Validation of the Nine Hole Peg Test as a measure of dexterity in myotonic dystrophy type 1

Abstract We aimed to validate the Nine Hole Peg Test as a measure of dexterity in myotonic dystrophy type 1 (DM1). Fifty patients with adult-onset, genetically confirmed DM1 were evaluated by Nine Hole Peg Test and re-evaluated at one week. Myotonia was not a limiting factor. The first test was compared with that performed by normal subjects ( n  = 28). Contextually, patients underwent handgrip and three-finger pinch assessments by handheld dynamometer. The Nine Hole Peg Test showed high intra-rater and inter-rater reliability in DM1 [ICC 0.86/0.83 for dominant and 0.90/0.88 for non-dominant hand, respectively]. Inverse correlation with handgrip and pinch strength values ( r  = −0.4; p r  = 0.4; p  p