Effects of electromyographic and mechanomyographic biofeedback on upper trapezius muscle activity during standardized computer work

Can biofeedback training in combination with ergonomic information reduce pain among young adult computer users with neck and upper extremity symptoms? - A randomized controlled intervention study

The aim of this randomized controlled study was to explore if an intervention with biofeedback training in combination with ergonomic discussions, could improve working technique and work postures, and reduce pain intensity and perceived exertion in young adult computer users with ongoing neck and upper extremity symptoms. 39 participants were divided into an intervention group and a control group. The intervention consisted of 4 sessions during a three-month period. Working technique, working postures, rated perceived exertion, pain intensity, and duration of computer use were measured at baseline and follow ups after 6 and 12 months. The intervention did not significantly improve working technique and working postures, nor reduce pain intensity and perceived exertion in the intervention group compared to the control group. However, there was a statistically significant reduction in reported pain intensity in the neck/shoulder for the whole group. Also, there was a trend that time spent with computer work without breaks was more reduced in the intervention group than in the control group.

Trapezius activity during personal computer work with progressive addition lenses for general purpose and for computer work in neophytes

INTRODUCTION

This study analysed the impact of general purpose progressive addition lenses (GP-PALs) and computer progressive addition lenses (PC-PALs) on the activity of the trapezius muscle during computer operation.

METHODS

In this randomised, single-blinded, crossover study, surface electromyography (SEMG) signals were recorded bilaterally from the trapezius muscle during a 30-min computer task performed wearing different presbyopic corrections. The amplitude probability distribution function and its percentiles, gap frequency, muscular rest time and sustained low-level muscle activity periods were analysed in 32 subjects with artificially induced presbyopia. Subjectively perceived differences in vision and postural load between lenses were evaluated using a seven-item questionnaire (non-standardised, visual analogue scale ranged from 1 [bad] to 100 [good]).

RESULTS

Considering the SEMG data, no significant difference in the muscular activity of the trapezius muscle was observed when using GP-PALs or PC-PALs for computer operation. However, PC-PALs showed statistically and clinically significantly higher results for subjectively perceived visual quality (78.4-31.3; p < 0.001), spontaneous tolerance (79.2-31.3; p < 0.001) and field of view (75.9-23.5; p < 0.001) compared with GP-PALs.

CONCLUSIONS

Even though the electromyographic approach did not show a significant differentiation between the lenses, the subjective evaluation was clearly in favour of PC-PALs. Eye care practitioners should always take an occupational history of presbyopes, ask about the workplace situation and consider the use of PC-PALs.

Effectiveness and usability of real-time vibrotactile feedback training to reduce postural exposure in real manual sorting work

Vibrotactile feedback training may be used as a complementary strategy to reduce time in demanding postures in manual handling. This study evaluated the short- and medium-term effects of concurrent posture-correction vibrotactile feedback training on trunk inclination exposure in real manual sorting work. Fifteen warehouse workers completed the training and the follow-up sessions. Trunk inclination angles were recorded using the ambulatory Smart Workwear System. Questionnaires were used for assessing system usability, perceived physical exertion, and work ability. The results showed reduced time in trunk inclination >30°, >45°, and >60°, and reductions in the 90th, 95th, and 99th percentile trunk inclination angles, when receiving feedback and immediately after feedback withdrawal. No significant reduction was retained after one and three weeks. The wearer's comfort was scored high, and the feedback did not increase the perceived cognitive demands. No significant effects attributed to changed trunk inclination exposure were observed for perceived physical exertion or work ability. The training program has the potential of contributing to reduced trunk inclination exposure in the short term. Future studies are needed to evaluate if improvements in the feedback training can transfer the short-term results to retained median- and long-term effects.Practitioner summary: A two-day training program with concurrent posture-correction vibrotactile feedback can contribute to reduced exposure of trunk inclination in real manual sorting work in the short term. More research is needed on how to design the feedback training programs in order to be effective in the long term.

Surface Electromyography of the Trapezius and Sternocleidomastoid during Computer Work with Presbyopic Corrections

SIGNIFICANCE

During computer work in controlled laboratory conditions, wearing multifocal contact lenses (MFCLs) showed no lower muscle load but increased subjective perception of comfort with equivalent visual quality and comparable tolerance.

PURPOSE

Because musculoskeletal complaints are frequent among computer workers, this study used the muscle electrophysiological activity of shoulder and neck muscles in presbyopic computer workers who received either progressive addition lenses for general purpose (GP-PALs) or MFCLs.

METHODS

For this crossover study, 11 presbyopic computer workers aged 55 ± 4 years (mean ± standard deviation) were equipped with GP-PALs and MFCLs in a randomized order. Surface electromyography signals were recorded bilaterally from shoulder and neck muscles during short-term computer work tasks using an optimally adjusted visual display unit workplace. The amplitude probability distribution function, the number and total duration of EMG gaps, and sustained low-level muscle activity periods of the surface electromyography signals were calculated. Comfort and correction type preferences were assessed. Head inclination was objectively evaluated.

RESULTS

Multifocal contact lenses elicited no significant lower muscle load than GP-PALs. The number of sustained low-level muscle activity periods longer than 60 seconds was similar between visual aids. The total amount of gaps was significantly higher with MFCLs (44 gaps) compared with progressive addition lenses for general purpose (15 gaps) in all analyzed periods for all participants. However, there were no significant differences for the median in the intraindividual comparisons (P = .22, dz = 0.52). Multifocal contact lenses scored statistically significant higher in comfort values with equivalent visual quality and comparable tolerance (P = .003, dz = 1.51).

CONCLUSIONS

Although the study failed to show clear results, wearing MFCLs seems to enhance working comfort compared with GP-PALs subjectively.

Evidence for the Effectiveness of Feedback from Wearable Inertial Sensors during Work-Related Activities: A Scoping Review

Background: Wearable inertial sensor technology (WIST) systems provide feedback, aiming to modify aberrant postures and movements. The literature on the effects of feedback from WIST during work or work-related activities has not been previously summarised. This review examines the effectiveness of feedback on upper body kinematics during work or work-related activities, along with the wearability and a quantification of the kinematics of the related device. Methods: The Cinahl, Cochrane, Embase, Medline, Scopus, Sportdiscus and Google Scholar databases were searched, including reports from January 2005 to July 2021. The included studies were summarised descriptively and the evidence was assessed. Results: Fourteen included studies demonstrated a 'limited' level of evidence supporting posture and/or movement behaviour improvements using WIST feedback, with no improvements in pain. One study assessed wearability and another two investigated comfort. Studies used tri-axial accelerometers or IMU integration (n = 5 studies). Visual and/or vibrotactile feedback was mostly used. Most studies had a risk of bias, lacked detail for methodological reproducibility and displayed inconsistent reporting of sensor technology, with validation provided only in one study. Thus, we have proposed a minimum 'Technology and Design Checklist' for reporting. Conclusions: Our findings suggest that WIST may improve posture, though not pain; however, the quality of the studies limits the strength of this conclusion. Wearability evaluations are needed for the translation of WIST outcomes. Minimum reporting standards for WIST should be followed to ensure methodological reproducibility.

Quantification of patellar tendon reflex using portable mechanomyography and electromyography devices

Deep tendon reflexes are one of the main components of the clinical nervous system examinations. These assessments are inexpensive and quick. However, evaluation can be subjective and qualitative. This study aimed to objectively evaluate hyperreflexia of the patellar tendon reflex using portable mechanomyography (MMG) and electromyography (EMG) devices. This study included 10 preoperative patients (20 legs) who had a pathology that could cause bilateral patellar tendon hyperreflexia and 12 healthy volunteers (24 legs) with no prior history of neurological disorders. We attached MMG/EMG sensors onto the quadriceps and tapped the patellar tendon with maximal and constant force. Our results showed a significantly high amplitude of the root mean square (RMS) and low frequency of the mean power frequency (MPF) in the rectus femoris, vastus medialis, and vastus lateralis muscles in both EMG and MMG with both maximal and constant force. Especially in the patients with cervical and thoracic myelopathy, the receiver operating characteristic (ROC) curve for diagnosing hyperreflexia of the patellar tendon showed a moderate to very high area under the curve for all EMG–RMS, EMG–MPF, MMG–RMS, and MMG–MPF values. The use of EMG and MMG for objectively quantifying the patellar tendon reflex is simple and desirable for future clinical applications and could help diagnose neurological disorders.

Reducing postural load in order picking through a smart workwear system using real-time vibrotactile feedback

Vibrotactile feedback training may be one possible method for interventions that target at learning better work techniques and improving postures in manual handling. This study aimed to evaluate the short term effect of real-time vibrotactile feedback on postural exposure using a smart workwear system for work postures intervention in simulated industrial order picking. Fifteen workers at an industrial manufacturing plant performed order-picking tasks, in which the vibrotactile feedback was used for postural training at work. The system recorded the trunk and upper arm postures. Questionnaires and semi-structured interviews were conducted about the users' experience of the system. The results showed reduced time in trunk inclination ≥20°, ≥30° and ≥45° and dominant upper arm elevation ≥30° and ≥45° when the workers received feedback, and for trunk inclination ≥20°, ≥30° and ≥45° and dominant upper arm elevation ≥30°, after feedback withdrawal. The workers perceived the system as useable, comfortable, and supportive for learning. The system has the potential of contributing to improved postures in order picking through an automated short-term training program.

A Wearable Sensor System for Physical Ergonomics Interventions Using Haptic Feedback

Work-related musculoskeletal disorders are a major concern globally affecting societies, companies, and individuals. To address this, a new sensor-based system is presented: the Smart Workwear System, aimed at facilitating preventive measures by supporting risk assessments, work design, and work technique training. The system has a module-based platform that enables flexibility of sensor-type utilization, depending on the specific application. A module of the Smart Workwear System that utilizes haptic feedback for work technique training is further presented and evaluated in simulated mail sorting on sixteen novice participants for its potential to reduce adverse arm movements and postures in repetitive manual handling. Upper-arm postures were recorded, using an inertial measurement unit (IMU), perceived pain/discomfort with the Borg CR10-scale, and user experience with a semi-structured interview. This study shows that the use of haptic feedback for work technique training has the potential to significantly reduce the time in adverse upper-arm postures after short periods of training. The haptic feedback was experienced positive and usable by the participants and was effective in supporting learning of how to improve postures and movements. It is concluded that this type of sensorized system, using haptic feedback training, is promising for the future, especially when organizations are introducing newly employed staff, when teaching ergonomics to employees in physically demanding jobs, and when performing ergonomics interventions.

An oculometrics-based biofeedback system to impede fatigue development during computer work: A proof-of-concept study

A biofeedback system may objectively identify fatigue and provide an individualized timing plan for micro-breaks. We developed and implemented a biofeedback system based on oculometrics using continuous recordings of eye movements and pupil dilations to moderate fatigue development in its early stages. Twenty healthy young participants (10 males and 10 females) performed a cyclic computer task for 31–35 min over two sessions: 1) self-triggered micro-breaks (manual sessions), and 2) biofeedback-triggered micro-breaks (automatic sessions). The sessions were held with one-week inter-session interval and in a counterbalanced order across participants. Each session involved 180 cycles of the computer task and after each 20 cycles (a segment), the task paused for 5-s to acquire perceived fatigue using Karolinska Sleepiness Scale (KSS). Following the pause, a 25-s micro-break involving seated exercises was carried out whether it was triggered by the biofeedback system following the detection of fatigue (KSS≥5) in the automatic sessions or by the participants in the manual sessions. National Aeronautics and Space Administration Task Load Index (NASA-TLX) was administered after sessions. The functioning core of the biofeedback system was based on a Decision Tree Ensemble model for fatigue classification, which was developed using an oculometrics dataset previously collected during the same computer task. The biofeedback system identified fatigue with a mean accuracy of approx. 70%. Perceived workload obtained from NASA-TLX was significantly lower in the automatic sessions compared with the manual sessions, p = 0.01 Cohen’s d_z = 0.89. The results give support to the effectiveness of integrating oculometrics-based biofeedback in timing plan of micro-breaks to impede fatigue development during computer work.

Effects of Shoulder Taping on Discomfort and Electromyographic Responses of the Neck While Texting on a Touchscreen Smartphone

Background

Prolonged neck flexion during smartphone use is known as a factor of neck pain and alteration of neck muscle activity. Studies on the effects of shoulder taping on neck discomfort and neck muscle responses while texting on a smartphone are still lacking. The aim of this study was to examine the effects of shoulder taping on neck discomfort using a numerical rating scale, and neck muscle activity and fatigue using a surface electromyography during a texting task on a touchscreen smartphone.

Methods

Twenty-five healthy adolescents used the dominant hand to perform a 30-minute texting task using a touchscreen smartphone at two separate times under one of the following two conditions: taping across the upper trapezius muscle and no taping. Neck discomfort, normalized root mean square, and normalized median frequency slopes for upper trapezius, cervical erector spinae, and sternocleidomastoid muscles were recorded.

Results

The results revealed that shoulder taping provided significantly lower neck discomfort than no taping (p < 0.001). However, shoulder taping did not significantly alter normalized root mean square and normalized median frequency slope values of all muscles when compared with no taping controls.

Conclusion

Shoulder taping reduces neck discomfort but does not affect neck muscle activity and fatigue while texting on a touchscreen smartphone.

Changing the sheets: a new system to reduce strain during patient repositioning

BACKGROUND

Manually repositioning patients puts healthcare providers at risk for injury; this may be reduced by using low-friction bedsheets.

OBJECTIVES

The aim of this study was to evaluate the physical properties and the physiological measures of muscle activity and perceptual participant accounts between a new slider sheet system and traditional hospital bedsheet makeup (soaker pad with a jersey bottom sheet).

METHOD

Surface electromyography was recorded from the arm and shoulder muscles of five healthcare providers executing a patient repositioning (boosting and turning) in a controlled laboratory setting to gain an indication of muscle activity required for two types of bedsheets (slider system and traditional sheet makeup). The Borg Scale was used to establish rating of perceived exertion for these repositioning tasks on the two types of bedsheet makeup. To evaluate the sheets independent of human interaction and contact, the physical resistive characteristics of the sheets were calculated by determining the coefficient of friction.

RESULTS

Patient repositioning on traditional sheets, compared with the slider system, resulted in 16% greater electromyography burst numbers and 11% longer duration for both boosting and turning. Moreover, ratings of perceived exertion for repositioning patients on traditional sheets versus on slider sheets were more than double. The coefficient of friction of the traditional sheets was 65% less in the slider sheet system.

DISCUSSION

This study suggests that manually repositioning patients on a low-friction slider system reduces muscular and perceived effort. Proper usage of this type of bedsheets may reduce the risks associated with musculoskeletal strain and injuries of the healthcare providers.

Comparing biofeedback with active exercise and passive treatment for the management of work-related neck and shoulder pain: a randomized controlled trial

OBJECTIVES

To compare the effects of biofeedback with those of active exercise and passive treatment in treating work-related neck and shoulder pain.

DESIGN

A randomized controlled trial with 3 intervention groups and a control group.

SETTING

Participants were recruited from outpatient physiotherapy clinics and a local hospital.

PARTICIPANTS

All participants reported consistent neck and shoulder pain related to computer use for more than 3 months in the past year and no severe trauma or serious pathology. A total of 72 potential participants were recruited initially, of whom a smaller group of individuals (n=60) completed the randomized controlled trial.

INTERVENTIONS

The 3 interventions were applied for 6 weeks. In the biofeedback group, participants were instructed to use a biofeedback machine on the bilateral upper trapezius (UT) muscles daily while performing computer work. Participants in the exercise group performed a standardized exercise program daily on their own. In the passive treatment group, interferential therapy and hot packs were applied to the participants' necks and shoulders. The control group was given an education booklet on office ergonomics.

MAIN OUTCOME MEASURES

Pain (visual analog scale), neck disability index (NDI), and surface electromyography were assessed preintervention and postintervention. Pain and NDI were reassessed after 6 months.

RESULTS

Postintervention, average pain and NDI scores were reduced significantly more in the biofeedback group than in the other 3 groups, and this was maintained at 6 months. Cervical erector spinae muscle activity showed significant reductions postintervention in the biofeedback group, and there were consistent trends of reductions in the UT muscle activity.

CONCLUSIONS

Six weeks of biofeedback training produced more favorable outcomes in reducing pain and improving muscle activation of neck muscles in patients with work-related neck and shoulder pain.

Biofeedback effectiveness to reduce upper limb muscle activity during computer work is muscle specific and time pressure dependent

Continuous electromyographic (EMG) activity level is considered a risk factor in developing muscle disorders. EMG biofeedback is known to be useful in reducing EMG activity in working muscles during computer work. The purpose was to test the following hypotheses: (1) unilateral biofeedback from trapezius (TRA) can reduce bilateral TRA activity but not extensor digitorum communis (EDC) activity; (2) biofeedback from EDC can reduce activity in EDC but not in TRA; (3) biofeedback is more effective in no time constraint than in the time constraint working condition. Eleven healthy women performed computer work during two different working conditions (time constraint/no time constraint) while receiving biofeedback. Biofeedback was given from right TRA or EDC through two modes (visual/auditory) by the use of EMG or mechanomyography as biofeedback source. During control sessions (no biofeedback), EMG activity was (mean ± SD): 2.4 ± 1.1, 2.5 ± 2.1, and 9.1 ± 3.1%max-EMGrms for right and left TRA and EDC, respectively. During biofeedback from TRA, activity was reduced in right TRA (1.7 ± 1.6%max-EMGrms) and left TRA (1.2 ± 2.0%max-EMGrms) compared to control. During biofeedback from EDC, activity in EDC was reduced (8.3 ± 3.3%max-EMGrms) compared with control. During time constraint, activity was reduced in right TRA (1.9 ± 1.3%max-EMGrms), left TRA (1.5 ± 1.5%max-EMGrms), and EDC (8.4 ± 3.2%max-EMGrms), during biofeedback compared to control.

CONCLUSION

biofeedback reduced muscle activity in TRA by ∼ 30-50% and in EDC by ∼ 10% when given from the homologous or bilateral muscle but not from the remote muscle, and was significant in the time constraint condition; while feedback source and presentation mode showed only minor differences in the effect on reducing homologous muscle activity. This implies that biofeedback should be given from the most affected muscle in the occupational setting for targeting relief and prevention of muscle pain most effectively.

A rationale for the provision of extrinsic feedback towards management of low back pain

Low back pain (LBP) is associated with dysfunction of global and local muscle systems, feedback and feedforward postural control mechanisms. Physiotherapists include the use of feedback as part of treatment protocols. Such feedback can focus on a variety of neuromuscular impairments, although the literature related to feedback on the management of LBP has focused mainly on local muscle system impairments. Furthermore, there are various characteristics of feedback that can lead to motor control enhancement or deterioration. The aim of this manuscript is to present a rationale for feedback provision as a rehabilitation tool on the management of LBP. Feedback provision should focus on the main neuromuscular impairment presented by the patient. The suggested rationale describes decision-making stages for the use and progress of feedback interventions. Local muscle system impairment might benefit more from parameter feedback provision, while global muscle system and feedback mechanism impairments may benefit better from program feedback. The described rationale has the potential to help clinicians select the appropriate feedback for the treatment of their patients. Additionally, the presented rationale could be used by researchers to assess how different forms of feedback provision impact on clinical outcomes.

The ability of limited exposure sampling to detect effects of interventions that reduce the occurrence of pronounced trunk inclination

Ergonomics interventions often focus on reducing exposure in those parts of the job having the highest exposure levels, while leaving other parts unattended. A successful intervention will thus change the form of the job exposure distribution. This disqualifies standard methods for assessing the ability of various exposure measurement strategies to correctly detect an intervention's effect on the overall job exposure of an individual worker, in particular for the safety or ergonomics practitioner who with limited resources can only collect a few measurements. This study used a non-parametric simulation procedure to evaluate the relationship between the number of measurements collected during a self-paced manufacturing job undergoing ergonomics interventions of varying effectiveness, and the probability of correctly determining whether and to which extent the interventions reduced the overall occurrence of pronounced trunk inclination, defined as an inclination of at least 20 degrees . Sixteen video-recordings taken at random times on multiple days for each of three workers were used to estimate the time distribution of each worker's exposure to pronounced trunk inclination. Nine hypothetical ergonomics intervention scenarios were simulated, in which the occurrence of pronounced trunk inclination in the upper 1/8, 1/4, and 1/2 of the job exposure distribution was reduced by 10%, 30% and 50%. Ten exposure measurement strategies were explored, collecting from one to ten pre- and post-intervention exposure samples from an individual worker. For each worker, intervention scenario and sampling strategy, data were bootstrapped from the measured (pre-intervention) and simulated (post-intervention) exposure distributions to generate empirical distributions of the estimated intervention effect. Results showed that for the one to three intervention scenarios that had the greatest effect on the overall occurrence of trunk inclination in the job, one to four pre- and post-intervention measurements, depending on worker, were sufficient to reach an 80% probability of detecting that the intervention did, indeed, have an effect. However, even for the intervention scenario that had the greatest effect on job exposure, seven or more samples were needed for two of the three workers to obtain a probability larger than 50% of estimating the magnitude of the intervention effect to within +/-50% of its true size. For almost all interventions affecting 1/8 or 1/4 of the job, limited exposure sampling led to low probabilities of detecting any intervention effect, let alone its correct size.

Uncovering patterns of forearm muscle activity using multi-channel mechanomyography

A coordinated activation of distal forearm muscles allows the hand and fingers to be shaped during movement and grasp. However, little is known about how the muscle activation patterns are reflected in multi-channel mechanomyogram (MMG) signals. The purpose of this study is to determine if multi-site MMG signals exhibit distinctive patterns of forearm muscle activity. MMG signals were recorded from forearm muscle sites of nine able-bodied participants during hand movement. By using 14 features selected by a genetic algorithm and classified by a linear discriminant analysis classifier (LDA), we show that MMG patterns are specific and consistent enough to identify 7+/-1 hand movements with an accuracy of 90+/-4%. MMG-based movement recognition required a minimum of three recording sites. Further, by classifying five classes of contraction patterns with 98+/-3% accuracy from MMG signals recorded from the residual limb of an amputee participant, we demonstrate that MMG shows pattern-specificity even in the absence of typical musculature. Multi-site monitoring of the RMS of MMG signals is suggested as a method of estimating the relative contributions of muscles to motor tasks. The patterns in MMG facilitate our understanding of the mechanical activity of muscles during movement.

Effects of a feedback signal in a computer mouse on movement behaviour, muscle load, productivity, comfort and user friendliness

To study the effects of a tactile feedback signal in a computer mouse on reduction of hovering behaviour and consequently on changes in muscle load, productivity, comfort and user friendliness, a comparative, experimental study with repeated measures was conducted. Fifteen subjects performed five trials with different mouse actions and a standardised task, once with a mouse with the feedback signal and once with a mouse without the feedback signal. Holding the hand just above the mouse caused higher muscle loading than clicking and scrolling. Holding the hand on the mouse caused higher muscle loading than resting the hand on the desk. The feedback signal effectively decreased hovering behaviour. It also led to a more dynamic activation pattern of the extensor muscles of the forearm. The overall opinion of the feedback signal for future use was rated as somewhat variable. No effects on discomfort or productivity were found. The use of a mouse with a tactile vibrating feedback signal seems promising for preventing arm complaints, although more research is needed to establish the clinical relevance.

The size of cycle-to-cycle variability in biomechanical exposure among butchers performing a standardised cutting task

The effects of employment duration and pain development on motor variability were investigated during repetitive work. Electromyographic (EMG) and kinematics data from two previous studies were re-analysed. Newly employed butchers were followed prospectively in relation to employment duration and pain development. Healthy butchers with long-term experience were compared with novices. The variability of the cycle time, EMG ratio and arm and trunk movement was expressed as cycle-to-cycle standard deviations. During the first 6 months of employment, cycle time variability decreased, while posture and movement variability increased (p < 0.05). In presence of pain, the variability of the initial arm position decreased while it increased for the trunk (p < 0.05). Experienced butchers showed a larger variability than novices for work cycle and several kinematic variables, but a smaller EMG ratio variability (p < 0.05). These findings indicate that the variability of motor patterns in repetitive work changes with experience and pain. A change towards a more variable motor strategy may protect workers from work-related musculoskeletal disorders.

Effects of ambulant myofeedback training and ergonomic counselling in female computer workers with work-related neck-shoulder complaints: a randomized controlled trial

OBJECTIVE

To investigate the effects of ambulant myofeedback training including ergonomic counselling (Mfb) and ergonomic counselling alone (EC), on work-related neck-shoulder pain and disability.

METHODS

Seventy-nine female computer workers reporting neck-shoulder complaints were randomly assigned to Mfb or EC and received four weeks of intervention. Pain intensity in neck, shoulders, and upper back, and pain disability, were measured at baseline, immediately after intervention, and at three and six months follow-up.

RESULTS

Pain intensity and disability had significantly decreased immediately after four weeks Mfb or EC, and the effects remained at follow up. No differences were observed between the Mfb and EC group for outcome and subjects in both intervention groups showed comparable chances for improvement in pain intensity and disability.

CONCLUSIONS

Pain intensity and disability significantly reduced after both interventions and this effect remained at follow-up. No differences were observed between the two intervention groups.