Description
- Compression of the neurovascular structures in the interscalene triangle as they pass between the clavicle and first rib, and then pass between the pectoralis minor muscle and the coracoid process (Hooper, Denton, McGalliard, Brismee, & Sizer, 2010)
- Thoracic outlet syndrome (TOS) is characterized by pain, paresthesia, weakness and discomfort in the upper limb. Symptoms are aggravated by upper extremity elevation or by exaggerated movements of the head and neck (Watson, Pizzari, & Balster, 2009)
- Over 90% are of neurogenic origin, 3-5% is of venous origin, and less than 1% is arterial (Sanders, Hammond, & Rao, 2007)
Demographics
- 8% of the population (Watson et al., 2009)
- Majority of TOS cases are diagnosed between 20 and 50 years of age, but it can occur in teenagers (Hooper et al., 2010; Huang & Zager, 2004)
- Women are 3-4 times more likely to develop neurogenic TOS than men (Hooper et al., 2010)
- Vascular TOS is equal between non-athletic men and women, but greater in competitive athletic men versus women (Hooper et al., 2010)
Risk Factors
- Female (Brantigan & Roos, 2004; Huang & Zager, 2004)
- Pregnancy (Urschel & Kourlis, 2007)
- Occupation or sports involving repetitious movements (Tilki, Stalberg, Incesu, & Basoglu, 2004; Urschel & Kourlis, 2007)
- Poor posture (Urschel & Kourlis, 2007)
- Sleeping with arm elevated overhead (Crosby & Wehbe, 2004)
- Congenital abnormalities including anomalies of the transverse process of the seventh cervical vertebra and rib, first rib, enlarged scalene tubercle, scalene muscles, costoclavicular ligaments, subclavius or pectoralis minor (Watson et al., 2009)
- Musician who practices 2-4 hrs/day (Pascarelli & Hsu, 2001); violinist, flautist (Brantigan & Roos, 2004)
- Hypertrophy or surgery of the breast, including implants and radical mastectomy (Urschel & Kourlis, 2007)
- Polio (Urschel & Kourlis, 2007)
Types of Thoracic Outlet Syndrome (TOS)
Causes
- Usual cause is from a structural lesion either cervical rib or other bony structure (Watson et al., 2009)
- Neurological TOS: irritation, compression or traction of the brachial plexus (Watson et al., 2009)
- Vascular TOS: Compression or angulation of either the subclavian or axillary artery or vein (Watson et al., 2009)
- Clavicular trauma (Urschel & Kourlis, 2007)
- Marked hyperextension-flexion of the cervical region (Brantigan & Roos, 2004)
- Postural deviations of forward head and shoulder protraction (Crosby & Wehbe, 2004; Watson et al., 2009)
- Bony pathology or soft tissue alterations (Hooper et al., 2010; Watson et al., 2009)
- Motor vehicle or sporting accident (Watson et al, 2009)
Referral/Red Flags
- Fever
- Unexplained weight loss
- History of cancer
- Significant trauma
- Osteoporosis
- Age over 50 years old
- Failure to improve with treatment
- Alcohol or drug abuse
- Lower extremity spasticity
- Loss of bowel or bladder function