard against which the clinical assessment results were compared. The kinematic parameters measured were sagittal rotation, sagittal translation, ratio of translation per degree of rotation (TRR), instantaneous axis of rotation (IAR), and centre of reaction (CR). Reference ranges for normal motion were calculated from the analysis of FE radiographs of 30 asymptomatic volunteers. The accuracy and validity of the clinical examination procedures were then calculated, and reported as sensitivity, specificity, and likelihood ratios for a positive test (LR+) and a negative test (LR-). Results: In patients with LBP, sagittal rotation LSR and sagittal translation LSR had a prevalence of approximately 5.7% (p <0.0005) in this cohort. Sagittal rotation LSI was not found in statistically significant numbers. Sagittal translation LSI was found at a prevalence of 3.6% (p <0.05). Abnormal TRR (23.3%), IAR (17.7%), and CR (16.5%) were more prevalent findings (all p <0.0005). Observation of the quantity of AROM, during FB, is not valid for the assessment of either total lumbar segmental sagittal rotation, or detection of individual segments with abnormal segmental motion. PPIVMs and PAIVMs are specific, but not sensitive, for the detection of rotation LSI and translation LSI. A positive test (grade 4 on a scale from 0 to 4) with BB PPIVMs may have some utility for the diagnosis of rotation LSI or translation LSI, with LR+ of 8.4 and 7.1 respectively (and 95% CIs from around 1.7 to 38). Likelihood ratio statistics for FB PPIVMs were not statistically significant. A positive test (grade 2 on a scale from 0 to 2) with PAIVMs may have some utility for the diagnosis of rotation LSI or translation LSI, with LR+ of 2.7 and 2.5 respectively (and 95% CIs from around 1.01 to 7.5). Neither PPIVMs nor PAIVMs were useful for the detection of LSR, or abnormal quality of motion as measured by TRR, CR, and IAR. Conclusions: Abnormal spinal segmental motion is associated with the symptom of LBP, in patients presenting to physiotherapists with a new episode of recurrent or chronic LBP, however prevalence is low due to highly variable lumbar segmental motion among asymptomatic individuals. Manual physical examination has moderate validity, but limited utility on its own, for the detection of translation LSI. Further research should investigate the utility of other clinical examination findings for the detection of lumbar segmental mobility disorders.

Thesis (MPhysio)--University of South Australia, 1998

Thesis (MAppSc) -- University of South Australia, 1997

Thesis (M.S.)--Indiana University, School of Health, Physical Education and Recreation, 2005.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 134-139).