Relationship Between Hand Strength and Function in Duchenne Muscular Dystrophy and Spinal Muscular Atrophy: Implications for Clinical Trials.
Decostre V., De Antonio M., Servais L., Hogrel J-Y.
BACKGROUND: Measurement of muscle strength and motor function is recommended in clinical trials of neuromuscular diseases, but the loss of hand strength at which motor function is impacted is not documented. OBJECTIVES: To establish the relationship between hand strength and function, and to determine the strength threshold that differentiates normal and abnormal hand function in individuals with Duchenne Muscular Dystrophy (DMD) or Spinal Muscular Atrophy (SMA). METHODS: Maximal handgrip and key pinch strength were measured with the MyoGrip and MyoPinch dynamometers, respectively. Hand function was assessed using the MoviPlate, the Motor Function Measure items for distal upper limb (MFM-D3-UL) and the Cochin Hand Function Scale (CHFS). RESULTS: Data from 168 participants (91 DMD and 77 SMA, age 6-31 years) were analyzed. Relationships between strength and function were significant (P