Low back pain patients demonstrate increased hip extensor muscle activity during standardized submaximal rotation efforts

Study Design. A comparative study of trunk and hip extensor muscle recruitment patterns in 2 subject groups. Objective. To examine for changes in recruitment of the hip and back extensor muscles during low level isometric trunk rotation efforts in chronic low back pain (CLBP) subjects by comparison with matched asymptomatic control subjects. Summary of Background Data. Anatomic and biomechanical models have provided evidence that muscles attaching to the thoracolumbar fascia (TLF) are important for providing stabilization to the lumbopelvic region during trunk rotation. This has guided rehabilitation programs. The muscles that link diagonally to the posterior layer of the TLF have not previously been examined individually and compared during low-level trunk rotation efforts in CLBP patients and matched controls. Methods. Thirty CLBP patients and 30 matched controls were assessed using surface electromyography (EMG) as they performed low-level isometric rotation efforts while standing upright. Muscles studied included latissimus dorsi, erector spinae, upper and lower gluteus maximus, and biceps femoris. Subjects performed the rotation exertion with various levels of external trunk support, related to different functional tasks. Results. EMG results demonstrated that subjects with CLBP had significantly higher levels of recruitment for the lower and upper gluteus maximus (P < 0.05), hamstrings (P < 0.05), and erector spinae muscles (P < 0.05) during rotation to the left compared with the control subjects. Conclusion. This study provided evidence of increased muscle recruitment in CLBP patients when performing a standardized trunk rotation task. These results may have implications for the design of therapeutic exercise programs for CLBP patients.

The rural medicine rotation: Increasing rural recruitment through quality undergraduate rural experiences

TITLE: The Rural Medicine Rotation: Increasing Rural Recruitment through Quality Undergraduate Rural Experiences Eley Diann, University of Queensland, School of Medicine, Rural Clinical Division, Toowoomba 4350, Queensland Australia Baker Peter, University of Queensland, School of Medicine Rural, Clinical Division, Toowoomba 4350, Queensland Australia Chater Bruce, University of Queensland, Chair, Clinical School Management Committee, School of Medicine Rural Clinical Division, Queensland Australia CONTEXT: While rural background and rural exposure during medical training increases the likelihood of rural recruitment (Wilkinson, 2003), the quality and content of that exposure is the key to altering undergraduatesâ?? perceptions of rural practice. The Rural Clinical Division at University of Queensland (UQ) runs the Rural Medicine Rotation (RMR) within the School of Medicine. The RMR is one of five eight week clinical rotations in Year three and is compulsory for all students. The RMR provides the opportunity to learn from a wide range of health professionals and clinical exposure is not restricted to general practice but also includes remote area nursing, Indigenous health care, allied health professionals and medical specialists. Week 1 involves preparation for their rural placement with workshops and seminars and Week 8 consolidates their placement and includes case and project presentations and a summative assessment. Weeks 2-7 are spent living and working as part of the health team in different rural communities. SETTING: Rural communities in and around Queensland including locations such as Arnham Land, Thursday Island, Mt. Isa and Alice Springs METHOD: All aspects of the RMR are evaluated with surveys using both qualitative and quantitative free response questions, completed by all students at the end of the Week 8. RESULTS: Overall the RMR is evaluated highly and narratives offered by students show that the RMR provides a positive rural experience. The overall impact of the RMR for students in 2004 ranked 3.45 on a scale of 1 to 4 (1 = lowest and 4 = highest), and is exemplified by the following quote; â??I enjoyed my placement so much I am now considering rural medicine something I definitely had not considered beforeâ??. OUTCOME: The positive impact of the RMR on studentâ??s perceptions of rural medicine is encouraging and can help achieve the overall aim of increasing recruitment of the rural workforce in Australia.

Objective analysis of toric intraocular lens rotation and centration

PURPOSE: To assess the repeatability of an objective image analysis technique to determine intraocular lens (IOL) rotation and centration. SETTING: Six ophthalmology clinics across Europe. METHODS: One-hundred seven patients implanted with Akreos AO aspheric IOLs with orientation marks were imaged. Image quality was rated by a masked observer. The axis of rotation was determined from a line bisecting the IOL orientation marks. This was normalized for rotation of the eye between visits using the axis bisecting 2 consistent conjunctival vessels or iris features. The center of ovals overlaid to circumscribe the IOL optic edge and the pupil or limbus were compared to determine IOL centration. Intrasession repeatability was assessed in 40 eyes and the variability of repeated analysis examined. RESULTS: Intrasession rotational stability of the IOL was ±0.79 degrees (SD) and centration was ±0.10 mm horizontally and ±0.10 mm vertically. Repeated analysis variability of the same image was ±0.70 degrees for rotation and ±0.20 mm horizontally and ±0.31 mm vertically for centration. Eye rotation (absolute) between visits was 2.23 ± 1.84 degrees (10%>5 degrees rotation) using one set of consistent conjunctival vessels or iris features and 2.03 ± 1.66 degrees (7%>5 degrees rotation) using the average of 2 sets (P =.13). Poorer image quality resulted in larger apparent absolute IOL rotation (r =-0.45,P<.001). CONCLUSIONS: Objective analysis of digital retroillumination images allows sensitive assessment of IOL rotation and centration stability. Eye rotation between images can lead to significant errors if not taken into account. Image quality is important to analysis accuracy.

Independent detectors for expansion and rotation, and for orthogonal components of deformation

It is well known that optic flow - the smooth transformation of the retinal image experienced by a moving observer - contains valuable information about the three-dimensional layout of the environment. From psychophysical and neurophysiological experiments, specialised mechanisms responsive to components of optic flow (sometimes called complex motion) such as expansion and rotation have been inferred. However, it remains unclear (a) whether the visual system has mechanisms for processing the component of deformation and (b) whether there are multiple mechanisms that function independently from each other. Here, we investigate these issues using random-dot patterns and a forced-choice subthreshold summation technique. In experiment 1, we manipulated the size of a test region that was permitted to contain signal and found substantial spatial summation for signal components of translation, expansion, rotation, and deformation embedded in noise. In experiment 2, little or no summation was found for the superposition of orthogonal pairs of complex motion patterns (eg expansion and rotation), consistent with probability summation between pairs of independent detectors. Our results suggest that optic-flow components are detected by mechanisms that are specialised for particular patterns of complex motion.

Multiwavelength fiber laser with fine adjustment, based on nonlinear polarization rotation and birefringence fiber filter

We have proposed and demonstrated a multiwavelength fiber laser based on nonlinear polarization rotation (NPR). The mechanism for stable room-temperature multiwavelength operation contributes to the ability of the intensity-dependent loss in NPR to effectively alleviate mode competition. In addition, through tuning the birefringence fiber filter, the lasing wavelength can be accurately tuned in the free spectrum range of the in-line periodic filter.