Multiple sclerosis (MS) is an inflammatory autoimmune disorder of the central nervous system and potentially the most common cause of neurological disability in young adults.

It is important to identify early decline in physical functioning in persons with MS. The data obtained from a population-based cohort of persons with MS (n = 277) living in Central Finland in 2000 give a clear indication of favourable functioning in mobility, self-care and domestic life. The results revealed the value of clinical outcome measures in detecting minor decrements in physical functioning that precede and often predict the onset of detectable dependence in performance.

This thesis provides recommendations for reliable, responsive and clinically useful physical functioning measures suitable for assessing ambulatory persons with MS. By using responsive measures it is possible to identify early decline and plan interventions to maintain functioning. The ICF was found to be helpful in supplementing the information provided by the measures and in describing the physical functioning.