Acromiohumeral distance in a seated position in persons with impingement syndrome

Abstract

Purpose:To compare the acromiohumeral distance (AHD) of both shoulders in subjects with a unilateral shoulder impingement syndrome (SIS) and healthy subjects in a seated position during free shoulder movements of large amplitude. Materials and Methods:Using a 0.5-Tesla SIGNA-SP/i™ open-configuration magnetic resonance imaging (MRI) system, the AHD was measured at several arm positions, in a standardized seated position. Results:In flexion (rest to 130°), the mean AHD of SIS varied from 8.3 to 2.8 mm, as compared to from 8.7 to 4.1 mm for asymptomatic contralateral shoulders. In abduction (rest to 110°), the AHD varied from 8.1 to 3.4 mm and from 8.8 to 4.6 mm for SIS and asymptomatic shoulders, respectively. The smallest AHD (P Ͻ .01) was observed at 110°. From 80°of arm elevation, the AHD was significantly smaller in impingement than in asymptomatic shoulders (P Ͻ .05). The AHD of asymptomatic shoulders did not differ from that of healthy subjects. In SIS, the AHD at rest was correlated with its reduction at all shoulder positions (r p ϭ 0.62-0.88), but was a poor predictor of the smallest AHD observed at 110°(flexion, R 2 ϭ 0.09; abduction, R 2 ϭ 0.08). Conclusion:In the critical arm elevation positions for impingement, AHD is discriminative for SIS, compared to asymptomatic shoulders and healthy ones. AHD at rest is a good indicator of the magnitude of its reduction in elevation, but not of the smallest AHD in arm elevation. ALTHOUGH INTRINSIC TENDON degeneration as a primary cause of rotator cuff rupture is still debated (1,2), one of the factors often proposed to explain the etiology of shoulder impingement syndrome (SIS) and rotator cuff tear is the reduction of the acromiohumeral distance (AHD) during elevation of the arm (3-8). SIS is thought to reflect the painful compression of the supraspinatus tendon, the subacromial-subdeltoid bursa, and/or the long head of the biceps tendon between the humeral head and the acromion (9). Neer (6) even postulated that as many as 95% of rotator cuff tears result from chronic impingement. Studies using scanning electron microscopy also support the idea that degenerative change of the cuff may be aggravated to the extent of a tear by friction and rubbing, irrespective of the initial cause of degeneration (10).In studies where plain conventional radiography was used, an AHD reduction to less than 6 mm is generally agreed to be pathological and indicative of a supraspinatus tendon rupture (12), and patients with an AHD of 7 mm or less, at rest, are likely to have multiple tendon tears (11) or a large cuff tear (5). With magnetic resonance imaging (MRI) in close-bore magnet gantries, which only allow for the evaluation of small shoulder motion and humeral rotations (13,14) in the supine position, evidence was found that the subacromial space of patients with SIS is significantly smaller than that in healthy persons (13). Other studies focused on detecting indirect signs such as osseous and soft-tissue abnormalities that may predispose to rotator cuff impingement (9,(15)(16...

Effect of Motor Control and Strengthening Exercises on Pain, Function, Strength and the Range of Motion of Patients with Shoulder Impingement Syndrome

“…The subjects of this study were thirty-five patients who had at least one positive finding in any of the following categories 9,19) : a painful arc of movement during flexion or a b d u c t i o n , p o s i t i v e N e e r o r K e n n e d y -H a w k i n s impingement signs, or pain on resisted lateral rotation, abduction or the Jobe test. The exclusion criteria were a type III acromion, calcification or fracture, shoulder instability, previous shoulder surgery and cervicobrachialgia or shoulder pain during neck movement.…”

“…Shoulder pain is exacerbated by lifting the arm, especially in forward bending like flexion, and the decreased ability to control the muscles due to inappropriate movement between the glenohumeral and scapulothoracic joints, muscle weakness, hypotonia and abnormal myotonus may lead to instability of the shoulder joint and a decrease of the subacromial space [5][6][7][8][9] .…”

Effect of Posture on Acromiohumeral Distance With Arm Elevation in Subjects With and Without Rotator Cuff Disease Using Ultrasonography

“…1,3,14,15,19 Studies using MRI reported a smaller AHD in patients with impingement syndrome as compared to healthy shoulders. 1,15,19 Studies using ultrasound imaging corroborate these findings with a smaller AHD in patients with RCD 3,14 and a smaller AHD with increased severity of the RCD. 3 Although these studies consistently indicated a smaller AHD with RCD, they varied on the location of the measurement of the SAS.…”

“…3 Although these studies consistently indicated a smaller AHD with RCD, they varied on the location of the measurement of the SAS. MRI studies 1,15,19 depicted the location as the anterior to middle aspect of the SAS, or at the location of the small- used as described in this study, using the same investigator to collect data and make AHD measurements. For the rest and 45° arm positions, respectively, the standard error of the measure (SEM) was 2.3 and 2.5 mm.…”

Uso del taping en el manejo clínico de sujetos con pinzamiento sub-acromial: revisión sistemática

“…Neer (8,9) fue el primero en utilizar este término quien lo define como: "una compresión y/o fricción entre el tendón del músculo supra-espinoso y los tejidos circundantes del espacio sub-acromial" (10)(11)(12)(13)(14). Las causas del SPS se pueden atribuir a diversos factores, entre ellos: la inflamación de la estructuras contenidas en el espacio sub-acromial (10,11,(14)(15)(16), el estrechamiento de la salida del múscu-lo supra-espinoso, ya sea por hipertrofia o contractura de este músculo (9,(17)(18)(19)(20)(21), otros factores anatómicos tales como: un acromion en forma de gancho (8,13,22,23), presencia de osteofitos en la articulación acromio-clavicular (8,13,22,23), o de tipo más funcional, por la inestabilidad dinámica de la escápula (24,25) que se asocia a la cinemá-tica alterada del mismo complejo (14,(26)(27)(28)(29)(30).…”