Inter- and intra-rater reliability of the modified modified ashworth scale in the assessment of muscle spasticity in cerebral palsy: A preliminary study.

Purpose: The aim of the study was to investigate the inter- and intra-rater reliability of the Modified Modified Ashworth Scale (MMAS) in the assessment of lower extremity spasticity in children with spastic cerebral palsy (CP).

Methods: Fifteen children (10 boys) with a mean age of 8.7±3.4 years participated. Two physiotherapists rated the spasticity of the hip adductors, knee extensors, and ankle plantar flexors for inter-rater reliability. Each child was examined again by one of the physiotherapists (same physiotherapist for all of the children) for intra-rater reliability (mean interval = 7 days). A random sequence of raters and muscles tested was applied.

Results: The reliability of the intraclass correlation coefficients (ICC) for individual muscle groups ranged between good to excellent (ICCagreement of 0.60-0.83). The ICC values for overall inter-rater (ICCagreement = 0.82) and intra-rater reliability (ICCagreement  = 0.85) were excellent.

Conclusion: The MMAS showed excellent reliability for the assessment of lower extremity muscle spasticity in children with cerebral palsy. However, an interpretation should be made with caution due to the small sample size and wide range of confidence interval values.