Postural Alignment of the Shoulder Complex and the Mechanism of Joint Stress and Injury

By Stephen M. Apatow,  Director of Research and Development, Sports Medicine & Science Institute.

Upper Extremity Alignment and Shoulder Injuries

Postural alignment of the shoulder complex in classical ballet training rarely produce impingement syndromes due  of the emphasis of correct upper extremity alignment. Illustration 1   

Port de bra demonstrating upper extremity alignment where (1) the shoulder complex is held back and down, (2) head of the humorous stabilized as far behind the clavicular head as possible, (3) major muscle groups include  concurrent contracture of the pectoral and latissimus muscles to stabilize the shoulder complex and stercliedomastoid muscle for the cervical spine.

The functional arc of elevation of the shoulder is forward with impingement occurring predominately against the anterior edge of the acromion and coracoclavicular ligament. 1  As the head of the humorous bone shifts anterior to the clavicular head, discomfort may be noted after the exercise and progress to pain during the exercise resulting in tenderness over the anterior acromion and greater tuberosity.  The dancer or athlete also has a painful or uncomfortable abduction arc and positive impingement signs.  If the bicipital tendon is involved, there will be (1) tenderness over the bicipital grove, (2) positive straight arm raising, (3) resistive forward flexion at 80 degrees with the elbow extended, and (4) positive resisted forearm suppuration.

The differential diagnosis of impingement syndrome includes (1) acute traumatic bursitis (caused by a direct blow) (2) primary acromioclavicular pathology (acute tenderness), or a (3) cervical disc (neck symptoms and nerve involvement beyond the elbow).

The complaints related to the shoulder complex and bicipital tendon are generally responsive to a restriction in activity accompanied by oral anti-inflammatory agents.

Ruptures of the bicipital tendon have been reported in gymnasts,  2  frequently occurring as a degenerative problem or as a consequence of sudden unexpected stress applied to the contracted biceps. Symptomatic bursa formation about the scapula raises the traditional question of osteochondroma and need for x-ray films to rule out this rare entity. 3

Thoracic Outlet Conditions

In thoracic outlet conditions, the neurologic examination is negative and radiographs normal with the structure involved difficult or impossible to identify.  It is assumed that the ligamentous support structure or the joints between the articular processes have been injured and occasionally, a symptomatic muscle may be indicated.

Treatment is tailored to the severity of the problem with analgesic, anti-inflammatory agents, and possibly a soft collar until there is full, spasm-free range of motion.  In some patients, a specific neck complaint is accompanied by intermittent numbness, tingling, heaviness, and fatigue of an upper extremity, which suggests a thoracic outlet syndrome. 

The outlet syndromes are related to lower elements of the brachial plexus from C-7 to T-1. X-ray films may reveal a cervical rib with greater suspicion attached to the incomplete or short cervical rib due to the congenital ligamentous bands coupling coupling the cervical rib to the first rib.

Brachial Plexus Injury

Upper extremity weakness as a consequence of participation in contact sports has been associated with injuries to the upper branch of the brachial plexus as a probable causative neurologic injury.  The is occasioned by downward force upon the shoulder and deviation of the head and neck backward or toward the opposite shoulder, suggestive of traction on the brachial plexus.  The distribution of nerves from the upper trunk includes (1) superscapular (supraspinatus and infraspinatus muscles), (2) upper and lower subscapular (subscapularus and teres major), musculocutaneous (coracobrachialis and biceps), (4) axillary (deltoid and teres minor).

Spontaneous serratus anterior paralysis is a relatively rare condition.  A common cause is backpacking 4 or a brachial neuritis.  The nerve is the most prominent over the second rib and may be injured by the undersurface of the scapula with forceful pulling of the arm.  It has also been suggested that injury is due to traction between the point of proximal fixation, the scalenus medius, and its point of distal fixation, the superior serratus anterior. 5

Neck Injury

Barre described a syndrome with symptoms of headache; retro-orbital pain; vasomotor disturbance of the face ; recurrent disturbances of vision, swallowing, and pronation due to alterations of the blood flow within the vertebral arteries; and associated disturbance of the periarterial nerve plexus.  The syndrome is one not frequently expressed in "whiplash" injuries. 

Cervical spondylosis in the middle and distal thirds of the neck is thought to be the usual provocative cause of irritation of the vertebral arteries. Limousin has pointed out that in young individuals, congenital abnormalities of the posterior arch of the atlas, the arcuate foramen, man produce the symptoms. 6 The possibility can be tested for by placing the head in a slightly extended position and firmly gripping the chin.  Firm pressure is then exerted between the thumb and finger, in a gripping action just below and lateral to the occipital protuberance, at the level of the lateral masses of the atlas.  Pain may be produced by the pressure accompanied by conjunctival injection and the shedding of tears.  In some cases there will be a feeling of vague faintness.

Since many of the patients are young anxious and impressionable, assurance and conservative therapy are generally all that is necessary.  Many of the symptoms are somewhat confusing and suggest a supratentorial origin,  nevertheless, they should be investigated.  Occasionally, more particularly with additional complaints of dizziness or staggering, some disturbance in the vestibular aspect may be established by nystagmography. 7

Range of Motion: The Shoulder Stretch  

While holding the shoulders back and down, the student grasps a rod or strap in the front of the body. The rod or strap is slowly brought overhead, keeping the arms straight while moving through the full rotation of the shoulder joint until the arms are behind the torso.  Note: The mechanical ideal is when the arms are approximately shoulder width throughout the entire range of motion. It is critical that the shoulders are held back and down during the stretch. The further the hands are spaced relates to the restriction that exists in the shoulder complex. With this restriction, the student is incapable of maintaining correct alignment of the shoulder to the torso in ballet or sports specific training.

References

1. Neer, C.S., and Welch, R.P.: The shoulder in Sports. Orthop. Clin. North. Am., 3:583-591, 1977.
2. Del Pizzo, W., Norwood, L.A., Jobe, F.W., et al.: Rupture of the biceps tendon in gymnastics. Am. J. Sports Med., 6:283-285, 1978.
3. McWilliams, C.A.: Subscapular extosis with advetitious bursa. J.A.M.A., 63: 1473-1474, 1914.
4. Ilfeld, F.W., and Holder, H.G.: Winged scapula: case occurring in soldier from knapsack. J.A.M.A.., 120:448-449, 1942.
5. Gregg, J.R., Labosky, D., harty, M., et al.: Serratus anterior paralysis in the young athlete. J. Bone Joint Surg., 61A: 825-832, 1979.
6. Limousin, C.A.: Foramen arculae and syndrome of Barre-Lieou. Int. Othop., 4:19-23, 1980.
7. Toglia, J.U., and Ronis, M.L.: Electronytagmograhpy in clinical and medical legal uses. trans. Pa. Acad. Ophthalmol. Otolaryngol., 22-23-27, 1969.

Selected Bibliography

Agrippina Vaganova, Basic Principles of Classical Ballet, Dover, 1969 
Alfred A Knopf, The Classic Ballet, New York, 1984
Clinics In Sports Medicine, Injuries to Dancers ,Saunders 1983 
White-Panjabi, Clinical Biomechanics of the Spine, J.B. Lippincott, 1978 
Rosse-Clawson, The Musculo-Skeletal System in Health and Disease, Harper & Row, 1970 
Stanley Hoppenfeld, Physical Examination of the Spine and Extremities, Appleton, 1976 
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Consultations

Classical Ballet & Sports Development.
Clinics, Seminars, Biomechanics Specialist Cerficiations.

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For questions or additional information, contact: 
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Stephen M. Apatow President, Director of Research and Development Biomechanics Specialist & Technical Consultant Sports Medicine & Science Institute 167 Cherry Street, # 260 Milford, Connecticut  06460 Telephone: (203) 668-0282 Internet: www.esportsmedicine.org Email: s.m.apatow@esportsmedicine.org