Injury mechanisms in supraclavicular stretch injuries of the brachial plexus.

The aim of this study was to describe the mechanisms involved in stretch injuries of the brachial plexus. One hundred and fifty consecutive patients with supraclavicular brachial plexus injuries (BPI) were asked about the mechanism of injury during the actual injury event, particularly about the type of trauma to their shoulder, shoulder girdle and head. Fifty-seven of the patients provided enough information about their accident to allow for analysis of the shoulder trauma. The injury mechanism for all patients having upper root or total palsy (n=46) was described as a direct vertical impact to the shoulder. In 44 of these patients, the trauma followed a motorcycle accident and, in most of them, the patient hit a fixed vertical structure before falling to the ground. The injury mechanism for the lower root palsy cases (n=11) was variable. The most frequent mechanism was forceful anterior shoulder compression by a car seat belt. We found that injury mechanisms differed significantly from the ones commonly discussed in published studies.