Score: Mallet classification
Use: Recovery after brachial plexus injury
Abduction
Grade I: No active motion
Grade II: <30°
Grade III: 30° - 90°
Grade IV: >°
Grade V: Normal movement
External rotation
Grade I: No active motion
Grade II: 0°
Grade III: <20°
Grade IV: >20°
Grade V: Normal movement
Hand to head
Grade I: No active motion
Grade II: Impossible
Grade III: Difficult
Grade IV: Easy
Grade V: Normal movement
Hand to back
Grade I: No active motion
Grade II: Impossible
Grade III: To S1 level
Grade IV: To T12 level
Grade V: Normal movement
Hand to mouth
Grade I: No active motion
Grade II: Trumpet sign
Grade III: Partial trumpet sign
Grade IV: <40° abduction
Grade V: Normal movement
The "trumpet sign" is named after the way of holding the trumpet in a particular unit of the French army (almost 90° abduction of affected arm when bringing hand to the mouth).
Reference
http://emedicine.medscape.com/article/317057-treatment