Effects of an adapted physical activity program in a group of elderly subjects with flexed posture: clinical and instrumental assessment
From: J Neuroeng Rehabil. 2008 Nov 25;5(1):32 [Epub ahead of print]
Posture is not static but is a dynamic process represented by alignment of the body’s anatomical units in relationship to one another at any given time. Posture can be influenced by multiple factors. These factors can be static, as in the anatomical makeup of an individual, or dynamic, related to neuromuscular systems. The flexed posturing that often develops places the center of gravity closer to their limit of stability.
Flexed posture commonly increases with age and is related to musculoskeletal impairment and reduced physical performance. A double-blind, two-arm, randomized 3-month clinical trial was conducted for 3 months in order to evaluate the effects of an Adapted Physical Activity program for flexed posture on the postural alignment and the physical performance of the elderly.
Participants were randomly divided into two groups: one followed an Adapted Physical Activity program for flexed posture inspired to the Sinaki proposal and the other one completed a non-specific physical activity protocol for the elderly. A multidimensional clinical assessment was performed at baseline and at 3 months including anthropometric data, clinical profile, measures of musculoskeletal impairment and disability. The instrumental assessment of posture was realized using a stereophotogrammetric system and a specific biomechanical model designed to describe the reciprocal position of the body segments on the sagittal plane in a upright posture.
(more…)
Analysis of lumbar disc degeneration using three-dimensional nonlinear finite element method
From: Zhonghua Yi Xue Za Zhi. 2008 Jun 17;88(23):1634-8
To explore the effects of intervertebral disc degeneration on the biomechanical behavior of the lumbar motion segment, a three-dimensional nonlinear finite element model of L4-L5 segment was established using CAD technique based on CT images. A normal disc model and three degenerative disc models were established by changing the parameters such as disc material properties and disc height. The effects of disc degeneration on the biomechanical properties, including stiffness, nucleus pressure, maximum von Mises stress in the annulus, and force of posterior structure were studied under two moment loads (flexion and extension) and for three different direct forces (compression, and anterior and posterior shear forces), and the stress distribution of vertebral body and endplate was also analyzed.
The stiffness of the lightly degenerative disc model was decreased compared with that of the normal disc, while it was increased in the moderately and severely degenerative disc models when compared with the normal disc. The force of posterior structure in the lightly degenerative disc model was increased while the values of force of posterior structure in the moderately and severely degenerative disc models were decreased gradually. The maximum von Mises stress in the annulus increased, and the nucleus pressure decreased as the disc degeneration progressed. Moreover, the stress of intervertebral disc, vertebral body, and endplate was distributed more peripherally.
Light degeneration of intervertebral disc leads to instability of lumbar spine, while the stability restores with further degeneration of disc. There is a negative correlation between the force of posterior structure and the load on the intervertebral disc. With the disc degeneration progressing, the intervertebral disc load pattern changes, the stress of intervertebral disc, vertebral body, and endplate is concentrated peripherally.
Advice for the management of low back pain: a systematic review of randomised controlled trials
From: Man Ther. 2007 Nov;12(4):310-27. Epub 2007 Mar 28
The socio-economic burden of low back pain continues to increase due largely to disproportionate rises in low back pain disability. Indeed, in the 3 years from 1992–1995, days of work disability in the UK are reported to have escalated from 27 to 125 million. While it is estimated that about 90% of acute back pain patients return to work within three months, many experience symptom recurrence and functional limitation.
Advice constitutes all the information that the patient receives verbally, in written, audiovisual, or electronic format during the course of treatment. Its value to the physiotherapist is well recognised, and as such is a common component in the management of low back pain; the use of ‘The Back Book’, produced by the Royal College of General Practitioners (RCGP), has been widely endorsed as a means of encouraging low back pain patients to stay active . At present, the provision of advice to promote an understanding of low back pain, and the importance of the patient playing an active role in their recovery, is largely dependent on the individual clinician, their available time and resources. As a result, the most efficacious means of delivering advice, what such advice may comprise, and the frequency with which it is provided, has not been widely investigated in the low back pain literature. While back schools have aimed to maximise the value of group-based advice and education, trials in this area to date have largely been of poor quality; furthermore, variations in the content of back schools have made it difficult to isolate their most beneficial features and, as a result, their cost-effectiveness is debatable. Waddell et al. have indicated that patients need clear and unambiguous advice about low back pain and its management, with individually tailored treatment being purported to improve outcomes. Tailored programmes are thought to promote adherence to treatment, increased patient responsibility, and sustainable behaviour change. Current guidelines are in place to recommend that acute low back pain patients are best to stay active for faster return to work and less chronic disability. Little attention has been directed at the specific type of advice offered to patients with low back pain, whether this advice varies depending on symptom duration, the value of advice used in conjunction with other interventions, and its relevance in terms of low back pain treatment outcomes.
(more…)
The association between prevalent neck pain and health related quality of life
From: Eur Spine J. 2008 Nov 20; [Epub ahead of print]
The aim of this study was to examine the association between grades of neck pain severity and health related quality of life, using a population-based, cross-sectional mailed survey. The literature suggests that physical and mental health related quality of life is worse for individuals with neck pain compared to those without neck pain. However, the strength of the association varies across studies. Discrepancies in study results may be attributed to the use of different definitions and measures of neck pain and differences in the selection of covariates used as control variables in the analyses. The Saskatchewan Health and Back Pain Survey was mailed to 2,184 randomly selected Saskatchewan adults of whom 1,131 returned the questionnaire. Neck pain was measured with the Chronic Pain Questionnaire and categorized into four increasing grades of severity. We measured health related quality of life with the SF-36 Health Survey and computed the physical and mental component summary scores. We built separate multiple linear regression models to examine the association between grades of neck pain and physical and mental summary scores while controlling for sociodemographic, general health and comorbidity covariates. The crude analysis suggests that a gradient exists between the severity of neck pain and health related quality of life.
Compared to individuals without neck pain, those with Grades III-IV neck pain have significantly lower physical and mental health related quality of life. Controlling for covariates greatly reduced the strength of association between neck pain and physical health related quality of life and accounted for the observed association between neck pain and mental health related quality of life. In the comorbidity model, the strength of association between Grades III-IV neck pain and PCS decreased by more than 50%. In the final PCS model, Grades III-IV neck pain coefficients changed only slightly from the comorbidity model. This suggests that comorbid conditions account for most of the association between neck pain and PCS score. It was concluded that prevalent neck pain is weakly associated with physical health related quality of life, and that it is not associated with mental health related quality of life. This cross-sectional analysis suggests that most of the observed association between prevalent neck pain and health related quality of life is attributable to comorbidities.
Intervertebral neural foramina deformation due to two types of repetitive combined loading
From: Clin Biomech (Bristol, Avon). 2008 Nov 11; [Epub ahead of print]
Tissue compression and noxious stimuli are known to elicit pain from neural tissues in the spine. Compression of nerve roots due to decreases in the intervertebral foramina may be caused by posture, sustained loading and disc height loss, herniation, or altered mechanics. It has been established that non-neutral postures combined with repeated loading can cause disc herniations, however information regarding the effect of repetitive axial twist loading is limited. The objectives of this study were twofold; to measure the occlusion of the foramina due to two types of repetitive loading and to investigate whether repetitive combined axial twist loading can contribute to disc injury.
Sixteen porcine cervical spine segments (C5/6) were subjected to 1500N of compression combined with either repetitive flexion-extension motions or 16.4 degrees (Standard Deviation 2.1) of static flexion with repetitive axial twist motions. The foramina pressure was measured bilaterally using plastic tubing and a custom pressure monitoring system. Specimens were loaded until 10,000 cycles were reached or disc herniation occurred.
Significantly larger pressure (pre-post difference) developed in the intervertebral foramina of specimens that were repetitively flexed-extended compared to those that were repetitively twisted. All of the flexed-extended specimens herniated, whereas in the twisted specimens five (62.5%) had incomplete herniations, one (12.5%) sustained a facet fracture, and two (25%) had no damage. There was no difference between the loading groups for vertical height loss.
Repetitive loading of flexion-extension motions are a viable pain generating pathway in absence of distinguishing height loss. This information may be useful to consider for the diagnosis and treatment of nerve root compression.
The Nordic back pain subpopulation program: predicting outcome among chiropractic patients in Finland
From: Chiropr Osteopat. 2008 Nov 7;16(1):13 [Epub ahead of print]
The causes of non specific low back pain are largely unknown. Obviously, this is a hindrance to a rational approach to both prevention and treatment. In general, both etiologic studies and randomized controlled clinical trials are based on the concept that non specific low back pain is one single entity. However, most clinicians with an interest in back pain probably consider it to consist of several specific conditions, which have not been properly recognized, understood and described.
Chiropractors in the Nordic countries use predominantly spinal manipulative therapy in their treatment of back problems, frequently in combination with soft tissue therapy, advice on exercise, ergonomic precautions, and lifestyle changes. Randomized controlled clinical trials have shown that spinal manipulative therapy has a positive effect on low back pain. However, overall, the magnitude of the effect seems to be relatively small. Those, who believe that back pain consists of several specific but (as yet) undefined subgroups, obviously think that the recognition of these would improve the quality of care and that the selection of homogeneous study populations in etiological studies and clinical trials would improve the quality of research.
Until recently it has not been documented which patients with low back pain are most likely to benefit from the chiropractic approach. However, the predictive value of a set of clinical observations has been previously studied in patients with low back pain receiving chiropractic care. This research, conducted in Norway and Sweden under the Nordic Back Pain Subpopulation Program, has been running over the past years, in which specific subgroups of patients with low back pain are systematically studied. For instance, it was shown that it is possible to predict which chiropractic patients with persistent low back pain will not report definite improvement early in the course of treatment, making it possible to exclude from treatment those who are unlikely to become low back pain free. Furthermore, early recovery at the 4th visit was noted to be a predictor for outcome 3 and 12 months later and the status already by the second visit predicted status at the fourth visit.
(more…)
