Ni daq card

The resting elbow joint of stroke subjects was passively stretched, using a computerized stretching program^{15 (link),16 (link)}. In the aforementioned experimental configuration, the axis of rotation of the elbow joint was aligned with the axis of rotation of a servomotor (model: FHA-25C-50-US250, Harmonic Drive LLC, MA, USA). The initial position was selected at which the subject rested naturally, i.e., resting angle ^{18 (link)}. A total amount of 50° elbow extension was applied to the elbow joint at a constant speed (5°/s or 100°/s). When the elbow passively moved to the end position, it was remained at the end position for 2 seconds. The elbow joint moved back to the initial position at the same speed. Three trials were collected for each stretch speed. The order of speeds was randomized.
Both force and EMG signals were collected using an NI-DAQ card (Model: PCI-6229, National Instruments, TX, USA). Elbow flexion torque and resistance torque were measured with a torque sensor (Model: TRS-500, Transducer Techniques, CA, USA). The sensor was located in line with the center of the rotation of the active elbow joint. The force and EMG signals were sampled at 1000 Hz. All the collected data were stored on a personal computer.

We quantified the anterior-posterior and medial-lateral COP from the force plate signals during the maximal and forward leaning task. We sampled anterior-posterior and medial-lateral COP at 1,000 Hz with a NI-DAQ card (model USB6218, National Instruments, Austin, TX, USA) and stored on a personal computer.