Modified Ashworth Scale
A six-point ordinal scale used to grade muscle tone and resistance to passive movement, providing a standardized clinical measure of spasticity severity in neurological rehabilitation.
Full Definition
The Modified Ashworth Scale (MAS) grades muscle tone from 0 (no increase in tone) through 1, 1+, 2, 3, to 4 (rigid limb). The inclusion of the 1+ grade (a slight increase in muscle tone, with a catch in less than half of the range) is a frequent editorial accuracy issue, as authors may omit it or incorrectly write '1.5'. The original Ashworth Scale (1964) did not include this intermediate grade; it was added in the 1987 modification by Bohannon and Smith. In geriatric rehabilitation documents, editors should ensure that MAS scores are reported with the correct notation (particularly the '1+' level) and that the full scale name is used on first mention. The scale is used for limbs, not for truncal tone.
Usage
Usage note: The intermediate grade is '1+', not '1.5'. Distinguish from the original (unmodified) Ashworth Scale. The Tardieu Scale is a distinct and arguably more clinically valid measure of spasticity; do not use the two scales interchangeably.
In Context
- "Tone in the left elbow flexors was rated 1+ on the Modified Ashworth Scale, indicating a slight catch at less than half the range of movement." — Upper limb spasticity clinic assessment
- "The editor corrected 'grade 1.5 spasticity' to '1+ on the Modified Ashworth Scale' in accordance with the scale's published notation." — Rehabilitation medicine journal manuscript editing