Alterations in central motor representation increase over time in individuals with rotator cuff tendinopathy

Effectiveness of movement representation techniques in non-specific shoulder pain: a systematic review and meta-analysis

This systematic review and meta-analysis aims to assess the effects of movement representation techniques (MRT) on pain, range of motion, functional outcomes, and pain-related fear in patients with non-specific shoulder pain (NSSP). A literature search conducted in PubMed, PEDro, EBSCO, Scopus, Cochrane Library, ScienceDirect, and gray literature on April 31, 2023. We selected seven randomized controlled trials based on the PICOS framework. Incomplete data or non-NSSP excluded. Study quality was assessed using the PEDro scale (mean score = 6.43), and certainty of evidence was evaluated with the GRADE approach. MRT demonstrated a large effect size for pain reduction (high heterogeneity, I2 = 85.2%, Hedges'g = 1.324, 95% CI = 0.388-2.260, P = 0.006), functional improvement (moderate heterogeneity, I2 = 70.82%, Hedges'g = 1.263, 95% CI = 0.622-1.904, P < 0.001), and reduction of pain-related fear (moderate heterogeneity, I2 = 70.86%, Hedges'g = 0.968, 95% CI = 0.221-1.716, P < 0.001). MRT also showed significant benefits for range of motion, particularly in flexion (low heterogeneity, I2 = 26.38%, Hedges'g = 0.683), abduction (low heterogeneity, I2 = 33.27%, Hedges'g = 0.756), and external rotation (low heterogeneity, I2 = 48.33%, Hedges'g = 0.542) (P < 0.001 for all), while no significant effect was found for internal rotation (P > 0.05). No publication bias was detected. While limited evidence and methodological concerns necessitate further research, MRT appears to positively impact pain, range of motion, functional outcomes, and pain-related fear in NSSP patients.

Upper extremity neuromuscular function can distinguish between individuals with and without glenohumeral labral repair

The purpose of this study was to determine whether common measures of neuromuscular function could distinguish injury status indicated by group membership (glenohumeral labral repair, uninjured controls). 16 individuals with glenohumeral labral repair (24.1 ± 5.0 years, 36.7 ± 33.3 months after surgery) and 14 uninjured controls (23.8 ± 2.7 years) volunteered. We measured mass-normalized shoulder abduction and wrist flexion maximal voluntary isometric contraction torque (Nm/kg), motoneuron pool excitability of the flexor carpi radialis (Hoffmann reflex), corticospinal excitability of the upper trapezius, middle deltoid, and flexor carpi radialis (active motor threshold [%]) bilaterally. Receiver operator characteristic curve analyses were performed to determine if each outcome could distinguish injury status along with their outcome thresholds. Binary logistic regression was used to determine the accuracy of classification for each outcome. Our results suggest shoulder abduction torque symmetry (≤95.5 %) and corticospinal excitability for the upper trapezius (≥41.0 %) demonstrated excellent diagnostic utility. Shoulder abduction torque (≤0.71 Nm/kg) and motoneuron pool excitability (≤0.23) demonstrated acceptable diagnostic utility. Shoulder abduction torque symmetry alone was the strongest indicator, and classified injury status with 90.0 % accuracy (p < 0.01). Overall, symmetric shoulder abduction strength most accurately distinguished individuals' injury status, suggesting the utility of bilateral assessment in this population.

Challenges and opportunities in testing sensorimotor processing with tendon vibration and transcranial magnetic stimulation in subacromial impingement syndrome: A case series

BACKGROUND

Non-invasive neurostimulation like muscle tendon vibration (VIB) and transcranial magnetic stimulation (TMS) can provide valuable insights on mechanisms underlying sensorimotor dysfunctions. However, their feasibility in the context of painful musculoskeletal disorders like shoulder impingement syndrome (SIS) remain uncertain.

METHODS

The present work used a case series design including 15 participants with SIS, as well as a secondary group-based analysis comparing participants with SIS to 15 healthy counterparts. Proprioceptive processing was tested by VIB-induced kinesthetic illusions of shoulder abduction, and TMS tested corticospinal excitability of the upper trapezius. Detailed individual data were collected, including any technical challenges and feasibility issues encountered.

RESULTS

VIB was in general well-tolerated and elicited a perceptible kinesthetic illusion in 13 participants with SIS and 14 controls. TMS presented with several challenges related to discomfort, fear-related behaviors, technical problems and high motor thresholds, especially in participants with SIS. It was only possible to collect all TMS measures in 5 participants with SIS (for both the painful and non/less-painful sides), in 7 controls on their dominant side and 10 controls on the non-dominant side. The only significant group-based analysis was a lower illusion speed/amplitude on the painful versus non-painful side in persons with SIS (p = 0.035).

CONCLUSION

Our study provides preliminary data on challenges encountered with TMS and VIB of trunk/proximal muscle in persons with SIS and healthy counterparts. It might help future studies to better address those challenges beforehand and improve the overall feasibility and impact of neurostimulation tools in musculoskeletal disorders.

Effects of Tempo-Controlled Resistance Training on Corticospinal Tract Plasticity in Healthy Controls: A Systematic Review

After musculoskeletal injuries, there is often a loss of corticospinal control. Current tendon rehabilitation may not adequately address the corticospinal control of the muscle which may contribute to the recalcitrance of symptom recurrence. This review provides a summary of the current literature regarding the effectiveness of tempo-controlled resistance training (TCRT) in (1) promoting corticospinal plasticity, (2) improving physical performance, and (3) improving strength outcomes in healthy adults. A comprehensive literature search was conducted using electronic databases (PubMed, CINAHL, Embase, and Google Scholar) to identify relevant studies published between 2010 and 2023. Randomized control (RCT) studies that included recreationally trained and untrained healthy adults between 18 and 60 years of age and that compared a TCRT intervention to a control condition were included. Twelve of the 1255 studies identified in the initial search were included in the final analysis. Throughout all included studies, TCRT was shown to elicit greater neural adaptations compared to traditional resistance training methods (i.e., self-paced strength training). These results indicate that TCRT holds promise as an effective method for modulating corticospinal plasticity in healthy adults and may enhance neuromuscular adaptations, including improvements in CSE, decreased SICI, enhanced motor unit synchronization, and voluntary muscle activation.

An Innovative EEG-Based Pain Identification and Quantification: A Pilot Study

OBJECTIVE

The present pilot study aimed to propose an innovative scale-independent measure based on electroencephalographic (EEG) signals for the identification and quantification of the magnitude of chronic pain.

METHODS

EEG data were collected from three groups of participants at rest: seven healthy participants with pain, 15 healthy participants submitted to thermal pain, and 66 participants living with chronic pain. Every 30 s, the pain intensity score felt by the participant was also recorded. Electrodes positioned in the contralateral motor region were of interest. After EEG preprocessing, a complex analytical signal was obtained using Hilbert transform, and the upper envelope of the EEG signal was extracted. The average coefficient of variation of the upper envelope of the signal was then calculated for the beta (13-30 Hz) band and proposed as a new EEG-based indicator, namely Piqβ, to identify and quantify pain.

MAIN RESULTS

The main results are as follows: (1) A Piqβ threshold at 10%, that is, Piqβ ≥ 10%, indicates the presence of pain, and (2) the higher the Piqβ (%), the higher the extent of pain.

CONCLUSIONS

This finding indicates that Piqβ can objectively identify and quantify pain in a population living with chronic pain. This new EEG-based indicator can be used for objective pain assessment based on the neurophysiological body response to pain.

SIGNIFICANCE

Objective pain assessment is a valuable decision-making aid and an important contribution to pain management and monitoring.

Scapula-Focused Exercises With or Without Biofeedback and Corticospinal Excitability in Recreational Overhead Athletes With Shoulder Impingement

CONTEXT

Individuals with shoulder impingement syndrome (SIS) exhibit changes in corticospinal excitability, scapular kinematics, and scapular muscle-activation patterns. To restore the scapular kinematics and muscle-activation patterns in individuals with SIS, treatment protocols usually include scapula-focused exercises, such as scapular-orientation and strength training.

OBJECTIVE

To investigate whether scapular-orientation and strength training can reverse the altered corticospinal excitability of recreational overhead athletes with SIS.

DESIGN

Randomized controlled clinical trial.

SETTING

University laboratory.

PATIENTS OR OTHER PARTICIPANTS

Forty-one recreational overhead athletes with SIS: 20 in the scapular-orientation group (age = 26.45 ± 4.13 years, height = 171.85 ± 7.88 cm, mass = 66.70 ± 10.68 kg) and 21 in the strengthening group (age = 26.43 ± 5.55 years, height = 171.62 ± 5.87 cm, mass = 68.67 ± 10.18 kg).

INTERVENTION(S)

Both groups performed a 30-minute training protocol consisting of 3 exercises to strengthen the lower trapezius (LT) and serratus anterior muscles without overactivating the upper trapezius muscles. Participants in the scapular-orientation group were instructed to consciously activate their scapular muscles with electromyographic biofeedback and cues, whereas the strengthening group did not receive biofeedback or cues for scapular motion.

MAIN OUTCOME MEASURE(S)

Corticospinal excitability was assessed using transcranial magnetic stimulation. Scapular kinematics and muscle activation during arm elevation were also measured.

RESULTS

After training, both groups demonstrated an increase in motor-evoked potentials in the LT (P = .004) and increases in scapular upward rotation (P = .03), LT activation (P < .001), and serratus anterior activation (P < .001) during arm elevation. Moreover, the scapular-orientation group showed higher LT activation levels during arm elevation after training than the strengthening group (P = .03).

CONCLUSIONS

With or without biofeedback and cues, scapula-focused exercises improved scapular control and increased corticospinal excitability. Adding biofeedback and cues for scapular control during exercise helped facilitate greater LT activation, so feedback and cues are recommended during scapula-focused training.

Novel Posterior Shoulder Stretching With Rapid Eccentric Contraction and Static Stretching in Patients With Subacromial Pain Syndrome: A Randomized Trial

BACKGROUND

In subacromial pain syndrome (SPS), it is unknown whether posterior shoulder stretching exercises (PSSE) with rapid eccentric contraction, a muscle energy technique, improve clinical and ultrasonographic outcomes more than no stretching or static PSSE.

HYPOTHESIS

PSSE with rapid eccentric contraction is superior to no stretching and static PSSE in improving clinical and ultrasonographic outcomes in SPS.

STUDY DESIGN

Randomized controlled trial.

LEVEL OF EVIDENCE

Level 1.

METHODS

Seventy patients with SPS and glenohumeral internal rotation deficit were randomized into the modified cross-body stretching with rapid eccentric contraction group (EMCBS; n = 24), static MCBS group (SMCBS; n = 23), or control group (CG; n = 23). In addition to 4-week physical therapy, EMCBS received PSSE with rapid eccentric contraction, SMCBS static PSSE, and CG no PSSE. The primary outcome was internal rotation range of motion (ROM). Secondary outcomes were posterior shoulder tightness, external rotation ROM (ERROM), pain, modified Constant-Murley score, short form of the disabilities of the arm, shoulder, and hand questionnaire (QuickDASH), rotator cuff strength, acromiohumeral distance (AHD), supraspinatus tendon thickness, and supraspinatus tendon occupation ratio (STOR).

RESULTS

Shoulder mobility, pain, function and disability, strength, AHD, and STOR improved in all groups (P < 0.05).

CONCLUSION

In patients with SPS, PSSE with rapid eccentric contraction and static PSSE were superior to no stretching in improving clinical and ultrasonographic outcomes. Stretching with rapid eccentric contraction was not superior to static stretching, but improved ERROM compared with no stretching.

CLINICAL RELEVANCE

In SPS, both PSSE with rapid eccentric contraction and static PSSE included in physical therapy program are beneficial to improve posterior shoulder mobility and other clinical and ultrasonographic outcomes. In the case of ERROM deficiency, rapid eccentric contraction might be preferred.

Effectiveness of a joint mobilizations protocol for shoulder subacromial pain syndrome: A pilot study

BACKGROUND

Subacromial pain syndrome (SPS) is the most frequent shoulder pathology. The aims of this prospective randomized study were to evaluate the effects of some specific shoulder joint mobilizations ("spin correction"), and the effectiveness of a rehabilitation program, named Shoulder Global Concept, in SPS patients.

METHODS

45 patients with SPS were randomly assigned to two groups, to benefit from a different first session of mobilizations: the experimental group received all specific mobilizations, while the control group received the same program but without the spin correction mobilizations. The second session was identical for both groups, with all specific mobilizations. Before and after the first two sessions, range of motion (ROM) in flexion, abduction, external and internal rotations, pain and functional status with Constant score and Quick Dash were evaluated. Evaluation was repeated with 24 patients after 11 rehabilitation sessions. Rehabilitation with Shoulder Global Concept included 13 mobilizations aiming at improving the ROM with passive and active-assisted mobilizations, static stretching, and muscle strengthening.

RESULTS

All ROM were improved at the end of the first session for both groups, but significantly more in the experimental group for glenohumeral (GH) abduction and external rotation (p < 0.05). Functional scores, pain and strength were significantly improved after 11 rehabilitation sessions with the Shoulder Global Concept.

CONCLUSION

This manual therapy method was able to improve shoulder mobility in one session. The additional joint mobilizations (spin correction) specifically increased GH abduction and external rotation. Rehabilitation of SPS with Shoulder Global Concept allowed to improve functional capacity and decrease pain.

Maximal Lower Limb Strength in Patellar Tendinopathy: A Systematic Review With Meta-Analysis

OBJECTIVE

To investigate whether lower limb strength is reduced in people with patellar tendinopathy (PT) compared with asymptomatic control individuals or the asymptomatic contralateral limb.

DATA SOURCES

MEDLINE, PubMed, Scopus, and Web of Science.

STUDY SELECTION

To be included in the systematic review and meta-analysis, studies were required to be peer reviewed, published in the English language, and case control investigations; include participants with a clinical diagnosis of PT and an asymptomatic control or contralateral limb group; and include an objective measure of lower limb maximal strength.

DATA EXTRACTION

We extracted descriptive statistics for maximal strength for the symptomatic and asymptomatic limbs of individuals with PT and the limb(s) of the asymptomatic control group, inferential statistics for between-groups differences, participant characteristics, and details of the strength-testing protocol. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for analytical cross-sectional studies.

DATA SYNTHESIS

Of the 23 included studies, 21 reported knee strength, 3 reported hip strength, and 1 reported ankle strength. Random-effects models (Hedges g) were used to calculate the pooled effect sizes (ESs) of muscle strength according to the direction of joint movement and type of contraction. The pooled ESs (95% CI) for maximal voluntary isometric contraction knee-extension strength, concentric knee-extension strength, and concentric knee-flexion strength were 0.54 (0.27, 0.80), 0.78 (0.30, 1.33), and 0.41 (0.04, 0.78), respectively, with all favoring greater strength in the asymptomatic control group. Researchers of 2 studies described maximal eccentric knee-extensor strength with no differences between the PT and asymptomatic control groups. In 3 studies, researchers measured maximal hip strength (abduction, extension, and external rotation), and all within-study ESs favored greater strength in the asymptomatic control group.

CONCLUSIONS

Isometric and concentric knee-extensor strength are reduced in people with PT compared with asymptomatic control individuals. In contrast, evidence for reduced eccentric knee-extension strength in people with PT compared with asymptomatic control individuals is limited and inconsistent. Although evidence is emerging that both knee-flexion and hip strength may be reduced in people with PT, more examination is needed to confirm this observation.

Specific versus general exercise programme in adults with subacromial impingement syndrome: a randomised controlled trial

Objectives

Current evidence on the clinical effectiveness about the different types of exercises in the subacromial impingement syndrome (SIS) remains controversial. This study aims to compare the short-term (at 5 weeks) effects of a specific exercise programme with a general exercise programme on shoulder function in adults with SIS.

Methods

In total, 52 adults with SIS were randomly allocated to 5 weeks to perform specific exercises (experimental group, n=26) or general exercises (control group, n=26). The primary outcome was change in shoulder function, it was assessed using the Shoulder Pain and Disability Index (SPADI) from baseline to 5 weeks. Secondary end points included changes in upper limb function (Disabilities of the Arm, Shoulder, and Hand (DASH) Questionnaire), pain intensity (Visual Analog Scale (VAS)) and kinesiophobia (Tampa Scale of Kinesiophobia (TSK)).

Results

All participants completed the trial. The between-group differences at 5 weeks were: SPADI, 13.5 points (95% CI: 4.3 to 15.6; ƞ2=0.22; p=0.001); DASH, 10.1 points (95% CI: 5.6 to 15.2; ƞ2=0.27; p<0.001); VAS at rest, 0.2 cm (95% CI: 0.1 to 0.3; ƞ2=0.07; p=0.553); VAS on movement, 1.7 cm (95% CI: 0.9 to 2.2; ƞ2=0.24; p<0.001); and TSK, 16.3 points (95% CI: 13.2 to 15.3; ƞ2=0.33; p<0.001). All differences favoured the experimental group and effect sizes were medium to large for most outcomes. Mediation analyses showed that the effect of the specific exercises on shoulder function was mediated by kinesiophobia (β=2.800; 95% CI: 1.063 to 4.907) and pain on movement (β= -0.690; 95% CI: -1.176 to -0.271).

Conclusion

In adults with SIS, specific exercises may have a larger effect than general exercises. However, most differences did not reach the minimum threshold to be considered clinically important and the evidence to support exercise as standard treatment warrant further study.

Trial registration number

Brazilian Registry of Clinical Trials UTN number U111-1245-7878. Registered on 17 January 2020 (https://ensaiosclinicos.gov.br/rg/RBR-4d5zcg).

Virtual embodiment for improving range of motion in patients with movement-related shoulder pain: an experimental study

BACKGROUND

Recent evidence supports the use of immersive virtual reality (VR) as a means of delivering bodily illusions that may have therapeutic potential for the treatment of musculoskeletal conditions. We wanted to investigate whether a single session of an embodiment-based immersive VR training program influences pain-free range of motion in patients with shoulder pain.

METHODS

We designed a rehabilitation program based on developing ownership over a virtual body and then "exercising" the upper limb in immersive VR, while the real arm remains static. We then carried out a single-arm pre-post experiment in which 21 patients with movement-related musculoskeletal shoulder pain were exposed to the 15-min VR program and measured their active pain-free range of motion immediately before and afterwards.

RESULTS

We found that shoulder abduction and hand-behind-back movements, but not shoulder flexion, were significantly and clinically improved post-intervention and that the level of improvement correlated with the level of embodiment. Following this one session, at 1-week follow-up the improvements were not maintained.

CONCLUSIONS

Virtual embodiment may be a useful therapeutic tool to help improve range of motion in patients with movement-related shoulder pain in the short term, which in turn could expedite rehabilitation and recovery in these conditions.

Efficacy of Externally Paced Training on Pain in Tendinopathy: A Systematic Review and Meta Analysis

Tendinopathy is a common condition with treatments focused on local tissue adaptations. Externally paced loading programs are designed to cue (visually, auditorily, or temporally) a person as to when to perform an exercise repetition during a set of repetitions. Externally paced loading programs propose central and peripheral changes with tendinopathy but conclusions regarding their efficacy on pain outcomes remain limited. Our review seeks to explore the efficacy of externally paced loading as a method to reduce self-reported pain in tendinopathic conditions. An electronic database search was conducted of PubMed, SPORTDiscus, Scopus, and CINAHL databases. A total of 2,104 studies were identified after a preliminary search; four reviewers narrowed the selection to seven articles based on inclusion and exclusion criteria. Articles selected for review (patellar = three, Achilles = two, rotator cuff = one, and lateral elbow tendinopathy = one) were randomized control trials assessing the externally paced loading programs' efficacy on tendon pain compared to the control; all were included in the meta-analysis. This review identified no superiority in externally paced loading compared to alternative treatment. There were potential population differences between non-athletic and athletic populations as identified with subgroup analyses. Current activity levels, region of tendinopathy, and chronicity of symptoms may explain the variability of findings. There is little clinically significant evidence to support the use of externally paced loading programs for reducing tendon pain over standard clinical care based on a low level of certainty which is based on the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) of articles included in the review. Clinicians should interpret outcomes between athletic and non-athletic participants with caution as further high-quality studies are required to confirm specific clinical outcomes in these populations.

Exercise for rotator cuff tendinopathy: Proposed mechanisms of recovery

Rotator cuff (RC) tendinopathy is a common recurrent cause of shoulder pain, and resistance exercise is the first-line recommended intervention. Proposed causal mechanisms of resistance exercise for patients with RC tendinopathy consist of four domains: tendon structure, neuromuscular factors, pain and sensorimotor processing, and psychosocial factors. Tendon structure plays a role in RC tendinopathy, with decreased stiffness, increased thickness, and collagen disorganization. Neuromuscular performance deficits of altered kinematics, muscle activation, and force are present in RC tendinopathy, but advanced methods of assessing muscle performance are needed to fully assess these factors. Psychological factors of depression, anxiety, pain catastrophizing, treatment expectations, and self-efficacy are present and predict patient-reported outcomes. Central nervous system dysfunctions also exist, specifically altered pain and sensorimotor processing. Resisted exercise may normalize these factors, but limited evidence exists to explain the relationship of the four proposed domains to trajectory of recovery and defining persistent deficits limiting outcomes. Clinicians and researchers can use this model to understand how exercise mediates change in patient outcomes, develop subgroups to deliver patient-specific approach for treatment and define metrics to track recovery over time. Supporting evidence is limited, indicating the need for future studies characterizing mechanisms of recovery with exercise for RC tendinopathy.

The major pain source of rotator cuff-related shoulder pain: A narrative review on current evidence

BACKGROUND

Rotator cuff-related shoulder pain (RCRSP) was proposed to have a complex pain mechanism, but the exact aetiology is still unclear. A recent review summarised the updated research to analyse the traditional concept of shoulder impingement which may not be accurate. Current studies have demonstrated that mechanical factors including a reduction in subacromial space, scapular dyskinesia and different acromial shapes are unlikely directly contributing to RCRSP.

AIMS

Since the precise RCRSP pain mechanism remains unclear, the aim of this narrative review is to discuss possible sources of pain contributing to RCRSP according to the mechanisms-based pain classifications.

RESULTS AND DISCUSSION

Research findings on potential mechanical nociceptive factors of RCRSP are conflicting; investigations of neuropathic and central pain mechanisms of RCRSP are limited and inconclusive. Overall, available evidence has indicated moderate to strong correlations between RCRSP and chemical nociceptive sources of pain.

CONCLUSION

Results from current research may provide new directions for future studies on the aetiology of RCRSP and its clinical management towards a biochemical view instead of the traditional mechanical hypothesis.

Reliability of active robotic neuro-navigated transcranial magnetic stimulation motor maps

Transcranial magnetic stimulation (TMS) motor mapping is a safe, non-invasive method used to study corticomotor organization and intervention-induced plasticity. Reliability of resting maps is well established, but understudied for active maps and unestablished for active maps obtained using robotic TMS techniques. The objective of  this study was to determine the reliability of robotic neuro-navigated TMS motor map measures during active muscle contraction. We hypothesized that map area and volume would show excellent short- and medium-term reliability. Twenty healthy adults were tested on 3 days. Active maps of the first dorsal interosseous muscle were created using a 12 × 12 grid (7 mm spacing). Short- (24 h) and medium-term (3-5 weeks) relative (intra-class correlation coefficient) and absolute (minimal detectable change (MDC); standard error of measure) reliabilities were evaluated for map area, volume, center of gravity (CoG), and hotspot magnitude (peak-to-peak MEP amplitude at the hotspot), along with active motor threshold (AMT) and maximum voluntary contraction (MVC). This study found that AMT and MVC had good-to-excellent short- and medium-term reliability. Map CoG (x and y) were the most reliable map measures across sessions with excellent short- and medium-term reliability (p < 0.001). Map area, hotspot magnitude, and map volume followed with better reliability medium-term than short-term, with a change of 28%, 62%, and 78% needed to detect a true medium-term change, respectively. Therefore, robot-guided neuro-navigated TMS active mapping is relatively reliable but varies across measures. This, and MDC, should be considered in interventional study designs.

The effect of combined Action Observation Therapy with eccentric exercises in the treatment of mid-portion Achilles-tendinopathy: a feasibility pilot randomised controlled trial

BACKGROUND

Mid-portion Achilles Tendinopathy (AT) is a common musculoskeletal condition with varying rehabilitation success rates. Despite the prevalence of this condition, a considerable proportion of individuals experience persisting pain and functional deficits. Current treatment approaches bias the biomedical model which emphasises physically treating and loading the tendon. Overall, there is a lack of consideration for the central nervous system that is commonly implicated in chronic injuries. The aim of this pilot study was to explore the feasibility of combining Action Observation Therapy (AOT), a treatment technique which targets central changes and influences motor learning, with eccentric exercises in the treatment of mid-portion AT. AOT involves the observation of movements and is commonly followed by the physical performance of these same movements.

METHODOLOGY

This was a double-blinded randomised controlled pilot feasibility study. All participants underwent the 12-week Alfredson eccentric training protocol. The intervention group watched videos of the exercises prior to performing these exercises, whilst the control group watched nature videos before performing the same exercises. Study feasibility was the primary outcome measure, with the Victorian Institute of Sports Assessment- Achilles (VISA-A) selected as the primary clinical outcome measure.

RESULTS

Thirty participants were recruited, reflecting a 75% eligibility rate and 100% of eligible participants enrolled in the study. The retention rate at week 12 was 80%. At week six the mean VISA-A score improved by 18.1 (95% CI 10.2-26.0) in the intervention group and 7.7 (95% CI 0.3-14.9) in the control group, and 75% and 33% of participants in the intervention and control group respectively exceeded the minimal clinically important difference (MCID). At week 12 the mean VISA-A score from baseline improved by 22.25 (95% CI 12.52-31.98) in the intervention group and 16.5-(95% CI 8.47-24.53) in the control group, equating to 75% and 58% in each group respectively exceeding the MCID.

CONCLUSION

The positive feasibility outcomes and exploratory data from the clinical outcome measures suggest that a larger scaled RCT is warranted to further investigate the impact of AOT in the rehabilitation of mid-portion AT. Trial registration ISRCTN58161116, first registered on the 23/12/2020.

Active versus resting neuro-navigated robotic transcranial magnetic stimulation motor mapping

Transcranial magnetic stimulation (TMS) motor mapping is a safe, non-invasive method that can be used to study corticomotor organization. Motor maps are typically acquired at rest, and comparisons to maps obtained during muscle activation have been both limited and contradictory. Understanding the relationship between functional activation of the corticomotor system as recorded by motor mapping is crucial for their use clinically and in research. The present study utilized robotic TMS paired with personalized neuro-navigation to examine the relationship between resting and active motor map measures and their relationship with motor performance. Twenty healthy right-handed participants underwent resting and active robotic TMS motor mapping of the first dorsal interosseous to 10% maximum voluntary contraction. Motor map parameters including map area, volume, and measures of map centrality were compared between techniques using paired sample tests of difference and Bland-Altman plots and analysis. Map area, volume, and hotspot magnitude were larger in the active motor maps, while map center of gravity and hotspot locations remained consistent between both maps. No associations were observed between motor maps and motor performance as measured by the Purdue Pegboard Test. Our findings support previous suggestions that maps scale with muscle contraction. Differences in mapping outcomes suggest rest and active motor maps may reflect functionally different corticomotor representations. Advanced analysis methods may better characterize the underlying neurophysiology of both types of motor mapping.

Efficacy of balance training on postural control in patients with rotator cuff disease: a randomized controlled study

We evaluated the efficacy of adding balance training to a physical therapy program on postural control and health-related quality of life in patients with rotator cuff disease. Forty-two participants were randomly allocated to the control and intervention groups. Both groups received physical therapy (education, stretching, supervised strength training, and home exercise program) 3 days/week for 6 weeks. The intervention group was instructed to perform balance exercises at home. The primary outcomes were the stability index, the Fourier transformation (F5 and F6), the weight distribution index, and the fall index, as assessed by the posturography during eight conditions with different combinations of standing (solid surface, pillows, and different head positions) and vision (eyes open/closed). The secondary outcomes included the Western Ontario Rotator Cuff Index to assess the health-related quality of life, the Shoulder Pain and Disability Index, and the Numeric Pain Rating Scale. The adherence to in-person and home-based therapy was high (>83%). The intervention group significantly improved the stability index, F5, and F6 parameters but each in only one condition (P < 0.05). No significant improvement was found in the conditions for the other primary outcomes and in the health-related quality of life. (P > 0.05). We conclude that adding the balance training protocol to the physical therapy program does not improve postural control and health-related quality of life in patients with rotator cuff disease.

Altered corticospinal excitability of scapular muscles in individuals with shoulder impingement syndrome

The purpose of this study is to assess and compare corticospinal excitability in the upper and lower trapezius and serratus anterior muscles in participants with and without shoulder impingement syndrome (SIS). Fourteen participants with SIS, and 14 without SIS were recruited through convenient sampling in this study. Transcranial magnetic stimulation assessment of the scapular muscles was performed while the participants were holding their arm at 90 degrees scaption. The motor-evoked potential (MEP), active motor threshold (AMT), latency of MEP, cortical silent period (CSP), activated area and center of gravity (COG) of cortical mapping were compared between groups using the Mann-Whitney U tests. The SIS group demonstrated following significances, higher AMTs of the lower trapezius (SIS: 0.60 ± 0.06; Comparison: 0.54 ± 0.07, p = 0.028) and the serratus anterior (SIS: 0.59 ± 0.04; Comparison: 0.54 ± 0.06, p = 0.022), longer CSP of the lower trapezius (SIS: 62.23 ± 22.87 ms; Comparison: 45.22 ± 14.64 ms, p = 0.019), and posteriorly shifted COG in the upper trapezius (SIS: 1.88 ± 1.06; Comparison: 2.76 ± 1.55, p = 0.048) and the serratus anterior (SIS: 2.13 ± 1.02; Comparison: 3.12 ± 1.88, p = 0.043), than the control group. In conclusion, participants with SIS demonstrated different organization of the corticospinal system, including decreased excitability, increased inhibition, and shift in motor representation of the scapular muscles.

Effectiveness of supervised physiotherapy versus home exercise in subjects with rotator cuff disorders treated surgically: A systematic review and meta-analysis

OBJECTIVE

The aim is to determine the effectiveness of supervised Physiotherapy (PT) versus a home exercise program for functional outcomes in patients with rotator cuff (RC) disorders treated surgically. TYPE: Systematic review and meta-analysis of randomized clinical trials.

METHODOLOGY

An electronic search was performed in the MEDLINE, CENTRAL, EMBASE, PEDro, LILACS, CINAHL, SPORTDiscus, and Web of Science databases. The eligibility criteria for selecting studies included randomized clinical trials that compared supervised PT versus home exercises in functional outcomes, such as shoulder or upper limb function, pain intensity, and range of motion, in subjects older than 18 years with RC disorders treated surgically.

SYNTHESIS

Six trials met the eligibility criteria, and for the quantitative synthesis, five studies were included. At 3 months, the mean difference (MD) for the Constant-Murley questionnaire (0-100 points) was -0.76 points (95% confidence interval (CI) = -15.64 to 14.12, p = 0.92), while the MD for the visual analog scale (0-10 cm) was -0.87 cm (95% CI = -2.8 to 1.06, p = 0.38). These differences were neither clinically nor statistically significant.

CONCLUSION

There was very low quality of evidence towards no better benefits in shoulder pain and function of supervised PT over home exercises programs in patients older than 18 years with RC disorders treated surgically.

PROSPERO REGISTRATION

CRD42020185805.

Structural and Functional Asymmetry in Precentral and Postcentral Gyrus in Patients With Unilateral Chronic Shoulder Pain

Objective

The purpose of this study was to explore the structural and functional asymmetry of precentral and postcentral gyrus in patients with unilateral chronic shoulder pain (CSP) utilizing MRI.

Patients and Methods

We collected structural and resting-state functional MRI (rs-fMRI) data in 22 left-sided, 15 patients with right-sided CSP, and 24 healthy controls (HCs). Here, we performed the structural asymmetry and seed-based functional connectivity (FC) analyses. We extracted regional cortical thickness and surface area measurements from T1-weighted MRI images, using asymmetry indexes (AIs) to assess asymmetries. We used Data Processing and Analysis for Brain Imaging software for seed-based FC analysis and selected unilateral-precentral and postcentral as the regions of interest. Then, we performed group comparisons of the neuroimaging metrics, and also explored the relationships between brain asymmetry and clinical variables.

Results

We found significant differences in surface area AIs of the precentral among three groups, the AI values were negatively correlated with the visual analog scale score and positively correlated with Constant–Murley scores (CMS) in the left-sided CSP group. Further, FC of left postcentral with cingulate gyrus and left paracentral lobule showed significant group differences; FC of right postcentral with left caudate, left paracentral, and left postcentral were different among groups; FC of right precentral with the cingulate gyrus, precuneus, and left paracentral revealed significant group differences. Besides, there was a positive correlation between right precentral-cingulate gyrus FC and CMS in the right-sided CSP group.

Conclusion

Surface area and FC patterns asymmetry exist in precentral and postcentral gyrus in patients with unilateral CSP. Asymmetry trend is associated with pain severity and shoulder joint function impairment. Brain structural and functional asymmetry may be an important indicator for understanding the potential mechanism of chronic pain.

Two-point discrimination and judgment of laterality in individuals with chronic unilateral non-traumatic shoulder pain

BACKGROUND

Cortical representation of the painful body region may be disrupted in several chronic pain conditions. The two-point discrimination test (TPDT) and the Left/Right Judgement Task (LRJT) have been used to identify changes in the cortical body schema in several chronic pain conditions. However, it is unclear if these changes are present for all chronic pain mechanisms.

OBJECTIVES

To investigate the integrity of the body schema of the painful shoulder in patients with chronic unilateral nociceptive shoulder pain.

METHODS

The sample consisted of 52 individuals with chronic unilateral nociceptive shoulder pain. The TPDT was measured over the anterosuperior and lateral regions of both shoulders using a staircase method. Participants also performed judgment tests of shoulder and foot laterality. The comparison of the TPDT and LRJT was performed using the linear regression model with mixed effects.

RESULTS

There was no difference in TPDT in the anterosuperior and lateral regions when comparing the symptomatic and asymptomatic shoulders. There was no difference in the LRJT accuracy and response time between the symptomatic and asymptomatic shoulders. No differences were observed when comparing LRJT variables from symptomatic shoulder and foot.

CONCLUSION

Therefore, results do not provide clear evidence of altered body schema in chronic nociceptive unilateral shoulder pain. This suggest that alterations in body representations may depend on the primary pain mechanism.

Neurophysiological and psychophysical effects of dry versus sham needling of the infraspinatus muscle in patients with chronic shoulder pain: a randomized feasibility study

BACKGROUND

Dry needling (DN) is increasingly used for treating myofascial trigger points (MTrPs) and has shown significant effects on pain and function. This study aimed to assess feasibility of conducting a randomized sham-controlled trial and to collect preliminary data on the effects of infraspinatus DN on corticospinal excitability and mechanical pain sensitivity.

METHOD

This randomized feasibility study included adults with chronic non-traumatic shoulder pain and a infraspinatus MTrP. Participants were randomized to receive real DN or sham DN in the infraspinatus MTrP. Feasibility outcomes included data pertaining to recruitment, retention of participants, completeness and safety of assessment procedures. Neurophysiological and psychophysical outcomes included corticospinal excitability and mechanical pain sensitivity measured by active motor threshold (aMT) and pressure pain threshold (PPT), respectively. They were assessed at baseline, immediately after and 24 h post-intervention.

RESULTS

Twenty-one participants were recruited over a 6-month period. Nineteen participants completed the treatment and follow-up assessment. Motor evoked potential responses were discernible in all but 1 participant. Only 1 minor adverse event related to transcranial magnetic stimulation (mild headache) affected the measurements. No DN adverse effects were recorded in both groups. An overall completeness rate of 81% was reached, with 70% completeness in the DN group and 91% in the sham group. Data analysis revealed that real DN increased corticospinal excitability (reduced aMT) 24 h post-intervention (Mdn = - 5.96% MSO, IQR = 5.17, p = 0.04) and that sham DN triggered similar responses immediately after the intervention (Mdn = - 1.93% MSO, IQR = 1.11, p = 0.03). Increased mechanical pain sensitivity (reduced PPT) was significant only in the sham group, both immediately (Mdn = - 0.44 kg/cm2, IQR = 0.49, p = 0.01) and 24 h post-intervention (Mdn = - 0.52 kg/cm2, IQR = 1.02, p = 0.02). Changes in corticospinal excitability was positively correlated with changes in mechanical pain sensitivity in the DN group, both immediately (r = 0.77, p = 0.02) and 24 h post-intervention (r = 0.75, p = 0.05).

CONCLUSION

The present study demonstrates the feasibility of quantifying the neurophysiological and psychophysical effects of DN, and provides recommendations and guidelines for future studies. Moreover, it provides preliminary evidence that DN may increase corticospinal excitability of the infraspinatus muscle in patients with chronic shoulder pain and that the relationship of neurophysiological and psychophysical effects is promising to better understand its mechanisms of action.

TRIAL REGISTRATION

NCT04316793 ; retrospectively registered November 3, 2020.

Physiotherapy Rehabilitation in Subjects Diagnosed with Subacromial Impingement Syndrome Does Not Normalize Periscapular and Rotator Cuff Muscle Onset Time of Activation

Clinicians suggest that rehabilitation of Subacromial Impingement Syndrome (SIS) should target improving movement patterns to ensure better clinical outcomes. Understanding changes in onset time of activation patterns and associated changes in clinical outcomes could improve our understanding of rehabilitation strategies. In this prospective longitudinal study, we examined neuromuscular firing patterns and clinical features before and after a standardized physiotherapy program in subjects diagnosed with SIS. Electromyography (EMG) recordings of eleven shoulder muscles were taken at the initial and discharge consultation in 34 male volunteers diagnosed with SIS. EMG recording was performed during flexion, scaption, and abduction at slow, medium, and fast speeds with a loaded (3 kg) and unloaded arm, as well as rotational motion, rotational strength, pain, and shoulder function. Completion of standardized shoulder physiotherapy program for SIS resulted in improvements in clinical outcomes. Resulted showed inconsistent differences of onset time of activation mainly in some of the periscapular muscles for all movements. No differences were seen on the EMG recordings for rotator cuff muscles. Differences in range of motion, strength and function were shown. Despite some changes in onset time of activation, this study was not able to demonstrate consistent changes of onset time of activation of the periscapular and rotator cuff muscles.

Left/right discrimination is not impaired in people with unilateral chronic Achilles tendinopathy

OBJECTIVE

Impaired left/right discrimination of an affected body part has been observed in various chronic pain states. This study aimed to examine whether people with unilateral chronic Achilles tendinopathy also present with impaired left/right discrimination.

DESIGN

Cross-sectional study.

METHODS

Nineteen runners with persistent unilateral Achilles tendinopathy and 19 matched healthy volunteers performed a left/right discrimination task in a laboratory setting. Participants were shown pictures of feet, hands and Shepard-Metzler figures and were asked to decide as accurately and as fast as possible whether the body part belonged to the left or right side of the body, or whether the Shepard-Metzler figures were rotated or mirrored. Performance was evaluated in terms of accuracy and response time. Data were analysed with mixed-design ANOVAs.

RESULTS

The decline in left/right discrimination ability at group level, if present, between affected and unaffected side, or compared to healthy participants, was negligible for both accuracy (<1.5%) and response time (<50 ms). There was no significant effect of side (affected versus unaffected side) or group (people with Achilles tendinopathy versus healthy) for accuracy (p > 0.36) or response time (p > 0.69).

CONCLUSIONS

People with Achilles tendinopathy recognised the affected side as accurately and as fast as the non-affected side and their performance was comparable to healthy participants. The absence of impaired left/right discrimination despite the chronicity of the condition may be attributable to the typical intermittent nature of Achilles tendinopathy pain and/or maintained sports activity.

A study on the immediate effects of neuromuscular electrical stimulation on the corticospinal tract excitability of the infraspinatus muscle

BACKGROUND

Rotator cuff muscles are structurally and functionally different from other upper-limb muscles because they are responsible for glenohumeral joint stability. Neuromuscular electrical stimulation (NMES) induces excitability changes (increase or decrease) of the corticospinal tract (CST) in the peripheral muscles, such as those of the finger. However, it remains unclear whether similar results are obtained when targeting the infraspinatus muscle, which has properties that differ from other muscles, in healthy subjects.

OBJECTIVE

We investigated the immediate effects of NMES on the corticospinal excitability of the infraspinatus muscle, a rotator cuff muscle, in healthy subjects.

METHODS

Thirteen healthy right-handed men (mean age: 26.77 ± 2.08 years) participated in this study. The motor evoked potentials (MEPs) and the maximum compound muscle action potential (Mmax) were recorded before NMES to the right infraspinatus and within 15 minutes after the end of the NMES.

RESULTS

NMES on the infraspinatus muscle significantly increased its MEP amplitude (Pre: 0.45 mV [0.33-0.48]; Post: 0.54 mV [0.46-0.60] (median [lower quartile to higher quartile]); p= 0.005) but had no effect on Mmax (Pre: 2.95 mV [2.59-4.71]; Post: 3.35 mV [2.76-4.72]; p= 0.753).

CONCLUSIONS

NMES application to the infraspinatus muscle increases CST excitability without producing immediate changes in the neuromuscular junction or muscle hypertrophy.

Analysis of Functional Recovery and Subjective Well-Being after Arthroscopic Rotator Cuff Repair

Background: Rotator cuff tears are common causes of functional shoulder instability and often lead to arthroscopic rotator cuff repair. A well-programmed rehabilitation leads to successful tendon healing, positive functional recovery and subjective well-being (SWB). Objective: To evaluate the changes in shoulder functioning and SWB pre-, post-outpatient rehabilitation and after one-month follow-up. Materials and Methods: A total of 44 patients were assessed three times: at the beginning (six weeks’ post-surgery), at the end of outpatient rehabilitation (2–3 weeks) and one month after rehabilitation. The outcome measures were the Disabilities of the Arm, Shoulder and Hand score (DASH), active range of motion (ROM), manual muscle testing (MMT), hand dynamometry (HD) and pain level by a Visual Analogue Scale (VAS). SWB was assessed by Rosenberg self-esteem scale (RSES), Positive and Negative Affect Schedule (PANAS) and the Lithuanian Psychological Well-Being Scale (LPWBS). Results are presented as a difference between periods. Results: Affected shoulder motor function (MMT, HD and ROM) significantly improved in three periods (p < 0.05); however, major recovery was observed in the follow-up period. VAS scores meaningfully decreased over all stages and negatively correlated with motor function recovery (p < 0.05). DASH rates exhibited significant retrieval in all phases, especially in follow-up. SWB results demonstrated the larger effects of self-evaluation in follow-up, improved daily functions and psychological wellness, then negative emotions significantly decreased (p < 0.05). Conclusions: The experienced pain and psychosocial factors significantly influence functional recovery of the shoulder during rehabilitation. The improvement in motor function, ability and pain relief during rehabilitation increases level of SWB, psychological wellness and positive emotional affect in long-term context.

Delayed Anticipatory Muscle Activation in Rotator Cuff Tendinopathy

BACKGROUND

Previous research investigating rotator cuff (RC) tendinopathy has usually focused on pathoanatomy. The pathologic response to anticipatory postural adjustments (APAs) has not yet been investigated.

PURPOSE/HYPOTHESIS

To explore changes in APAs as detected by pre-emptive activation of shoulder muscles during ball catching. It was hypothesized that anticipatory muscle activation (AMA) would be present in the unaffected shoulder but delayed or absent in the affected shoulder in patients with RC tendinopathy.

STUDY DESIGN

Controlled laboratory study.

METHODS

This study included 21 RC tendinopathy patients with a mean age of 49.5 years. Patients were required to grab a ball embedded with an electromyography sensor when it dropped on their hand, and surface electromyography signals were recorded from the infraspinatus, upper trapezius, anterior deltoid, and biceps. The trials utilized 2 balls, weighing 200 g and 500 g. Each ball was used in 2 trials, 1 involving a number count preceding the ball drop (predictable) and the other involving a sudden drop (unpredictable). The onsets of AMA between the affected and unaffected limbs were compared.

RESULTS

Regardless of the experimental condition, significantly delayed AMA onsets were identified in all investigated muscles of the affected side compared with those of the unaffected side, except for the biceps muscle in the 500-g predictable trial. For the infraspinatus, the mean onset time in the 200-g predictable trial was -141.0 ± 60.2 ms on the affected side and -211.9 ± 67.1 ms on the unaffected side (P < .001); in the 200-g unpredictable trial this value was -139.5 ± 54.9 ms on the affected side and -199.5 ± 56.2 ms on the unaffected side (P < .001).

CONCLUSION

Delayed AMA was observed in the affected shoulder compared with the unaffected shoulder in patients with RC tendinopathy, not only in the RC muscle but also in the periscapular and upper arm muscles. This may indicate that central hypoexcitability is partly responsible.

CLINICAL RELEVANCE

The basis for RC tendinopathy treatment should not be limited to the tendon pathoanatomy. Delayed AMA around the shoulder joint could provide insight into potential mechanisms related to the central nervous system.

The effect of experimental and clinical musculoskeletal pain on spinal and supraspinal projections to motoneurons and motor unit properties in humans: A systematic review

BACKGROUND AND OBJECTIVE

Numerous studies have examined the influence of pain on spinal reflex excitability, motor unit behaviour and corticospinal excitability. Nevertheless, there are inconsistencies in the conclusions made. This systematic review sought to understand the effect of pain on spinal and supraspinal projections to motoneurons and motor unit properties by examining the influence of clinical or experimental pain on the following three domains: H-reflex, corticospinal excitability and motor unit properties.

DATABASES AND DATA TREATMENT

MeSH terms and preselected keywords relating to the H-reflex, motor evoked potentials and motor unit decomposition in chronic and experimental pain were used to perform a systematic literature search using Cumulative Index of Nursing and Allied Health Literature (CINAHL), Excerpta Medica dataBASE (EMBASE), Web of Science, Medline, Google Scholar and Scopus databases. Two independent reviewers screened papers for inclusion and assessed the methodological quality using a modified Downs and Black risk of bias tool; a narrative synthesis and three meta-analyses were performed.

RESULTS

Sixty-one studies were included, and 17 different outcome variables were assessed across the three domains. Both experimental and clinical pain have no major influence on measures of the H-reflex, whereas experimental and clinical pain appeared to have differing effects on corticospinal excitability. Experimental pain consistently reduced motor unit discharge rate, a finding which was not consistent with data obtained from patients. The results indicate that when in tonic pain, induced via experimental pain models, inhibitory effects on motoneuron behaviour were evident. However, in chronic clinical pain populations, more varied responses were evident likely reflecting individual adaptations to chronic symptoms.

SIGNIFICANCE

This is a comprehensive systematic review and meta-analysis which synthesizes evidence on the influence of pain on spinal and supraspinal projections to motoneurons and motor unit properties considering measures of the H-reflex, corticospinal excitability and motor unit behaviour. The H-reflex is largely not influenced by the presence of either clinical or experimental pain. Whilst inhibitory effects on corticospinal excitability and motor unit behaviour were evident under experimental pain conditions, more variable responses were observed for people with painful musculoskeletal disorders.

Shockwave therapy associated with progressive exercises in rotator cuff tendinopathy: a clinical trial protocol

The aim of the present study is to determine whether adding shockwave therapy (SWT) to a progressive exercise program improves shoulder pain and function in individuals with rotator cuff tendinopathy (RC tendinopathy). Ninety patients diagnosed with rotator cuff tendinopathy will be randomly allocated into two groups: active SWT plus a progressive exercise program or placebo SWT plus a progressive exercise program. Primary outcomes will be measured using the Constant-Murley Score function questionnaire and by assessing patient-reported pain intensity with the numerical pain rating scale. The secondary outcomes will be measured using the Global Perceived Effects Scale and Shoulder Pain and Disability Index. All the outcomes will be measured immediately after the end of treatment and at 3-month follow-up.

Transcranial direct current stimulation (a-tCDS) after subacromial injections in patients with subacromial pain syndrome: a randomized controlled pilot study

BACKGROUND

Subacromial pain syndrome (SAPS) is a common complaint in orthopaedics. Subacromial corticosteroid injections (CSI) can relieve pain in the short term. Anodal transcranial direct current stimulation (a-tDCS) has been used for symptomatic pain relief in a variety of chronic pain conditions. The aim of this pilot study was to assess whether the application a-tDCS could enhance the symptomatic relief provided by CSI in patients affected by SAPS.

METHODS

Thirty-eight participants (18 to 65-year-old) suffering from SAPS were recruited to have a CSI and randomly allocated to receive, 1 weeks post CSI, real a-tDCS (r-tDCS), sham tDCS (s-tDCS) or no intervention (Control). Upper limb function was measured 1 week prior to the CSI, at the 2- and 4-week follow-ups using self-administered questionnaires and physical measures. Self-reported pain and activity during each day were logged by the participants using visual analog scales (VAS). Differences between groups were tested using repeated-measures ANOVAs.

RESULTS

Pain VAS and the Single Assessment Numeric Evaluation scale (SANE) showed significant improvement from baseline 2 weeks and 4 weeks after CSI in all groups (p < 0.05). There were no significant group X time interaction 2 weeks following tDCS treatment in any of the variables.

CONCLUSION

All groups showed significant improvement in pain VAS and SANE scores following the CSI. One session of a-tDCS treatment 2 weeks following CSI did not result in any additive or potentializing effects when compared to a s-tDCS or a control group.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03967574 . Registered 30 May 2019 - Retrospectively registered.

A Neurophysiological Pattern as a Precursor of Work-Related Musculoskeletal Disorders Using EEG Combined with EMG

We aimed to determine the neurophysiological pattern that is associated with the development of musculoskeletal pain that is induced by biomechanical constraints. Twelve (12) young healthy volunteers (two females) performed two experimental realistic manual tasks for 30 min each: (1) with the high risk of musculoskeletal pain development and (2) with low risk for pain development. During the tasks, synchronized electroencephalographic (EEG) and electromyography (EMG) signals data were collected, as well as pain scores. Subsequently, two main variables were computed from neurophysiological signals: (1) cortical inhibition as Task-Related Power Increase (TRPI) in beta EEG frequency band (β.TRPI) and (2) muscle variability as Coefficient of Variation (CoV) from EMG signals. A strong effect size was observed for pain measurement under the high risk condition during the last 5 min of the task execution; with muscle fatigue, because the CoV has decreased below 18%. An increase in cortical inhibition (β.TRPI >50%) was observed after the 5th min of the task in both experimental conditions. These results suggest the following neurophysiological pattern—β.TRPI ≥ 50% and CoV ≤ 18%—as a possible indicator to monitor the development of musculoskeletal pain in the shoulder in the context of repeated and prolonged exposure to manual tasks.

Biopsychosocial Aspects in Individuals with Acute and Chronic Rotator Cuff Related Shoulder Pain: Classification Based on a Decision Tree Analysis

Biopsychosocial aspects seem to influence the clinical condition of rotator cuff related shoulder pain (RCRSP). However, traditional bivariate and linear analyses may not be sufficiently robust to capture the complex relationships among these aspects. This study determined which biopsychosocial aspects would better classify individuals with acute and chronic RCRSP and described how these aspects interact to create biopsychosocial phenotypes in individuals with acute and chronic RCRSP. Individuals with acute (<six months of pain, n = 15) and chronic (≥six months of pain, n = 38) RCRSP were included. Sociodemographic data, biological data related to general clinical health status, to shoulder clinical condition and to sensory function, and psychosocial data were collected. Outcomes were compared between groups and a decision tree was used to classify the individuals with acute and chronic RCRSP into different phenotypes hierarchically organized in nodes. Only conditioned pain modulation was different between the groups. However, the tree combined six biopsychosocial aspects to identify seven distinct phenotypes in individuals with RCRSP: three phenotypes of individuals with acute, and four with chronic RCRSP. While the majority of the individuals with chronic RCRSP have no other previous painful complaint besides the shoulder pain and low efficiency of endogenous pain modulation with no signs of biomechanical related pain, individuals with acute RCRSP are more likely to have preserved endogenous pain modulation and unilateral pain with signs of kinesiophobia.

Motor Imagery Performance and Tactile Spatial Acuity: Are They Altered in People with Frozen Shoulder?

Frozen shoulder (adhesive capsulitis) is a severe chronic pain condition that is not well understood and current treatment is suboptimal. In several other chronic pain conditions motor imagery and tactile acuity deficits are present, which are thought to represent associated neuroplastic changes. The aims of this study were to determine if motor imagery performance assessed by the left/right judgement task, and tactile acuity assessed by two-point discrimination, are altered in people with unilateral frozen shoulder. In this cross-sectional, prospective study eighteen adults diagnosed with frozen shoulder in a physiotherapy clinic setting completed a left/right judgement task, response times (RT) and accuracy for the left/right judgement task were determined. Next, tactile acuity over both shoulders was assessed with a novel, force-standardised two-point discrimination test. Results corresponding to the affected side were compared to the pain free shoulder; Left/right judgement task: mean RT (SD) corresponding to the affected shoulder was significantly slower than RT for the healthy shoulder (p = 0.031). There was no side-to-side difference in accuracy (p > 0.05). Neither RT nor accuracy was related to pain/disability scores or duration of symptoms (p > 0.05). Two-point discrimination: mean two-point discrimination threshold of the affected shoulder was significantly larger than the contralateral healthy shoulder (p < 0.001). Two-point discrimination threshold was not related to pain/disability scores or pain duration (p > 0.05); One explanation for these findings is altered sensorimotor processing and/or disrupted sensorimotor cortex representations of the affected shoulder. A case then exists for the use of treatments aimed at reversing these changes, training the brain to reduce chronic shoulder pain.

The Short-term Effect of Graded Motor Imagery on the Affective Components of Pain in Subjects with Chronic Shoulder Pain Syndrome: Open-Label Single-Arm Prospective Study

OBJECTIVE

To determine the short-term effect of graded motor imagery (GMI) on the affective components of pain and range of motion in subjects with chronic shoulder pain syndrome.

DESIGN

Open-label single-arm prospective study.

SETTING

The Physical Therapy Laboratory, Universidad de las Americas.

SUBJECTS

One hundred seven patients with chronic shoulder pain syndrome.

METHODS

The subjects received a six-week GMI program based on laterality training, imagined movements, and mirror therapy. We assessed pain intensity using a visual analog scale (VAS), fear of movement was assessed using the Tampa Scale of Kinesiophobia (TSK), and catastrophizing was assessed using the Pain Catastrophizing Scale (PCS). The patient's flexion active range of motion (AROM) was also recorded.

RESULTS

At the end of treatment, the VAS showed a decrease of 4.2 cm (P < 0.001, Cohen's d = 3.3), TSK showed a decrease of 17.0 points (P < 0.001, Cohen's d = 2.8), catastrophizing showed a decrease of 19.2 points (P < 0.001, Cohen's d = 3.2), and shoulder flexion AROM showed an increment of 30.3º (P < 0.000, Cohen's d = 1.6).

CONCLUSIONS

We conclude that a short-term GMI program improves the affective components of pain and shoulder flexion AROM in patients with chronic shoulder pain syndrome.

Is implicit motor imagery altered in people with shoulder pain? The shoulder left/right judgement task

BACKGROUND

Implicit motor imagery performance is altered in a variety of chronic pain conditions, but it is not known whether this is the case in shoulder pain.

OBJECTIVES

The aim of this study was to assess implicit motor imagery performance, using a valid and reliable shoulder left/right judgement task in people with shoulder pain.

DESIGN

Cross-sectional observational study.

METHODS

Participants with (n = 369) and without (n = 747) shoulder pain completed the shoulder left/right judgement task (LRJT). Response times (RT), accuracy were determined. Age, gender, hand dominance, current pain intensity, Shoulder Pain and Disability Index (SPADI) and pain duration recorded. Planned analysis included ANOVAs for current pain, RT and accuracy.

RESULTS

Gender and hand dominance distribution were similar between groups (p > 0.5). The shoulder pain participants were older, mean age (SD); 47(14)years, than the control group; 41(14)years, p < 0.01. Participants with shoulder pain were slower, mean RT(SD); 1809(746)ms than the controls; 1701(749)ms; p = 0.02, but no different in accuracy, mean % (SD); 93.2(8.5)% to controls; 94.1(9.4)%; p = 0.13. The differences in RT were resolved when age was entered as a covariate (p = 0.83). Regression of the data from the shoulder pain group only found that current pain was positively related to RT (B = 43.97) and negatively to accuracy (B = -0.70).

CONCLUSIONS

Participants with shoulder pain do not demonstrate poorer implicit motor imagery performance than people who are pain-free. However, more intense shoulder pain is associated with poorer implicit motor imagery performance. We recommend further research utilising the LRJT in well-defined clinically homogenous groups, with verified pain severity, functional disability, and chronicity.

External rotator strength deficits in non-athletic people with rotator cuff related shoulder pain are not associated with pain intensity or disability levels

BACKGROUND

Strength deficits are often reported in people with rotator cuff related shoulder pain. However, these have mainly been tested in athletic populations and pain interference with testing has not been considered.

OBJECTIVES

To examine strength without pain interference in non-athletic people with rotator cuff related shoulder pain and its association with pain intensity and disability.

DESIGN

Cross-sectional study.

METHODS

Sixty-seven participants with rotator cuff related shoulder pain were assessed for isometric strength of shoulder external rotator and internal rotator muscles without pain interference with a hand-held dynamometer. Strength was normalized (%body weight). Differences in external and internal rotation strength and external:internal rotator strength ratio between symptomatic and asymptomatic sides were examined (Independent t-tests, Wilcoxon rank sum tests). Spearman's rank correlation coefficients were used to examine associations between strength and pain and disability levels.

RESULTS

There was no significant difference in internal rotator strength normalized to body weight between symptomatic and asymptomatic sides. There was a significant difference in external rotator strength normalized to body weight (p < .001) and external:internal ratio (p < .001) between sides. No significant correlations were found between strength and pain or disability levels.

CONCLUSION

Non-athletic people with rotator cuff related shoulder pain had external rotator strength deficits without pain interference during strength testing, which were not associated with pain and disability levels.

Seven Key Themes in Physical Therapy Advice for Patients Living With Subacromial Shoulder Pain: A Scoping Review

OBJECTIVE

To systematically scope the reported advice and education in physical therapy management of patients with subacromial shoulder pain, and to define key themes of the advice and education.

DESIGN

Scoping review.

LITERATURE SEARCH

We searched MEDLINE, Scopus, Web of Science, and CINAHL, with publication dates from 2007 to September 2019.

STUDY SELECTION CRITERIA

We included quantitative and qualitative research that reported on physical therapy interventions for subacromial shoulder pain.

DATA SYNTHESIS

We performed a qualitative synthesis that identified items included in patient advice and education.

RESULTS

Of 89 original studies included, there were 61 randomized controlled trials; 5 prospective studies; 16 nonrandomized observational intervention studies or case series; and 7 surveys, audits of physical therapy patient records, and focus groups with physical therapists. We identified 7 key themes for advice and education: exercise intensity and pain response, activity modification advice, posture advice, pain self-management advice, pathoanatomical and diagnosis information, behavioral approaches, and pain biology advice.

CONCLUSION

While advice focused predominantly on the local tissue pathology model, 10% of studies included information about pain neuroscience education, psychosocial factors, motor imagery, or behavior change. J Orthop Sports Phys Ther 2020;50(6):285-293. doi:10.2519/jospt.2020.9152.

Laterality judgement and tactile acuity in patients with frozen shoulder: A cross-sectional study

BACKGROUND

Disrupted tactile acuity and poor laterality judgement have been shown in several chronic musculoskeletal pain conditions. Whether they are impaired in people with frozen shoulder (FS) remains unknown.

OBJECTIVES

To determine whether there is impairment in tactile acuity and laterality judgement in subjects with FS.

METHODS

Thirty-eight subjects with idiopathic FS and 38 sex and age-matched healthy controls were enrolled. The two-point discrimination threshold (TPDT) over the affected and unaffected shoulder of patients with FS and shoulder of healthy controls was evaluated. In addition, all participants performed a left/right judgment task (LRJT). Independent and dependent t-tests were used to compare group means. Pearson-product moment coefficient correlations between pain intensity and duration and LRJT and TPDT were calculated for the FS group.

RESULTS

The TPDT over the affected shoulder was significantly increased compared to the unaffected shoulder (mean difference, 3.82 mm; 95% confidence interval [CI]:0.53, 7.10; p = .02) and controls (mean difference, 5.80 mm; 95% CI: 1.09, 10.52; p = .02). Patients with FS were less accurate (mean difference, 5.90%; 95% CI: 0.36, 11.43; p = .03) and slower (mean difference, -0.26 s; 95% CI: 0.06, 0.45; p = .01) responding to images of their affected shoulder compared to their unaffected shoulder. No associations were found between pain intensity and duration and either TPDT or laterality judgement.

CONCLUSIONS

Participants with FS demonstrated reduced tactile acuity and impaired laterality judgement over their affected shoulder compared to their unaffected shoulder. When compared to controls, subjects with FS showed reduced tactile acuity. TRIAL REGISTRATION CLINICALTRIALS.

GOV IDENTIFIER

NCT03320200.

Using transcranial magnetic stimulation to map the cortical representation of lower-limb muscles

Objective

To evaluate the extent to which transcranial magnetic stimulation (TMS) can identify discrete cortical representation of lower-limb muscles in healthy individuals.

Methods

Motor evoked potentials were recorded from resting vastus medialis, rectus femoris, vastus lateralis, medial and lateral hamstring, and medial and lateral gastrocnemius muscles on the right leg of 16 young healthy adults using bipolar surface electrodes. TMS was delivered through a 110-mm double-cone coil at 63 sites over the left hemisphere. Location and size of cortical representation and number of discrete peaks were quantified.

Results

Within the quadriceps group there was a main effect of muscle on anterior-posterior centre of gravity (p = 0.010), but the magnitude of the difference was small. There was also a main effect of muscle on medial-lateral hotspot (p = 0.027) and map volume (p = 0.047), but no post-hoc tests were significant. The topography of each lower-limb muscle was complex and variable across individuals.

Conclusions

TMS delivered with a 110-mm double-cone coil could not reliably identify discrete cortical representations of resting lower-limb muscles when responses were measured using bipolar surface electromyography.

Significance

The characteristics of the cortical representation provide a basis against which to evaluate cortical reorganisation in clinical populations.

Is rotator cuff related shoulder pain a multidimensional disorder? An exploratory study

Background and aims

Rotator cuff related shoulder pain has been associated with factors from multiple dimensions such as strength changes, psychosocial measures, comorbidities and level of education. However, to date little research has been undertaken to evaluate which factors explain the greatest variance in pain and disability levels in people with rotator cuff related shoulder pain. The objective of this study was therefore to evaluate which multidimensional examination findings were associated with higher pain and disability in a primary care cohort with rotator cuff related shoulder pain.

Methods

This was an exploratory cross-sectional cohort study. Sixty-seven participants with rotator cuff related shoulder pain were assessed for: pain intensity, disability; demographic, psychological, social and lifestyle characteristics, and isometric strength of shoulder internal and external rotator muscles. Univariable associations between pain intensity/disability and each variable were assessed using linear regression. Variables with univariable associations (p < 0.1) were entered into backwards stepwise multivariable regression models.

Results

The multivariable model for pain intensity included sleep and perceived persistence and explained 46.5% of the variance (37.6% uniquely by sleep, 5.4% uniquely by perceived persistence). The multivariable model for disability included sleep and sex and explained 26.8% of the variance (4.5% shared by predictors, 16.4% uniquely by sleep, 5.9% uniquely by sex).

Conclusions

Rotator cuff-related shoulder pain and disability are associated with sleep disturbance, perceived symptom persistence and sex. Rotator cuff related shoulder pain may be considered a multidimensional disorder.

Implications

Clinicians need to evaluate sleep and perceived symptom persistence in people with rotator cuff related shoulder pain. Future research may examine whether management strategies for RCRSP directed towards these factors afford improved treatment outcomes.

Altered Strength Profile in Achilles Tendinopathy: A Systematic Review and Meta-Analysis

BACKGROUND

Persistent strength deficits secondary to Achilles tendinopathy (AT) have been postulated to account for difficulty engaging in tendon-loading movements, such as running and jumping, and may contribute to the increased risk of recurrence. To date, little consensus exists on the presence of strength deficits in AT. Consequently, researchers are uncertain about the appropriate methods of assessment that may inform rehabilitation in clinical practice.

OBJECTIVE

To evaluate and synthesize the literature investigating plantar-flexion (PF) strength in individuals with AT.

STUDY SELECTION

Two independent reviewers searched 9 electronic databases using an agreed-upon set of key words.

DATA EXTRACTION

Data were extracted from studies comparing strength measures (maximal, reactive, and explosive strength) between individuals with AT and healthy control participants or between the injured and uninjured sides of people with AT. The Critical Appraisal Skills Programme Case-Control Study Checklist was used to assess the risk of bias for the included studies.

DATA SYNTHESIS

A total of 19 studies were eligible. Pooled meta-analyses for isokinetic dynamometry demonstrated reductions in maximal strength (concentric PF peak torque [PT] slow [Hedges g = 0.52, 44% deficit], concentric PF PT fast [Hedges g = 0.61, 38% deficit], and eccentric PF PT slow [Hedges g = 0.26, 18% deficit]). Reactive strength, particularly during hopping, was also reduced (Hedges g range = 0.32-2.61, 16%-35% deficit). For explosive strength, reductions in the rate of force development (Hedges g range = 0.31-1.73, 10%-21% deficit) were observed, whereas the findings for ground reaction force varied but were not consistently altered.

CONCLUSIONS

Individuals with AT demonstrated strength deficits compared with the uninjured side or with asymptomatic control participants. Deficits were reported across the strength spectrum for maximal, reactive, and explosive strength. Clinicians and researchers may need to adapt their assessment of Achilles tendon function, which may ultimately help to optimize rehabilitation outcomes.

Is the Organization of the Primary Motor Cortex in Low Back Pain Related to Pain, Movement, and/or Sensation?

AIM/BACKGROUND

Primary motor cortex (M1) organization differs between individuals with and without chronic low back pain (CLBP), in parallel with motor and sensory impairments. This study investigated whether movement behaviour and tactile/pain sensation are related to M1 organisation in CLBP.

METHODS

Transcranial magnetic stimulation (TMS) was used to map the M1 representation of the erector spinae and multifidus muscles in 20 participants with and without CLBP. Cortical organisation was quantified by: map volume; center of gravity (CoG); number of peaks; and primary and secondary peak location. Movement behaviour was assessed as the ability to dissociate lumbar from thorax motion and sensory function as two-point discrimination, pressure pain thresholds, and pain intensity (visual analogue scale).

RESULTS

People with CLBP showed more anterior location of the CoG than controls. Map peaks were more numerous in CLBP participants who performed the movement task good than those with poor performance. In CLBP, smaller map volume correlated with greater pain during the movement task. Movement behaviour was not linearly correlated with M1 features.

CONCLUSIONS

This study confirms that M1 maps differ between people with and without CLBP, but these changes are variable within the CLBP group and are not related to motor and sensory features in a simple manner.

The Addition of Glenohumeral Adductor Coactivation to a Rotator Cuff Exercise Program for Rotator Cuff Tendinopathy: A Single-Blind Randomized Controlled Trial

BACKGROUND

Treatments for rotator cuff tendinopathy include rotator cuff muscle strengthening to promote better muscle recruitment in order to minimize subacromial narrowing during active movement. Glenohumeral adductor recruitment has also been shown to prevent such narrowing in asymptomatic individuals; therefore, adding glenohumeral adductor coactivation during rotator cuff strengthening could enhance the efficacy of rotator cuff strengthening. However, no study has explored its benefits.

OBJECTIVES

To compare the short-term efficacy of adding glenohumeral adductor coactivation to a rotator cuff-strengthening program to improve function, reduce symptoms, and increase acromiohumeral distance in adults with rotator cuff tendinopathy.

METHODS

In this single-blind randomized controlled trial, 42 participants with rotator cuff tendinopathy were randomly assigned to 2 groups, one that received strengthening of the scapular and rotator cuff muscles or one that received rotator cuff strengthening plus coactivation with pectoralis major and latissimus dorsi recruitment. The daily programs were performed at home for 6 weeks, with supervised training and follow-up sessions. Functional limitations/symptoms (Disabilities of the Arm, Shoulder and Hand [DASH] questionnaire as the primary outcome, and the Western Ontario Rotator Cuff index), pain (visual analog scale), and acromiohumeral distance were measured at baseline, 3 weeks, and 6 weeks. Data were analyzed using a mixed-model analysis of variance.

RESULTS

No significant group-by-time interaction was observed for the Disabilities of the Arm, Shoulder and Hand questionnaire, Western Ontario Rotator Cuff index, visual analog scale, and acromiohumeral distance (P≥.055). Significant time effects were obtained for the Western Ontario Rotator Cuff index and visual analog scale for pain with movement (P<.001).

CONCLUSION

The present findings show that adding glenohumeral adductor coactivation to a rotator cuff-strengthening program does not result in improved short-term efficacy in any of the measured outcomes. This study was registered with ClinicalTrials.gov (NCT02837848).

LEVEL OF EVIDENCE

Therapy, level 1b. J Orthop Sports Phys Ther 2019;49(3):126-135. Epub 30 Nov 2018. doi:10.2519/jospt.2019.8240.

Left Right Judgement Task and Sensory, Motor, and Cognitive Assessment in Participants with Wrist/Hand Pain

The Left Right Judgement Task (LRJT) involves determining if an image of the body part is of the left or right side. The LRJT has been utilized as part of rehabilitation treatment programs for persons with pain associated with musculoskeletal injuries and conditions. Although studies often attribute changes and improvement in LRJT performance to an altered body schema, imaging studies suggest that the LRJT implicates other cortical regions. We hypothesized that cognitive factors would be related to LRJT performance of hands and feet and that sensory, motor, and pain related factors would be related to LRJT in the affected hand of participants with wrist/hand pain. In an observational cross-sectional study, sixty-one participants with wrist/hand pain participated in a study assessing motor imagery ability, cognitive (Stroop test), sensory (Two-Point Orientation Discrimination, pressure pain thresholds), motor (grip strength, Purdue Pegboard Test), and pain related measures (West Haven Yale Multidimensional Pain Inventory) as well as disability (Disability of the Arm, Shoulder and Hand). Multiple linear regression found Stroop test time and motor imagery ability to be related to LRJT performance. Tactile acuity, motor performance, participation in general activities, and the taking of pain medications were predictors of LRJT accuracy in the affected hand. Participants who took pain medications performed poorly in both LRJT accuracy (p=0.001) and reaction time of the affected hand (p=0.009). These participants had poorer cognitive (p=0.013) and motor function (p=0.002), and higher pain severity scores (p=0.010). The results suggest that the LRJT is a complex mental task that involves cognitive, sensory, motor, and behavioural processes. Differences between persons with and without pain and improvement in LRJT performance may be attributed to any of these factors and should be considered in rehabilitation research and practice utilizing this task.

Tendon neuroplastic training for lateral elbow tendinopathy: 2 case reports

OBJECTIVE

To report 2 cases of lateral elbow tendinopathy treated with a novel adaptation of tendon neuroplastic training (TNT).

CLINICAL FEATURES

Patient 1: A 61-year-old male machine operator presented with one year of bilateral lateral elbow pain related to his occupation of using torque wrenches.Patient 2: A 37-year-old male electrician presented with two months of recurrent left lateral elbow pain related to repetitive motions of gripping and pulling at work.

INTERVENTION AND OUTCOME

Both patients underwent 8 weeks of a novel rehabilitation program, including TNT, which involved pacing their resistance exercises to a metronome. Both patients experienced clinically meaningful improvements in pain and functional outcome scores that were sustained at the 3-month follow-up.

SUMMARY

Recent evidence suggests that the central nervous system may play a role in chronic tendinopathies. It is possible that TNT may address the central nervous system component of chronic/recurrent tendinopathy that is not addressed by traditional passive therapies. However, further research is needed.

Anodal Transcranial Direct-Current Stimulation to Enhance Rehabilitation in Individuals With Rotator Cuff Tendinopathy: A Triple-Blind Randomized Controlled Trial

Background Anodal transcranial direct-current stimulation (a-tDCS) has been shown to enhance the effects of sensorimotor training in neurological populations. Sensorimotor training leads to reduced pain and increased function in the treatment of rotator cuff tendinopathy. The addition of a-tDCS during a rehabilitation program centered on sensorimotor training may improve treatment outcomes in individuals with rotator cuff tendinopathy. Objective To compare 2 groups of individuals with rotator cuff tendinopathy, one receiving a rehabilitation program centered on sensorimotor training with a-tDCS and the other receiving the same rehabilitation program with sham a-tDCS. Methods In this triple-blind, parallel-group randomized controlled trial, 40 adults with rotator cuff tendinopathy participated in a 6-week rehabilitation program (8 treatments with home exercises and including sensorimotor training, patient education, and strengthening). They were randomly assigned to 1 of 2 groups to receive either real a-tDCS (stimulation, 1.5 mA for 30 minutes) or sham a-tDCS during the first 5 treatments. Symptoms and functional limitations (Disabilities of the Arm, Shoulder and Hand questionnaire, Western Ontario Rotator Cuff index) of all participants were evaluated at baseline and at 3, 6, and 12 weeks. Acromiohumeral distances (ultrasonographic measurement at 0°, 45°, and 60° of arm elevation) were assessed at baseline and 6 weeks. Two-way or 3-way repeated-measures analyses of variance were used for statistical analyses. Results Both groups showed statistically significant improvement in Disabilities of the Arm, Shoulder and Hand questionnaire and Western Ontario Rotator Cuff index scores at 3, 6, and 12 weeks, and in acromiohumeral distance at 45° and 60° at 6 weeks (P<.05). No significant group-by-time interaction was observed for all outcomes (P>.43). Conclusion Results do not demonstrate any improved treatment outcomes from the addition of a-tDCS during a rehabilitation program for individuals with rotator cuff tendinopathy. Level of Evidence Therapy, level 1b. J Orthop Sports Phys Ther 2018;48(7):541-551. Epub 10 May 2018. doi:10.2519/jospt.2018.7871.

Shoulder Taping and Neuromuscular Control

CONTEXT

  Scapular taping can offer clinical benefit to some patients with shoulder pain; however, the underlying mechanisms are unclear. Understanding these mechanisms may guide the development of treatment strategies for managing neuromusculoskeletal shoulder conditions.

OBJECTIVE

  To examine the mechanisms underpinning the benefits of scapular taping.

DESIGN

  Descriptive laboratory study.

SETTING

  University laboratory.

PATIENTS OR OTHER PARTICIPANTS

  A total of 15 individuals (8 men, 7 women; age = 31.0 ± 12.4 years, height = 170.9 ± 7.6 cm, mass = 73.8 ± 14.4 kg) with no history of shoulder pain.

INTERVENTION(S)

  Scapular taping.

MAIN OUTCOME MEASURE(S)

  Surface electromyography (EMG) was used to assess the (1) magnitude and onset of contraction of the upper trapezius (UT), lower trapezius (LT), and serratus anterior relative to the contraction of the middle deltoid during active shoulder flexion and abduction and (2) corticomotor excitability (amplitude of motor-evoked potentials from transcranial magnetic stimulation) of these muscles at rest and during isometric abduction. Active shoulder-flexion and shoulder-abduction range of motion were also evaluated. All outcomes were measured before taping, immediately after taping, 24 hours after taping with the original tape on, and 24 hours after taping with the tape removed.

RESULTS

  Onset of contractions occurred earlier immediately after taping than before taping during abduction for the UT (34.18 ± 118.91 milliseconds and 93.95 ± 106.33 milliseconds, respectively, after middle deltoid contraction; P = .02) and during flexion for the LT (110.02 ± 109.83 milliseconds and 5.94 ± 92.35 milliseconds, respectively, before middle deltoid contraction; P = .06). These changes were not maintained 24 hours after taping. Mean motor-evoked potential onset of the middle deltoid was earlier at 24 hours after taping (tape on = 7.20 ± 4.33 milliseconds) than before taping (8.71 ± 5.24 milliseconds, P = .008). We observed no differences in peak root mean square EMG activity or corticomotor excitability of the scapular muscles among any time frames.

CONCLUSIONS

  Scapular taping was associated with the earlier onset of UT and LT contractions during shoulder abduction and flexion, respectively. Altered corticomotor excitability did not underpin earlier EMG onsets of activity after taping in this sample. Our findings suggested that the optimal time to engage in rehabilitative exercises to facilitate onset of trapezius contractions during shoulder movements may be immediately after tape application.