Reliability and validity of arm function assessment with standardized guidelines for the Fugl-Meyer Test, Action Research Arm Test and Box and Block Test: a multicentre study. To establish: inter-rater and test-retest reliability of standardized guidelines for the Fugl-Meyer upper limb section, Action Research Arm Test and Box and Block Test in patients with paresis secondary to stroke, multiple sclerosis or traumatic brain injury and correlation between these arm motor scales and more general measures of impairment and activity limitation.