The impact of different lenses on visual and musculoskeletal complaints in VDU workers with work-related neck complaints : a randomized controlled trial

Objectives: The impact of wearing lenses on visual and musculoskeletal complaints in VDU workers is currently unknown. The goal of this study was 1) to evaluate the impact of wearing VDU lenses on visual fatigue and self-reported neck pain and disability, compared to progressive lenses, and 2) to measure the effect of both lenses on head inclination and pressure pain thresholds during the performance of a VDU task. Methods: Thirty-five eligible subjects were randomly assigned to wear progressive VDU lenses (VDU group) (n = 18) or progressive lenses (P group) (n = 17). They were enquired about visual complaints (VFQ), self-perceived pain (NRS) and disability (NDI) at baseline (with old lenses), and 1 week, 3 months and 6 months after wearing their new lenses. In addition, Forward Head Angle (FHA) and PPTs were assessed during and after a VDU task before and 6 months after wearing the new lenses. A short questionnaire concerning the satisfaction about the study lenses was completed at the end of the study. Results: In both groups, visual fatigue and neck pain was decreased at 3 and 6 months follow up, compared to baseline. All PPTs were higher during the second VDU task, independent of the type of lenses. The VDU group reported a significantly higher suitability of the lenses for VDU work. Conclusion: It can be concluded that there is little difference in effect of the different lenses on visual and musculoskeletal comfort. Lenses should be adjusted to the task-specific needs and habits of the participant

Foci of segmentally contracted sarcomeres in trapezius muscle biopsy specimens in myalgic and nonmyalgic human subjects : preliminary results

Objective The myofascial trigger point hypothesis postulates that there are small foci of contracted sarcomeres in resting skeletal muscle. Only one example, in canine muscle, has been published previously. This study evaluated human muscle biopsies for foci of contracted sarcomeres. Setting The Departments of Rehabilitation Sciences and Physiotherapy at Ghent University, Ghent, Belgium. Subjects Biopsies from 28 women with or without trapezius myalgia were evaluated, 14 in each group. Methods Muscle biopsies were obtained from regions of taut bands in the trapezius muscle and processed for light and electron microscopy and for histochemical analysis. Examination of the biopsies was blinded as to group. Results A small number of foci of segmentally contracted sarcomeres were identified. One fusiform segmental locus involved the entire muscle fiber in tissue from a myalgic subject. Several transition zones from normal to contracted sarcomeres were found in both myalgic and nonmyalgic subjects. The distance between Z-lines in contracted sarcomeres was about 25–45% of the same distance in normal sarcomeres. Z-lines were disrupted and smeared in the contracted sarcomeres. Conclusions A small number of foci of segmentally contracted sarcomeres were found in relaxed trapezius muscle in human subjects, a confirmation of the only other example of spontaneous segmental contraction of sarcomeres (in a canine muscle specimen), consistent with the hypothesis of trigger point formation and with the presence of trigger point end plate noise

Differences in the mitochondrial and lipid droplet morphology in female office workers with trapezius myalgia, compared to healthy controls : a muscle biopsy study

Objective: Trapezius myalgia, or more specific, myofascial dysfunction of the upper trapezius mainly affects women performing jobs requiring prolonged low level activation of the muscle. This continuous low muscle load can be accompanied by a shift to a more anaerobic energy metabolism, causing pain. To investigate whether morphological signs of an impaired aerobic metabolism are present in female office workers with trapezius myalgia. Design: Muscle biopsy analysis, using electron and light microscopy, was performed to compare mitochondrial and fat droplet morphology, and irregular muscle fibers, between female office workers with (n=17) and without (n= 15) work-related trapezius myalgia. Results: The patient group showed a significantly higher mean area (P=0.023) and proportion (P=0.029) for the subsarcolemmal and intermyofibrillar mitochondria respectively, compared to the control group. A significantly lower mean area of subsarcolemmal lipid droplets was found in the patient group (P=0.015), which also displayed a significantly higher proportion of lipid droplets touching the mitochondria (P=0.035). A significantly higher amount of muscle fibers with COX deficient areas were found in the patient group (P=0.030). Conclusion: The results of the present study may be indicatve for an impaired oxidative metabolism in work-related trapezius myalgia. However, additional research is necessary to confirm this hypothesis

Exploring the underlying mechanisms of action of dry needling

Objective: Dry needling is a commonly used treatment technique for myofascial pain syndromes, such as trapezius myalgia. Despite the shown positive clinical effects on pain, the underlying mechanisms of action, such as the effect on muscle electrophysiology, remain unclear. The aim of this study was to investigate the effect of dry needling, compared with sham needling, in the upper trapezius muscle on surface electromyography activity and the relation with pain in office workers with trapezius myalgia. Design: For this experimental randomized controlled trial, 43 office workers with work-related trapezius myalgia were included. Surface electromyography activity was measured before and after a pain-provoking computer task and immediately after, 15, and 30 mins after treatment with dry or sham needling. Pain scores were evaluated at the same time points as well as 1, 2, and 7 days after treatment. Results: No significant differences in surface electromyography activity between dry needling and sham needling were found. Significant positive low to moderate Spearman correlations were found between surface electromyography activity and pain levels after dry needling treatment. Conclusions: This study shows no immediate effects of dry needling on the electrophysiology of the upper trapezius muscle, compared with sham needling

Exploring the underlying mechanisms of action of dry needling : what is the immediate effect on muscle electrophysiology? An experimental randomized controlled trial

Objective: Dry needling is a commonly used treatment technique for myofascial pain syndromes, such as trapezius myalgia. Despite the shown positive clinical effects on pain, the underlying mechanisms of action, such as the effect on muscle electrophysiology, remain unclear. The aim of this study was to investigate the effect of dry needling, compared with sham needling, in the upper trapezius muscle on surface electromyography activity and the relation with pain in office workers with trapezius myalgia. Design: For this experimental randomized controlled trial, 43 office workers with work-related trapezius myalgia were included. Surface electromyography activity was measured before and after a pain-provoking computer task and immediately after, 15, and 30 mins after treatment with dry or sham needling. Pain scores were evaluated at the same time points as well as 1, 2, and 7 days after treatment. Results: No significant differences in surface electromyography activity between dry needling and sham needling were found. Significant positive low to moderate Spearman correlations were found between surface electromyography activity and pain levels after dry needling treatment. Conclusions: This study shows no immediate effects of dry needling on the electrophysiology of the upper trapezius muscle, compared with sham needling

The relation between hearing status, cognition and listening effort in adults with and without tinnitus

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Clinical classification criteria for nonspecific low back pain: A Delphi-survey of clinical experts

BACKGROUND: Nonspecific low back pain (NSLBP) is a common problem. Attempts have been made to classify NSLBP patients into homogenous subgroups. Classification systems based on identifying the underlying mechanism(s) driving the disorder are clinically useful to guide specific interventions. OBJECTIVE: To establish consensus among experts regarding clinical criteria suggestive of a dominance of 'articular', 'myofascial', 'neural', 'central', and 'sensorimotor control' dysfunction patterns (DPs) in NSLBP patients. STUDY DESIGN: A 2-phase sequential design of a focus group and Delphi-study. METHODS: A focus group with 10 academic experts was organized to elaborate on the different DPs discernible in LBP patients. Consecutively, a 3-round online Delphi-survey was designed to obtain consensual symptoms and physical examination findings for the 5 DPs resulting from the focus group. RESULTS: Fifteen musculoskeletal physical therapists from Belgium and the Netherlands experienced in assessing and treating LBP patients completed the Delphi-survey. Respectively, 34 (response rate, 100.0%), 20 (58.8%) and 15 (44.12%) respondents replied to rounds 1, 2 and 3. Twenty-two 'articular', 20 'myofascial', 21 'neural', 18 'central' and 11 'sensorimotor control' criteria reached a predefined ≥80% consensus level. For example, after round 2, 85.0% of the Delphi-experts agreed to identify 'referred pain below the knee' as a subjective examination criterion suggestive for a predominant 'neural DP'. CONCLUSION: These indicators suggestive of a clinical dominance of the proposed DPs could help clinicians to assess and diagnose NSLBP patients. Future reliability and validity testing is needed to determine how these criteria may help to improve physical therapy outcome for NSLBP patients.status: publishe