The Modified Ashworth and Modified Tardieu Scales differ in their classification of lower limb spasticity

Abstract

Objective

To investigate agreement in spasticity classification between the Modified Ashworth Scale (MAS) and the Modified Tardieu Scale (MTS) when performed on four lower limb muscles in adults following neurological injury.

Design

Observational trial.

Setting

Inpatient and outpatient neurological rehabilitation unit.

Participants

Ninety adults with lower limb spasticity.

Main Measures

Ninety participants underwent a spasticity assessment of their hamstrings at 40° and 90° of hip flexion, quadriceps, gastrocnemius and soleus using the MAS and MTS. Assessment findings were dichotomised into spastic (MAS ≥ 1 or MTS X ≥ 2) or not spastic (MAS = 0 or MTS X ≤ 1) categories. To evaluate agreement, 2 × 2 contingency tables were generated to calculate positive, negative and overall agreement. Statistical association was calculated using the Fisher's Exact Test.

Results

The MAS classified the presence of spasticity more frequently than the MTS. The proportion of trials with agreement in spasticity classifications according to both scales and their Fishers exact test were hamstrings at 90° hip flexion (17.6%; p = 0.009); hamstrings at 40° hip flexion (75.0%; p = 0.166); quadriceps (67.1%; p = 0.020); gastrocnemius (77.9%; p = 0.586); and soleus (67.8%; p = 0.113).

Conclusion

The MAS and MTS demonstrated a level of disparity in their classification of lower limb spasticity across all four muscles, particularly the more proximal muscle groups.