Changes in sensorimotor function and increased trunk muscle fatigability have been identified in patients with chronic low back pain (cLBP). This study assessed the control of trunk force production ...in conditions with and without local erector spinae muscle vibration and evaluated the influence of muscle fatigue on trunk sensorimotor control.
Twenty non-specific cLBP patients and 20 healthy participants were asked to perform submaximal isometric trunk extension torque with and without local vibration stimulation, before and after a trunk extensor muscle fatigue protocol. Constant error (CE), variable error (VE) as well as absolute error (AE) in peak torque were computed and compared across conditions. Trunk extensor muscle activation during isometric contractions and during the fatigue protocol was measured using surface electromyography (sEMG).
Force reproduction accuracy of the trunk was significantly lower in the patient group (CE = 9.81 ± 2.23 Nm; AE = 18.16 ± 3.97 Nm) than in healthy participants (CE = 4.44 ± 1.68 Nm; AE = 12.23 ± 2.44 Nm). Local erector spinae vibration induced a significant reduction in CE (4.33 ± 2.14 Nm) and AE (13.71 ± 3.45 Nm) mean scores in the patient group. Healthy participants conversely showed a significant increase in CE (8.17 ± 2.10 Nm) and AE (16.29 ± 2.82 Nm) mean scores under vibration conditions. The fatigue protocol induced erector spinae muscle fatigue as illustrated by a significant decrease in sEMG median time-frequency slopes. Following the fatigue protocol, patients with cLBP showed significant decrease in sEMG root mean square activity at L4-5 level and responded in similar manner with and without vibration stimulation in regard to CE mean scores.
Patients with cLBP have a less accurate force reproduction sense than healthy participants. Local muscle vibration led to significant trunk neuromuscular control improvements in the cLBP patients before and after a muscle fatigue protocol. Muscle vibration stimulation during motor control exercises is likely to influence motor adaptation and could be considered in the treatment of cLBP. Further work is needed to clearly identify at what levels of the sensorimotor system these gains are achievable.
Abstract Objective The purpose of this study was to evaluate the effect of augmented soft tissue mobilization (ASTM) on the treatment of lateral epicondylitis. Methods This randomized clinical study ...assessed 27 subjects (12 men and 15 women) with lateral epicondylitis and were divided randomly into 2 groups. The experimental group (n = 15) received ASTM twice a week for 5 weeks. The subjects of the control group (n = 12) received advice on the natural evolution of lateral epicondylitis, computer ergonomics, and stretching exercises. Patient-rated outcome was assessed at baseline and after 6 weeks and 3 months using a visual analog scale and the Patient-Rated Tennis Elbow Evaluation. The function was assessed using the pain-free grip strength at baseline and after 6 weeks. Results Both groups showed improvements in pain-free grip strength, visual analog scale, and Patient-Rated Tennis Elbow Evaluation. Sample size for larger future randomized clinical trial was 116 participants. Conclusion A larger study investigating the same hypothesis is warranted to detect difference in the effects of these treatments strategies. The study design is feasible, and minor improvements will help to minimize the potential bias.
Purpose Cost-effectiveness analyses (CEAs) of screening can be highly sensitive to the health-related quality of life (HRQoL) effects of screen tests and subsequent treatment. Accordingly, accurate ...assessment of HRQoL is essential. We reviewed the literature regarding HRQoL in cervical prevention and management in order to appraise the current evidence regarding this important input to CEA. Methods We searched the MEDLINE, Scopus and EconLit databases for studies that estimated HRQoL in cervical cancer prevention and management published January 1995-December 2015. The primary inclusion criterion was for studies that assess HRQoL using the EQ-5D. Data were abstracted from eligible studies on setting, elicitation group, sample size, elicitation instruments, health state valuations, study design and follow-up. We assessed the quality and comparability of the studies with a particular focus on the HRQoL reported across states and groups. Results Fifteen papers met the inclusion criteria. Most used patient elicitation groups (n = 11), 2 used the general public and 2 used a mix of both. Eight studies were cross-sectional and seven were longitudinal. Six studies used both the EQ-5D-3L and the EQ-VAS together with other measures of overall HRQoL or condition-specific instruments. Extensive heterogeneity was observed across study characteristics. Conclusions Our results reveal the challenges of sourcing reliable estimates of HRQoL for use in CEAs of cervical cancer prevention and treatment. The EQ-5D appears insufficiently sensitive for some health states. A more general problem is the paucity of HRQoL estimates for many health states and their change over time.
Abstract Objective The aims of this study were to determine whether the application of vibration on a postural lower limb muscle altered the sensorimotor control of its joint as measured by isometric ...force production parameters and to compare present findings with previous work conducted on trunk muscle. Methods Twenty healthy adults were asked to reproduce submaximal isometric plantar flexion under 3 different conditions: no vibration and vibration frequencies of 30 and 80 Hz on the soleus muscle. Time to peak torque, variable error, as well as constant error and absolute error in peak torque were calculated and compared across conditions. Results Under vibration, participants were significantly less accurate in the force reproduction task, as they mainly undershot the target torque. Applying an 80-Hz vibration resulted in a significantly higher negative constant error than lower-frequency vibration (30 Hz) or no-vibration condition. Decreases in isometric force production accuracy under vibration influence were also observed in a previous study conducted on trunk muscle. However, no difference in constant error was found between 30- and 80-Hz vibration conditions. Conclusion The results suggest that acute soleus muscle vibration interferes with plantar flexion torque generation by distorting proprioceptive information, leading to decreases in accuracy of a force reproduction task. Similar results in an isometric trunk extension force reproduction task were found with vibration applied on erector spinae muscle. However, high-frequency vibration applied on soleus muscle elicited higher force reproduction errors than low-frequency stimulation.
Background The Arctic tundra is subject to the greatest climate change-induced temperature rises of any biome. Both terrestrial and freshwater biota are responding to recent climate warming through ...variability in their distribution, abundance, and richness. However, uncertainty arises within models of future change when considering processes that operate over centennial timescales. A systematic evidence synthesis of centennial-scale variability in biodiversity does not currently exist for the Arctic biome. Here, we sought to address the primary research question: what evidence exists for temporal variability in Arctic terrestrial and freshwater biodiversity throughout the Holocene (11,650 years before present (yBP)--0yBP)? Methods Consultation with stakeholders informed key definitions, scoping and the appropriateness of the research question. The research question was structured using a PECO framework--Arctic biota (P), a timestamped year in the Holocene (E), another year in the Holocene (C), and the dimensions of biodiversity that have been measured (O)--to inform the search strategy. Search strings were benchmarked against a test list of 100 known sources to ensure a specific and comprehensive return of literature. Searches will occur across 13 bibliographic databases. The eligibility criteria specify that sources must: (a) use 'proxy' methods to measure biodiversity; (b) fall within the spatial extent of the contemporary Arctic tundra biome; and (c) consist of a time-series that overlaps with 11,650yBP to 0yBP (1950AD). Information coded from studies will include proxy-specific information to account for both temporal uncertainty (i.e., the characteristics of age-depth models and dating methods) and taxonomic uncertainty (i.e., the samples and processes used for taxonomic identification). We will assess temporal uncertainty within each source by determining the quality of dating methods and measures; this information will be used to harmonise dates onto the IntCal20 calibration curve and determine the available temporal resolution and extent of evidence through space. Key outputs of this systematic map will be: (1) a graph database containing the spatial-temporal properties of each study dataset with taxonomic harmonisation; and (2) a geographical map of the evidence base. Keywords: Palaeoecology, Dendrochronology, Late Quaternary, Lake sediments, Environmental archives, Environmental proxies
Vibration is known to alter proprioceptive afferents and create a tonic vibration reflex. The control of force and its variability are often considered determinants of motor performance and ...neuromuscular control. However, the effect of vibration on paraspinal muscle control and force production remains to be determined.
Twenty-one healthy adults were asked to perform isometric trunk flexion and extension torque at 60% of their maximal voluntary isometric contraction, under three different vibration conditions: no vibration, vibration frequencies of 30 Hz and 80 Hz. Eighteen isometric contractions were performed under each condition without any feedback. Mechanical vibrations were applied bilaterally over the lumbar erector spinae muscles while participants were in neutral standing position. Time to peak torque (TPT), variable error (VE) as well as constant error (CE) and absolute error (AE) in peak torque were calculated and compared between conditions.
The main finding suggests that erector spinae muscle vibration significantly decreases the accuracy in a trunk extension isometric force reproduction task. There was no difference between both vibration frequencies with regard to force production parameters. Antagonist muscles do not seem to be directly affected by vibration stimulation when performing a trunk isometric task.
The results suggest that acute erector spinae muscle vibration interferes with torque generation sequence of the trunk by distorting proprioceptive information in healthy participants.
Spinal manipulation is a widely accepted therapeutic approach in the treatment of back pain. In standard training programs, feedback on student performances is provided by an instructor based on ...teaching and clinical experience. Systematic study of the type of augmented feedback provided and skill learning is lacking in the literature.
The goal of this investigation is to compare the performance of two groups of chiropractic students, one receiving traditional training from experienced instructors, and the other, augmented feedback on specific biomechanical aspects of spinal manipulation therapy using an instrumented manikin.
Randomized controlled study.
Thirty-one fourth-year students from the Department of Chiropractic of Université du Québec à Trois-Rivières participated in this study.
Kinetic parameters (force-time curves) of spinal manipulation were evaluated.
Spinal manipulation parameters were measured before and after a 5-week training period in which one group received standard chiropractic training while a second group received augmented feedback about specific biomechanical parameters of spinal manipulation. For both groups, practice scheduling and time duration were similar and consisted of a weekly practice session of 90 minutes for five consecutive weeks. Both groups had to practice thoracic spine manipulation throughout the training period.
Both groups showed a decrease in peak force applied, with a diminution in the number of trials where a downward incisural point was present in preload force. Participants in the feedback training group significantly reduced their peak force variability and significantly increased their preload force. No significant difference was observed for time to peak force.
The results of this study highlight the merits of practicing with an instrumented manikin or other instrumented training aids. Such a device can provide specific feedback on specific parameters of the task during learning; it can also serve as a tool to assess the progress of students and eliminate the risks relating to repetitive spinal manipulative therapy practice on student colleagues.
Abstract Introduction No questionnaire is available to evaluate disability levels in French-speaking patients suffering from tennis elbow. Purpose of the Study To perform a cross-cultural adaptation ...of the English version of the Patient-rated Tennis Elbow Evaluation (PRTEE) into Canadian French. Methods The PRTEE was cross-culturally adapted to Canadian French according to well-established guidelines. Thirty-two patients with tennis elbow completed the prefinal version of the PRTEE. The construct validity, longitudinal validity, and responsiveness were assessed through comparisons with the Visual Analog Scale (VAS) measuring pain and the pain-free grip (PFG) at baseline, six weeks and three months. The internal consistency was assessed by Cronbach's alpha and the item-total correlations. Results The adaptation process resolved the discrepancy between the forward and back translation. The scores of PRTEE were adequately distributed without floor or ceiling effect. Item completion was good. The correlation between the PRTEE and the VAS was moderate to high ( r = 0.64–0.77) and statistically significant. There was also a low but significant correlation between the PRTEE and PFG ( r = −0.38 to −0.48). For the longitudinal construct validity, the correlation with the VAS was moderate to high and statistically significant ( r = 0.68 and 0.88, p < 0.01). The effect size (0.8; 1.0) and the standardized response mean (0.9; 1.0) were high and at least as good as the other outcomes. Internal consistency of the total score was high (Cronbach alpha = 0.93) and item-total correlations were substantial for all items (0.58–0.85). Conclusions This study supports linguistic and conceptual equivalence of our Canadian French version. Because this version of the PRTEE demonstrated good acceptability, construct validity, internal consistency, and responsiveness, it may be used in both research and clinical setting. Level of Evidence N/A.
Abstract Objective This study correlates changes in trunk isometric force parameters and trunk muscle recruitment strategies in subjects with low back pain (LBP) and healthy participants. Methods A ...control group study with repeated measures was performed. Study participants included 15 control subjects and 14 patients with LBP. Participants were required to exert 50% and 75% of their maximal trunk flexion and extension. In a learning phase, feedback was provided, after which study participants were asked to perform 10 trials without any feedback. Spatiotemporal parameters of muscular activity and force production were recorded. Dependent variables included time to peak force, peak force variability, absolute error in peak force, electromyogram (EMG) burst duration for agonist muscles, and normalized integrated EMG. Results Average time to peak force was significantly longer for subjects with LBP than for healthy subjects. Subjects with LBP showed longer burst duration for all 4 muscles recorded. No group difference was noted in normalized integrated EMG. Conclusions We suggest that the observed changes in trunk motor control and trunk muscle recruitment strategies are not only mediated by a neurophysiologic adaptation to chronic pain but also by cognitive adaptations modulated by fear of movement and fear of reinjury.
Abstract Objective This study examines whether there is a relationship between clinical correlates of osteoarthritic changes of the cervical spine and changes in postural stability. Methods This was ...a control group study with repeated measures. Twenty-three patients were recruited from the chiropractic University Clinic to participate in this study. The presence and severity of osteoarthritic changes of the cervical spine were determined radiologically. Balance control was evaluated by testing subjects' postural stability on a force platform with and without vision. A general clinical assessment of the neuromusculoskeletal system was performed to screen for any physical condition that could affect postural stability. Participants' characteristics were compared between each group using a 1-way analysis of variance for independent samples, and postural stability variables were submitted to a 2-way repeated measures analysis of variance. Results Subjects with signs of osteoarthritis of the cervical spine showed an increased range of sway, a faster sway speed, and a greater excursion than control subjects. They also showed a larger degree of lower limb neuropathy than control subjects. Conclusion The postural instability shown by the osteoarthritic group may be due to the effects of the lower limb peripheral neuropathy alone or due to a combination of both cervical degenerative changes and peripheral changes. Further research is needed to clearly isolate the effects of the degeneration of the cervical spine on postural control.
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