Ashworth Scale (AS) and Modified Ashworth Scale (MAS)

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The Modified Ashworth Scale (MAS) is a rating scale to measure abnormality in tone or the resistance to passive movements. It is considered the primary clinical measure of muscle spasticity. MAS is a revised version of the Ashworth Scale (AS) which was designed to assess the effectiveness of antispasticity drugs on spasticity in people with multiple sclerosis.

Assesment Type


Patient Group

Cerebral Palsy | Neurodisability (Other)

Age Group

Children (3-12 years) | Adolescents (13-17 years) | Young Adult (18+ years)

ICF domain

Body Structure & Function

Area of assessment

Joints and muscles

Key description

The Modified Ashworth Scale is a 6-point scale. Scores range from 0 to 4, where lower scores represent normal muscle tone and higher scores represent spasticity or increased resistance to passive movement.

0 - No increase in muscle tone

1 - Slight increase in muscle tone, manifested by a catch and release or by minimal resistance at the end of the range of motion when the affected part(s) is moved in flexion or extension

1+ - Slight increase in muscle tone, manifested by a catch, followed by minimal resistance throughout the remainder (less than half) of the ROM

2 - More marked increase in muscle tone through most of the ROM, but affected part(s) easily moved

3 - Considerable increase in muscle tone, passive movement difficult

4 - Affected part(s) rigid in flexion or extension

Although there are no standardized guidelines for its use, the Modified Ashworth Scale can be applied to muscles of both the upper or lower body. Upper limb joints are generally tested with the child in supine, lower limb joints with the child in side lying.

The rater should extend the client’s limb from a position of maximal flexion to maximal extension until the first soft resistance is felt. Moving a client’s limb through its full range of motion should be done within one second by counting “one thousand and one”.  Throughout testing the client should be instructed to remain calm and relaxed, and when repeated testing is undertaken, testing should be initiated at the same time of the day to minimize possible changes in spasticity levels due to medication interaction (Bohannon and Smith, 1987).



Equipment required

Mat or therapy bench

Training required


Considerations & references

  • The MAS is quick and easy to administer and requires no formal training.
  • Reliability appears to be muscle-dependent. In general, assessments of the elbow and wrist showed better results when compared to assessments of the knee and ankle plantar muscle.
  • Inter-rater reliability varies from moderate to good.
  • Test-retest results vary from poor to moderate.
  • Lack of standardised assessment procedures can affect comparisons.
  • Scores may be affected by non-contractile stuctural components.
  • For further information about reliability and validity see information on the Stroke Engine and Physiopedia websites.

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