Obstetric brachial plexus palsy: the mallet grading system for shoulder function--revisited.

The Mallet grading system is a commonly used functional scoring system to assess shoulder abduction/external rotation deficits in children with obstetric brachial plexus palsy. One feature of the Mallet score is that each grade is translated into certain degrees of deficiencies in both shoulder abduction and external rotation. The aim of the current study is to investigate the percentage of children in which the Mallet score could not be applied because of a discrepancy between the deficiency of shoulder abduction and shoulder external rotation. The study group included 50 consecutive unoperated older children (over 5 years of age) with Erb's palsy and deficits in shoulder movements. The Mallet score could be applied in 40 cases (80%). In the remaining 10 cases (20%), the Mallet score could not be applied either because shoulder abduction had a better grade than the grade of shoulder external rotation (n = 7) or vice versa (n = 3). It was concluded that documenting the deficits in shoulder abduction and external rotation are best done separately and this can be accomplished by using other grading systems.