Which MAS grade is described as 'Affect part(s) rigid in flexion or extension'?

• A. No increase in muscle tone
• B. Slight increase in muscle tone with a catch
• C. Affect part(s) rigid in flexion or extension
• D. More marked increase in muscle tone through most of ROM

Answer: (C)

Modified Ashworth Scale gauges how muscle tone changes with passive movement, from none to rigidity. The description “Affect part(s) rigid in flexion or extension” is the highest level on the scale, indicating severe spasticity where the limb becomes essentially fixed in a flexed or extended posture and passive movement is not possible. This is grade 4. Earlier grades describe increasing tone that is present but not fixed (slight catch, increased tone through most of the range, very hard movement), culminating in this rigid presentation at the top end.