Modified Ashworth Scale

Original Editor - Habibu Salisu Badamasi

Top Contributors - Habibu Salisu Badamasi

Objective

Modified Ashworth Scale (MAS) is used to assess spasticity.[1]

Intended Population

Modified Ashworth Scale (MAS) have been utilized in the following populations: stroke, spinal cord injury, multiple sclerosis, cerebral palsy, traumatic brain injury, pediatric hypertonia and central nervous system lesions[2]

Method of Use

Description

its performed by extending the patients limb first from a position of maximal possible flexion to maximal possible extension ( the point at which the first soft resistance is met). Afterwards, the modified Ashworth scale is assessed while

moving from extension to flexion[3]

scoring

0 No increase in tone

1 slight increase in tone giving a catch when slight increase in muscle tone, manifested by the limb was moved in flexion or extension.

1+ slight increase in muscle tone, manifested by a catch followed by minimal resistance throughout (ROM )

2 more marked increase in tone but more marked increased in muscle tone through most limb easily flexed

3 considerable increase in tone, passive movement difficult

4 limb rigid in flexion or extension

Evidence

Studies that have investigated the reliability of the modified Ashworth Scale as measures of spasticity[4]

Reference Study details Relevant results
Bohannon and Smith (1987)13 Inter-rater reliability of the MAS. Muscles tested: elbow flexors in the impaired arm. Ns = 30 [MS (1), HI (5), CVA (24) ] Na = 2 [physiotherapist] The assessors independently assessed each subject once 86.7% agreement between assessors (Kendall’s τ = 0.847; p <0.001) Cohen’s κ was calculated as 0.826a
Bodin and Morris (1991)48 Inter-rater reliability of the MAS. Muscle tested: wrist flexors. Ns = 18 [CVA] Na = 2 [physiotherapist] The assessors independently assessed each subject under three different conditions (immediately after positioning, after a 90 s stretch of the flexors and after a 90 s stretch of the extensors). 76% agreement between assessors (Kendall’s τ of 0.857) Cohen’s κ was calculated as 0.745a
Sloan et al. (1992)49 Inter-rater reliability of the MAS. Muscles tested: elbow flexors and extensors, and knee flexors. Measurements taken bilaterally. Ns = 34 [hemiplegia] Na = 4 [physiotherapist (2), doctor (2) ] The assessors serially assessed each subject Spearman’s ρ varied from 0.56 and 0.90 at the elbow and between 0.26 and 0.62 at the knee
Allison et al. (1996)50 Inter- and Intra-rater reliability of the MAS. Muscles tested: ankle plantar flexors. Measurements were taken bilaterally. Day-1 of testing Ns = 30 [HI] Na = 2 [physiotherapist] Both testers assessed all subjects independently. Day-2 of testing Tester 1 assessed Ns = 21 subjects. Day-1 Inter-rater reliability tester 1 and tester 2: 55% agreement (ρ = 0.727; τ = 0.647; κ = 0.397) Intra-rater reliability of tester 1: 53% agreement (ρ = 0.741; τ = 0.674; κ = 0.694) Intra-rater reliability of tester 2: 48% agreement (ρ = 0.550; τ = 0.478; κ = 0.286) Day-2 Intra-rater reliability of tester 1: 58% agreement (ρ = 0.821; τ = 0.739; κ 0.422)

Reliability

Interrater/Intrarater Reliability:

muscle tested; Elbow flexor and extensor and knee flexor in Hemiplegia patients

49 Measurements taken bilaterally. Ns = 34 [hemiplegia] Na = 4 [physiotherapist (2), doctor (2) ] The assessors serially assessed each subject)[5]

  • Spearman’s ρ varied from 0.56 and 0.90 at the elbow and between 0.26 and 0.62 at the knee

In daily practice the use of the Modified Ash-worth Scale procedure is quick and easy and is a common tool in the measurement of spasticity. Additionally,the Modified Ashworth Scale is widely used in research, In different patient groups such as stroke,multiple sclerosis and spinal cord injury, moderate to good intra-rater reliability and poor to moderate inter-rater reliability of the scale was found.[6]

Validity

Criterion Validity

35 have shown good correlations between the modified Ashworth scores and EMG parameters derived from simultaneous surface EMG recordings from the muscles tested,[7]

  • it is not possible to draw unequivocal support for the modified Ashworth score being a valid and ordinal measure of spasticity due to one key methodological inconsistency.
  • The actual time to grade spasticity (by passively moving the limb) was reported to be between 0.25 and 0.33 s, however, many of the derived EMG parameters were poorly referenced to this time window[4]

Construct Validity:

13 modified the original scale by adding an additional category, a 1+ falling between 1 and 2, with the aim of increasing its sensitivity. Both scales have since been used as measures of spasticity for clinical and research purposes. A clinical rating of spasticity on the Ashworth Scales is made after an assessor tests the resistance to passive movement about a joint.Both scales describe the resistance perceived while moving a joint through its full range of movement – except in grade ‘4[8]

Content Validity:

The Ashworth Scale was initially developed as a simple clinical tool to test the efficacy of an anti-spastic drug in patients with multiple sclerosis, Ashworth Scales are measures of spasticity

Miscellaneous

Modified Tardieu Scale

The modified Tardieu Scale (MTS) are clinical measures of muscle spasticity in patients with neurological conditions and it quantify spasticity by assessing the muscle's response to stretch applied at given velocities. the quality of the muscle reaction at specified velocities and the angle at which the muscle reaction occurs are incorporated into the measurement of spasticity using the Modified Tardieus Scale (MTS).[2]

Scoring

Quality of Muscle Reaction

0 No resistance throughout passive movement
1 Slight resistance throughout,with no clear catch at a precise angle
2 Clear catch at a precise angle followed by release
3 Fatiguable Clonus (< 10 secs) occurring at a precise angleFatiguable Clonus (< 10 secs) occurring at a precise angle
4 Unfatiguable Clonus (> 10 secs) occurring at a precise angle
5 Joint immobile

Velocity to Stretch

V1 As slow as possible
V2 Speed of the limb segment falling (with gravitational pull)
V3 At a fast rate (>gravitational pull)

Spasticity Angle

R1 Angle of catch seen at Velocity V2 or V3
R2 Full range of motion achieved when muscle is at rest and tested at V1 velocity

Links

Spasticity

References

  1. Charalambous CP. Interrater reliability of a modified Ashworth scale of muscle spasticity. InClassic papers in orthopaedics 2014 (pp. 415-417). Springer, London.
  2. 2.0 2.1 Morris S. Ashworth and Tardieu Scales: Their clinical relevance for measuring spasticity in adult and paediatric neurological populations. Physical Therapy Reviews. 2002 Mar 1;7(1):53-62.
  3. Rw B, Smith MB. Interrater reliability of a modified Ashworth scale of muscle spasticity. Phys ther. 1987;67(2):206-7.
  4. 4.0 4.1 Ad P, Johnson GR. Price CiM, Curless RH, Barnes MP, Rodgers H. A review of the properties and limitations of the Ashworth and modified Ashworth Scales as measures of spasticity. Clin Rehabil. 1999;13(5):373-83.
  5. Pandyan AD, Johnson GR, Price CI, Curless RH, Barnes MP, Rodgers H. A review of the properties and limitations of the Ashworth and modified Ashworth Scales as measures of spasticity. Clinical rehabilitation. 1999 Oct;13(5):373-83.
  6. Mehrholz J, Wagner K, Meißner D, Grundmann K, Zange C, Koch R, Pohl M. Reliability of the Modified Tardieu Scale and the Modified Ashworth Scale in adult patients with severe brain injury: a comparison study. Clinical rehabilitation. 2005 Nov;19(7):751-9.
  7. Ansari NN, Naghdi S, Younesian P, Shayeghan M. Inter-and intrarater reliability of the Modified Modified Ashworth Scale in patients with knee extensor poststroke spasticity. Physiotherapy theory and practice. 2008 Jan 1;24(3):205-13.
  8. Bohannon RW, Smith MB. Assessment of strength deficits in eight paretic upper extremity muscle groups of stroke patients with hemiplegia. Physical therapy. 1987 Apr 1;67(4):522-5.
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