Differential patterns of muscle activation in patients with symptomatic and asymptomatic rotator cuff tears

2005 ◽  
Vol 14 (2) ◽  
pp. 165-171 ◽  
Author(s):  
Bryan T. Kelly ◽  
Riley J. Williams ◽  
Frank A. Cordasco ◽  
Sherry I. Backus ◽  
James C. Otis ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Muscle Activation ◽  
Rotator Cuff Tears

Muscle Activity Before and After Subacromial Injection

2021 ◽  
pp. 1-7
Author(s):  
Lucas Ettinger ◽  
Matthew Shaprio ◽  
Andrew Karduna
Keyword(s):  
Rotator Cuff ◽  
Muscle Activation ◽  
Rotator Cuff Tears ◽  
Subacromial Impingement ◽  
Upper Trapezius ◽  
Subacromial Injection ◽  
Shoulder Muscle ◽  
Shoulder Muscles ◽  
Before And After ◽  
Arm Elevation

Context: Shoulder muscle activation in patients with subacromial impingement is highly cited and variable in the literature. Differences between studies could be due to artifacts introduced by normalization practices in the presence of pain. Ultimately, this lack of knowledge pertaining to pathogenesis limits the clinical treatment and restoration of muscular function. Design: A total of 21 patients with stage 2 subacromial impingement and 21 matched controls were recruited for EMG testing of their affected shoulder during an arm elevation task. The patients were tested before and after receiving an injection to their subacromial bursa. Methods: The EMG from 7 shoulder muscles were measured before and after treatment during humeral motion in the scapular plane. Results: Our findings indicate an increase in anterior deltoid, middle deltoid, and upper trapezius activity following the injection; further, this trend extended to the controls. The control subjects had a greater activation of the latissimus dorsi at peak arm elevation when compared with the patient group postinjection. Conclusions: Our results indicate that a reduction in subacromial pain is associated with changes in shoulder muscle recruitment, primarily of the deltoid. This change in deltoid activity may lend evidence to rotator cuff function in patients without rotator cuff tears.

scholarly journals An in-vitro biomechanical assessment of humeral head migration following irreparable rotator cuff tear and subacromial balloon reconstruction

2019 ◽  
Vol 12 (4) ◽  
pp. 265-271
Author(s):  
Jacob M Reeves ◽  
Supriya Singh ◽  
G Daniel G Langohr ◽  
George S Athwal ◽  
James A Johnson
Keyword(s):  
Rotator Cuff ◽  
Humeral Head ◽  
Muscle Activation ◽  
Rotator Cuff Tears ◽  
Biomechanical Assessment ◽  
Intact State ◽  
Optical Markers ◽  
Irreparable Rotator Cuff Tear ◽  
Head Translation

Background A resorbable subacromial balloon has been developed to address humeral head migration following posterosuperior rotator cuff tears. The purpose of this experimental assessment was to quantify the effect of balloon augmentation on humeral head position. Methods Eight cadaveric shoulders were subjected to 0°, 30°, 60° and 90° of abduction via a shoulder simulator. The deltoid was activated at 40N, then 80N. The subscapularis and infraspinatus with teres minor were then applied independently and together to create four muscle activation states for each deltoid load. The shoulder was tested intact, torn, then with the balloon. The centre of the humeral head was tracked using active optical markers. Results When the rotator cuff was torn, the humeral head translated superior by 1.4 ± 1 mm overall (P = 0.009). Following balloon augment, the humeral head translated inferiorly by 2 ± 2 mm relative to the intact state (P = 0.042), and significantly more anterior than the intact (3 ± 2 mm; P = 0.005) state. Rotator cuff variation was only significantly different when the balloon was used, with the subscapularis translating the humeral head posteriorly (P = 0.006). Discussion The subacromial balloon inferiorized the humeral head compared to the torn state. Unexpected anterior humeral head translation was attributed to the posterosuperior balloon placement relative to the humeral head.

Pathological muscle activation patterns in patients with massive rotator cuff tears, with and without subacromial anaesthetics

2006 ◽  
Vol 11 (3) ◽  
pp. 231-237 ◽  
Author(s):  
F. Steenbrink ◽  
J.H. de Groot ◽  
H.E.J. Veeger ◽  
C.G.M. Meskers ◽  
M.A.J. van de Sande ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Muscle Activation ◽  
Rotator Cuff Tears ◽  
Activation Patterns ◽  
Massive Rotator Cuff Tears ◽  
Muscle Activation Patterns

Accuracy of Rotator Cuff Tears and Tendinosis Diagnoses on Shoulder Ultrasound Performed by a Short-experienced Operator

2018 ◽  
Vol 1 ◽  
pp. 9
Author(s):  
Harshad Arvind Vanjare ◽  
Jyoti Panwar
Keyword(s):  
Rotator Cuff ◽  
Negative Predictive Value ◽  
Rotator Cuff Tear ◽  
Predictive Value ◽  
Rotator Cuff Tears ◽  
Mri Findings ◽  
Cuff Tear ◽  
Experienced Operator ◽  
Magnetic Resonance Imaging Mri ◽  
Sensitivity Specificity

Objective The objective of the study was to assess the accuracy of ultrasound examination for the diagnosis of rotator cuff tear and tendinosis performed by a short experienced operator, compared to magnetic resonance imaging (MRI) results. Method A total of 70 subjects suspected to have rotator cuff tear or tendinosis and planned for shoulder MRI were included in the study. Shoulder ultrasound was performed either before or after the MRI scan on the same day. Ultrasound operator had a short experience in performing an ultrasound of the shoulder. Ultrasound findings were correlated to MRI findings. Results Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the diagnosis of tendinosis were 58%, 84%, 63%, 80%, and 75%, respectively, and it was 68%, 91%, 73%, 88%, and 85%, respectively, for the diagnosis of rotator cuff tear. Conclusions Sensitivity for diagnosing rotator cuff tear or tendinosis was moderate but had a higher negative predictive value. Thus, the ultrasound operator with a short experience in performing shoulder ultrasound had moderate sensitivity in diagnosing tendinosis or tears; however, could exclude them with confidence.

scholarly journals Use of Gracile and semi-tendinosus tendons (GRAST) for the reconstruction of irreparable rotator cuff tears

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Marie Protais ◽  
Maxime Laurent-Perrot ◽  
Mickaël Artuso ◽  
M. Christian Moody ◽  
Alain Sautet ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Donor Site ◽  
Anatomical Study ◽  
Donor Site Morbidity ◽  
Rotator Cuff Tears ◽  
Subacromial Space ◽  
Greater Tuberosity ◽  
Working Zone ◽  
Superior Capsular Reconstruction

Abstract Background Irreparable rotator cuff tears are common and difficult to treat. Techniques for “filling the loss of substance” require fixation to the rotator cuff stump (tendon augmentation) or to the glenoid (superior capsular reconstruction), which are complicated by the narrow working zone of the subacromial space. The main objective of this study was to determine whether a braided graft of gracilis (GR) and semitendinosus (ST) could fill a loss of tendon substance from an irreparable rupture of the supra- and infraspinatus, by fixing the graft to the greater tuberosity and the spine of the scapula. Methods This was a cadaveric study with the use of ten specimens. The GRA and ST tendons were harvested, braided and reinforced with suture. An experimental tear of the supraspinatus (SS) and upper infraspinatus (IS) retracted at the glenoid was made. The GRAST transplant was positioned over the tear. The transplant was attached to the greater tuberosity by two anchors and then attached to the medial third of the scapular spine by trans-osseous stitching. The percentage of filling obtained was then measured and passive mobility of the shoulder was assessed. We proceeded to the same technique under arthroscopy for a 73 years old patient whom we treated for a painful shoulder with irreparable cuff tear. We inserted a GRAST graft using arthroscopy. Results The Braided-GRAST allowed a 100% filling of the loss of tendon substance. Mobility was complete in all cases. Conclusion This technique simplifies the medial fixation and restores the musculo-tendinous chain where current grafting techniques only fill a tendinous defect. The transplant could have a subacromial “spacer” effect and lower the humeral head. The donor site morbidity and the fate of the transplant in-vivo are two limits to be discussed. This anatomical study paves the way for clinical experimentation.

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