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EMG activity of selected rotator cuff musculature during grade III distraction and posterior glide glenohumeral mobilization: results of a pilot trial comparing painful and non-painful shoulders.

ABSTRACT: The objectives of this pilot study were to investigate rotator cuff activity that may be present during grade III distraction and posterior glide mobilization of the glenohumeral (GH) joint, as well as to examine any differences in response between painful and non-painful shoulders utilizing these techniques.EMG data were collected using Delsys EMGworks(®) software and Trigno(®) mini-wireless electrodes for the supraspinatus, infraspinatus and upper trapezius musculature during grade III GH distraction and posterior glide mobilization. A total of 20 shoulders (10 painful, 10 non-painful) were recruited from a sample of convenience. Submaximal voluntary dynamic contraction against gravity was used as reference for each of the three selected muscles. Participants underwent two trials of each mobilization, and the mean results for each group were assessed using descriptive statistics (mean, standard deviation) and effect size.Both the painful and non-painful groups exhibited considerable levels of rotator cuff activity during each test parameter, with the painful group consistently generating higher supraspinatus and infraspinatus RMS and peak force activity. Analysis of the peak combined rotator cuff activity during distraction (d = 0.58) and posterior glides (d = 0.64) suggests moderate-to-high practical significance of the results.GH distraction and posterior glide mobilizations have traditionally been thought of as passive treatment procedures. The results of this pilot study indicate that the supraspinatus and infraspinatus are significantly active during these techniques. Findings suggest that during these techniques, the total infra/supraspinatus EMG activity approaches the level produced while raising the arm against gravity.2b.

SUBMITTER: Swanson BT

PROVIDER: S-EPMC4870035 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature

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EMG activity of selected rotator cuff musculature during grade III distraction and posterior glide glenohumeral mobilization: results of a pilot trial comparing painful and non-painful shoulders.

Swanson Brian T BT Holst Brian B Infante John J Poenitzsch James J Ortiz Alexis A

The Journal of manual & manipulative therapy 20160201 1

<h4>Objectives</h4>The objectives of this pilot study were to investigate rotator cuff activity that may be present during grade III distraction and posterior glide mobilization of the glenohumeral (GH) joint, as well as to examine any differences in response between painful and non-painful shoulders utilizing these techniques.<h4>Methods</h4>EMG data were collected using Delsys EMGworks(®) software and Trigno(®) mini-wireless electrodes for the supraspinatus, infraspinatus and upper trapezius m ...[more]

PMID: 27252577

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Project description:Rotator cuff tears are a common cause for pain and reduced function. Tears of the tendons of the cuff can be a result of a degenerative process or as a consequence of trauma. Management of cuff tears are surrounded by controversy from indications for surgical management to rehabilitation protocol post-surgical repair. The aim of post surgical rehabilitation is to improve functional outcome, reduce pain and promote tendon healing. In the case of rotator cuff repair, rehabilitation can be broadly divided into early passive range of motion (EPM) and delayed range of motion (DRM). The EPM regime is defined by minimal immobilisation of the shoulder and passive mobilisation of the joint within the first post-operative period. In contrast, DRM immobilises the shoulder joint up to six weeks post-operatively. Proponents of EPM state various advantages of their rehabilitation protocol including improved range of motion and earlier return to normal activities of daily living. However, there has also been concern that this rehabilitation regime may result in an increased rate of re-rupture. Since this is a highly controversial issue, various high quality literature have been published looking to clarify which regime is best following rotator cuff surgery. Reviewing these articles, it appears that there is an increase rate of re-tear of the repaired rotator cuff tendon when the EPM regime is employed. Statistical significance however was limited by small sample sizes. Range of motion post-repair also appears to be associated with post-operative rehabilitation regime. As expected, the EPM regime has been shown to improve range of motion post-repair. Despite this, literature reports patients managed with the DPM showed a statistically better patient reported outcome measure. We conclude that based on the evidence we currently have, early range of motion post rotator cuff repair is related with an increase risk of re-tear. The DPM regime reduces this risk with the possible complication of reduced range of shoulder movement. This problem is thought to be an easier clinical issue to deal with compared to re-rupture of the repaired rotator cuff tendon. There is however lack of data to achieve statistical significance in most of these analysis. There is a definite need for a large, multi-centre single blinded randomised controlled trial to further shed light on this controversial topic.

Project description:BackgroundSynovitis of the glenohumeral (GH) joint and the subacromial (SA) space is commonly observed during arthroscopic rotator cuff surgery.PurposeTo investigate the distribution, severity, and clinical implications of synovitis in the GH joint and SA space in patients with a full-thickness rotator cuff tear (RCT).Study designCase series; Level of evidence, 4.MethodsData were retrospectively collected from 207 patients with a full-thickness RCT who underwent arthroscopic repair. Preoperative parameters used in the clinical assessment included pain, range of motion (ROM), muscle strength, and functional scores. Macroscopic assessment of synovitis was performed intraoperatively in the 3 regions of interest (ROIs) of the GH joint and 4 ROIS of the SA space using an evaluation system. The distribution and severity of synovitis and the association between synovitis and clinical assessment were evaluated.ResultsSynovitis was more severe in the GH joint than in the SA space (P < .001). Synovitis in the posterior GH joint and the lateral SA space, where most of the rotator cuff was located, was the most severe area among the ROIs of the GH joint and the SA space, respectively (P < .05). All types of pain, except for pain at rest, were associated with synovitis in the posterior GH joint (P < .05). All ROM measures were associated with synovitis in the posterior and inferior GH joint (|r| > 0.20; P < .05 for both). The strength of the supraspinatus and the infraspinatus was associated with synovitis in the posterior GH joint (P < .05). Shoulder function was associated with synovitis in the posterior and inferior GH joint and more in the posterior GH joint (P < .05 for both). Synovitis in the SA space was not associated with any of the clinical parameters.ConclusionSynovitis in the posterior GH joint was the most severe form of synovitis in the GH joint in patients with a full-thickness RCT. Synovitis in the posterior GH joint was closely associated with increased pain and decreased ROM, muscle strength, and functional score. Synovitis in the SA space was milder and not associated with any clinical parameters.

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Project description:Introduction: A massive rotator cuff tear (RCT) leads to glenohumeral joint destabilization and characteristic degenerative changes, termed cuff tear arthropathy (CTA). Understanding the response of articular cartilage to a massive RCT will elucidate opportunities to promote homeostasis following restoration of joint biomechanics with rotator cuff repair. Mechanically activated calcium-permeating channels, in part, modulate the response of distal femoral chondrocytes in the knee against injurious loading and inflammation. The objective of this study was to investigate PIEZO1-mediated mechanotransduction of glenohumeral articular chondrocytes in the altered biomechanical environment following RCT to ultimately identify potential therapeutic targets to attenuate cartilage degeneration after rotator cuff repair. Methods: First, we quantified mechanical susceptibility of chondrocytes in mouse humeral head cartilage ex vivo with treatments of specific chemical agonists targeting PIEZO1 and TRPV4 channels. Second, using a massive RCT mouse model, chondrocytes were assessed for mechano-vulnerability, PIEZO1 expression, and calcium signaling activity 14-week post-injury, an early stage of CTA. Results: In native humeral head chondrocytes, chemical activation of PIEZO1 (Yoda1) significantly increased chondrocyte mechanical susceptibility against impact loads, while TRPV4 activation (GSK101) significantly decreased impact-induced chondrocyte death. A massive RCT caused morphologic and histologic changes to the glenohumeral joint with decreased sphericity and characteristic bone bruising of the posterior superior quadrant of the humeral head. At early CTA, chondrocytes in RCT limbs exhibit a significantly decreased functional expression of PIEZO1 compared with uninjured or sham controls. Discussion: In contrast to the hypothesis, PIEZO1 expression and activity is not increased, but rather downregulated, after massive RCT at the early stage of cuff tear arthropathy. These results may be secondary to the decreased axial loading after glenohumeral joint decoupling in RCT limbs.

Project description:Myosteatosis is the pathological accumulation of lipid that occurs in conjunction with atrophy and fibrosis following skeletal muscle injury or disease. Little is known about the mechanisms by which lipid accumulates in myosteatosis, but many studies have demonstrated the degree of lipid infiltration negatively correlates with muscle function and regeneration. Our goal was to identify biochemical pathways that lead to muscle dysfunction and lipid accumulation in injured rotator cuff muscles, a model that demonstrates severe myosteatosis. Adult rats were subjected to a massive tear to the rotator cuff musculature. After a period of either 0 (healthy control), 10, 30, or 60 days, muscles were prepared for RNA sequencing, shotgun lipidomics, metabolomics, biochemical measures, electron microscopy, and muscle fiber contractility. Following rotator cuff injury, there was a decrease in muscle fiber specific force production that was lowest at 30d. There was a dramatic time dependent increase in triacylglyceride content. Interestingly, genes related to not only triacylglyceride synthesis, but also lipid oxidation were largely downregulated over time. Using bioinformatics techniques, we identified that biochemical pathways related to mitochondrial dysfunction and reactive oxygen species were considerably increased in muscles with myosteatosis. Long chain acyl-carnitines and L-carnitine, precursors to beta-oxidation, were depleted following rotator cuff tear. Electron micrographs showed injured muscles displayed large lipid droplets within mitochondria at early time points, and an accumulation of peripheral segment mitochondria at all time points. Several markers of oxidative stress were elevated following rotator cuff tear. The results from this study suggest that the accumulation of lipid in myosteatosis is not a result of canonical lipid synthesis, but occurs due to decreased lipid oxidation in mitochondria. A failure in lipid utilization by mitochondria would ultimately cause an accumulation of lipid even in the absence of increased synthesis. Further study will identify whether this process is required for the onset of myosteatosis.

Dataset Information

EMG activity of selected rotator cuff musculature during grade III distraction and posterior glide glenohumeral mobilization: results of a pilot trial comparing painful and non-painful shoulders.

Publications

EMG activity of selected rotator cuff musculature during grade III distraction and posterior glide glenohumeral mobilization: results of a pilot trial comparing painful and non-painful shoulders.

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