Risk Factors:
- Symptoms may be related to occupational activities (e.g. carrying heavy loads, working with arms overhead), poor posture, sleeping with arms elevated over the head, or acute injuries such as cervical flexion/extension (whiplash).
- Athletes (swimmers, volleyball players, tennis players, and baseball pitchers) are at increased risk for compression of the neurovascular structures.
- Most people become symptomatic in third or fourth decade, and women (especially during pregnancy) are affected three times more often than men 2.