Upper Limb
Rui Diogo, Drew M. Noden, Christopher M. Smith, Julia Molnar, Julia C. Boughner, Claudia Barrocas, Joana Bruno in Understanding Human Anatomy and Pathology, 2018
In primates, including humans, the supraspinatus lies mainly on the superior side of the scapula and shoulder joint. The superior position of the supraspinatus within the shoulder girdle makes it well suited to abduct the arm when the muscle contracts (in particular of the first 15° of abduction, the remaining abduction being mainly performed by or in concert with the deltoid). Therefore, although the supraspinatus muscle is often grouped in the “rotator cuff” functional group with the subscapularis, infraspinatus, and teres minor, it is not a major shoulder rotator in humans. Unlike the supraspinatus, the infraspinatus in humans lies in a position similar to that seen in more generalized quadrupedal mammals, running from the posterior aspect of the scapula to the posterior proximal humerus and thus being a strong lateral rotator of the arm (Table 4.1; see Box 4.3).
Treatment of Myofascial Pain Syndromes
Mark V. Boswell, B. Eliot Cole in Weiner's Pain Management, 2005
Awareness of generic risk factors in work-related musculoskeletal disorders is important. They include awkward postures, musculoskeletal loading, task invariability, cognitive demands, and organizational and psychosocial work characteristics (Kuorinka & Forcier, 1995). Prolonged static postures, awkward postures, excessive force, and repetitiveness are the most likely specific risk factors for MPS (Armstrong, 1986a). Several studies have confirmed that occupational groups with repetitive arm movements and constrained work postures have high rates of MPS (Amano et al., 1988; Bjelle, Hagberg, & Michaelsson, 1979; Hünting, Läubli, & Grandjean, 1981). Awkward postures include wrist flexion and extension, ulnar and radial abduction, forearm supination and pronation, extended reaches beyond the shoulder-reach envelope, and pinch grips that are either too wide or too narrow (Armstrong, 1986b; Feuerstein & Hickey, 1992). For example, the intramuscular pressure in the supraspinatus muscle exceeds 30 mmHg at 30° flexion or abduction, resulting in impairment of blood circulation, mechanical overload of the muscle and adjacent muscles, and increased risk for myofascial pain (Järvholm et al., 1988). Particular occupational groups at increased risk include data entry operators, typists (Hünting et al., 1981), musicians (Norris & Dommerholt, 1996), teachers and nurses (Onishi et al., 1976), and industrial and assembly line workers (Amano et al., 1988; Silverstein, 1985).
Intra-articular and local soft-tissue injections
Harald Breivik, William I Campbell, Michael K Nicholas in Clinical Pain Management, 2008
Tendonosis usually of the supraspinatus tendon, sometimes with a partial tear or small complete tear of the rotator cuff, or subacromial bursitis, causes pain in the upper arm, which is made worse when the arm is abducted through the middle range. Pain may limit abduction above 90° although the passive range is often better. The pain is less if the arm is elevated in flexion, reducing impingement against the acromion. Rotator cuff pathology may be due to direct injury following a fall onto the outstretched arm, to working with the hands above the head or to impingement against the acromion and/or an osteoarthritic or unstable acromio-clavicular joint. Eventually the supraspinatus muscle wastes and this increases impingement because it helps to hold the humeral head down as it rotates under the acromion against the strong upward pull of deltoid.
Ultrasound-guided versus blind subacromial bursa corticosteroid injection for paraplegic spinal cord injury patients with rotator cuff tendinopathy: a randomized, single-blind clinical trial
Published in International Journal of Neuroscience, 2021
Mohaddeseh Azadvari, Seyede Zahra Emami-Razavi, Farhad Torfi, Najmeh Sadat Boland Nazar, Ali Akbar Malekirad
Musculoskeletal pains are very common among SCI patients and different percentages have been reported in various studies [12]. Shoulder pain is one of the most common complaints of paraplegic SCI patients. Demographic factors as well as time duration of the injury and mobility from the wheelchair are among the effective factors on the shoulder pain [13]. Subacromial bursitis is the most important pathology of shoulder pain which is created as the result of over-use, in a potential location, just beneath the acromion bump; this makes the tendon of supraspinatus muscle prone to entrapment and tendinitis. Chronic pain has direct impacts on the quality of life of SCI patients as well as their mood [1,13]. Subacromial injection of corticosteroid mainly conducted in blind manner by anatomic landmarks is one of the effective treatments for this pain. Depending the body size of the patients, soft tissue thickness, physician experience and length of the needle, blind method could have some errors. On the other hand, the shoulder pain in these patients is usually chronic, resistant and recurring [14,15].
Did the prevalence of suprascapular neuropathy in professional volleyball players decrease with the changes occurred in serving technique?
Published in The Physician and Sportsmedicine, 2021
Daniele Mazza, Raffaele Iorio, Piergiorgio Drogo, Edoardo Gaj, Edoardo Viglietta, Giuseppe Rossi, Edoardo Monaco, Andrea Ferretti
In our study, we performed an MRI of the shoulder in patients with clinical evidence of IS, and we did not consider the necessity of additional exams (e.g. EMG) to confirm the diagnosis. We used the scoring system proposed by Ludig et al. [28], which allows for an easy assessment of the trophicity of the supraspinatus and infraspinatus muscles. At the clinical evaluation, infraspinatus muscle hypotrophy was found in all the subjects. A grade 1 lesion was found in one female athlete, and grade 2 lesions were reported in the other eight subjects. Together with infraspinatus muscle hypotrophy, one male athlete presented with teres minor hypertrophy. Teres minor hypertrophy could be secondary to the infraspinatus muscle weakness. Indeed, both of these muscles work as agonists in the external rotation of the shoulder. If one reduces its effectiveness, the other has to increase its size as a compensative mechanism. In all cases, a normal convex profile of the supraspinatus muscle was found, indicating distal compression of the suprascapular nerve.
Electromyographic analysis of select eccentric-focused rotator cuff exercises
Published in Physiotherapy Theory and Practice, 2022
Takumi Fukunaga, Karl F. Orishimo, Malachy P. McHugh
The principal findings of this study were that short-to-long scaption and sit-to-stand scaption exercises effectively activated the supraspinatus muscle; however, these exercises also involved high activities in the other muscles tested, including upper trapezius. Standing ER and sidelying ER exercises were effective at specifically activating the infraspinatus and lower trapezius muscles over and above other muscles of the shoulder girdle. The horizontal adduction exercise effectively activated the infraspinatus, lower trapezius, and middle deltoid muscles. These results may guide rehabilitation professionals in selecting appropriate exercises and loads to target specific rotator cuff exercises for their patients.
Related Knowledge Centers
- Acromion
- Brachial Plexus
- Greater Tubercle
- Infraspinatus Muscle
- Suprascapular Nerve
- Tendon
- Scapula
- Rotator Cuff
- Humerus
- Supraspinous Fossa