This condition arises when the required space at the thoracic outlet or inlet (Thoracic outlet is a space between the first rib, clavicle and the scalene muscles) decrease due to any cause, this decrease space result in compression of passing nerves (brachial plexus) and vessels (subclavian artery and vein, axillary artery and vein) that cause sensation of pain and tingling.
structures are compressed when this space gets narrowed either due to hypertrophy of the existing muscles or due to any other causes like congenital, trauma, etc.
WHERE IT CAUSE COMPRESSION: –
The sites of compression could be either supraclavicular, sub-clavicular or infraclavicular. • Supraclavicular At the interscalene triangle between the anterior scalene muscles.
• Sub-clavicular Interval between the second thoracic rib, clavicle and subclavius.
• Infraclavicular Beneath an enclosure formed by the coracoid process, pectoralis minor, and costocoracoid membrane.
• Rare causes Scissor-like encirclement of axillary artery by the median nerve.
FACTORS THAT CONTRIBUTE IN CAUSING TOS: –
1. Dynamic factors (while movement): –
Arm when in full abduction, pulls up the artery by 180° causing compression in the short retroclavicular space
2. Static factors: –
• Vigorous occupation Increases the muscle bulk and thereby decreases the space.
• Inactive occupation Decreases the muscle bulk and thereby increases the space.
• Congenital Cervical rib decreases the interscalene space and thereby decreases the retroclavicular space.
• Traumatic Malunion or nonunion of fracture clavicle.
• Arteriosclerosis.
• Anomalies of the first thoracic rib.
• Miscellaneous
— Tumor arising from the upper lobe of the lung.
— Cervicothoracic scoliosis.
— Abnormal variations of the scalene muscles.
CLINICAL FEATURES OF TOS: –
Obviously, this syndrome poses two major problems.
The first one relates to the compression of the major vessels and secondly to the compression of the nerves.
1. Vascular problems – limb swollen and discolored after exercises
2. Neurogenic problems – complain of paraesthesia along with weakness in hand
INVESTIGATIONS FOR TOS: –
X-ray neck – To rule out intrinsic causes like cervical spondylosis, cervical rib, etc.
Nerve conduction studies Difficult to determine the nerve conduction velocity through the thoracic outlet, but its biggest value is to rule out problems like entrapment, e.g. ulnar nerve at elbow, wrist, etc.
TREATMENT PROTOCOL FOLLOWED IN CASE OF TOS: –
• Conservative treatment Consists of rest, pain killers, etc.
• Surgical treatment.
Indications: Gangrene and post-stenotic dilatation.
• Physiotherapy Treatment protocol for TOS
The following physiotherapy treatment procedure are followed for TOS:
• Thermotherapy For pain relief and relaxation.
• Strengthening exercises for all the shoulder joint muscles.
• Self-resisted strengthening exercises for shoulder elevation and adduction muscles.
• PRE with weight belts for shoulder girdle muscles
• Exercises For the active arm especially the hand are advised.
• Postural training
– DR. HEMANT KUMAR
Assistant Professor, Department of Physiotherapy, Madhav University