The measurement of balance for people who have multiple sclerosis

Introduction: Multiple sclerosis (MS) is a progressive, neurological condition in which balance difficulties and falls are commonly reported. Measuring balance is important for assessment and to measure outcome of intervention and measures used should have known levels of reliability and validity. This research aimed to identify the measures used by physiotherapists for balance, walking and gait, and to review psychometric testing of commonly used measures for people with MS. Research tested psychometric properties of the measures among patients with MS.
Method: A survey of physiotherapists identified widespread outcome measurement, that reliability and validity of measures was important and that the Berg balance scale (BBS) and 10-metre walking test (10MWT) were commonly used measures. A literature review highlighted limited evidence of psychometric testing of these measures among people with MS. The short form BBS (sfBBS) had not been tested at all. The BBS and sfBBS were tested for reliability and validity among people with MS. The 10MWT and objective force-plate data were also tested as measures of balance.
Results: The national survey of physiotherapists yielded an encouraging 77.5% return rate and showed that therapists valued measurement. The patient-based study recruited a smaller sample than desired leading to caution in interpretation. The sfBBS was strongly related to the BBS and both had acceptable levels of intra-rater reliability. Inter-rater reliability was affected by interpretation of scoring guidelines and the sfBBS had significant measurement error. The 10MWT, especially at maximal pace, may be used as an estimator of balance ability.
Conclusion: There must be clear instructions for scoring the BBS particularly between raters. Caution is required in generalising from a small sample size however analyses demonstrated acceptable levels of intra-rater reliability in MS. The sfBBS and 10MWT, as balance estimates, may save time for patients and clinicians and reduce the burden on patients.