Markus Hübscher

Neuromuscular training for sports injury prevention: a systematic review.

PURPOSE The aim of this systematic review was to assess the effectiveness of proprioceptive/neuromuscular training in preventing sports injuries by using the best available evidence from methodologically well-conducted randomized controlled trials and controlled clinical trials without randomization. METHODS Two independent researchers performed a literature search in various electronic databases and reference lists. The reviewers independently assessed trials for inclusion criteria and methodological quality and extracted the data. Focusing on studies of high methodological quality, relative risks (RR) and 95% confidence intervals (CI) were used to estimate treatment effects. RESULTS From a total of 32 relevant studies, 7 methodologically well-conducted studies were considered for this review. Pooled analysis revealed that multi-intervention training was effective in reducing the risk of lower limb injuries (RR = 0.61, 95% CI = 0.49-0.77, P < 0.01), acute knee injuries (RR = 0.46, 95% CI = 0.28-0.76, P < 0.01), and ankle sprain injuries (RR = 0.50, 95% CI = 0.31-0.79, P < 0.01). Balance training alone resulted in a significant risk reduction of ankle sprain injuries (RR = 0.64, 95% CI = 0.46-0.9, P < 0.01) and a nonsignificant risk reduction for injuries overall (RR = 0.49, 95% CI = 0.13-1.8, P = 0.28). Exercise interventions were more effective in athletes with a history of sports injury than in those without. CONCLUSION On the basis of the results of seven high-quality studies, this review showed evidence for the effectiveness of proprioceptive/neuromuscular training in reducing the incidence of certain types of sports injuries among adolescent and young adult athletes during pivoting sports. Future research should focus on the conduct of comparative trials to identify the most appropriate and effective training components for preventing injuries in specific sports and populations.

Balance Training for Neuromuscular Control and Performance Enhancement: A Systematic Review

OBJECTIVE As a result of inconsistencies in reported findings, controversy exists regarding the effectiveness of balance training for improving functional performance and neuromuscular control. Thus, its practical benefit in athletic training remains inconclusive. Our objective was to evaluate the effectiveness of training interventions in enhancing neuromuscular control and functional performance. DATA SOURCES Two independent reviewers performed a literature search in Cochrane Bone, Joint and Muscle Trauma Group Register and Cochrane Controlled Trials Register, MEDLINE, EMBASE, PEDro (Physiotherapy Evidence Database), and SCOPUS. STUDY SELECTION Randomized controlled trials and controlled trials without randomization with healthy and physically active participants aged up to 40 years old were considered for inclusion. Outcomes of interest were postural control, muscle strength, agility, jump performance, sprint performance, muscle reflex activity, rate of force development, reaction time, and electromyography. DATA EXTRACTION Data of interest were methodologic assessment, training intervention, outcome, timing of the outcome assessment, and results. Standardized mean differences and 95% confidence intervals were calculated when data were sufficient. DATA SYNTHESIS In total, 20 randomized clinical trials met the inclusion criteria. Balance training was effective in improving postural sway and functional balance when compared with untrained control participants. Larger effect sizes were shown for training programs of longer duration. Although controversial findings were reported for jumping performance, agility, and neuromuscular control, there are indications for the effectiveness of balance training in these outcomes. When compared with plyometric or strength training, conflicting results or no effects of balance training were reported for strength improvements and changes in sprint performance. CONCLUSIONS We conclude that balance training can be effective for postural and neuromuscular control improvements. However, as a result of the low methodologic quality and training differences, further research is strongly recommended.

How does pain lead to disability? A systematic review and meta-analysis of mediation studies in people with back and neck pain

Abstract Disability is an important outcome from a clinical and public health perspective. However, it is unclear how disability develops in people with low back pain or neck pain. More specifically, the mechanisms by which pain leads to disability are not well understood. Mediation analysis is a way of investigating these mechanisms by examining the extent to which an intermediate variable explains the effect of an exposure on an outcome. This systematic review and meta-analysis aimed to identify and examine the extent to which putative mediators explain the effect of pain on disability in people with low back pain or neck pain. Five electronic databases were searched. We found 12 studies (N = 2961) that examined how pain leads to disability with mediation analysis. Standardized regression coefficients (&bgr;) of the indirect and total paths were pooled. We found evidence to show that self-efficacy (&bgr; = 0.23, 95% confidence interval [CI] = 0.10 to 0.34), psychological distress (&bgr; = 0.10, 95% CI = 0.01 to 0.18), and fear (&bgr; = 0.08, 95% CI = 0.01 to 0.14) mediated the relationship between pain and disability, but catastrophizing did not (&bgr; = 0.07, 95% CI = −0.06 to 0.19). The methodological quality of these studies was low, and we highlight potential areas for development. Nonetheless, the results suggest that there are significant mediating effects of self-efficacy, psychological distress, and fear, which underpins the direct targeting of these constructs in treatment.

Effect of Primary Care–Based Education on Reassurance in Patients With Acute Low Back Pain: Systematic Review and Meta-analysis

IMPORTANCE Reassurance is a core aspect of daily medical practice, yet little is known on how it can be achieved. OBJECTIVE To determine whether patient education in primary care increases reassurance in patients with acute or subacute low back pain (LBP). DATA SOURCES Medline, EMBASE, Cochrane Central Register for Controlled Trials, and PsychINFO databases were searched to June 2014. DESIGN Systematic review and meta-analysis of randomized and nonrandomized clinical trials. STUDY SELECTION To be eligible, studies needed to be controlled trials of patient education for LBP that were delivered in primary care and measured reassurance after the intervention. Eligibility criteria were applied, and studies were selected by 2 independent authors. MAIN OUTCOMES AND MEASURES The primary outcomes were reassurance in the short and long term and health care utilization at 12 months. DATA EXTRACTION AND SYNTHESIS Data were extracted by 2 independent authors and entered into a standardized form. A random-effects meta-analysis tested the effects of patient education compared with usual care on measures of reassurance. To investigate the effect of study characteristics, we performed a preplanned subgroup analysis. Studies were stratified according to duration, content, and provider of patient education. RESULTS We included 14 trials (n=4872) of patient education interventions. Trials assessed reassurance with questionnaires of fear, worry, anxiety, catastrophization, and health care utilization. There is moderate- to high-quality evidence that patient education increases reassurance more than usual care/control education in the short term (standardized mean difference [SMD], -0.21; 95% CI, -0.35 to -0.06) and long term (SMD, -0.15; 95% CI, -0.27 to -0.03). Interventions delivered by physicians were significantly more reassuring than those delivered by other primary care practitioners (eg, physiotherapist or nurse). There is moderate-quality evidence that patient education reduces LBP-related primary care visits more than usual care/control education (SMD, -0.14; 95% CI, -0.28 to -0.00 at a 12-month follow-up). The number needed to treat to prevent 1 LBP-related visit to primary care was 17. CONCLUSIONS AND RELEVANCE There is moderate- to high-quality evidence that patient education in primary care can provide long-term reassurance for patients with acute or subacute LBP.

Effects of Acupuncture on Symptoms and Muscle Function in Delayed-Onset Muscle Soreness

OBJECTIVE This study was done to investigate the effects of a standardized acupuncture treatment on symptoms and muscle function in exercise-induced delayed-onset muscle soreness (DOMS). METHODS A prospective, randomized, controlled, observer and subject-blinded trial was undertaken. Twenty-two (22) healthy subjects (22-30 years; 10 males and 12 females) were randomly assigned to three treatment groups: real acupuncture (deep needling at classic acupuncture points and tender points; n = 7), sham-acupuncture (superficial needling at nonacupuncture points; n = 8), and control (no needling; n = 7). DOMS of the nondominant elbow-flexors was experimentally induced through eccentric contractions until exhaustion. The outcome measures were pain perception (visual analogue scale; VAS; range: 0-10 cm), mechanical pain threshold (MPT; pressure algometer), and maximum isometric voluntary force (MIVF; force transducer). Treatment was applied immediately, 24 and 48 hours after DOMS induction. Measurements of MPT and MIVF were made prior to DOMS induction as well as before and after every treatment session. VAS data were acquired after DOMS induction as well as pre- and post-treatment. Final pain, MPT, and MIVF measurements were performed 72 hours after DOMS induction. RESULTS Following nonparametric testing, there were no significant differences between groups in outcome measures at baseline. After 72 hours, pain perception (VAS) was significantly lower in the acupuncture group compared to the sham acupuncture and control subjects. However, the mean MPT and MIVF scores were not significantly different between groups. CONCLUSIONS Although acupuncture seemed to have no effects on mechanical pain threshold and muscle function, it proved to reduce perceived pain arising from exercise-induced muscle soreness.

Pain education to prevent chronic low back pain: a study protocol for a randomised controlled trial

Introduction Low back pain (LBP) is the leading cause of disability worldwide. Of those patients who present to primary care with acute LBP, 40% continue to report symptoms 3 months later and develop chronic LBP. Although it is possible to identify these patients early, effective interventions to improve their outcomes are not available. This double-blind (participant/outcome assessor) randomised controlled trial will investigate the efficacy of a brief educational approach to prevent chronic LBP in ‘at-risk’ individuals. Methods/analysis Participants will be recruited from primary care practices in the Sydney metropolitan area. To be eligible for inclusion participants will be aged 18–75 years, with acute LBP (<4 weeks’ duration) preceded by at least a 1 month pain-free period and at-risk of developing chronic LBP. Potential participants with chronic spinal pain and those with suspected serious spinal pathology will be excluded. Eligible participants who agree to take part will be randomly allocated to receive 2×1 h sessions of pain biology education or 2×1 h sessions of sham education from a specially trained study physiotherapist. The study requires 101 participants per group to detect a 1-point difference in pain intensity 3 months after pain onset. Secondary outcomes include the incidence of chronic LBP, disability, pain intensity, depression, healthcare utilisation, pain attitudes and beliefs, global recovery and recurrence and are measured at 1 week post-intervention, and at 3, 6 and 12 months post LBP onset. Ethics/dissemination Ethical approval was obtained from the University of New South Wales Human Ethics Committee in June 2013 (ref number HC12664). Outcomes will be disseminated through publication in peer-reviewed journals and presentations at international conference meetings. Trial registration number https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12612001180808

Estimating the Risk of Chronic Pain: Development and Validation of a Prognostic Model (PICKUP) for Patients with Acute Low Back Pain

Background Low back pain (LBP) is a major health problem. Globally it is responsible for the most years lived with disability. The most problematic type of LBP is chronic LBP (pain lasting longer than 3 mo); it has a poor prognosis and is costly, and interventions are only moderately effective. Targeting interventions according to risk profile is a promising approach to prevent the onset of chronic LBP. Developing accurate prognostic models is the first step. No validated prognostic models are available to accurately predict the onset of chronic LBP. The primary aim of this study was to develop and validate a prognostic model to estimate the risk of chronic LBP. Methods and Findings We used the PROGRESS framework to specify a priori methods, which we published in a study protocol. Data from 2,758 patients with acute LBP attending primary care in Australia between 5 November 2003 and 15 July 2005 (development sample, n = 1,230) and between 10 November 2009 and 5 February 2013 (external validation sample, n = 1,528) were used to develop and externally validate the model. The primary outcome was chronic LBP (ongoing pain at 3 mo). In all, 30% of the development sample and 19% of the external validation sample developed chronic LBP. In the external validation sample, the primary model (PICKUP) discriminated between those who did and did not develop chronic LBP with acceptable performance (area under the receiver operating characteristic curve 0.66 [95% CI 0.63 to 0.69]). Although model calibration was also acceptable in the external validation sample (intercept = −0.55, slope = 0.89), some miscalibration was observed for high-risk groups. The decision curve analysis estimated that, if decisions to recommend further intervention were based on risk scores, screening could lead to a net reduction of 40 unnecessary interventions for every 100 patients presenting to primary care compared to a “treat all” approach. Limitations of the method include the model being restricted to using prognostic factors measured in existing studies and using stepwise methods to specify the model. Limitations of the model include modest discrimination performance. The model also requires recalibration for local settings. Conclusions Based on its performance in these cohorts, this five-item prognostic model for patients with acute LBP may be a useful tool for estimating risk of chronic LBP. Further validation is required to determine whether screening with this model leads to a net reduction in unnecessary interventions provided to low-risk patients.

Contributions of mood, pain catastrophizing, and cold hyperalgesia in acute and chronic low back pain: a comparison with pain-free controls.

Objectives:Quantitative sensory testing (QST) has been used to elucidate the peripheral and central mechanisms that underlie changes in pain sensitivity associated with low back pain (LBP). However, it remains unclear to what degree peripheral and central changes contribute to the generation and maintenance of LBP. The aim of this study was to compare thermal pain sensitivity, measured using QST, in participants with acute LBP, chronic LBP, and pain-free controls. Materials and Methods:Participant groups with acute LBP (N=20), chronic LBP (N=30), and pain-free controls (N=30) were assessed by thermal QST. The unique contributions of pain-related psychological and QST variables to predict membership to the acute and chronic pain groups were also determined. Results:We found that participants with chronic LBP demonstrated significantly lower cold pain threshold (CPT) in the primary area of pain (low back) as well as in an area anatomically remote from the primary area of pain (forearm) when compared with controls. Participants with acute LBP did not show significantly elevated pain sensitivity. CPT at the remote site was a significant independent predictor of membership to the chronic pain group, after the adjustment for mood and pain catastrophizing. CPT explained 8% of the total variance of 46% related to group membership. Discussion:We found evidence for localized and generalized cold hyperalgesia in chronic, but not acute LBP. We might speculate that hyperalgesia develops as a consequence of long-lasting LBP, but prospective studies are needed to confirm this assumption.

Functional capacity and fear of falling in cancer patients undergoing chemotherapy

Cancer patients, particularly during chemotherapy, often encounter functional status limitations. This study examines fear of falling, balance, gait and lower limb strength in cancer patients during ongoing or recently completed (≤12 months) chemotherapeutic treatment in comparison to age-matched and senior controls (≥65 years). Data were obtained from 69 subjects; 21 cancer patients (51±7 years) with histological confirmed diagnosis and two control groups (2×n=24): one age-matched (53±7 years) and one senior group (70±3 years). Fear of falling (FoF) was evaluated using the Falls Efficacy Scale-International Version. Motor function measurement included postural sway (centre of pressure) in upright stance with eyes covered, gait speed (comfortable fluid walking) and maximum voluntary isometric quadriceps strength (MIVF). One-way ANOVA followed by corrected post hoc paired-sample t-test revealed inferior values in cancer patients than in age-matched healthy regarding all parameters. Gait speed and MIVF of cancer patients were higher than in the senior control group (p<.05), whereas their FoF and postural sway were comparable (p>.05). Physical performance parameters of cancer patients were found to be lower in comparison to healthy age-matched subjects. Cancer patients show physical impairments which may limit independence and may increase fall risk. The present findings call for routine screening of physical function in cancer patients, and further stress the relevance of exercise interventions during and after chemotherapy.

The Association Between Clinical Characteristics of Migraine and Brain GABA Levels: An Exploratory Study

UNLABELLED Migraine is prevalent and disabling yet is poorly understood. One way to better understand migraine is to examine its clinical characteristics and potential biomarkers such as gamma-aminobutyric acid (GABA). The primary objective of this study was to explore whether relevant disease characteristics of migraine are associated with brain GABA levels. Twenty adults fulfilling the established diagnostic criteria for migraine and 20 age- and gender-matched controls completed this cross-sectional study. Pain, central sensitization, negative emotional state, and perceived disability were measured using Short-form McGill Pain Questionnaire-2, Central Sensitization Inventory, Depression Anxiety Stress Scales-21, and Headache Impact Test-6, respectively. Secondary analysis of brain GABA levels of the same cohort measured using proton magnetic resonance spectroscopy was conducted. The migraine group had significantly higher scores than the control group on pain, central sensitization, and disability. Correlation analyses showed fair positive association between GABA levels and pain and central sensitization scores. No association was found between GABA levels and emotional state and disability. These findings are preliminary evidence supporting the use of questionnaires and GABA levels in characterizing migraine better and broadening the diagnostic process. These findings also strengthen the rationale for the role of GABA in migraine pathophysiology and corroborate the potential of GABA as a migraine biomarker. PERSPECTIVE Higher pain and central sensitization scores were associated with increased brain GABA levels in individuals with migraine. These findings offer preliminary evidence for the usefulness of measuring pain and central sensitization in migraine and provide some support for the possible role of GABA in migraine pathophysiology and its potential as a diagnostic marker.