Qualitative and quantitative measurement of plantarflexor muscle spasticity in patients with traumatic brain injury: Reliability, prediction and sensitivity to cryotherapy

hree studies were conducted to evaluate the characteristics of potential quantitative measures of plantarflexor muscle spasticity in adult patients with traumatic brain injury. The first study assessed reliability of the Modified Ashworth Scale (MAS), the validity criterion variable with which the quantitative measures would be compared. Two physical therapists used the MAS independently to score thirty subjects assembled into three groups. Repeated measurements yielded multiple scores for intrarater reliability assessment. Twenty-one of the subjects returned for additional measurements to assess temporal reliability. Spearman's correlation coefficients were 0.73 for interrater reliability, 0.74 and 0.55 for intrarater reliability, and 0.82 for temporal reliability. The second study explored relationships among the MAS, three potential quantitative spasticity measures and a measure of ankle muscle function. Of the 34 subjects measured, 26 were tested for both ankles, resulting in 60 ankles for the analyses. Tests were: MAS scoring; H-reflexes with and without dorsiflexor contraction (Hdf/Hctrl ratio); H-reflexes with and without Achilles tendon vibration (Hvib/Hctrl ratio); reflex threshold angle (RTA) and timed toe tapping (TTT). Spearman's coefficients for correlation of quantitative spasticity measures with MAS scores ranged from 0.39 to 0.49 with associated probabilities...