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.
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ABSTRACT: Different measurements are used to assess shoulder function, including range of motion, strength, functional performance and self-report function. To understand disablement, it is necessary to understand the relationship between impairments and function in persons without shoulder problems. This study was conducted to enhance existing comparative data in subjects without upper extremity pathology, and to assess the relationships between impairments (range of motion, strength) and self-reported or measured function/disability. The impact of age, gender and dominance was determined. Two-hundred ninety-four subjects with unaffected shoulders were recruited. The subjects (mean age: 37 years old) were divided into three subgroups, 18-39, 40-59, and over 60 years of age. During a single session, at least two of the following variables were measured: self-reported function (shoulder disability scales), range of motion, isometric rotational strength, or upper limb functional performance (FIT-HaNSA). Two-way analysis of variance was used to determine, for each variable, the effects of age and gender. The relationship between the outcomes was established using Pearson product correlations. Men were significantly stronger than women for all age categories. There was an age-related decline in strength in men in the over-60 age category. Significant negative correlations between strength and range of motion were demonstrated (-0.22 <r < -0.32). Women had a significantly higher range of motion than men for external rotation in the 40-59 age category. Furthermore, the subjects in the over-60 age category experienced a decrease of range of motion. There was minimal disability reported in all age groups on self-report scales. Only the Simple Shoulder Test demonstrated significant decreases in the over-60 age category and correlated with age (r = -0.202). Self-reported disability was low in individuals without upper extremity problems, although recruitment of such individuals was difficult in the older age groups due to the high prevalence of shoulder pathology. A low correlation between self-report disability and strength/range of motion in these unaffected subjects reflects the lack of disability reported by all subjects without pathology despite normal variations in strength and motion.Sports Medicine Arthroscopy Rehabilitation Therapy & Technology 02/2009; 1:4. DOI:10.1186/1758-2555-1-4
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ABSTRACT: Our aim was to determine whether subjects with shoulder impingement syndrome (SIS) have abnormal multijoint torque patterns compared to healthy subjects during normalized isometric force along specific directions. Subjects had to generate an isometric force corresponding to 40% of the maximal pain-free force. Eight targets were displayed on a monitor (0, 45, 90, 135, 180, 225, 270, and 315 degrees ). We calculated shoulder and elbow torques (kinetic strategies) using a biomechanical model. Regardless of the target location, the SIS group succeeded in reaching the target; however, when compared to the healthy subjects, they needed more time to do so, suggesting that SIS may slow down the execution of the kinetic strategies. Moreover, the SIS group produced lower shoulder external/internal torque to reach the targets located at 0 degrees and 225 degrees, and they generated greater abduction/adduction torque for targets located at 0, 135, and 180 degrees. In addition, they had lower elbow extension/flexion torque for the target located at 315 degrees. The investigation of atypical kinetic strategies is essential to provide an understanding of the pathomechanics of the SIS and to develop more effective treatment strategies.Journal of Orthopaedic Research 01/2009; 28(1):6-11. DOI:10.1002/jor.20940 · 2.97 Impact Factor
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ABSTRACT: Few researchers have examined shoulder strength in adolescent volleyball athletes despite increasing levels of participation in this age group. To compare medial and lateral isokinetic peak torque of the rotator cuff among skill levels and between athletes with and without a history of shoulder injury. Cross-sectional design. The Human Performance Lab and Athletic Training Lab. Thirty-eight female adolescent club volleyball athletes from 10 to 15 years of age (mean = 13.02 +/- 1.60 years). We measured concentric and eccentric peak torque of the medial and lateral rotators of the shoulder and calculated resultant cocking and spiking ratios based on peak torque values. Athletes at higher skill levels had higher peak torque measurements in concentric and eccentric medial and lateral rotation compared with the athletes at lower skill levels. No differences in peak torque existed between participants with or without an injury history 6 months before the study. Strength ratios did not differ across skill levels, but previously injured participants produced lower eccentric medial rotation to concentric lateral rotation ratios compared with participants without a history of injury (P = .02). At the highest skill level, previously injured participants produced lower eccentric lateral rotation to concentric medial rotation ratios compared with participants without an injury history (P = .04). Differences in medial and lateral shoulder rotator strength ratios appear to be related more to injury prevalence than to absolute strength. Shoulder dysfunction related to strength ratio deficits also may exist in adolescent female volleyball athletes. Preventive shoulder strengthening programs focused on improving eccentric strength and correcting imbalances between medial and lateral rotators may be warranted for all female adolescent volleyball athletes.Journal of athletic training 11/2008; 43(6):571-7. DOI:10.4085/1062-6050-43.6.571 · 1.51 Impact Factor