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Ashworth Scale / Modified Ashworth Scale

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Purpose

The Modified Ashworth Scale (MAS) is a revised version of the original Ashworth Scale that measures spasticity in patients with lesions to the central nervous system. MAS is an assessment that is used to measure the increase in muscle tone. MAS assigns a grade of spasticity from a 0-4 ordinal scale. The grade is assigned by moving a joint/muscle through a high velocity quick stretch.

The Ashworth Scale (AS) was designed to assess the effectiveness of antispasticity drugs on spasticity in people with multiple sclerosis.

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Instrument Details

Acronym AS / MAS

Area of Assessment

Spasticity

Assessment Type

Observer

Administration Mode

Paper & Pencil

Cost

Free

CDE Status

Classification
Supplemental - Highly Recommended: Multiple Sclerosis (MS)

 

  • Highly recommended for clinical trials in spasticity.
 
Supplemental: Cerebral Palsy (CP); Amyotrophic Lateral Sclerosis (ALS), Spinal Cord Injury (SCI), Chiari I Malformation
 
Exploratory: SCI - Pediatric, Chiari I Malformation

Diagnosis/Conditions

  • Brain Injury Recovery
  • Cerebral Palsy
  • Multiple Sclerosis
  • Spinal Cord Injury
  • Stroke Recovery

Populations

Stroke
Spinal Injuries
Pediatric Disorders
Non-Specific Patient Population
Multiple Sclerosis
Limb Loss and Amputation
Cerebral Palsy
Brain Injury

Key Descriptions

  • Original Ashworth Scale:
    Tests resistance to passive movement about a joint with varying degrees of velocity.
    Scores range from 0-4, with 5 choices.
    A score of 1 indicates no resistance, and 5 indicates rigidity.
  • Original Ashworth Scale Scores (1964):
    0 (0) - No increase in tone
    1 (1) - Slight increase in tone giving a catch when the limb was moved in flexion or extension
    2 (2) - More marked increase in tone but limb easily flexed
    3 (3) - Considerable increase in tone - passive movement difficult
    4 (4) - Limb rigid in flexion or extension
  • Modified Ashworth Scale:
    Similar to Ashworth, but adds a 1+ scoring category to indicate resistance through less than half of the movement.
    Scores range from 0-4, with 6 choices (Bohannon & Smith, 1987).
  • Modified Ashworth Scale Scores (1987):
    0 (0) - No increase in muscle tone
    1 (1) - Slight increase in muscle tone, manifested by a catch and release or by minimal resistance at the end of the range of motion when the affected part(s) is moved in flexion or extension
    1+ (2) - Slight increase in muscle tone, manifested by a catch, followed by minimal resistance throughout the remainder (less than half) of the ROM (range of movement)
    2 (3) - More marked increase in muscle tone through most of the ROM, but affect part(s) easily moved
    3 (4) - Considerable increase in muscle tone passive, movement difficult
    4 (5) - Affected part(s) rigid in flexion or extension

Number of Items

Depends on number of muscles/joints tested

Equipment Required

  • Mat Table

Time to Administer

Less than 5 minutes

Depends on the number of muscles/joints tested

Required Training

Reading an Article/Manual

Age Ranges

Child

6 - 12

years

Adult

18 - 64

years

Instrument Reviewers

Initially reviewed by the Rehabilitation Measures Team; Updated by Phyllis Palma PT, DPT and Christopher Newman PT, MPT, NCS and the SCI EDGE task force of the Neurology section of the APTA in 9/2012; Updated with references for the TBI population by Irene Ward, PT, DPT, NCS and the TBI EDGE task force of the Neurology Section of the APTA in 2012; Updated with references for Pediatrics and Cerebral Palsy by Anna Wetzel, SPT, Brian Baranyi, SPT, and Stephanie Johnson, SPT in 11/2012.Updated with references for the TBI population by Irene Ward, PT, DPT, NCS and the TBI EDGE task force of the Neurology Section of the APTA in 2012; Updated with references for Pediatrics and Cerebral Palsy by Anna Wetzel, SPT, Brian Baranyi, SPT, and Stephanie Johnson, SPT in 11/2012; Updated by Dorian, Rose, PhD, PT and Carmen Capo-Lugo, PhD, PT of the StrokEdge II Task Force, Neurology Section of the APTA. General update (2021) completed by Meredith Boe MOT, OTR/L, Selina Brijbasi, MS, OTR/L and Karen Ruiz, MS, OTR/L at George Washington University

Body Part

Upper Extremity
Lower Extremity

ICF Domain

Body Structure
Body Function

Measurement Domain

Motor

Professional Association Recommendation

Recommendations for use of the instrument from the Neurology Section of the American Physical Therapy Association’s Multiple Sclerosis Taskforce (MSEDGE), Parkinson’s Taskforce (PD EDGE), Spinal Cord Injury Taskforce (PD EDGE), Stroke Taskforce (StrokEDGE), Traumatic Brain Injury Taskforce (TBI EDGE), and Vestibular Taskforce (VEDGE) are listed below. These recommendations were developed by a panel of research and clinical experts using a modified Delphi process.

For detailed information about how recommendations were made, please visit:  http://www.neuropt.org/go/healthcare-professionals/neurology-section-outcome-measures-recommendations

Abbreviations:

HR

Highly Recommend

R

Recommend

LS / UR

Reasonable to use, but limited study in target group  / Unable to Recommend

NR

Not Recommended

Recommendations for use based on acuity level of the patient:

 

Acute

(CVA < 2 months post)

(SCI < 1 month post)

(Vestibular < 6 months post)

Subacute

(CVA 2 to 6 months)

(SCI 3 to 6 months)

Chronic

(> 6 months)

SCI EDGE

NR

NR

NR

StrokEDGE

R

R

R

Recommendations based on level of care in which the assessment is taken:

 

Acute Care

Inpatient Rehabilitation

Skilled Nursing Facility

Outpatient

Rehabilitation

Home Health

StrokEDGE

R

R

R

R

R

Recommendations for entry-level physical therapy education and use in research:

 

Students should learn to administer this tool? (Y/N)

Students should be exposed to tool? (Y/N)

Appropriate for use in intervention research studies? (Y/N)

Is additional research warranted for this tool (Y/N)

SCI EDGE

No

No

No

Not reported

StrokEDGE

No

Yes

Yes

Not reported

Ashworth Scale, Modified

Recommendations for use of the instrument from the Neurology Section of the American Physical Therapy Association’s Multiple Sclerosis Taskforce (MSEDGE), Parkinson’s Taskforce (PD EDGE), Spinal Cord Injury Taskforce (PD EDGE), Stroke Taskforce (StrokEDGE), Traumatic Brain Injury Taskforce (TBI EDGE), and Vestibular Taskforce (VEDGE) are listed below. These recommendations were developed by a panel of research and clinical experts using a modified Delphi process.

For detailed information about how recommendations were made, please visit:  http://www.neuropt.org/go/healthcare-professionals/neurology-section-outcome-measures-recommendations

Abbreviations:

HR

Highly Recommend

R

Recommend

LS / UR

Reasonable to use, but limited study in target group  / Unable to Recommend

NR

Not Recommended

Recommendations for use based on acuity level of the patient:

 

Acute

(CVA < 2 months post)

(SCI < 1 month post)

(Vestibular < 6 months post)

Subacute

(CVA 2 to 6 months)

(SCI 3 to 6 months)

Chronic

(> 6 months)

SCI EDGE

LS

LS

LS

Recommendations based on level of care in which the assessment is taken:

 

Acute Care

Inpatient Rehabilitation

Skilled Nursing Facility

Outpatient

Rehabilitation

Home Health

MS EDGE

UR

UR

UR

UR

UR

TBI EDGE

LS

R

R

R

R

Recommendations based on SCI AIS Classification:

 

AIS A/B

AIS C/D

SCI EDGE

LS

LS

Recommendations for use based on ambulatory status after brain injury:

 

Completely Independent

Mildly dependant

Moderately Dependant

Severely Dependant

TBI EDGE

N/A

N/A

N/A

N/A
 

Recommendations based on EDSS Classification:

 

EDSS 0.0 – 3.5

EDSS 4.0 – 5.5

EDSS 6.0 – 7.5

EDSS 8.0 – 9.5

MS EDGE

UR

UR

UR

UR
 

Recommendations based on vestibular diagnosis

 

Peripheral

Central

Benign Paroxysmal Positional Vertigo (BPPV)

Other

  Recommendations for entry-level physical therapy education and use in research:

 

Students should learn to administer this tool? (Y/N)

Students should be exposed to tool? (Y/N)

Appropriate for use in intervention research studies? (Y/N)

Is additional research warranted for this tool (Y/N)

MS EDGE

No

No

No

Yes

SCI EDGE

No

Yes

No

Not reported

TBI EDGE

Yes

Yes

Yes

Not reported

Considerations

  • Adequate training is required to ensure inter-rater reliability
  • Reliability differs from muscle to muscle
  • Assessment technique must be standardized
  • Some critics question the validity of the Ashworth scale and Modified Ashworth Scale in measuring spasticity. It may be a description of resistance to passive movement. Therefore, measuring only one aspect of spasticity, not a comprehensive assessment. (Salter et al, 2005)
  • It was concluded that the Ashworth scale is of limited use in the assessment of spasticity in the lower limb of patients with SCI
  • The Ashworth scale produces a global assessment of the resistance to passive movement of an extremity, not just stretch-reflex hyperexcitability. Specifically, the Ashworth score is likely to be influenced by non-contractile soft tissue properties, by persistent muscle activity (dystonia), by intrinsic joint stiffness, and by stretch reflex responses (Kamper et al., 2001)
  • Ambiguity of wording and lack of standardized procedures limit the scale’s usefulness for comparison across studies as well as reliability
  • The Modified Ashworth scale does not comply with the concept of spasticity (a velocity-dependent increase in muscle tone) (Scholtes, 2007)
  • The Modified Ashworth Scale measures muscle tone intensity at one, unspecified, velocity which can make comparisons difficult (Scholtes, 2007)

 

Translated Modified Ashworth Scale:

Chinese (simplified): http://www.haodf.com/zhuanjiaguandian/liubaoqiong_1077075591.htm

French:
http://www.cofemer.fr/UserFiles/File/ECH.1.2.2.Asworth.pdf

German: 
http://www.patientensicherheit.ch/dms/de/themen/3126_sturz_testbeschreibung_chedoke_master_d/Testbeschreibung%20chedoke%20MC%20Master.pdf

Italian (p103): 
http://www.iss.it/binary/publ/cont/08-39%20web.1233562284.pdf

Japanese (p2):
https://www.jstage.jst.go.jp/article/jkpt/12/0/12_1/_pdf

Korean:
http://blog.naver.com/PostView.nhn?blogId=3c273&logNo=10000521558

Spanish (p40):
http://www.tdx.cat/bitstream/handle/10803/3840/nml1de1.pdf;jsessionid=1CF6D8957E26C2A044019951FEBF24F2.tdx2?sequence=1

These translations, and links to them, are subject to the Terms and Conditions of Use of the Rehab Measures Database. RIC is not responsible for and does not endorse the content, products or services of any third-party website, and does not make any representations regarding its quality, content or accuracy. If you would like to contribute a language translation to the RMD, please contact us at rehabmeasures@ric.org.

Do you see an error or have a suggestion for this instrument summary? Please e-mail us!

Stroke

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Minimal Detectable Change (MDC)

Stroke:

(Shaw et al, 2010; n = 333; adults with upper limb spasticity at the shoulder, elbow, wrist or hand and reduced upper limb function due to stroke more than 1 month previously.)

  • Response to Botox: the magnitude of initial change in muscle tone/spasticity was approximately a one-point decrease on the MAS which reflects a clinically significant improvement.

Minimally Clinically Important Difference (MCID)

Stroke: (Chen et al., 2019; n = 115)

  • Effect Size at 0.5 SD: Upper extremity = 0.48, Lower extremity = 0.45
  • Effect Size at 0.8 SD:  Upper extremity = 0.76, Lower extremity = 0.73

Test/Retest Reliability

Modified Ashworth Scale

Stroke:

(Gregson et al, 2000; n = 32; median age = 74 years; median Barthel score = 8; median time since onset = 40 (IQR = 19 - 78) days. Blackburn et al, 2002; n = 32; mean age = 76.1 (7.89) years; assessed 12 weeks post-stroke, Acute Stroke)

  • Excellent intra-rater reliability for elbow (kw = 0.84) (Gregson et al, 1999)
  • Adequate intra-rater reliability for elbow (kw = 0.77 – 0.84); ankle (kw = 0.59 – 0.64); wrist (kw = 0.80 – 0.88) and knee (kw = 0.77 – 0.94) (Gregson et al, 2000)
  • Adequate intra-rater reliability in the lower extremity of 73.3% (Kendall tau-b = 0.567) (Blackburn et al, 2002)

Interrater/Intrarater Reliability

Modified Ashworth Scale:

Stroke:

(Blackburn et al, 2002, Acute Stroke)

  • Adequate intrarater reliability. Agreement ranged from 57.5% (Kendall Tau-b = 0.44) to 85% (Kendall Tau-b = 0.66)
  • Poor interrater reliability. Agreement ranged from 50% (Kendall Tau-b = 0.20) to 42.5% (Kendall Tau-b = 0.16)
    • The authors concluded that the MAS was a reliable measurements for lower limb assessments made by a single rater, with highest agreement at the grade of 0. However, reliability between examiners was poor

 

Original Ashworth Scale:

 

Stroke:

(Kaya et al, 2011, n = 64, mean age = 60.5 (11.9) years; mean time since stroke = 15.7 (10.2) weeks, Stroke)

  • Excellent for both MAS and MMAS, with weighted kappa values of 0.868 and 0.892
  • MAS and MMAS have very good inter-rater reliability for assessment of poststroke elbow flexor spasticity
  • Neither scale is superior to grade spasticity in patients with hemiplegia for this particular muscle group

(Brashear et al, 2002, n = 10, mean age = 59.9 (16.17) years, Chronic Stroke)

  • Adequate intrarater reliability (across 10 raters)
Elbow
Wrist
Fingers
Thumb
Overall weighted K
0.668
0.740
0.740
0.680
p

0.998

0.972

1.000

0.985
  • Adequate to excellent interrater reliability (depending on joint) 

Mean of evaluations 1 and 2 (Kendall W)

 

 

 

 

Elbow

Wrist

Fingers

Thumb

0.765

0.598

0.792

0.611

 

(Li et al, 2014; chronic stroke (3.7 +/- 4.30 months post-stroke); n=51)

This study assessed intra- and inter-rater reliability for the MAS.

Reliability

 

Kappa

Standard error

T-value

P-values

Interpretation

Inter-rater

Elbow flexors

0.66

0.09

6.64

<0.001

Moderate agreement

Plantar flexors

0.48

0.09

5.73

<0.001

Weak agreement

Intra-rater

Elbow flexors

0.69

0.09

7.06

<0.001

Moderate agreement

Plantar flexors

0.48

0.10

5.42

<0.001

Weak agreement

Interpretation provided by McHugh 2012.

 

Construct Validity

Modified Ashworth Scale:

 

Stroke:

(Lin & Sabbahi, 1999, n = 10, mean age = 59 (4) years, Chronic Stroke)

  • Excellent convergent validity with:
    • Fugl-Meyer (r = -0.83 Day 1, -0.76 Day 2)
    • Box-Block Test (r=-0.83 Day 1, -0.76 Day 2)
    • Active Range of Motion (r=-0.74 Day 1, -0.62 Day 2)
    • Grip Strength (r=-0.86 Day 1, -0.85 Day 2)

(Lee et al, 2015; chronic stroke (15.21 +/- 3.32 months post-stroke); n=43)

  • This study assessed correlation between outcome measures using Pearson correlations coefficients. MAS was negatively correlated with Fugl-Meyer Upper Extremity (FM-UE; -0.72, p<0.05), FM-wrist/hand (-0.34, p<0.05), and Action Research Arm Test (ARAT; -0.41, p<0.05).

 

Content Validity

Theoretical basis of the Modified Ashworth Scale:

 

Stroke:

(Hong Min et al., 2012; n = 21; mean age = 58.0 (13.9) years; mean time post stroke = 32.2 (7.3) days, Stroke)

  • Adequate Spearman Correlation Coefficient between MAS and amplitude of biceps T-reflex (0.464 and 0.573 for two different raters)

Responsiveness

Stroke: (Chen et al., 2019; n = 115)

  • Markedly Responsive for upper extremity muscles (SRM = 0.99)

  • Markedly Responsive for lower extremity muscles (SRM = 0.82)

Spinal Injuries

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Cut-Off Scores

Spasticity: (Harb & Kishner, 2021)

0: No increase in muscle tone

1: Slight increase in muscle tone, with a catch and release or minimal resistance at the end of the range of motion when an affected part is moved in flexion or extension

1+: Slight increase in muscle tone, manifested as a catch, followed by minimal resistance through the remained (less than half) of the range)

2: A marked increase in muscle tone throughout most of the range of motion, but affected parts are still easily moved

3: Considerable increase in muscle tone, passive movement difficult 

4: Affect part(s) rigid in flexion or extension

Test/Retest Reliability

Spinal Cord Injuries: (Akpinar et al., 2017; n = 65, Age = 18-88 Years, Mean Age = 44(14) Years)  

  • Adequate test-retest reliability for hip abductors: (K = 0.580)
  • Excellent test-retest reliability for hip extensors: (K = 0.716)
  • Excellent test-retest reliability for knee flexors: (K = 0.636)
  • Excellent test-retest reliability for knee extensors: (K = 0.644)
  • Excellent  test-retest reliability for ankle plantar flexors: (K = 0.682)

 

 

SCI:

(Tederko et al, 2007, n = 30; 5 = unable to sit up, 14 = adapted to sitting position, 11 patients = adapted to standing position or able to walk; mean age = 33.9 (range = 17-65); mean time since injury 14.1 months, Chronic SCI)

  • Adequate reliability for individual muscle groups (ICC = 0.56), however the MAS may be a more appropriate measure of global muscle tone.
  • The reliability of muscle tone assessments were weaker among younger patients
  • Joint contractures decreased the reliability of the MAS

Interrater/Intrarater Reliability

Spinal Cord Injuries: (Akpinar et al., 2017)  

  • Adequate test-retest reliability for hip abductors: (K = 0.580)
  • Adequate test-retest reliability for hip extensors: (K = 0.574)
  • Excellent test-retest reliability for knee flexors: (K = 0.607)
  • Adequate test-retest reliability for knee extensors: (K = 0.531)
  • Excellent test-retest reliability for ankle plantar flexors: (K = 0.774)

SCI:

(Haas et al, 1996, n = 30, mean age = 40.3 years, mean time since injury = 17.23 months; Frankel Grade A = 18, B = 3, C = 2, D = 6, E = 1, Chronic SCI)

  • Poor to adequate interrater reliability depending on the muscle group (Kappa = 0.21 to 0.61)

(Craven et al, 2010, n = 20, C5-T10, AIS A-D > 12 months, Chronic SCI)

  • Inter-rater reliability was poor to adequate (Kappa < 0.6) for all muscle groups
  • Inter-session reliability for a single rater was adequate (0.4 < ICC < 0.75) for all muscle groups
  • MAS not reliable as an intrarater tool for all raters, and showed poor inter-rater and adequate inter-session reliability.
  • MAS has poor reliability for determining lower extremity spasticity between raters (interrater) or over time (intersession)

(Toderko et al, 2007; n = 30 (16 complete & 14 with incomplete); mean age = 33.9 (14.7) years; time since injury = 4-66; rated by 6 independent observers, Acute SCI)

  • Adequate interrater reliability (ICC = 0.56)

Construct Validity

Modified Ashworth Scale:

SCI:

(Smith et al, 2002; n = 22; 14 quadriplegia (3 incomplete), 8 paraplegia (1 incomplete); mean age = 33.4 (12.5) years, SCI)

  • Excellent: Correlation with the Wartenberg Pendulum Test & MAS (r = -0.69)

Responsiveness

Spinal Cord Injury: (Boviatsis et al., 2005; n = 7 (2 female, 5 male); average age = 38.1; average disease duration (years) = 2.71) 

  • Significant decrease in mean Ashworth score from 4.57 to 2.57 (p = 0.0134) at 9 months postoperatively following implantation of an intrathecal baclofen delivery system.

Brain Injury

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Test/Retest Reliability

Traumatic Brain Injury:

  • Adequate test-retest reliability for the Shoulder, elbow, wrist, hip, knee and ankle (kappa = 0.47-0.62) (Mehrholz et al, 2005)
  • Excellent test-retest for the ankle (r = 0.82; k = 0.422) (Allison et al, 1996)

Interrater/Intrarater Reliability

Modified Ashworth Scale:

TBI:

(Allison et al, 1996, n = 30, mean age = 28.3 (10.8) years; mean time since injury = 56 (48.4) months, Chronic TBI)

  • Adequate interrater reliability (r = 0.727) for plantar flexor spasticity

 

Original Ashworth Scale:

TBI:

(Ansari et al., n = 15; mean age of 57.3 (14.4) years. They had brain injury on average of 33.3 (26.2) months earlier, Chronic TBI)

  • Adequate: the weighted Kappa (kappaw) values were calculated for reliability. The kappaw was 0.61 (adequate) for elbow flexor and 0.78 (excellent) for wrist flexor. Results support the adequate to excellent interrater reliability of the MMAS for persons with upper limb spasticity

Criterion Validity (Predictive/Concurrent)

Traumatic Brain Injury:

(Allison & Abraham, 1995, n = 34, mean age = 30.3 years)

  • Adequate concurrent validity with:
    • Timed toe tapping (r = -0.042)
    • Reflex Threshold Angle (r = 0.49)
    • H-reflex during dorsiflexion (r = 0.47)
    • H-wave during vibration (r = 0.39)

Pediatric Disorders

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Test/Retest Reliability

Modified Ashworth Scale

Children with Cerebral Palsy:

(Mutlu et al, 2008; n = 38; mean age = 52.9 (19.6) months, Children with CP)

  • Poor to Excellent test-retest reliability (ICC = 0.36-0.83)

(Fosang at al, 2003; n = 18; mean age = 6.4 years, Children with CP)

  • Adequate to excellent test-retest reliability for hamstrings (ICC = 0.66-0.80)
  • Poor to adequate test-retest reliability for calf (ICC = 0.21-0.72)
  • Adequate to excellent test-retest reliabilty for hip adductors (ICC = 0.59-0.82)

Interrater/Intrarater Reliability

Original Ashworth Scale:

Children with Cerebral Palsy:

(Mutlu, 2008, Children with CP)

  • Excellent interrater reliability for measures hamstrings (ICC = 0.76, 0.73)
  • Excellent interrater reliability for measures of hip adductors (ICC = 0.83, 0.87)
  • Adequate to excellent interrater reliability for measure of hip internal rotators (ICC = 0.61, 0.84)
  • Adequate interrater reliability for measures of hip flexors (ICC = 0.71, 0.74)
  • Adequate interrater reliability for measures of gastrocnemius (ICC = 0.64, 0.68)
  • Poor to excellent intrarater reliability:
    • Lowest intrarater reliability found for hip internal rotators (ICC = 0.36)
    • Highest intrarater reliability found for hip flexors (ICC = 0.83)
  • Authors concluded that assessments of spasticity using the Modified Ashworth Scale are not very reliable for this population and should be used with caution

 (Fosang, 2003, Children with CP)

  • Hamstrings
    • Poor to adequate interrater reliability (ICC = 0.37-0.48)
    • Adequate to Excellent intrarater reliability (ICC = 0.66-0.80)
  • Calf
    • Poor to Adequate interrater reliability (ICC: 0.27-0.45)
    • Poor to Adequate intrarater reliability (ICC: 0.21-0.70)
  • Adductors
    • Adequate interrater reliability (ICC = 0.54-0.56)
    • Adequate intrarater reliability (ICC = 0.59-0.72)

(Yam, 2005; n = 17, mean age=7.9 years, Children with CP)

  • Poor to adequate interrater reliability for hip adductors, knee flexed (ICC = 0.41)
  • Adequate interrater reliability for hip adductors, knee extended (ICC = 0.73)
  • Adequate interrater reliability for ankle plantarflexors, knee extended (ICC = 0.56)
  • Adequate interrater reliability for ankle plantarflexors, knee flexed (ICC = 0.46)
  • The authors caution the use of this test in this population due to none of the measures possessing excellent interrater reliability (ICC > 0.75)

 

Pediatric Hypertonia:

(Clopton, 2005; n = 17, mean age = 7 years, Pediatric Hypertonia)

  • Excellent interrater relibility for elbow flexors and hamstrings (ICC > 0.75)
  • Poor to adequate interrater reliability for other muscles (ICC < 0.50)
    • Lower than clinically acceptable
  • Excellent intrarater reliability for hamstrings (ICC > 0.75)
  • Adequate intrarater reliability for other muscles (ICC 0.50-0.75)
    • Potentially lower than clinically acceptable

Criterion Validity (Predictive/Concurrent)

Modified Ashworth Scale:

 

Children with Cerebral Palsy:

(Alhusani, 2010; n = 27, mean age = 7 (1.9) years, Children with CP)

  • Percentage of Exact Agreement with lab measurement (stretch-induced electromyographic activity) in identifying spasticity
    • 81.5% non-significant fair agreement (K = 0.24)
    • P = 0.057 non-significant
  • Pearson Correlation with lab measurement to identify the severity of spasticity
    • R = 0.009 not a significant correlation
    • P = 0.7 not a significant correlation

Cerebral Palsy

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Test/Retest Reliability

Modified Ashworth Scale

Children with Cerebral Palsy:

(Mutlu et al, 2008; n = 38; mean age = 52.9 (19.6) months, Children with CP)

  • Poor to Excellent test-retest reliability (ICC = 0.36-0.83)

(Fosang at al, 2003; n = 18; mean age = 6.4 years, Children with CP)

  • Adequate to excellent test-retest reliability for hamstrings (ICC = 0.66-0.80)
  • Poor to adequate test-retest reliability for calf (ICC = 0.21-0.72)
  • Adequate to excellent test-retest reliabilty for hip adductors (ICC = 0.59-0.82)

Interrater/Intrarater Reliability

Modified Ashworth Scale:

Patients with severe cerebral damage:

(Mehrholz et al, 2005, patients with severe cerebral damage)

  • Poor to adequate Inter-rater reliability (kappa = 0.16 to 0.42)

 

Original Ashworth Scale:

 

Children with Cerebral Palsy:

(Mutlu, 2008, Children with CP)

  • Excellent interrater reliability for measures hamstrings (ICC = 0.76, 0.73)
  • Excellent interrater reliability for measures of hip adductors (ICC = 0.83, 0.87)
  • Adequate to excellent interrater reliability for measure of hip internal rotators (ICC = 0.61, 0.84)
  • Adequate interrater reliability for measures of hip flexors (ICC = 0.71, 0.74)
  • Adequate interrater reliability for measures of gastrocnemius (ICC = 0.64, 0.68)
  • Poor to excellent intrarater reliability:
    • Lowest intrarater reliability found for hip internal rotators (ICC = 0.36)
    • Highest intrarater reliability found for hip flexors (ICC = 0.83)
  • Authors concluded that assessments of spasticity using the Modified Ashworth Scale are not very reliable for this population and should be used with caution

 (Fosang, 2003, Children with CP)

  • Hamstrings
    • Poor to adequate interrater reliability (ICC = 0.37-0.48)
    • Adequate to Excellent intrarater reliability (ICC = 0.66-0.80)
  • Calf
    • Poor to Adequate interrater reliability (ICC: 0.27-0.45)
    • Poor to Adequate intrarater reliability (ICC: 0.21-0.70)
  • Adductors
    • Adequate interrater reliability (ICC = 0.54-0.56)
    • Adequate intrarater reliability (ICC = 0.59-0.72)

(Yam, 2005; n = 17, mean age=7.9 years, Children with CP)

  • Poor to adequate interrater reliability for hip adductors, knee flexed (ICC = 0.41)
  • Adequate interrater reliability for hip adductors, knee extended (ICC = 0.73)
  • Adequate interrater reliability for ankle plantarflexors, knee extended (ICC = 0.56)
  • Adequate interrater reliability for ankle plantarflexors, knee flexed (ICC = 0.46)
  • The authors caution the use of this test in this population due to none of the measures possessing excellent interrater reliability (ICC > 0.75)

Criterion Validity (Predictive/Concurrent)

Modified Ashworth Scale:

 

Children with Cerebral Palsy:

(Alhusani, 2010; n = 27, mean age = 7 (1.9) years, Children with CP)

  • Percentage of Exact Agreement with lab measurement (stretch-induced electromyographic activity) in identifying spasticity
    • 81.5% non-significant fair agreement (K = 0.24)
    • P = 0.057 non-significant
  • Pearson Correlation with lab measurement to identify the severity of spasticity
    • R = 0.009 not a significant correlation
    • P = 0.7 not a significant correlation

Limb Loss and Amputation

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Content Validity

Theoretical basis of the Modified Ashworth Scale:

 

Implicit Assumptions:

(Pandyan et al, 1999, Implicit Assumptions)

  • Changes in the resistance to passive movement are due to changes in spasticity
  • Stretch mechanoreceptors in the muscle would elongate with similar velocity during repeated measures
  • Range of movement on each joint during repeated measures is unaltered

These authors suggested:

  • Caution is required when stating that the Modified Ashworth Scale is a measure of spasticity
  • Evidence suggests that the resistance to passive movement is not an exclusive measure of spasticity
  • Resistance will vary according to the level of activity in the alpha motor neuron of agonist and antagonist muscles, the viscoelastic properties of soft tissues and joints.

Non-Specific Patient Population

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Interrater/Intrarater Reliability

Modified Ashworth Scale:

 

Patients with central nervous system lesions:

(Bohannon & Smith, 1987, n = 30, mean age = 59.3 (17.6) years, patients with centeral nervous system lesions)

  • Excellent interrater reliability between two experienced raters (Kendall's tau = 0.847, p < 0.001)

 

Patients with severe cerebral damage:

(Mehrholz et al, 2005, patients with severe cerebral damage)

  • Poor to adequate Inter-rater reliability (kappa = 0.16 to 0.42)

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