The effect of rotator cuff tear size on shoulder strength and range of motion.
ABSTRACT Prospective cohort study.
To determine the effect of rotator cuff tear size on shoulder strength and range of motion.
Patients with rotator cuff pathology typically present with weakness and motion loss in various motions. The extent to which the presence of a rotator cuff tear and the size of the tear affect strength and range of motion is not well understood.
Sixty-one patients scheduled for surgery, with a diagnosis of a rotator cuff tear and/or subacromial impingement, underwent examination for shoulder pain, function, range of motion, and strength. The extent of rotator cuff pathology was documented during subsequent surgery (presence of tear, tear size, tear thickness).
There were 10 massive tears, 15 large tears, 13 medium tears, 12 small tears, and 11 rotator cuffs without a tear. Patients had marked weakness in abduction strength at 90 degrees and 10 degrees of abduction, in external rotation strength at 90 degrees, and in the "full can test" (all, P<.0001). Marked range of motion losses in shoulder flexion and external rotation at 0 degrees and 90 degrees abduction (all, P<.001) were also observed. Abduction strength deficit at 10 degrees was affected by rotator cuff tear size (P<.0001). Twenty of 25 patients with large or massive tears had deficits greater than 50%, compared with only 1 of 11 patients with no tear, 2 of 12 patients with a small tear, and 5 of 13 patients with a medium tear (P<.0001). Other strength and range of motion deficits or indices of pain and function were unaffected by tear size.
Weakness of greater than 50% relative to the contralateral side in shoulder abduction at 10 degrees of abduction was indicative of a large or massive rotator cuff tear.
- SourceAvailable from: Mark LaslettThe Journal of manual & manipulative therapy 01/2008; 17(2):E67-E70.
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ABSTRACT: The debate on the clinical and functional role of the Supraspinatus in relation to the Deltoid necessitates experimental assessment of their contributions to arm elevation. Our goal was to evaluate the responses of both muscles to increased elevation moment loading. Twenty-three healthy volunteers applied 30N elevation forces at the proximal and distal humerus, resulting in small and large glenohumeral elevation moment tasks. The responses of the Deltoid and Supraspinatus were recorded with surface and fine-wire electromyography, quantified by (EMGdistal-EMGproximal), and normalized by the summed activations (EMGdistal+EMGproximal) to RMuscle ratios. Deltoid activity increased with large elevation moment loading (RDE=.11, 95%-CI [.06-.16]). Surprisingly, there was no significant average increase in Supraspinatus activation (RSSp=.06, 95%-CI [-.08 to .20]) and its response was significantly more variable (Levene's test, F=11.7, p<.001). There was an inverse association between the responses (ß=-1.02, 95%-CI [-2.37 to .32]), indicating a potential complementary function of the Supraspinatus to the Deltoid. The Deltoid contributes to the glenohumeral elevation moment, but the contribution of the Supraspinatus is variable. We speculate there is inter-individual or intra-muscular function variability for the Supraspinatus, which may be related to the frequently reported variations in symptoms and treatment outcome of Supraspinatus pathologies.Human movement science 11/2013; · 2.15 Impact Factor
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ABSTRACT: Rotator cuff tears are a common and disabling complaint. The early diagnosis of medium and large size rotator cuff tears can enhance the prognosis of the patient. The aim of this study was to identify clinical features with the strongest ability to accurately predict the presence of a medium, large or multitendon (MLM) rotator cuff tear in a primary care cohort. Participants were consecutively recruited from primary health care practices (n = 203). All participants underwent a standardized history and physical examination, followed by a standardized X-ray series and diagnostic ultrasound scan. Clinical features associated with the presence of a MLM rotator cuff tear were identified (P<0.200), a logistic multiple regression model was derived for identifying a MLM rotator cuff tear and thereafter diagnostic accuracy was calculated. A MLM rotator cuff tear was identified in 24 participants (11.8%). Constant pain and a painful arc in abduction were the strongest predictors of a MLM tear (adjusted odds ratio 3.04 and 13.97 respectively). Combinations of ten history and physical examination variables demonstrated highest levels of sensitivity when five or fewer were positive [100%, 95% confidence interval (CI): 0.86-1.00; negative likelihood ratio: 0.00, 95% CI: 0.00-0.28], and highest specificity when eight or more were positive (0.91, 95% CI: 0.86-0.95; positive likelihood ratio 4.66, 95% CI: 2.34-8.74). Combinations of patient history and physical examination findings were able to accurately detect the presence of a MLM rotator cuff tear. These findings may aid the primary care clinician in more efficient and accurate identification of rotator cuff tears that may require further investigation or orthopedic consultation.The Journal of manual & manipulative therapy 08/2013; 21(3):148-59.