Description

The Modified Ashworth Scale (MAS) is a scale used to assess spasticity in patients with neurological disorders such as stroke, spinal cord injury, and multiple sclerosis. Spasticity refers to increased muscle tone that leads to stiffness and restricted movement.

Analysis

The Modified Ashworth Scale (MAS) evaluates spasticity based on the resistance a muscle presents during passive movement. The scale includes:
Resistance Assessment: The examiner applies a slow, continuous passive movement to the patient’s muscles and records the resistance encountered.
Categorization: Resistance is classified into five levels, ranging from no spasticity to extremely severe spasticity.

Purpose

The main goals of the Modified Ashworth Scale (MAS) are:
Spasticity Evaluation: To identify the presence and severity of muscle spasticity.
Progress Monitoring: To monitor treatment progress and response to pharmacological or physical therapy interventions.
Therapeutic Strategy: To guide the selection and adjustment of treatment strategies for managing spasticity.

Scoring

The scoring of the Modified Ashworth Scale (MAS) involves:
Application of Passive Movement: The examiner slowly and carefully moves different joints of the patient passively.
Resistance Recording: The degree of resistance is recorded and classified according to the scale’s scoring criteria.
Spasticity Categories:
0: No spasticity
1: Slight increase in muscle tone, minimal resistance at end of movement
1+: Slight increase in muscle tone, catch followed by minimal resistance through less than half of the range of motion
2: More marked increase in muscle tone through most of the range of motion
3: Considerable increase in muscle tone, passive movement difficult
4: Affected part rigid in flexion or extension, movement impossible

References

Ashworth, B. (1964). Preliminary trial of carisoprodol in multiple sclerosis. Practitioner, 192, 540–545.
Bohannon, R. W., & Smith, M. B. (1987). Interrater reliability of a modified Ashworth scale of muscle spasticity. Physical Therapy, 67(2), 206–207.
Lance, J. W. (1980). The control of muscle tone, reflexes, and movement: Robert Wartenberg’s 1979 lecture. Advances in Neurology, 26, 185–204.