Perceived and actual arm performance in multiple sclerosis: relationship with clinical tests according to hand dominance

Background: The real-life relevance of frequently applied clinical arm tests is not well known in multiple sclerosis (MS). Objective: This study aimed to determine the relation between real-life arm performance and clinical tests in MS. Methods: Thirty wheelchair-bound MS patients and 30 healthy controls were included. Actual and perceived real-life arm performance was measured by using accelerometry and a self-reported measure (Motor Activity Log). Clinical tests on 'body functions & structures' (JAMAR handgrip strength, Motricity Index (MI), Fugl Meyer (FM)) and 'activity' level (Nine Hole Peg Test (NHPT), Action Research Arm test) of the International Classification of Functioning were conducted. Statistical analyses were performed separately for current dominant and non-dominant arm. Results: For all outcome measures, MS patients scored with both arms significantly lower than the control group. Higher correlations between actual arm performance and clinical tests were found for the non-dominant arm (0.63-0.80). The FM (55%) was a good predictor of actual arm performance, while the MI (46%) and NHPT (55%) were good predictors of perceived arm performance. Conclusions: Real-life arm performance is decreased in wheelchair-bound MS patients and can be best predicted by measures on 'body functions & structures' level and fine motor control. Hand dominance influenced the magnitude of relationships.