The Ashworth measure of spasticity was developed as a simple clinical classification to assess the anti-spastic effects of carisoprodol in multiple sclerosis (Ashworth 1964).  It is a 5-point nominal scale using subjective clinical assessments of tone ranging from 0 – ‘no increases in tone’ to 4 – ‘limb rigid in flexion or extension [abduction/adduction]’. An additional grade was added (1+) for the Modified Ashworth (MAS) to enhance sensitivity and accommodate hemiplegic patients who typically graded at the lower end of the scale (Bohannon & Smith 1986). These measures have been adopted for measuring spasticity in a variety of other diagnoses, including SCI (Haas et al. 1996).

Number of items: N/a

Procedure/Administration: Both tests (Ashworth and MAS) are clinical examination performed on a relaxed patient in the supine position. The muscle is assessed by rating the resistance to passive range of motion (ROM) about a single joint.

How scored: N/a

Interpretability: The Ashworth scale is easily interpretable with discrete categories that reflect clinical experience. The MAS adds an additional grade at the lower end of spasticity.

Acceptability: N/a    

Languages: N/a

Usability: These measures are easily administered during routine clinic visits and don’t require specialized equipment. The assessments are well accepted and tolerated by patients.

Time to administer: N/a

Time to score: N/a

Training required: None specifically indicated, however the observation of resistance is subjective and requires experienced clinical judgment.

Availability: N/a

Equipment required: None

Summary:

• These measures are the clinical gold standard for assessing spasticity in people with SCI. However, it should be noted that spasticity is a multi-faceted construct with individual components of spasticity weakly related to each other suggesting that different clinical scales measure unique aspects of spasticity (Priebe et al. 1996).
• These measures assess single-joint resistance to passive ROM or a velocity dependent stretch reflex. They do not address spasm frequency or severity, nor do they differentiate between phasic and tonic components of spasticity. Therefore, the overall construct of spasticity is best measured with an appropriate battery of tests including the Ashworth or MAS.

Psychometric Summary

Note: TR= Test re-test; IC= Internal Consistency; Inter-O= Inter-observer; Intra-O= Intra-observer; SS= Sensitivity/Specificity.

Red light= A single study involving SCI subjects which has less than adequate findings of reliability, validity, and/or responsiveness.

Yellow light= A single study involving subjects with SCI which has adequate to excellent findings of reliability, validity, and/or responsiveness.

Green light= At least 2 studies involving subjects with SCI which have adequate to excellent findings of reliability, validity, and/or responsiveness.

N/a= No information.

References

• Ashworth B. Preliminary trial of carisoprodol in multiple sclerosis. Practitioner 1964;192:540-542.
• Benz EN, Hornby TG, Bode RK, Scheidt RA, Schmit BD. A physiologically based clinical measure for spastic reflexes in spinal cord injury. Arch Phys Med Rehabil 2005;86:52-59.
• Bohannon RW, Smith MB. Interrater reliability of a modified Ashworth scale of muscle spasticity. Phys Ther 1987;67:206-207.
• Craven BC, Morris AR. Modified Ashworth scale reliability for measurement of lower extremity spasticity among patients with SCI. Spinal Cord advance online publication, 29 Spetember 2009; doi:10.1038/sc.2009.107.
• Haas BM, Bergstrom E, Jamous A, Bennie A. The inter rater reliability of the original and of the modified Ashworth scale for the assessment of spasticity in patients with spinal cord injury. Spinal Cord 1996;34:560-564.
• Lechner HE, Frotzler A, Eser P. Relationship between self- and clinically rated spasticity in spinal cord injury. Arch Phys Med Rehabil 2006;87:15-19.
• Noth J. Trends in the pathophysiology and pharmacotherapy of spasticity. J Neurol 1991;238:131-139.
• Priebe MM, Sherwood AM, Thornby JI, Kharas NF, Markowski J. Clinical assessment of spasticity in spinal cord injury: a multidimensional problem. Arch Phys Med Rehabil 1996; 77:713-716.
• Skold C. Spasticity in spinal cord injury: self- and clinically rated intrinsic fluctuations and intervention-induced changes. Arch Phys Med Rehabil 2000;81:144-149.