Spasticity Outcome Measures

This is a teaching hospital and students of all disciplines have clinical placements here. A rehabilitation therapy student having a placement on the SCI service wants to know how one actually measures spasticity.
Q16. List the most common outcome measures for spasticity used in clinical practice (how are each performed and what is the measurement scale).
The most common outcome measures used in clinical practice include:
1. Ashworth Scale (AS)
2. Penn Spasm Frequency Scale (PSFS)
3. Surface Electromyography (sEMG)
Ashworth Measure of Spasticity

A 5-point nominal scale using subjective clinical assessment 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 to enhance sensitivity and accommodate hemiplegic patients who typically graded at the lower end of the scale. Clinical examination is performed on a relaxed supine patient. The muscle is assessed by rating the resistance to passive range of motion about a single joint.

The Penn Spasm Frequency Scale (PSFS)

A self-report measure of the frequency or reported muscle spasms which is commonly used to quantify spasticity. The PSFS is a 2 component self-report scale developed to augment clinical ratings of spasticity and provide a more comprehensive understanding of an individual’s spasticity status. The first component is a 5 point scale assessing the frequency with which spasms occur ranging from “0 = No spasms” to “4 = Spontaneous spasms occurring more than ten times per hour”. The second component is a 3 point scale assessing the severity of spasms ranging from “1 = Mild” to “3 = Severe”. The second component is not answered if the person indicates they have no spasms in part 1. Patients report their perceptions of spasticity with regards to frequency and severity.

Surface Electromyography (sEMG)

A noninvasive technique used to measure muscle activity (both voluntary and involuntary) in individuals with neuromuscular diseases. Surface electrodes are placed on the skin overlying the muscles of interest. Patients are instructed to voluntarily activate lower limb muscles to provide either maximal muscle strength or to perform simple movements (e.g. ankle flexion/extension).

For more information, please see: Ashworth Measure of Spasticity, Penn Spasm Frequency Scale (PSFS), Surface Electromyography (sEMG).