Limited hip mobility is known to affect the lumbar spine. Much of the previous research has utilized a participant population whose hip mobility is compromised due to arthritic or neurological dysfunctions. Such aetiologies may confound the outcomes, as their effects may not be limited to the hip. The purpose of this thesis was to recruit a healthy young adult population with limited hip mobility to further investigate its effect on the lumbar spine, as well as the role of exercise intervention. Several cascading studies were conducted that were unified around a central theme of links between hip and spine function: Study # 1 investigated the normal distribution of passive hip extension and rotation in a group of 77 males (age 19-30). Data was collected using an infra-red motion capture system and compared to goniometric measurements. The resulting angles represent the 5th – 95th percentiles, including the averages and standard deviations. Study # 2 compared movement patterns between groups of males with limited and excessive hip mobility. Participants were required to perform simple functional activities (lunging, twisting, walking, etc) as well as use the elliptical trainer. Resulting hip and spine angles demonstrated that the men with limited hip mobility stood with a more anteriorly tilted pelvis, and assumed a posture with more lumbar and hip flexion on the elliptical trainer, compared to those with greater mobility. This, in turn, resulted in a greater lumbar compression load due to increased back muscle activity. Study #3 involved recruitment of 24 young adult males with limited hip mobility. Their movement patterns were assessed (as in study #2), then they were assigned to one of four intervention groups: hip stretching, spine stabilizing, hip stretching combined with spine stabilization, and control. Participants in the 3 exercise groups attended supervised exercise sessions once/week for 6 weeks, but were expected to exercise a minimum of 4 times/week on their own. At the end of the 6 weeks, intake parameters were re-assessed, and movement pattern assessment repeated. Despite significant increases in available hip flexibility and/or large increases in trunk muscle endurance and trunk motor control, there were few indications that participants were any more adept at decreasing lumbar motion, or utilizing their newfound hip flexibility during functional activities. Study #4 compared those in the 10th and 90th percentiles of available hip rotation, using a frictionless apparatus to investigate passive stiffness properties of the hip. Participants adopted a posture of upright standing, with one leg supported on a turntable apparatus, and upper body and pelvis secured. A an applied rotational moment resulted in passive hip internal and external rotation. Outcomes demonstrate that those with limited hip mobility stand with the leg more externally rotated and require a larger moment to initiate motion. Passive stiffness curves indicate greater stiffness properties in those with limited hip mobility, and more resistance to an external rotation moment than internal rotation. Study #5 investigated passive hip stiffness in the sagittal plane, comparing those with limited and excessive hip extension. Using a frictionless jig, with the participants lying on their left side, the left hip was pulled into extension with knee position varying. Those with limited hip mobility demonstrated increased passive stiffness compared to the more mobile group, and stiffness was greater when the knee was in extension. The group with limited mobility also showed a trend of increased back extension compared to the more mobile group, when the hip and lumbar spine were both free to react to the applied extension moment. Study #6 summarizes the spine/hip kinematics and muscle activation levels produced when using the elliptical trainer, as well as lumbar compressive and shear forces. It differs significantly from walking in that it produces more lumbar motion in flexion/extension and lumbar twist, but less lateral bend. Participants also tended to adopt a greater mean lumbar flexion angle on the elliptical, which in turn resulted in greater muscle activity in the back extensors. Varying hand position, velocity and stride length were all found to significantly affect the amount of lumbar motion. Highly phasic muscle activity is seen, with the gluteal muscles and internal obliques demonstrating the greatest activation levels.

No description available.

Lacrosse, Canada’s national summer sport, is a sport anchored in first nations’ tradition. Its growing popularity in North America has not been reflected by a similar interest in the scientific literature more specifically on the biomechanics of the lumbar spine with its throwing motion. The aim of this study was to describe the motions, forces and muscle actions of the lumbar spine with the hybrid, overhand and sidearm throw. Twelve subjects were asked to throw at maximal speed while captured by a 3D motion analysis system. Flexion, extension and axial rotation angular velocities as well as positive and negative powers in the two planes were calculated. The first research question pertained to consistency in angular velocities and powers between trials of a given throwing technique. Subjects showed a fairly high variation on all variables but mostly with the angular velocities in extension and the peak positive power in flexion/extension which had high coefficient of variations (CVs). The contralateral rotation velocity and the positive rotation power had the lowest CVs. Overall the CVs for powers exceeded the angular velocities’. The second research question addressed if a difference in variables was present between the three throwing methods. A significant difference was observed in the peak negative power in flexion/extension and the peak positive power in rotation. The contralateral rotation angular velocity also showed a significant difference but the sphericity assumption failed. No other variable showed a significant difference but the observed power for those variables was also quite small. Due to the lack of power and the further need for controlling some unforeseen sources of error, this study can be used as a pilot study to further define and improve future studies in the field of lacrosse biomechanics.

Thesis (M App Sci) -- University of South Australia, 1992

Thesis (M.App.Sc. (Physio))--University of South Australia, 1998.

Thesis (M.S.)--University of Toledo, 2009. / Typescript. "Submitted as partial fulfillment of the requirements for the Master of Science Degree in Mechanical Engineering." "A thesis entitled"--at head of title. Bibliography: leaves 92-98.

A dynamic lumbar spinal stabilizer with a helical machined spring element was created in the first stage. The stabilizer was built with 30 N/mm of axial stiffness because if the human body is moved to flexion and extension, this amount of a compressive and tensile load would be applied to the intervertebral disc. The stabilizer supports the loads instead of the disc. The stiffness was influenced by the number of coils, the thickness of coils, and length of the coil element. The stiffness can be determined by analytical equations or by finite element analysis (FE), such as ANSYS Workbench. In the second stage, the lumbar spine FE model was successfully constructed by using Autodesk Inventor 2010. There were three different analyzed models; (1) intact model, (2) fused model, and (3) dynamically stabilized model. This intact model is a simplified and basic model used for fused model and dynamically stabilized model. The range of motion (ROM) was the key term in this study. In other words, examination of each model was based on how much ROM was shown when the flexion, extension, and bending moments have been applied on the spine. The ROM of each model with three moments produced appropriate values compared to the references. The stress analysis is also important to optimize the design of the dynamic stabilizer. The maximum stress was 472 MPa on the stabilizer that is less than yield strength of Titanium alloy.

M.Tech. / Manual medicine practitioners rely on clinical skills to diagnose and treat patients with musculoskeletal complaints. Palpatory analysis of a patient is used to identify their problem, treat the problems found and evaluate the result of the treatment (Ward 1996). Despite this reliance on palpation as a clinical tool, the reliability of palpation remains to be proven (O'Haire & Gibbons 2000). Chiropractors' and other manual medicine practitioners' ability to accurately identify bony anatomical landmarks needs to be validated as static palpation, followed by motion palpation are based on the assumption of this ability (O'Haire & Gibbons 2000). The most common method of identifying lumbar interspaces is to use the intercrestal line, which is drawn between the two iliac crests (Reynolds 2000). The intercrestal line is reported to most frequently cross the vertebral column at the L4-5 disc (Mac Gibbon & Farfan 1979; Quinelle & Stockdale 1983), L4 spinous process (Cunningham & Romanes 1979; Nimmo et al 1994), or L4-5 interspinous space (Render 1996). From this it is clear that no clear consensus exists, at least not in the literature, as to where exactly the intercrestal line intersects the spine. This study aimed to determine whether palpation of the superior aspect of the iliac crest is a reliable, accurate and/or valid method of determining the location of the spinous process of the fourth lumbar vertebra in the standing, seated and prone positions. Thirty participants were marked by three examiners in the standing, seated and prone positions, using the iliac crests to locate the fourth lumbar vertebra. An X-ray was taken of each participant in each of the three positions, after being marked by all three examiners. Measurements were then made on the x-rays, as well as visual assessments by examiners to assess the location of the markers on the lumbar anatomy. The results demonstrated consistent inter-examiner reliability, however the accuracy of using the iliac crest to locate the fourth lumbar vertebra was poor. This is disappointing as the ability to palpate spinal levels is a basic skill and a pre-requisite to more complex palpatory tasks within manual medicine. As for the validity aspect of using the iliac crests to locate the fourth lumbar vertebra, this method was found to be valid in locating the spinous process of the fourth lumbar vertebra. However, it is not a very reliable method, considering that there is only a 53.3% chance of locating the spinous process of L4 once in three attempts in the standing and seated positions and only a 46.7% in the prone position. The reliability of palpation of anatomical landmarks needs to be validated further in future studies as motion palpation and the palpatory assessment of effectiveness of treatment applied to correct motion restriction are predicted upon accurate localization of anatomical landmarks The large variation in intersection points of the intercrestal line does however possibly explain the different opinions found in the literature, and it can be said that to a certain degree all of them are correct.

M.Tech. / OBJECTIVE: The aim of this study was to determine the electromyographic effect of flexion distraction therapy of the lumbar spine on the Erector Spinae muscles in participants with lumbar facet dysfunction. STUDY DESIGN: Thirty participants with lumbar facet dysfunction underwent 6 flexion distraction therapy treatments on alternate days over a 2-week period (excluding weekends) to test the electromyographic effect on the Erector Spinae muscle. SETTING: University of Johannesburg Chiropractic Clinic, Johannesburg, South Africa. SUBJECTS: Thirty participants with lumbar facet dysfunction participated in this study. The participants were divided into two groups of fifteen participants each and matched according to age and gender. Group 1, the study group, received flexion distraction therapy to the restricted segments in the lumbar spine. Group 2, the control group, did not receive any flexion distraction therapy and rested during the duration of the treatment. METHODS: Lumbar Erector Spinae muscle electrical activity was tested before and after treatment one, three and six using surface electromyography (sEMG). One pair of bipolar electrodes was placed bilaterally over the Erector Spinae muscles at the level of L3. Participants were asked to lie down in a prone position with their arms next to their sides. They were then instructed to perform five maximum voluntary lower back extension exercises by lifting their chests and shoulders as high off the plinth as possible. Each contraction lasted five seconds, with a rest period of ten seconds between each contraction. The average rest and work surface electromyography readings were recorded, analysed and compared for reference. Information regarding the intensity of the pain experienced by the vii subjects was also collected at the start of treatment one, three and five using the Numerical Pain Rating Scale. RESULTS: Comparison of the results indicated a statistically significant difference between the two groups and their responses to the treatments. Subjectively, a statistically significant improvement was observed in Group 1 between the third and the sixth treatments and the first and the sixth treatments, with an overall 80% improvement in pain, thus demonstrating the medium to long term effects of flexion distraction therapy. Objectively, Group 1 demonstrated a statistically significant medium to long term improvement in the resting rate of the Erector Spinae muscles as observed between the first and sixth treatments. Statistically, the two groups responded differently over time with regards to the contraction ability of the Erector Spinae muscle. A statistically significant and immediate improvement was observed in the sixth treatment in Group 1, thus further supporting the long term effects and benefits of flexion distraction therapy. CONCLUSION: In light of these findings it can be concluded that flexion distraction therapy, as represented by Group 1, demonstrated favourable treatment results in terms of the pain experienced by the subjects, the resting rate and contraction ability of the Erector Spinae muscles. The trends observed in this study should be used and tested in future research studies of a similar nature incorporating larger sample groups.

Lacrosse, Canada’s national summer sport, is a sport anchored in first nations’ tradition. Its growing popularity in North America has not been reflected by a similar interest in the scientific literature more specifically on the biomechanics of the lumbar spine with its throwing motion. The aim of this study was to describe the motions, forces and muscle actions of the lumbar spine with the hybrid, overhand and sidearm throw. Twelve subjects were asked to throw at maximal speed while captured by a 3D motion analysis system. Flexion, extension and axial rotation angular velocities as well as positive and negative powers in the two planes were calculated. The first research question pertained to consistency in angular velocities and powers between trials of a given throwing technique. Subjects showed a fairly high variation on all variables but mostly with the angular velocities in extension and the peak positive power in flexion/extension which had high coefficient of variations (CVs). The contralateral rotation velocity and the positive rotation power had the lowest CVs. Overall the CVs for powers exceeded the angular velocities’. The second research question addressed if a difference in variables was present between the three throwing methods. A significant difference was observed in the peak negative power in flexion/extension and the peak positive power in rotation. The contralateral rotation angular velocity also showed a significant difference but the sphericity assumption failed. No other variable showed a significant difference but the observed power for those variables was also quite small. Due to the lack of power and the further need for controlling some unforeseen sources of error, this study can be used as a pilot study to further define and improve future studies in the field of lacrosse biomechanics.