Tonic Stretch Reflex Threshold as a Measure of Ankle Plantar-Flexor Spasticity After Stroke

Andreanne K. Blanchette; Aditi A. Mullick; Karina Moïn-Darbari; Mindy F. Levin

doi:10.2522/ptj.20140243

Figures

Figure 3.

Interevaluator agreement for tonic stretch reflex threshold (TSRT) estimations. The scatterplot illustrates TSRTs obtained in evaluation 1 (EVAL 1) and evaluation 2 (EVAL 2) for each participant. Each point represents one participant. Points falling on the dashed gray line would indicate perfect agreement between evaluators. The solid black line represents the best fit for all data. R²=coefficient of determination.

Figure 1.

Examples of dynamic stretch reflex threshold (DSRT) identification in spastic ankle plantar-flexor muscles at 3 different velocities (slow, moderate, and fast) for participant 16. For each velocity of stretch, ankle angular position (top), velocity (middle), and rectified plantar-flexor electromyographic (EMG) activity (bottom) are shown. Vertical dashed lines indicate DSRTs (combinations of threshold position and velocity) for each trial. DF=dorsiflexion.

Figure 2.

Examples of tonic stretch reflex threshold (TSRT) estimations in 2 representative participants (participant 5 [left panel] and participant 27 [right panel]). Dynamic stretch reflex thresholds (DSRTs) in plantar-flexor muscles at different velocities in evaluation 1 (EVAL 1) (gray diamonds) and evaluation 2 (EVAL 2) (black diamonds) are shown. Regression line equations, coefficients of determination (R²), inverse of the slope of the velocity/angle curve (μ), and TSRTs are shown.