Shoulder Impingement: Biomechanical Considerations in Rehabilitation NIH Public Access (original) (raw)
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Shoulder Impingement and its Association with Acromial Morphology- A Review
JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH
Shoulder with its chronic disability recognized by impingement of the rotator cuff beneath the coracoacromial arch. Varying acromial morphology revealed alterations attributable to mechanical impingement. The undersurface of the anterior part of the acromion and the front lip were always implicated. Extrinsic factors caused impingement and tendonopathy, with the antero-lateral acromion 'impinging' on the superior surface of the rotator cuff. The present review clearly describes the acromial morphology and its role as extrinsic causative factor in shoulder impingement. Treatment options for confirmed impingement range from analgesics and physiotherapy to injectable therapy and, open and arthroscopic surgery. In most studies, the results of arthroscopic subacromial decompression are positive, and data suggest that, the operation minimises the occurrence of rotator cuff injuries when compared to a control group. Complete acromionectomy and lateral acromionectomy yielded dismal ...
Anatomical and biomechanical mechanisms of subacromial impingement syndrome
Clinical Biomechanics, 2003
Subacromial impingement syndrome is the most common disorder of the shoulder, resulting in functional loss and disability in the patients that it affects. This musculoskeletal disorder affects the structures of the subacromial space, which are the tendons of the rotator cuff and the subacromial bursa. Subacromial impingement syndrome appears to result from a variety of factors. Evidence exists to support the presence of the anatomical factors of inflammation of the tendons and bursa, degeneration of the tendons, weak or dysfunctional rotator cuff musculature, weak or dysfunctional scapular musculature, posterior glenohumeral capsule tightness, postural dysfunctions of the spinal column and scapula and bony or soft tissue abnormalities of the borders of the subacromial outlet. These entities may lead to or cause dysfunctional glenohumeral and scapulothoracic movement patterns. These various mechanisms, singularly or in combination may cause subacromial impingement syndrome.
Impingement is not impingement: the case for calling it "Rotator Cuff Disease
Muscles, ligaments and tendons journal, 2013
Historically, many causes have been proposed for rotator cuff conditions. The most prevalent theory is that the rotator cuff tendons, especially the supraspinatus, make contact with the acromion and coracoacromial ligament, resulting in pain and eventual tearing of the tendon. However, more recent evidence suggests that this concept does not explain the changes in rotator cuff tendons with age. The role of acromioplasty and coracoacromial ligament release in the treatment of rotator cuff disease has become questioned. Evidence now suggests that tendinopathy associated with aging may be a predominant factor in the development of rotator cuff degeneration. We propose that the overwhelming evidence favors factors other than "impingement" as the major cause of rotator cuff disease and that a paradigm shift in the way the development of rotator cuff pathology is conceptualized allows for a more comprehensive approach to the care of the patient with rotator cuff disease.
In vivo anatomy of the Neer and Hawkins sign positions for shoulder impingement
Journal of Shoulder and Elbow Surgery, 2006
The Neer and Hawkins impingement signs are commonly used to diagnose subacromial pathology, but the anatomy of these maneuvers has not been well elucidated in vivo. This 3-dimensional open magnetic resonance imaging study characterized shoulder anatomy and rotator cuff impingement in 8 normal volunteers placed in the Neer and Hawkins positions. Subacromial and intraarticular contact of the rotator cuff was graded, and minimum distances were computed between the tendon insertion sites and the glenoid, acromion, and coracoid. Both the Neer and Hawkins maneuvers significantly decreased the distance from the supraspinatus insertion to the acromion and posterior glenoid and from the subscapularis insertion to the anterior glenoid. However, the Hawkins position resulted in significantly greater subacromial space narrowing and subacromial rotator cuff contact than the Neer position. In the Hawkins position, subacromial contact of the supraspinatus and infraspinatus was observed in 7 of 8 and 5 of 8 subjects, respectively. In contrast, rotator cuff contact with the acromion did not occur in any subject in the Neer position. Intraarticular contact of the supraspinatus with the posterosuperior glenoid was observed in all subjects in both positions. Subscapularis contact with the anterior glenoid was also seen in 7 of 8 subjects in the Neer position and in all subjects in the Hawkins position. This extensive intraarticular contact suggests that internal impingement may play a role in the Neer and Hawkins signs. (J Shoulder Elbow Surg 2006;15:40-49.) Impingement syndrome is a common cause of shoulder pain arising from the repetitive or excessive contact of the rotator cuff tendons with other anatomic structures in the shoulder. Shoulder impingement can be classified as either external or internal. First described by Neer 33 in 1972, external impingement is characterized by contact of the superficial aspect of the rotator cuff against the acromion, coracoid process, or coracoacromial ligament. In 1992 internal impingement was described in arthroscopic and cadaveric studies as contact of the undersurface of the supraspinatus and infraspinatus tendons with the posterosuperior glenoid rim or labrum. 27,41 Internal impingement has been proposed as an etiologic mechanism of pathology observed on the articular side of the rotator cuff.
2018
Background: Current conservative management of subacromial impingement syndrome (SIS) involves generic strengthening exercises, especially for internal (IR) and external (ER) shoulder rotators. So far, no study has directly investigated the difference in muscle strength between patients with SIS and normal subjects. Accordingly, the purpose of the current study was to compare the shoulder rotator muscles eccentric and concentric peak torque in patients with SIS and normal subjects. Methods: This study was a cross sectional research. Twenty-four patients with SIS (23.33±2.47 Years) and 24 normal subjects (22.83±2.15 Years), matched for hand dominance and physical activity level, completed isokinetic shoulder IR and ER testing. Within the SIS group, 18 patients had the symptoms in their dominant and 6 patients in their non-dominant side. The IR and ER strengths of both sides were measured separately using continuous reciprocal concentric and eccentric contraction cycles at speeds of 6...
Anterior-superior internal impingement of the shoulder: an evidence-based review
Knee Surgery Sports Traumatology Arthroscopy Official Journal of the Esska, 2010
Internal impingement syndrome is a painful shoulder condition related to the impingement of the soft tissue, including the rotator cuff, joint capsule and the long head of the biceps tendon and glenoid labrum. Two types of internal impingement syndrome can be differentiated: posterior-superior impingement and anterior-superior impingement (ASI). The aetiology of ASI in particular is not clear. The purpose of this paper is to discuss the different aetiological theories relating to ASI, try to clarify the clinical, radiological and arthroscopic findings and, finally, suggesting treatment for this complex shoulder syndrome. The article is based on own research and clinical experience, as well as a non-systematic search in the PubMed database. The aetiology of ASI appears to be related to the pulley lesion and instability of the long head of the biceps tendon. It can be caused by trauma or degenerative factors, which produces anterior shoulder pain in middle-aged patients, particularly when performing overhead activities. The ASI is probably more frequent than previously reported. There is no evidence to prove the efficacy of a specific rehabilitative protocol, and the gold standard of surgical management has to be ascertained. However, in patients with a pulley lesion, there is some evidence that early surgical management, when minor soft injury lesions are present, produces better clinical outcomes.