From the Guidelines
The Modified Ashworth Scale is the recommended tool for measuring spasticity in patients with neurological conditions, as it provides a simple and practical way to assess muscle tone on a scale from 0 to 4. This scale is widely used in clinical settings due to its ease of use and ability to monitor changes in spasticity over time or evaluate the effectiveness of interventions such as medications, physical therapy, or injections 1. The scale rates muscle tone from 0 (no increase in tone) to 4 (affected part rigid), with intermediate ratings including 1 (slight increase with a catch and release or minimal resistance), 1+ (slight increase with minimal resistance through less than half the range), 2 (more marked increase but limb easily moved), and 3 (considerable increase making passive movement difficult) 1.
Some of the key points to consider when using the Modified Ashworth Scale include:
- It is a subjective measure, and clinicians should obtain training to establish administration and scoring consistency, as well as routine retraining to ensure they maintain this consistency 1.
- The scale has been questioned in terms of its validity and interrater reliability, but it remains one of the most widely used clinical measures of spasticity due to its simplicity and practicality 1.
- The scale can be used to assess spasticity at all joints or only a few, and it takes approximately 10 minutes to administer 1.
- The Modified Ashworth Scale improves upon the original Ashworth Scale by adding the 1+ grade for more precise assessment, making it a useful tool for monitoring changes in spasticity over time or evaluating the effectiveness of interventions.
From the Research
Modified Ashworth Scale
The Modified Ashworth Scale is a clinical tool used to measure spasticity, which is a predominant clinical sign appearing in different neurological diseases 2. It is used to assess the severity of spasticity in patients with various conditions, including stroke and spinal cord injury.
Characteristics and Limitations
The Ashworth Scale and the modified Ashworth Scale are the primary clinical measures of spasticity, but they have limitations 3. The Ashworth Scale can be used as an ordinal level measure of resistance to passive movement, but not spasticity. The modified Ashworth Scale will need to be treated as a nominal level measure of resistance to passive movement until the ambiguity between the '1' and '1+' grades is resolved.
Inter-Rater Reliability
The Modified Modified Ashworth Scale (MMAS) has been shown to have very good inter-rater reliability in the assessment of elbow flexor spasticity in adult patients with post-stroke hemiplegia 4. The weighted Kappa value was 0.81, and the weighted percentage agreement was 97.4%.
Clinical Applications
The Modified Ashworth Scale is widely used to assess spasticity in patients with stroke and other neurological conditions 5, 6. It has been shown to be responsive to changes in muscle tone in patients with stroke, and the minimal clinically important differences have been established 6. The scale can be used to evaluate the efficacy of treatments for spasticity, such as botulinum toxin type A and baclofen 5.
Key Points
- The Modified Ashworth Scale is a clinical tool used to measure spasticity.
- It has limitations, including ambiguity between grades and limited reliability.
- The scale has been shown to be responsive to changes in muscle tone in patients with stroke.
- The minimal clinically important differences have been established for the upper and lower extremity muscles.
- The scale can be used to evaluate the efficacy of treatments for spasticity.