66 research outputs found

    An electromyographic comparison of neck conditioning exercises in healthy controls

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    The purpose of this study was to compare surface electromyography (EMG) activation levels of selected neck muscles for two common neck-training modalities (Thera-Band and Cybex). Seventeen asymptomatic subjects (eight men and nine women) with a mean age 23.4 years were recruited. EMG activation normalized to maximal voluntary isometric contraction (MVIC) was measured with subjects performing exercises with green, blue, and black Thera-Bands and 50%, 70%, and 90% of 3RM for the Cybex modality. Four variables were used to depict exercise intensity: average and peak EMG activation in the concentric and eccentric phases. Significant differences (P &lt;= 0.05) in EMG activation were evident when comparing intensities of the Cybex modality with each other and when comparing the Cybex intensities with Thera-Band intensities in most cases. Minimal differences were found among differing intensities of Thera-Band. Thera-Band exercise resulted in low-level EMG activation (range, flexion 3.8-15.7% MVIC; range, extension 20.2-34.8% MVIC); therefore, such exercise may be useful in rehabilitation programs. Cybex exercise (range, flexion 20.9-83.5% MVIC; range, extension 40.6-95.8% MVIC) may be useful for occupation-related injury prevention. However, exercise prescription should be undertaken with care as the mechanical loading on passive spinal structures is unknown.<br /

    Neck exercises compared to muscle activation during aerial combat maneuvers

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    Introduction: Performing specific neck strengthening exercises has been proposed to decrease the incidence of neck injury and pain in high performance combat pilots. However, there is little known about these exercises in comparison to the demands on the neck musculature in flight. Methods: Eight male non-pilots performed specific neck exercises using two different modalities (elastic band and resistance machine) at six different intensities in flexion, extension, and lateral bending. Six Royal Australian Air Force Hawk pilots flew a sortie that included combinations of three +Gz levels and four head positions. Surface electromyography (EMG) from selected neck and shoulder muscles was recorded in both activities. Results: Muscle activation levels recorded during the three elastic band exercises were similar to in-flight EMG collected at +1 Gz (15% MVIC). EMG levels elicited during the 50% resistance machine exercises were between the +3 Gz (9-40% MVIC) and +5 Gz (16-53% MVIC) ranges of muscle activations in most muscles. EMG recorded during 70% and 90% resistance machine exercises were generally higher than in-flight EMG at +5 Gz. Discussion: Elastic band exercises could possibly be useful to pilots who fly low +Gz missions while 50% resistance machine mimicked neck loads experienced by combat pilots flying high +Gz ACM. The 70% and 90% resistance machine intensities are known to optimize maximal strength but should be administered with care because of the unknown spinal loads and diminished muscle force generating capacity after exercise.<br /

    Chronic low back pain is associated with reduced vertebral bone mineral measures in community-dwelling adults

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    <p>Abstract</p> <p>Background</p> <p>Chronic low back pain (CLBP) experienced in middle-age may have important implications for vertebral bone health, although this issue has not been investigated as a primary aim previously. This study investigated the associations between CLBP and dual energy X-ray absorptiometry (DXA)-derived vertebral bone mineral measures acquired from postero-anterior and lateral-projections, among community-dwelling, middle-aged adults.</p> <p>Methods</p> <p>Twenty-nine adults with CLBP (11 male, 18 female) and 42 adults with no history of LBP in the preceding year (17 male, 25 female) were evaluated. Self-reported demographic and clinical data were collected via questionnaires. Areal bone mineral density (aBMD) was measured in the lumbar spine by DXA. Apparent volumetric (ap.v) BMD in the lumbar spine was also calculated. Multiple linear regression models were used to examine associations between study group (CLBP and control) and vertebral DXA variables by gender, adjusting for height, mass and age.</p> <p>Results</p> <p>There was no difference between groups by gender in anthropometrics or clinical characteristics. In the CLBP group, the mean (SD) duration of CLBP was 13.3 (10.4) years in males and 11.6 (9.9) years in females, with Oswestry Disability Index scores of 16.2 (8.7)% and 15.4 (9.1)%, respectively. Males with CLBP had significantly lower adjusted lateral-projection aBMD and lateral-projection ap.vBMD than controls at L3 with mean differences (standard error) of 0.09 (0.04) g/cm<sup>2 </sup>(<it>p </it>= 0.03) and 0.02 (0.01) g/cm<sup>3 </sup>(<it>p </it>= 0.04). These multivariate models accounted for 55% and 53% of the variance in lateral-projection L3 aBMD and lateral-projection L3 ap.vBMD.</p> <p>Conclusions</p> <p>CLBP in males is associated with some lumbar vertebral BMD measures, raising important questions about the mechanism and potential clinical impact of this association.</p

    The effect of coaching intervention on elite fast bowling technique over a two year period

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    Fast bowling in cricket is an activity that is well recognised as having high injury prevalence and there has been debate regarding the most effective fast bowling technique. The aim of this study was to determine whether two-year coaching interventions conducted in a group of elite young fast bowlers resulted in fast bowling technique alteration. Selected kinematics of the bowling action of 14 elite young fast bowlers were measured using an 18 camera Vicon Motion Analysis system before and after two-year coaching interventions that addressed specific elements of fast bowling technique. Mann-Whitney tests were used to determine whether any changes in kinematic variables occurred pre- and post-intervention between those who had the coaching interventions and those who didn’t. The coaching interventions, when applied, resulted in a more side-on shoulder alignment at back foot contact (BFC) (p ¼ 0.002) and decreased shoulder counter-rotation (p ¼ 0.001) however, there was no difference in the degree of change in back and front knee flexion angles or lower trunk side-flexion. This study has clearly shown that specific aspects of fast bowling technique are changeable over a two-year period in elite level fast bowlers and this may be attributed to coaching intervention

    Low back pain beliefs are associated to age, location of work, education and pain-related disability in Chinese healthcare, professionals working in China: a cross sectinal survey

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    Background: Low back pain (LBP) is the leading cause of disability worldwide. Evidence pointing towards a more efficacious model of care using a biopsychosocial approach for LBP management highlights the need to understand the pain-related beliefs of patients and those who treat them. The beliefs held by healthcare professionals (HCPs) are known to influence the treatment advice given to patients and consequently management outcomes. Back pain beliefs are known to be influenced by factors such as culture, education, health literacy, place of work, personal experience of LBP and the sequelae of LBP such as disability. There is currently a knowledge gap among these relationships in non-western countries. The aim of this study was to examine the associations between LBP-related beliefs among Chinese HCPs and characteristics of these HCPs. Methods: A convenience sample of 432 HCPs working in various health settings in Shanghai, China, completed a series of questionnaires assessing their demographic characteristics, LBP status, pain-related disability and their beliefs about their own LBP experience, using the Back beliefs Questionnaire (BBQ) and the Fear Avoidance Beliefs Questionnaire (FABQ).Results: Younger Chinese HCPs (20–29 years) held more negative beliefs and attitudes related to LBP compared to older HCPs (>40years; BBQ mean difference [95% CI]: 2.4 [0.9 - 3.9], p = 0.001). HCPs working outside tertiary hospitals had poorer beliefs concerning the inevitable consequences of LBP (BBQ mean difference [95% CI]: -2.4 [-3.8 - -1.0], p = 0.001). HCPs who experienced LBP had higher level of fear avoidance beliefs when experiencing high LBP-related disability (FABQ-physical mean difference [95% CI]: 2.8 [1.5 - 4.1], p < 0.001; FABQ-work mean difference [95% CI]: 6.2 [4.0 - 8.4], p < 0.001)) and had lower level of fear avoidance beliefs if they had completed postgraduate study(FABQ-physical mean difference [95% CI]: 2.9 [-5.8 - 0.0], p = 0.049).Conclusion: This study suggests that LBP-related beliefs and attitudes among Chinese HCPs are influenced by age, location of work, level of LBP-related disability and education level. Understanding back pain beliefs of Chinese HCPs forms an important foundation for future studies into the condition and its management in China

    Regional differences in lumbar spinal posture and the influence of low back pain

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    <p>Abstract</p> <p>Background</p> <p>Spinal posture is commonly a focus in the assessment and clinical management of low back pain (LBP) patients. However, the link between spinal posture and LBP is not fully understood. Recent evidence suggests that considering regional, rather than total lumbar spine posture is important. The purpose of this study was to determine; if there are regional differences in habitual lumbar spine posture and movement, and if these findings are influenced by LBP.</p> <p>Methods</p> <p>One hundred and seventy female undergraduate nursing students, with and without LBP, participated in this cross-sectional study. Lower lumbar (LLx), Upper lumbar (ULx) and total lumbar (TLx) spine angles were measured using an electromagnetic tracking system in static postures and across a range of functional tasks.</p> <p>Results</p> <p>Regional differences in lumbar posture and movement were found. Mean LLx posture did not correlate with ULx posture in sitting (r = 0.036, p = 0.638), but showed a moderate inverse correlation with ULx posture in usual standing (r = -0.505, p < 0.001). Regional differences in range of motion from reference postures in sitting and standing were evident. BMI accounted for regional differences found in all sitting and some standing measures. LBP was not associated with differences in regional lumbar spine angles or range of motion, with the exception of maximal backward bending range of motion (F = 5.18, p = 0.007).</p> <p>Conclusion</p> <p>This study supports the concept of regional differences within the lumbar spine during common postures and movements. Global lumbar spine kinematics do not reflect regional lumbar spine kinematics, which has implications for interpretation of measures of spinal posture, motion and loading. BMI influenced regional lumbar posture and movement, possibly representing adaptation due to load.</p

    Individuals with chronic low back pain have greater difficulty in engaging in positive lifestyle behaviours than those without back pain: An assessment of health literacy

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    Background: Despite the large volume of research dedicated to understanding chronic low back pain (CLBP), patient outcomes remain modest while healthcare costs continue to rise, creating a major public health burden. Health literacy - the ability to seek, understand and utilise health information - has been identified as an important factor in the course of other chronic conditions and may be important in the aetiology of CLBP. Many of the currently available health literacy measurement tools are limited since they measure narrow aspects of health literacy. The Health Literacy Measurement Scale (HeLMS) was developed recently to measure broader elements of health literacy. The aim of this study was to measure broad elements of health literacy among individuals with CLBP and without LBP using the HeLMS.Methods: Thirty-six community-dwelling adults with CLBP and 44 with no history of LBP responded to the HeLMS. Individuals were recruited as part of a larger community-based spinal health study in Western Australia. Scores for the eight domains of the HeLMS as well as individual item responses were compared between the groups.Results: HeLMS scores were similar between individuals with and without CLBP for seven of the eight health literacy domains (p &gt; 0.05). However, compared to individuals with no history of LBP, those with CLBP had a significantly lower score in the domain &lsquo;Patient attitudes towards their health&rsquo; (mean difference [95% CI]: 0.46 [0.11- 0.82]) and significantly lower scores for each of the individual items within this domain (p &lt; 0.05). Moderate effect sizes ranged from d = 0.47-0.65.Conclusions: Although no differences were identified in HeLMS scores between the groups for seven of the health literacy domains, adults with CLBP reported greater difficulty in engaging in general positive health behaviours. This aspect of health literacy suggests that self-management support initiatives may benefit individuals with CLBP.<br /

    Self-oligomerization regulates stability of survival motor neuron protein isoforms by sequestering an SCF<sup>Slmb</sup> degron

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    Spinal muscular atrophy (SMA) is caused by homozygous mutations in human SMN1. Expression of a duplicate gene (SMN2) primarily results in skipping of exon 7 and production of an unstable protein isoform, SMNΔ7. Although SMN2 exon skipping is the principal contributor to SMA severity, mechanisms governing stability of survival motor neuron (SMN) isoforms are poorly understood. We used a Drosophila model system and label-free proteomics to identify the SCFSlmb ubiquitin E3 ligase complex as a novel SMN binding partner. SCFSlmb interacts with a phosphor degron embedded within the human and fruitfly SMN YG-box oligomerization domains. Substitution of a conserved serine (S270A) interferes with SCFSlmb binding and stabilizes SMNΔ7. SMA-causing missense mutations that block multimerization of full-length SMN are also stabilized in the degron mutant background. Overexpression of SMNΔ7S270A, but not wild-type (WT) SMNΔ7, provides a protective effect in SMA model mice and human motor neuron cell culture systems. Our findings support a model wherein the degron is exposed when SMN is monomeric and sequestered when SMN forms higher-order multimers
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