Effect of physical training on function of chronically painful muscles: a randomized controlled trial

Effects of matched vs. unmatched physical therapy interventions on pain or disability in patients with neck pain - a systematic review and meta-analysis

BACKGROUND

The interventions performed in most randomized controlled trials (RCTs) on neck pain patients are standardized, irrespective of the high heterogeneity of patients. However, clinicians tend to choose an intervention based on the patients' clinical characteristics, and thus match the treatment to the patient.

OBJECTIVES

To investigate the effectiveness of interventions matched to the clinical characteristics of patients with neck pain versus the same, but unmatched treatment for improving pain or disability.

DESIGN

A systematic review and meta-analysis conducted following Cochrane guidelines.

METHODS

Databases searches were performed from inception to September 2023. RCTs were included if the patients in the experimental group received a treatment matched to clinical presentation or to clinicians' assessment, if the patients in the control group received a similar but unmatched treatment, and if pain or disability were reported as outcome measures.

RESULTS

The literature search produced 9516 records of which 27 met the inclusion criteria. Matched exercise therapy was superior to unmatched exercise for pain (SMD -0.57; 95% CI -0.95, -0.18) and for disability (SMD -0.69; 95% CI -1.14, -0.23) at short term, but not at intermediate-term follow-up. Matched manual treatment was not superior to unmatched manual therapy for pain or for disability at short or intermediate-term follow-up.

CONCLUSIONS

Results suggest that matching exercise to movement limitation, trapezius myalgia, or forward head position may lead to better outcomes in the short term, but not in the intermediate-term. Matched manual therapy was not superior to unmatched treatment either short or intermediate-term. Further research is warranted to verify if those criteria are potentially useful matching criteria.

The effectiveness of aerobic exercise on pain and disability in individuals with neck pain: A systematic review and meta-analysis

The present review aimed to investigate the effectiveness of aerobic exercise (AE) compared to other interventions in decreasing pain intensity and reducing disability in individuals with neck pain. A systematic review (SR) of randomized controlled trials was conducted. This SR was registered in PROSPERO (CRD42021231231). Searches were conducted in five electronic databases (MEDLINE, Embase, CINAHL, Cochrane and SCOPUS). Studies were selected if they included adults over 18 years old with neck pain. The primary outcomes were pain intensity and physical function. A meta-analysis was conducted when applicable. Cochrane RoB Tool-2 was used to determine the risk of bias of included studies, and the certainty of the evidence was determined using the GRADE approach. Out of 4669 initial records screened, six studies published in 12 articles were included. AE was not statistically different compared to no-treatment or other interventions (e.g., localized exercise or acupuncture) on pain intensity measured with a visual analogue scale (VAS) (mean difference (MD) [95%CI]: 5.16 mm [-6.38, 16.70]). Contrarily, strengthening exercise was better than AE for pain intensity (MD [95%CI]: -11.34 mm [-21.6, -1.09]) after treatment. However, when AE was combined with other therapy (strengthening exercises or acupuncture), the combined therapy was better than isolated treatments (MD [95%CI]: 7.71 mm [1.07, 14.35]). A high heterogeneity was observed between protocols, comparisons, and results (magnitudes and directions). In conclusion, AE had positive results only when combined with other therapies to reduce pain intensity and disability in patients with neck pain. However, the evidence is limited, low-quality, and heterogeneous.

Altered muscle recruitment patterns during isometric shoulder abduction in individuals with chronic upper trapezius pain: a cross sectional study

BACKGROUND

Upper trapezius (UT) pain with myofascial trigger points (MTrPs) can affect movement at the glenohumeral joint as well as at the scapulothoracic joint. The investigation of muscle recruitment patterns can discern motor control strategies. The purpose of this study was to compare shoulder muscle recruitment patterns and muscle activity according to various loads between individuals with and without chronic UT pain.

METHODS

In this cross-sectional study, twenty-four participants that had UT pain with MTrPs and sex, age, body weight matched 24 controls with no UT pain were recruited. Surface EMG electrodes were attached to the UT, the serratus anterior (SA), the lower trapezius (LT) and the middle deltoid (MD). All participants performed isometric shoulder abduction with a load of 25%, 50%, or 75% of the maximum strength at 60° of shoulder abduction. The EMG activity, the activity ratio (SA/UT, LT/UT, MD/UT), and the relative contribution of each muscle activity were calculated.

RESULTS

MD activity was significantly decreased in the UT pain group compared to that in the control group (p < 0.05). The EMG activity ratio of SA/UT (p < 0.025) and the relative contribution of SA activity to shoulder abduction (p < 0.05) were significantly greater in the UT pain group than in the control group in the 25% loading condition.

CONCLUSION

The results of present study showed that UT pain with MTrPs may increase the relative contribution of SA activity and decrease MD activity at low loads. Altered recruitment patterns of scapular upward rotators can be altered in the proper scapular position, which results in decreased MD activity. Clinicians should consider altered recruitment patterns when managing UT pain.

TRIAL REGISTRATION

Clinical Research Information Service: Clinical Research Information Service (KCT0007370; 08/06/2022).

The elixir of muscle activity and kinesiology in a health perspective: Evidence of worksite tailored exercise training alleviating muscle disorders

Physical activity is known to benefit health while muscle activation and movements performed during occupational work in contrast may result in work-related musculoskeletal disorders. Therefore, we posed the research question: which mode of muscle activation may result in a reversal of work-related disorders? To address this, we performed electromyographic (EMG) and kinematic assessments of workers with diverse exposure categories: sedentary monotonous work, prolonged walking/standing, and physically heavy work. The various job-specific exposure variables could be categorized in terms of duration, intensity, repetition, static component, peak force etc. that were subsequently identified as risk factors. Based on sports science principles we developed tailored exercise programs to counteract job exposure. EMG activity during exercise training was monitored to identify principal differences between exercise training and job patterns. Evidence from more than 20 RCT studies including >4000 workers showed positive effects such as decreased muscle pain and increased workability. Finally, we identified plausible underlying mechanisms in muscle tissue - human and animal - that confirmed metabolic, morphological, and hormonal changes with e.g. repetitive work that were reversal to adaptations reported with exercise training. Progress has been made in developing intelligent physical exercise training, IPET, as the best complementary activity to job exposure and includes muscle activations and movements that limit work-related inactivity atrophy as well as overload injury.

Scapular exercise combined with cognitive functional therapy is more effective at reducing chronic neck pain and kinesiophobia than scapular exercise alone: a randomized controlled trial

Objective:

The aim of this study was to compare the effectiveness of scapular exercises alone and combined with cognitive functional therapy in treating patients with chronic neck pain and scapular downward rotation impairment.

Design:

Single-blind randomized controlled trial.

Setting:

Outpatient.

Subjects:

A total of 72 patients (20–45 years old) with chronic neck pain were studied.

Intervention:

Allocation was undertaken into three groups: scapular exercise ( n = 24), scapular exercise with cognitive functional therapy ( n = 24) and control ( n = 24) groups. Each programme lasted three times a week for six weeks.

Main outcomes:

The primary outcome measure was pain intensity measured by the visual analogue scale scores. The secondary outcome measures included kinesiophobia and muscles activity.

Results:

Statistically significant differences in pain intensity were found when multidisciplinary physiotherapy group including a cognitive functional approach was compared with the scapular exercise alone group at six weeks (effect size (95% CI) = −2.56 (−3.32 to −1.80); P = 0.019). Regarding kinesiophobia, a significant between-group difference was observed at six-week (effect size (95% CI) = −2.20 (−2.92 to −1.49); P = 0.005), with the superiority of effect in multidisciplinary physiotherapy group. A significant between-group differences was observed in muscle activity. Also, there were significant between-group differences favouring experimental groups versus control.

Conclusion:

A group-based multidisciplinary rehabilitation programme including scapular exercise plus cognitive functional therapy was superior to group-based scapular exercise alone for improving pain intensity, kinesiophobia and muscle activation in participants with chronic neck pain.

Importance of Frequency and Intensity of Strength Training for Reduced Musculoskeletal Pain in the Back, Neck-Shoulder, and Arm-Hand Among Physical Therapists

BACKGROUND

Musculoskeletal pain (MP) is common among health care professionals, including physical therapists (PTs). The physically demanding nature of their work might contribute to increase MP rates. Strength training has a positive effect on musculoskeletal health and MP. However, no studies have evaluated the association of strength training during leisure time on MP among PTs. This study aims to analyze the association between frequency and intensity of strength training during leisure time and MP in the back, neck-shoulder, and arm-hand among PTs.

METHODS

Data on MP and intensity and frequency of strength training were obtained using a questionnaire responded by 1006 PTs. The odds for having lower level of MP as a function of intensity or frequency of the strength training were estimated using binary logistic regression.

RESULTS

High-intensity strength training showed strong associations with lower intensity of MP in neck-shoulder (odds ratio = 5.08; 95% confidence interval, 1.36-18.92), arm-hand (odds ratio = 5.22; 95% confidence interval, 1.11-24.51), and back (odds ratio = 5.22; 95% confidence interval, 1.41-19.28). However, frequency and lower intensities were not significantly associated with MP in any body part.

CONCLUSIONS

High-intensity strength training is strongly associated with lower levels of MP in arm-hand, neck-shoulder, and back, whereas no association was found with frequency or lower intensities.

Dose-response of resistance training for neck-and shoulder pain relief: a workplace intervention study

Background

Musculoskeletal disorders are highly prevalent among office workers, with strong evidence suggesting that workplace-based resistance training programs can prevent several upper extremity musculoskeletal disorders. The aim of the present study was to examine the dose-response relationship between resistance training frequency and pain relief among office workers with neck- and shoulder pain.

Methods

Thirty participants with mild to moderate neck- and shoulder pain attended a 16-week intervention starting with an eight-week control period followed by an eight-week training period. After the control period, the participants were randomized into either a 10 min (TG10) or 2 × 10 min (TG2) workplace-based, high-intensity neck- and shoulder specific resistance training program that was executed 5 days per week and consisting of four exercises. The participants were tested pre and post each period for mean and worst pain using the 0-100 mm visual analog scale (VAS), 0-100 mm health-related quality of life and isometric strength of the neck-and shoulder region. The analysis of variance (ANOVA) and Friedman with Bonferroni post hoc corrections were used to assess differences in between and within groups for the three testing times pre, mid and post intervention.

Results

No differences were observed between the groups in any of the variables in the control period (p = 0.27–0.97) or training period (p = 0.37–0.68). When merging the two groups, the mean and worst pain was reduced by 25 and 43% (p = 0.05 and < 0.01, ES = 0.41 and 0.55) in the training period in addition to 10.6% increase in health-related quality of life (p = 0.01, ES = 0.52). No difference in strength was observed (p = 0.29–0.85).

Conclusion

Daily bouts of specific high-intensity resistance training of the shoulder and neck region at the workplace reduced neck- and shoulder pain and improved quality of life of office workers. However, 10 min bouts were equally effective as 2 × 10 min bouts per day. The authors recommend office workers to perform daily neck- and shoulder resistance training to possibly prevent and/or decrease pain in the neck- and shoulder area.

Trial registration

ISRCTN69968888, retrospectively registered (24/09/2019).

Prevalence and potential risk factors of flight-related neck, shoulder and low back pain among helicopter pilots and crewmembers: a questionnaire-based study

BACKGROUND

Flight-related neck, shoulder and low back pain are the most common musculoskeletal disorders among helicopter pilots and their crewmembers, thus becoming a growing concern. Information on the combined prevalence of these types of pain and related risks are scarce. The aim of this study was therefore to estimate pain prevalence and to evaluate potential risk factors for neck pain among helicopter pilots and crewmembers within the armed forces, the airborne police and airborne rescue organizations in Austria.

METHODS

Among a cohort of 104 helicopter pilots and 117 crewmembers (69.8% compliance), demographics, flying experience, use of Night Vision Goggles (NVG), helicopter type flown, prevalence and intensity of musculoskeletal symptoms (pain was defined as any reported pain experience, ache or discomfort) were collected by an online-based questionnaire.

RESULTS

For helicopter pilots the 12-month prevalence of neck pain was 67.3%, followed by low back (48.1%) and shoulder pain (43.3%). Among crewmembers, the 12-month pain prevalence were 45.3, 36.8 and 30.8% among the neck, lower back and shoulder, respectively. During this period, 41.8% of these helicopter pilots had experienced 8-30 pain days in the areas of neck (45.7%), shoulder (37.8%) and lower back (42.0%) whereas 47.8% of crewmembers self-reported 1-7 days of neck (54.7%), low back (44.2%) and shoulder (44.4%) pain in the previous year. The 3-month prevalence of neck pain was 64.4% followed by low back (42.3%) and shoulder pain (38.5%) for helicopter pilots. Among crewmembers, 41.9% suffered from neck, 29.9% from low back and 29.1% from shoulder pain the previous 3 months. Multivariate regression analysis revealed NVG use (OR 1.9, 95% CI, 1.06-3.50, p = 0.032), shoulder pain (OR 4.9, 95% CI, 2.48-9.55, p < 0.001) and low back pain (OR 2.3, 95% CI, 1.21-4.31, p = 0.011) to be significantly associated with neck pain.

CONCLUSIONS

The 12- and 3-month prevalence of neck, shoulder and low back is considerably high among both, helicopter pilots and crewmembers confirming the existence of this growing concern. The use of NVG devices, shoulder and low back pain in the previous 12 months represent independent risk factors for neck pain. These findings highlight the need for longitudinal studies.

Spinal and supraspinal control of motor function during maximal eccentric muscle contraction: Effects of resistance training

Neuromuscular activity is suppressed during maximal eccentric (ECC) muscle contraction in untrained subjects owing to attenuated levels of central activation and reduced spinal motor neuron (MN) excitability indicated by reduced electromyography signal amplitude, diminished evoked H-reflex responses, increased autogenic MN inhibition, and decreased excitability in descending corticospinal motor pathways. Maximum ECC muscle force recorded during maximal voluntary contraction can be increased by superimposed electrical muscle stimulation only in untrained individuals and not in trained strength athletes, indicating that the suppression in MN activation is modifiable by resistance training. In support of this notion, maximum ECC muscle strength can be increased by use of heavy-load resistance training owing to a removed or diminished suppression in neuromuscular activity. Prolonged (weeks to months) of heavy-load resistance training results in increased H-reflex and V-wave responses during maximal ECC muscle actions along with marked gains in maximal ECC muscle strength, indicating increased excitability of spinal MNs, decreased presynaptic and/or postsynaptic MN inhibition, and elevated descending motor drive. Notably, the use of supramaximal ECC resistance training can lead to selectively elevated V-wave responses during maximal ECC contraction, demonstrating that adaptive changes in spinal circuitry function and/or gains in descending motor drive can be achieved during maximal ECC contraction in response to heavy-load resistance training.

Comparison of shoulder strength in males with and without myofascial trigger points in the upper trapezius

BACKGROUND

This study was conducted in order to compare the strength of scapular elevator and shoulder abductor with and without restricted scapular elevation between male subjects with and without myofascial trigger points in the upper trapezius.

METHODS

In total, 15 male subjects with myofascial trigger points, and 15age- and weight-matched male subjects without myofascial trigger points in the upper trapezius. Each subject was measured in the strength of maximum isometric scapular elevation and shoulder abduction with and without restricted scapular elevation. Maximum isometric contractions were measured using the Smart KEMA strength measurement system. Independent t-tests were used to compare shoulder strength values between the myofascial trigger points and non- myofascial trigger points groups.

FINDING

The results showed that shoulder abductor strength in the group with myofascial trigger points (5.64kgf) was significantly lower than in the group without myofascial trigger points (11.96kgf) when scapular elevation was restricted (p<0.05). However, there was no significant difference in the strength of the scapular elevator or shoulder abductor between groups (p>0.05).

INTERPRETATION

These findings suggest that decreased strength in the shoulder abductor with restricted scapular elevation should be considered in evaluating and treating individuals with myofascial trigger points of the upper trapezius.

Self-administered physical exercise training as treatment of neck and shoulder pain among military helicopter pilots and crew: a randomized controlled trial

Background

Neck pain is frequent among military helicopter pilots and crew-members, and pain may influence individual health and work performance. The aim of this study was to examine if an exercise intervention could reduce neck pain among helicopter pilots and crew-members.

Methods

Thirty-one pilots and thirty-eight crew-members were randomized to either an exercise-training-group (n = 35) or a reference-group (n = 34). The exercise-training-group received 20-weeks of specific neck/shoulder training. The reference-group received no training. Primary outcome: Intensity of neck pain previous 3-months (scale 0-10). Secondary outcomes: additional neck/shoulder pain intensity variables and pressure-pain-threshold in the trapezius muscle (TRA) and upper-neck-extensor muscles (UNE). Regular training adherence was defined as ≥1 training session a week. Statistical analyses performed were intention-to-treat and per-protocol. Students t-test was performed (p < 0.05).

Results

Intensity of neck pain previous 3-months at baseline was: 2.2 ± 1.8 and previous 7-days: 1.0 ± 1.5, and pressure-pain-threshold in TRA and UNE (right/left) was in kPa: 424 ± 187 / 434 ± 188 and 345 ± 157 / 371 ± 170 in the exercise-training-group, and 416 ± 177 / 405 ± 163 and 334 ± 147 / 335 ± 163 in the reference-group, with no differences between groups. Intention-to-treat-analysis revealed no significant between-group-differences in neck pain intensity and pressure-pain-threshold. Between-group-differences, including participants who trained regularly (n = 10) were also non-significant. Within-group-changes were significant among participants with regular training adherence in the exercise-training-group regarding intensity of neck pain previous 3-months (from 2.2 ± 0.6 to 1.3 ± 1.3, p = 0.019). Likewise, within the whole exercise-training-group, neck pain previous 7-days decreased (from 1.0 ± 1.4 to 0.6 ± 1.1, p = 0.024). Additional within-group-changes regarding pressure-pain-threshold in kPa were for the reference-group a reduction in TRA and UNE (right/left) to: 342 ± 143 / 332 ± 154 and 295 ± 116 / 292 ± 121 implying increased pain sensitivity, while for the exercise-training-group only a reduction in left TRA was seen: 311 ± 113.

Conclusions

The exercise intervention did not reduce neck pain among helicopter pilots and crew-members as no significant between-group-differences were found. However, some trends were demonstrated as some neck pain intensity and sensitivity improved more within the exercise-training-group but not within the reference-group. The lack of effect may be due to low adherence since only ~ 1/3 of subjects in the exercise-training-group engaged in regular training which may be due to the self-administration of the training.

Trial registrations

Ethical committee of Southern Denmark (S-20120121) 29 August, 2012. Clinical Trail Registration (NCT01926262) 16 August, 2013.

A protocol for a new methodological model for work-related shoulder complex injuries: From diagnosis to rehabilitation

Background

Work-related injuries of the shoulder complex represent a challenge for clinicians because of the large variety of clinical entities involved and the broad anatomic structures that can be affected. Furthermore, commonly performed orthopedic tests have demonstrated limited accuracy for diagnosing the injury despite considerable research efforts. The aim of this study protocol is therefore to describe a comprehensive approach integrating both a clinical- and functional status-based pathology and an adapted rehabilitation prescription.

Methods/Design

A longitudinal cohort study will be performed at the Department of Rehabilitation and Medical Assistance of a mutual insurance society for work-related injury management in Spain (Mutua Navarra, Pamplona, Navarra Spain). Patients will be attended by an occupational physician who specializes in work-related injuries and is part of the project team that will systematically visit all the participants. After the medical diagnosis and any requested supplementary evaluations (i.e., radiological examinations), the patients will be referred to the rehabilitation service. Before the physiotherapeutic rehabilitation program is initiated, the patients will undergo a comprehensive functional screening at the biomechanics laboratory. Using a decision-making scheme, the identified functional deficits will be used to customize the individual rehabilitation plan.

Discussion

The proposed objective criteria-based shoulder diagnosis and rehabilitation model could be a new effective strategy for minimizing the time required to regain functional capacity and recover from symptoms among patients with work-related shoulder injuries.

Trial registration

The study protocol has been registered on Clinical Trials.gov as NCT02732002 (April 10^th 2016).

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1435-2) contains supplementary material, which is available to authorized users.

Factors affecting pain relief in response to physical exercise interventions among healthcare workers

The aim of this study is to identify factors associated with musculo-skeletal pain reduction during workplace-based or home-based physical exercise interventions among healthcare workers. Two hundred female healthcare workers (age: 42.0, BMI: 24.1, average pain intensity: 3.1 on a scale of 0-10) from three hospitals participated. Participants were randomly allocated at the cluster level (18 departments) to 10 weeks of (i) workplace physical exercise (WORK) performed in groups during working hours for 5 × 10 minutes per week and up to five group-based coaching sessions on motivation for regular physical exercise, or (ii) home-based physical exercise (HOME) performed alone during leisure-time for 5 × 10 minutes per week. Linear mixed models accounting for cluster identified factors affecting pain reduction. On average 2.2 (SD: 1.1) and 1.0 (SD: 1.2) training sessions were performed per week in WORK and HOME, respectively. The multi-adjusted analysis showed a significant effect on pain reduction of both training adherence (P=.04) and intervention group (P=.04) with participants in WORK experiencing greater reductions compared with HOME. Obesity at baseline was associated with better outcome. Leisure-time exercise, daily patient transfer, age, and chronic pain did not affect the changes in pain. In conclusion, even when adjusted for training adherence, performing physical exercise at the workplace is more effective than home-based exercise in reducing musculo-skeletal pain in healthcare workers. Noteworthy, obese individuals may especially benefit from physical exercise interventions targeting musculo-skeletal pain.

When Intervention Meets Organisation, a Qualitative Study of Motivation and Barriers to Physical Exercise at the Workplace

OBJECTIVE

To provide a comprehensive understanding of the motivational factors and barriers that are important for compliance with high-intensity workplace physical exercise that is aimed at reducing musculoskeletal disorders.

METHOD

The present study, which used semideductive, thematic, and structured in-depth interviews, was nested in a 20-week cluster randomised controlled trial among office workers. Interviews were conducted with 18 informants with diverse fields of sedentary office work who participated in strength training at the workplace for 20 minutes, three times per week. Organisational, implementational, and individual motives and barriers were explored.

RESULTS & DISCUSSION

The results show that attention should be given to the interaction between the management, the employees, and the intervention, as the main barrier to compliance was the internal working culture. The results emphasised the need for a clear connection between the management's implementational intentions and the actual implementation. The results emphasise the importance of ensuring the legitimacy of the intervention among managers, participants, and colleagues. Moreover, it is important to centrally organise, structure, and ensure flexibility in the working day to free time for participants to attend the intervention. Recommendations from this study suggest that a thorough intervention mapping process should be performed to analyse organisational and implementational factors before initiating workplace physical exercise training.

Exercises for mechanical neck disorders

BACKGROUND

Neck pain is common, disabling and costly. Exercise is one treatment approach.

OBJECTIVES

To assess the effectiveness of exercises to improve pain, disability, function, patient satisfaction, quality of life and global perceived effect in adults with neck pain.

SEARCH METHODS

We searched MEDLINE, MANTIS, ClinicalTrials.gov and three other computerized databases up to between January and May 2014 plus additional sources (reference checking, citation searching, contact with authors).

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing single therapeutic exercise with a control for adults suffering from neck pain with or without cervicogenic headache or radiculopathy.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted trial selection, data extraction, 'Risk of bias' assessment and clinical relevance. The quality of the evidence was assessed using GRADE. Meta-analyses were performed for relative risk and standardized mean differences (SMD) with 95% confidence intervals (CIs) after judging clinical and statistical heterogeneity.

MAIN RESULTS

Twenty-seven trials (2485 analyzed /3005 randomized participants) met our inclusion criteria.For acute neck pain only, no evidence was found.For chronic neck pain, moderate quality evidence supports 1) cervico-scapulothoracic and upper extremity strength training to improve pain of a moderate to large amount immediately post treatment [pooled SMD (SMDp) -0.71 (95% CI: -1.33 to -0.10)] and at short-term follow-up; 2) scapulothoracic and upper extremity endurance training for slight beneficial effect on pain at immediate post treatment and short-term follow-up; 3) combined cervical, shoulder and scapulothoracic strengthening and stretching exercises varied from a small to large magnitude of beneficial effect on pain at immediate post treatment [SMDp -0.33 (95% CI: -0.55 to -0.10)] and up to long-term follow-up and a medium magnitude of effect improving function at both immediate post treatment and at short-term follow-up [SMDp -0.45 (95%CI: -0.72 to -0.18)]; 4) cervico-scapulothoracic strengthening/stabilization exercises to improve pain and function at intermediate term [SMDp -14.90 (95% CI:-22.40 to -7.39)]; 5) Mindfulness exercises (Qigong) minimally improved function but not global perceived effect at short term. Low evidence suggests 1) breathing exercises; 2) general fitness training; 3) stretching alone; and 4) feedback exercises combined with pattern synchronization may not change pain or function at immediate post treatment to short-term follow-up. Very low evidence suggests neuromuscular eye-neck co-ordination/proprioceptive exercises may improve pain and function at short-term follow-up.For chronic cervicogenic headache, moderate quality evidence supports static-dynamic cervico-scapulothoracic strengthening/endurance exercises including pressure biofeedback immediate post treatment and probably improves pain, function and global perceived effect at long-term follow-up. Low grade evidence supports sustained natural apophyseal glides (SNAG) exercises.For acute radiculopathy, low quality evidence suggests a small benefit for pain reduction at immediate post treatment with cervical stretch/strengthening/stabilization exercises.

AUTHORS' CONCLUSIONS

No high quality evidence was found, indicating that there is still uncertainty about the effectiveness of exercise for neck pain. Using specific strengthening exercises as a part of routine practice for chronic neck pain, cervicogenic headache and radiculopathy may be beneficial. Research showed the use of strengthening and endurance exercises for the cervico-scapulothoracic and shoulder may be beneficial in reducing pain and improving function. However, when only stretching exercises were used no beneficial effects may be expected. Future research should explore optimal dosage.

Evidence-informed physical therapy management of performance-related musculoskeletal disorders in musicians

Playing a musical instrument at an elite level is a highly complex motor skill. The regular daily training loads resulting from practice, rehearsals and performances place great demands on the neuromusculoskeletal systems of the body. As a consequence, performance-related musculoskeletal disorders (PRMDs) are globally recognized as common phenomena amongst professional orchestral musicians. These disorders create a significant financial burden to individuals and orchestras as well as lead to serious consequences to the musicians’ performance and ultimately their career. Physical therapists are experts in treating musculoskeletal injuries and are ideally placed to apply their skills to manage PRMDs in this hyper-functioning population, but there is little available evidence to guide specific injury management approaches. An Australia-wide survey of professional orchestral musicians revealed that the musicians attributed excessively high or sudden increase in playing-load as major contributors to their PRMDs. Therefore, facilitating musicians to better manage these loads should be a cornerstone of physical therapy management. The Sound Practice orchestral musicians work health and safety project used formative and process evaluation approaches to develop evidence-informed and clinically applicable physical therapy interventions, ultimately resulting in favorable outcomes. After these methodologies were employed, the intervention studies were conducted with a national cohort of professional musicians including: health education, onsite injury management, cross-training exercise regimes, performance postural analysis, and music performance biomechanics feedback. The outcomes of all these interventions will be discussed alongside a focussed review on the existing literature of these management strategies. Finally, a framework for best-practice physical therapy management of PRMDs in musicians will be provided.

Effects of two different specific neck exercise interventions on palmitoylethanolamide and stearoylethanolamide concentrations in the interstitium of the trapezius muscle in women with chronic neck shoulder pain

PURPOSE

Chronic neck/shoulder pain (CNSP) is one of the most common pain conditions. The understanding of mechanisms, including the peripheral balance between nociceptive and antinociceptive processes, is incomplete. N-acylethanolamines (NAEs) are a class of endogenous compounds that regulate inflammation and pain. The aim of this study was to investigate the levels of two NAEs: the peroxisome proliferator-activated receptor type-α ligand palmitoylethanolamide (PEA) and stearoylethanolamide (SEA) in the muscle interstitium of the trapezius muscle in women with CNSP randomized to two different neck specific training programs and in a healthy pain-free control group (CON).

MATERIALS AND METHODS

Fifty-seven women with CNSP were randomized to strength + stretch or stretch alone exercise programs. Twenty-nine subjects underwent microdialysis procedure before and after 4-6 months of exercise. Twenty-four CON subjects underwent microdialysis procedure before and after 4-6 months without any intervention in between. Microdialysate samples were collected from the trapezius muscle and analyzed by mass spectrometry for PEA and SEA levels.

RESULTS

PEA and SEA levels were significantly higher in CNSP patients compared with CON. PEA was significantly higher in CNSP than in CON after both training programs. SEA was significantly higher in CNSP than in CON after stretch alone but not after strength + stretch training. A significant positive correlation was found between changes in pain intensity and in SEA levels in the strength + stretch group, but not in the stretch alone group.

CONCLUSION

Our results indicate that exercise interventions differentially affect the levels of the bioactive lipids PEA and SEA in the interstitium of the trapezius muscle in women with CNSP.

Time-wise change in neck pain in response to rehabilitation with specific resistance training: implications for exercise prescription

PURPOSE

To determine the time-wise effect of specific resistance training on neck pain among industrial technicians with frequent neck pain symptoms.

METHODS

Secondary analysis of a parallel-group cluster randomized controlled trial of 20 weeks performed at two large industrial production units in Copenhagen, Denmark. Women with neck pain >30 mm VAS (N = 131) were included in the present analysis. The training group (N = 77) performed specific resistance training for the neck/shoulder muscles three times a week, and the control group (N = 54) received advice to stay active. Participants of both groups registered neck pain intensity (0-100 mm VAS) once a week.

RESULTS

Neck pain intensity was 55 mm (SD 23) at baseline. There was a significant group by time interaction for neck pain (F-value 2.61, P<0.001, DF = 19). Between-group differences in neck pain reached significance after 4 weeks (11 mm, 95% CI 2 to 20). The time-wise change in pain showed three phases; a rapid decrease in the training group compared with the control group during the initial 7 weeks, a slower decrease in pain during the following weeks (week 8-15), and a plateau during the last weeks (week 16-20). Adherence to training followed a two-phase pattern, i.e. weekly participation rate was between 70-86% during the initial 7 weeks, dropping towards 55-63% during the latter half of the training period.

CONCLUSION

Four weeks of specific resistance training reduced neck pain significantly, but 15 weeks is required to achieve maximal pain reduction. The time-wise change in pain followed a three-phase pattern with a rapid effect during the initial 7 weeks followed by a slower but still positive effect, and finally a plateau from week 15 and onwards. Decreased participation rate may explain the decreased efficacy during the latter phase of the intervention.

Ask the Experts: Chronic neck pain: risk factors, consequences and solutions

Lars L Andersen, MSc PhD, is Professor of Musculoskeletal Disorders at National Research Centre for the Working Environment in Copenhagen (Denmark). With a background in exercise physiology, he has a special interest in the effect of strength training on health, performance and disease. Currently, he performs epidemiological and interventional research primarily in the field of musculoskeletal disorders, but also in psychosocial work environment, behavioral psychology, stroke, early aging, physical activity and workplace health promotion. He has led several research projects and published more than 90 original articles with peer-review in international journals. He is an editorial board member of BMC Musculoskeletal Disorders, Journal of Aging and Health and ISRN Pain. His research on treatment of musculoskeletal disorders using strength training and kettlebell training has been highlighted in the media, for example, by USA Today, the New York Times and Reuters.

High-intensity strength training improves function of chronically painful muscles: case-control and RCT studies

Aim. This study investigates consequences of chronic neck pain on muscle function and the rehabilitating effects of contrasting interventions. Methods. Women with trapezius myalgia (MYA, n = 42) and healthy controls (CON, n = 20) participated in a case-control study. Subsequently MYA were randomized to 10 weeks of specific strength training (SST, n = 18), general fitness training (GFT, n = 16), or a reference group without physical training (REF, n = 8). Participants performed tests of 100 consecutive cycles of 2 s isometric maximal voluntary contractions (MVC) of shoulder elevation followed by 2 s relaxation at baseline and 10-week follow-up. Results. In the case-control study, peak force, rate of force development, and rate of force relaxation as well as EMG amplitude were lower in MYA than CON throughout all 100 MVC. Muscle fiber capillarization was not significantly different between MYA and CON. In the intervention study, SST improved all force parameters significantly more than the two other groups, to levels comparable to that of CON. This was seen along with muscle fiber hypertrophy and increased capillarization. Conclusion. Women with trapezius myalgia have lower strength capacity during repetitive MVC of the trapezius muscle than healthy controls. High-intensity strength training effectively improves strength capacity during repetitive MVC of the painful trapezius muscle.

Evaluation of pain and function after two home exercise programs in a clinical trial on women with chronic neck pain - with special emphasises on completers and responders

Background

Different types of exercises can help manage chronic neck pain. Supervised exercise interventions are widely used, but these protocols require substantial resources. The aim of this trial, which focused on adherence, was to evaluate two home exercise interventions.

Methods

This parallel group randomized controlled trial included 57 women randomly allocated into two groups – a strength training group (STRENGTH, 34 subjects) and a stretching group (STRETCH, 23 subjects). The interventions focused on the neck and shoulder muscles and lasted for 12 months. The STRENGTH group performed weight training and ended each session with stretching exercises. These stretching exercises constituted the entirety of the STRETCH group’s training session. Both groups were instructed to exercise three times per week. All the participants kept an exercise diary. In addition, all participants were offered support via phone and e-mail. The primary outcomes were pain intensity and function. The trial included a four- to six-month and a twelve-month follow-up. A completer in this study exercised at least 1,5 times per week during eight unbroken weeks. A responder in this study reported clinically significant improvements on pain and function. The statistical analyses used the Mann Whitney U-test, Wilcoxon signed-rank test, and X² test.

Results

At four- to six-months, the numbers of completers were 19 in the STRENGTH group and 17 in the STRETCH group. At twelve months, the corresponding numbers were 11 (STRENGTH) and 10 (STRETCH). At four- to six-months, the proportions of subjects reporting clinically important changes (STRENGTH and STRETCH) were for neck pain: 47% and 41%, shoulder pain: 47% and 47%, function: 37% and 29%. At twelve months, the corresponding numbers were for neck pain: 45% and 40%, shoulder pain: 55% and 50%, function: 55% and 20%.

Conclusions

No differences in the two primary outcomes between the two interventions were found, a finding that may be due to the insufficient statistical power of the study. Both interventions based on home exercises improved the two primary outcomes, but the adherences were relatively low. Future studies should investigate ways to improve adherence to home exercise treatments.

Trial registration

ClinicalTrials.gov Id: NCT01876680

Shoulder muscle function in frozen shoulder syndrome patients following manipulation under anesthesia: a 6-month follow-up study

INTRODUCTION

The present study evaluates changes in shoulder muscle function in patients with frozen shoulder syndrome (FSS) following manipulation under general anesthesia (MUA).

PATIENTS AND METHODS

Fifteen FSS patients with mean (±SD) age of 53.6±9.7 years were included in this study. Isometric endurance of the shoulder muscles was characterized by time and net impulse (NI), which were assessed with the patient holding a weight in the hand until exhaustion. Fatigability of the deltoid and trapezius muscles during isometric endurance test was assessed by electromyogram power spectrum median frequency (MF) slope per minute. Patients were also screened for daytime pain. Data were collected before MUA, and at 1 and 6 months postoperatively.

RESULTS

Six months postoperatively, the MF slope for the trapezius and deltoid muscles of the involved and uninvolved shoulders did not differ (P>0.05), whereas NI remained lower and endurance time was longer (P<0.05). Shoulder pain was reduced as compared to preoperative levels (on visual analog scale) 1 and 6 months postoperatively (P<0.05).

DISCUSSION

In patients with FSS, the fastest improvements in shoulder muscle NI, fatigability and pain take place in the first month after MUA; 6 months after MUA, however, NI and endurance time remained impaired for the involved shoulder. Physiotherapy should pay more attention to muscle function recovery.

LEVEL OF EVIDENCE

Level III, prospective follow-up study.

Psychological Care, Patient Education, Orthotics, Ergonomics and Prevention Strategies for Neck Pain: An Systematic Overview Update as Part of the ICON Project

OBJECTIVES

To conduct an overview on psychological interventions, orthoses, patient education, ergonomics, and 1⁰/2⁰ neck pain prevention for adults with acute-chronic neck pain.

SEARCH STRATEGY

Computerized databases and grey literature were searched (2006-2012).

SELECTION CRITERIA

Systematic reviews of randomized controlled trials (RCTs) on pain, function/disability, global perceived effect, quality-of-life and patient satisfaction were retrieved.

DATA COLLECTION & ANALYSIS

Two independent authors selected articles, assessed risk of bias using AMSTAR tool and extracted data. The GRADE tool was used to evaluate the body of evidence and an external panel to provide critical review.

MAIN RESULTS

We retrieved 30 reviews (5-9 AMSTAR score) reporting on 75 RCTs with the following moderate GRADE evidence. For acute whiplash associated disorder (WAD), an education video in emergency rooms (1RCT, 405participants] favoured pain reduction at long-term follow-up thus helping 1 in 23 people [Standard Mean Difference: -0.44(95%CI: -0.66 to -0.23)). Use of a soft collar (2RCTs, 1278participants) was not beneficial in the long-term. For chronic neck pain, a mind-body intervention (2RCTs, 1 meta-analysis, 191participants) improved short-term pain/function in 1 of 4 or 6 participants. In workers, 2-minutes of daily scapula-thoracic endurance training (1RCT, 127participants) over 10 weeks was beneficial in 1 of 4 participants. A number of psychosocial interventions, workplace interventions, collar use and self-management educational strategies were not beneficial.

REVIEWERS' CONCLUSIONS

Moderate evidence exists for quantifying beneficial and non-beneficial effects of a limited number of interventions for acute WAD and chronic neck pain. Larger trials with more rigorous controls need to target promising interventions.

Specific neck training induces sustained corticomotor hyperexcitability as assessed by motor evoked potentials

STUDY DESIGN

Experimental investigation of short-term and long-term corticomotor effects of specific neck training, coordination training, and no training.

OBJECTIVE

To determine the effects of different training programs on the motor neurons controlling the neck muscles as well as the effects of training on muscle strength and muscle fatigue, and the correlations between corticomotor control and motor learning.

SUMMARY OF BACKGROUND DATA

Training is usually recommended for unspecific neck pain and consists of neck and upper body coordination, strengthening, and endurance exercises. However, it is unclear which type of training is the most effective. No studies have previously investigated the neural effect of neck training and the possible differential effect of specific versus coordination training on corticomotor control.

METHODS

Transcranial magnetic stimulation and electromyography were used to elicit and monitor motor evoked potentials (MEPs) from the trapezius and thumb muscles before and 30 minutes, 1 hour, and 7 days after training. Parameters measured were MEP amplitude, MEP latency, strength, learning effects, and muscle fatigue.

RESULTS

Only specific neck training yielded a 67% increase in MEP amplitudes for up to 7 days after training compared with baseline (P < 0.001). No significant changes were seen after coordination training, no training, and in the within-subject control muscle. The mean muscle strength increased immediately after specific neck training from 56.6 to 61 kg (P < 0.001). No subjective or objective measures of fatigue were observed.

CONCLUSION

Specific neck training induced a sustained hyperexcitability of motor neurons controlling the neck muscles compared with coordination training and controls. These findings may prove valuable in the process of developing more effective clinical training programs for unspecific neck pain.

Muscle activity during leg strengthening exercise using free weights and elastic resistance: effects of ballistic vs controlled contractions

The present study's aim was to evaluate muscle activity during leg exercises using elastic vs. isoinertial resistance at different exertion and loading levels, respectively. Twenty-four women and eighteen men aged 26-67 years volunteered to participate in the experiment. Electromyographic (EMG) activity was recorded in nine muscles during a standardized forward lunge movement performed with dumbbells and elastic bands during (1) ballistic vs. controlled exertion, and (2) at low, medium and high loads (33%, 66% and 100% of 10 RM, respectively). The recorded EMG signals were normalized to MVC EMG. Knee joint angle was measured using electronic inclinometers. The following results were obtained. Loading intensity affected EMG amplitude in the order: low<medium<high loads (p<.001). Ballistic contractions always produced greater EMG activity than slow controlled contractions, and for most muscles ballistic contractions with medium load showed similar EMG amplitude as controlled contractions with high load. At flexed knee joint positions with elastic resistance, quadriceps and gluteus EMG amplitude during medium-load ballistic contractions exceeded that recorded during high-load controlled contractions. Quadriceps and gluteus EMG amplitude increased at flexed knee positions. In contrast, hamstrings EMG amplitude remained constant throughout ROM during dumbbell lunge, but increased at more extended knee joint positions during lunges using elastic resistance. Based on these results, it can be concluded that lunges performed using medium-load ballistic muscle contractions may induce similar or even higher leg muscle activity than lunges using high-load slow-speed contractions. Consequently, lunges using elastic resistance appear to be equally effective in inducing high leg muscle activity as traditional lunges using isoinertial resistance.

Exercises for mechanical neck disorders

BACKGROUND

Neck disorders are common, disabling and costly. The effectiveness of exercise as a physiotherapy intervention remains unclear.

OBJECTIVES

To improve pain, disability, function, patient satisfaction, quality of life and global perceived effect in adults with neck pain.

SEARCH METHODS

Computerized searches were conducted up to February 2012.

SELECTION CRITERIA

We included single therapeutic exercise randomized controlled trials for adults with neck pain with or without cervicogenic headache or radiculopathy.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted selection, data extraction, 'Risk of bias' assessment, and clinical relevance. The quality of the body of evidence was assessed using GRADE. Relative risk and standardized mean differences (SMD) were calculated.  After judging clinical and statistical heterogeneity, we performed meta-analyses.

MAIN RESULTS

Six of the 21 selected trials had low risk of bias. Moderate quality evidence shows that combined cervical, scapulothoracic stretching and strengthening are beneficial for pain relief post treatment (pooled SMD -0.35, 95% confidence interval (CI): -0.60, -0.10) and at intermediate follow-up (pooled SMD -0.31, 95% CI: -0.57, -0.06), and improved function short term and intermediate term (pooled SMD -0.45, 95% CI: -0.72, -0.18) for chronic neck pain. Moderate quality evidence demonstrates patients are very satisfied with their care when treated with therapeutic exercise. Low quality evidence shows exercise is of benefit for pain in the short term and for function up to long-term follow-up for chronic neck pain. Low to moderate quality evidence shows that chronic neck pain does not respond to upper extremity stretching and strengthening or a general exercise program.Low to moderate quality evidence supports self-mobilization, craniocervical endurance and low load cervical-scapular endurance exercises in reducing pain, improving function and global perceived effect in the long term for subacute/chronic cervicogenic headache. Low quality evidence supports neck strengthening exercise in acute cervical radiculopathy for pain relief in the short term.

AUTHORS' CONCLUSIONS

Low to moderate quality evidence supports the use of specific cervical and scapular stretching and strengthening exercise for chronic neck pain immediately post treatment and intermediate term, and cervicogenic headaches in the long term. Low to moderate evidence suggests no benefit for some upper extremity stretching and strengthening exercises or a general exercise program.  Future trials should consider using an exercise classification system to establish similarity between protocols and adequate sample sizes. Factorial trials would help determine the active treatment agent within a treatment regimen where a standardized representation of dosage is essential. Standardized reporting of adverse events is needed for balancing the likelihood of treatment benefits over potential harms.

Scapular muscle rehabilitation exercises in overhead athletes with impingement symptoms: effect of a 6-week training program on muscle recruitment and functional outcome

BACKGROUND

Previous research has identified some specific exercises to correct scapular muscle balance and onset timing in healthy subjects. However, evidence for their effectiveness in overhead athletes with impingement symptoms has been lacking until now.

HYPOTHESIS

A 6-week exercise program consisting of previously selected exercises is able to improve muscle activation and onset timing during shoulder elevation. This program may also change pain and functionality levels in overhead athletes with mild impingement symptoms.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Forty-seven overhead athletes with mild impingement symptoms (25 men and 22 women) were enrolled in this study. Before and after the 6-week training program, the Shoulder Pain and Disability Index (SPADI) score was individually obtained and maximum voluntary isometric contraction (MVIC) values were determined by surface electromyography. Mean muscle activation levels, muscle ratio data, and muscle onset timing were assessed for the upper (UT), middle (MT), and lower (LT) trapezius and serratus anterior (SA) muscle during arm elevation in the scapular plane.

RESULTS

Forty participants completed the exercise program. The SPADI scores significantly decreased from 29.86 ± 17.03 during initial assessment to 11.7 ± 13.78 during postmeasurements (P < .001). The 3 trapezius muscle parts showed increased MVIC values and decreased activation levels during arm elevation, whereas this was not the case for the SA muscle. After the training program, UT/SA significantly decreased, whereas UT/MT and UT/LT did not change (P < .05). No differences in muscle timing between pre- and postmeasurements could be identified. The LT showed significant earlier activation compared with UT (-0.47; P < .001) and MT (-0.49; P < .001). The serratus anterior showed significant earlier activation compared with the UT (-0.74; P < .001), MT (-0.76; P < .001), and LT muscles (F = 0.27; P = .046).

CONCLUSION

This is the first longitudinal study to demonstrate that previously selected exercises (1) improve pain and function based on SPADI scores, (2) reduce relative trapezius muscle activation, and (3) alter UT/SA ratios. However, they were unable to change the timing of the scapular muscles during arm elevation when compared before and after a 6-week training program in overhead athletes with mild impingement symptoms.

Patient education for neck pain

BACKGROUND

Neck disorders are common, disabling, and costly. The effectiveness of patient education strategies is unclear.

OBJECTIVES

To assess the short- to long-term effects of therapeutic patient education (TPE) strategies on pain, function, disability, quality of life, global perceived effect, patient satisfaction, knowledge transfer, or behaviour change in adults with neck pain associated with whiplash or non-specific and specific mechanical neck pain with or without radiculopathy or cervicogenic headache.

SEARCH METHODS

We searched computerised bibliographic databases (inception to 11 July 2010).

SELECTION CRITERIA

Eligible studies were randomised controlled trials (RCT) investigating the effectiveness of TPE for acute to chronic neck pain.

DATA COLLECTION AND ANALYSIS

Paired independent review authors conducted selection, data abstraction, and 'Risk of bias' assessment. We calculated risk ratio (RR) and standardised mean differences (SMD). Heterogeneity was assessed; no studies were pooled.

MAIN RESULTS

Of the 15 selected trials, three were rated low risk of bias. Three TPE themes emerged.Advice focusing on activation: There is moderate quality evidence (one trial, 348 participants) that an educational video of advice focusing on activation was more beneficial for acute whiplash-related pain when compared with no treatment at intermediate-term [RR 0.79 (95% confidence interval (CI) 0.59 to 1.06)] but not long-term follow-up [0.89 (95% CI, 0.65 to 1.21)]. There is low quality evidence (one trial, 102 participants) that a whiplash pamphlet on advice focusing on activation is less beneficial for pain reduction, or no different in improving function and global perceived improvement from generic information given out in emergency care (control) for acute whiplash at short- or intermediate-term follow-up. Low to very low quality evidence (nine trials using diverse educational approaches) showed either no evidence of benefit or difference for varied outcomes. Advice focusing on pain & stress coping skills and workplace ergonomics: Very low quality evidence (three trials, 243 participants) favoured other treatment or showed no difference spanning numerous follow-up periods and disorder subtypes.  Low quality evidence (one trial, 192 participants) favoured specific exercise training for chronic neck pain at short-term follow-up.Self-care strategies: Very low quality evidence (one trial, 58 participants) indicated that self-care strategies did not relieve pain for acute to chronic neck pain at short-term follow-up.

AUTHORS' CONCLUSIONS

With the exception of one trial, this review has not shown effectiveness for educational interventions, including advice to activate, advice on stress-coping skills, workplace ergonomics and self-care strategies. Future research should be founded on sound adult learning theory and learning skill acquisition.

Effects of intensive physical rehabilitation on neuromuscular adaptations in adults with poststroke hemiparesis

Hemiparesis-disability and muscle weakness of 1 side of the body-is a common consequence of stroke. High-intensity strength training may be beneficial to regain function, but strength coaches in the field of rehabilitation need evidence-based guidelines. The purpose of this study was to evaluate the effect of intensive physical rehabilitation on neuromuscular and functional adaptations in outpatients suffering from hemiparesis after stroke. A within-subject repeated-measures design with the paretic leg as the experimental leg and the nonparetic leg as the control leg was used. Eleven outpatients with hemiparesis after stroke participated in 12 weeks of intensive physical rehabilitation comprising unilateral high-intensity strength training with near-maximal loads (4-12 repetition maximum) and body weight supported treadmill training. At baseline and 12-week follow-up, the patients went through testing consisting of isokinetic muscle strength, neuromuscular activation measured with electromyography (EMG), electrically evoked muscle twitch contractile properties, and gait performance (10-m Walk Test and 6-min Walk Test). After the 12-week conditioning program, knee extensor and flexor strength increased during all contraction modes and velocities in the paretic leg. Significant increases were observed for agonist EMG amplitude at slow concentric and slow eccentric contraction. Twitch torque increased, whereas twitch time-to-peak tension remained unchanged. By contrast, no significant changes were observed in the nonparetic control leg. Gait performance increased 52-68%. In conclusion, intensive physical rehabilitation after stroke leads to clinically relevant neuromuscular improvements, leading to increased voluntary strength during a wide range of contraction modes and velocities, and improved gait velocity. Strength training coaches working in the field of rehabilitation can use this knowledge to safely and efficiently add high-intensity strength training to existing rehabilitation paradigms.

Effect of specific resistance training on forearm pain and work disability in industrial technicians: cluster randomised controlled trial

OBJECTIVES

To determine the effect of specific resistance training on forearm pain and work disability in industrial technicians.

DESIGN AND SETTING

Two-armed cluster randomised controlled trial of 20 weeks performed at two industrial production units in Copenhagen, Denmark.

PARTICIPANTS

Working-age industrial technicians both with and without pain and disability.

INTERVENTIONS

The training group (n=282) performed specific resistance training for the shoulder, neck and arm muscles three times a week. The control group (n=255) was advised to continue normal physical activity.

OUTCOME

All participants rated forearm pain intensity (Visual Analogue Scale, 0-100 mm) once a week (primary outcome) and replied to a questionnaire on work disability (Disability of the Arm Shoulder and Hand, 0-100) at baseline and follow-up (secondary outcome).

RESULTS

Questionnaires were sent to 854 workers of which 30 (n=282) and 27 (n=255) clusters were randomised to training and control, respectively. Of these, 211 and 237 participants, respectively, responded to the follow-up questionnaire. Intention-to-treat analyses including both individuals with and without pain showed that from baseline to follow-up, pain intensity and work disability decreased more in the training group than in the control group (4-5 on a scale of 0-100, p<0.01-0.001). Among those with pain >30 mm Visual Analogue Scale at baseline (n=54), the OR for complete recovery at follow-up in the training group compared with the control group was 4.6 (95% CI 1.2 to 17.9). Among those with work disability >30 at baseline (n=113), the OR for complete recovery at follow-up in the training group compared with the control group was 6.0 (95% CI 1.8 to 19.8).

CONCLUSION

Specific resistance training of the shoulder, neck and arm reduces forearm pain and work disability among industrial technicians.

TRIAL REGISTRATION NUMBER

NCT01071980.

Strength training increases the size of the satellite cell pool in type I and II fibres of chronically painful trapezius muscle in females

While strength training has been shown to be effective in mediating hypertrophy and reducing pain in trapezius myalgia, responses at the cellular level have not previously been studied. This study investigated the potential of strength training targeting the affected muscles (SST, n = 18) and general fitness training (GFT, n = 16) to augment the satellite cell (SC) and macrophage pools in the trapezius muscles of women diagnosed with trapezius myalgia. A group receiving general health information (REF, n = 8) served as a control. Muscle biopsies were collected from the trapezius muscles of the 42 women (age 44 ± 8 years; mean ± SD) before and after the 10 week intervention period and were analysed by immunohistochemistry for SCs, macrophages and myonuclei. The SC content of type I and II fibres was observed to increase significantly from baseline by 65% and 164%, respectively, with SST (P < 0.0001), together with a significant correlation between the baseline number of SCs and the extent of hypertrophy (r = -0.669, P = 0.005). SST also resulted in a 74% enhancement of the trapezius macrophage content (P < 0.01), accompanied by evidence for the presence of an increased number of actively dividing cells (Ki67(+)) post-SST (P < 0.001). GFT resulted in a significant 23% increase in the SC content of type II fibres, when expressed relative to myonuclear number only (P < 0.05). No changes in the number of myonuclei per fibre or myonuclear domain were detected in any group. These findings provide strong support at the cellular level for the potential of SST to induce a strong myogenic response in this population.

Myofeedback training and intensive muscular strength training to decrease pain and improve work ability among female workers on long-term sick leave with neck pain: a randomized controlled trial

Abstract

The theoretical framework is that muscle tension in the neck is related to insufficient muscular rest and is a risk factor for chronic pain and reduced work ability. Promoting muscle strength and muscle rest may increase work ability and reduce neck pain.

Objectives

To test whether myofeedback training or intensive strength training leads to decreased pain and increased work ability in women on long-term sick leave.

Methods

This is a randomized controlled trial of two 1-month interventions with myofeedback or muscular strength training in the home environment. Female human service organization workers (n = 60) on long-term (>60 days) sick leave and with chronic neck pain were followed with self-reported and laboratory-observed data of health, pain, muscular activation, and work ability, at baseline, immediately after the intervention and 3 months after baseline.

Results

For both intervention groups, pain was lowered over time compared with the control group. Decreased pain and muscular activity was associated with increased self-rated work ability and with laboratory-observed work ability at 3-month follow-up. Decreased pain was also associated with increased self-rated work ability at 1-month follow-up. Muscular strength training was associated with increased self-rated work ability and mental health. Myofeedback was associated with increased observed work ability and self- rated vitality.

Conclusions

The two interventions showed positive results, suggesting that they could be developed for use in health care practice to address pain and work ability. The intensive muscular strength training program, which is both easy to conduct at home and easy to coach, was associated with increased work ability.

Neck pain and anxiety do not always go together

Chronic pain and psychosocial distress are generally thought to be associated in chronic musculoskeletal disorders such as non-specific neck pain. However, it is unclear whether a raised level of anxiety is necessarily a feature of longstanding, intense pain amongst patient and general population sub-groups. In a cohort of 70 self-selected female, non-specific neck pain sufferers, we observed relatively high levels of self-reported pain of 4.46 (measured on the 11 point numerical pain rating scale (NRS-101)) and a longstanding duration of symptoms (156 days/year). However, the mean anxiety scores observed (5.49), fell well below the clinically relevant threshold of 21 required by the Beck Anxiety Inventory. The cohort was stratified to further distinguish individuals with higher pain intensity (NRS>6) and longer symptom duration (>90 days). Although a highly statistically significant difference (p = 0.000) was subsequently observed with respect to pain intensity, in the resulting sub-groups, none such a difference was noted with respect to anxiety levels. Our results indicate that chronic, intense pain and anxiety do not always appear to be related. Explanations for these findings may include that anxiety is not triggered in socially functional individuals, that individual coping strategies have come into play or in some instances that a psychological disorder like alexithymia could be a confounder. More studies are needed to clarify the specific role of anxiety in chronic non-specific musculoskeletal pain before general evidence-driven clinical extrapolations can be made.

Effect of contrasting physical exercise interventions on rapid force capacity of chronically painful muscles

Rapid force capacity of chronically painful muscles is inhibited markedly more than maximal force capacity and is therefore relevant to assess in rehabilitation settings. Our objective was to investigate the effect of two contrasting types of physical exercise on rapid force capacity, as well as neural and muscular adaptations in women with chronic neck muscle pain. A group of employed women ( n = 42) with a clinical diagnosis of trapezius myalgia participated in a 10-wk randomized controlled trial; specific strength training of the neck/shoulder muscles, general fitness training performed as leg-bicycling; or a reference intervention without physical activity. Maximal voluntary shoulder abductions were performed at static angles of 35° and 115° with simultaneous recording of electromyography (EMG) in the trapezius and deltoid. Maximal muscle strength and activation (peak torque and peak EMG) as well as rapid muscle strength and activation [rate of torque development (RTD) and rate of EMG rise] were subsequently determined. Trapezius muscle fiber characteristics were determined with ATPase histochemistry. Significant changes were observed only in the specific strength training group. Whereas peak torque increased 18–29% ( P < 0.01), RTD increased 61–115% ( P < 0.001). Peak EMG and rate of EMG rise increased correspondingly ( P < 0.05–0.001), and trapezius type II muscle fibers hypertrophied 20% ( P < 0.001). In conclusion, rapid force capacity of chronically painful muscles is highly responsive to rehabilitation with specific strength training. The underlying mechanisms were related to both pain reduction and general neuromuscular adaptations to strength training. Potentially, the present method can be a useful clinical screening tool of muscle function in rehabilitation settings.