Fig. 3

Illustration of each of the measurement protocols, includes a sketch of the participant's measurement assessment in the SEP, example recorded data of a stroke patient, and the processed data of the same stroke patient in comparison with the range of values of the healthy controls. A Muscle strength measurement, showing maximal isometric contraction in 90° elbow flexion for extension and flexion direction. Recorded data: Maximum torque (red diamond) during one torque profile of a stroke patient. We performed three repetitions, and maximum torque values were averaged. Processed Data: The flexion and extension torque of the stroke patient (red diamond) presented against the 10–90th percentile (blue area) of healthy controls. B Synergy, measured during an active extension movement of the elbow, repeated for five different arm weight support levels (100, 75, 50, 25, 0%). Recorded Data: Five position trajectories of the elbow extension with different arm weight support levels over time. The maximal extension angle (red diamond) of each trajectory was calculated, the elbow extension angle at 100% weight support was subtracted from each extension angle at 0, 25, 50, 75% arm weight support. Then, a regression line was fitted through these end positions and the slope of this regression line was used as an outcome parameter for synergy. Processed Data: The regression slope (red line) over de arm support levels for the stroke patients shown against in blue the 10-90th percentile of healthy controls. C Elasticity, measured during a slow (6°/s) passive movement from flexion to extension and back. Recorded data: A regression line fitted through the torque–angle trajectory of a stroke patient. We performed three repetitions, and the slope of the regression lines was averaged as outcome parameter. Processed Data: The regression line of the stroke patient (red line) shown against the 10-90th percentile of healthy controls (blue area). (D) Spasticity, measured during a fast (100°/s) passive movement trajectory from flexion to extension. Recorded data: The maximum resistance (red diamond) was calculated during the movement trajectory (orange line). We performed three repetitions, and the maximum torques were averaged as outcome parameter. Processed Data: The averaged maximum torque of the stroke patient was presented against 10-90th percentile of healthy controls (blue area)