Dataset of symmetry of bilateral lower limb kinematic and kinetic variables during sit-stand and stand-sit tasks in hemiplegia stroke patients

MOtoNMS was used to generate OpenSim compatible files from the C3D files collected by the 3DMC system. Joint angles and torques during sit-stand and stand-sit movements were calculated using the inverse kinematics (IK) and inverse dynamics (ID) tools of Opensim software, respectively.The data of joint angle, joint moment, ground reaction force and center of pressure were processed using a written matlab program. The joint angle was filtered using a zero-lag fourth-order low-pass Butterworth filter with a cutoff frequency of 6 Hz. The GRF and center of pressure (COP) data were low-pass filter with a zero-lag fourth-order Butterworth filter with a cut-off frequency of 20 Hz. The ground reaction forces GRFs and joint moments were normalized to body weight, and the COP data were normalized to the “foot length”, which is defined as the distance from the heel to the first metatarsal. All data were then time-normalized to 100% motion cycle. The symmetry of the bilateral lower limbs was assessed using the symmetry index (SI). The 10% of the SI was set as asymmetry threshold. Bilateral motor variables were reclassified "greater values" and "lesser values". SI = 100%*(1-lesser values/greater values).For the description of the data, IK files included the SI of hip-knee-ankle angle at different phases (initial, peak and final phases) during the sit-stand and stand-sit movements, as well as the average SI and range of motion (ROM) SI of hip-knee-ankle joint angles for sit-stand and stand-sit movements. ID files included the SI of hip-knee-ankle moment at different phases (initial, peak and final phases) during the sit-stand and stand-sit movements, as well as the average SI of hip-knee-ankle joint moment for sit-stand and stand-sit movements. GRF_COP files included the SI of vertical GRF (VGRF), anterior-posterior COP (AP-COP) and medial-lateral COP (ML-COP) at different phases (initial, peak and final phases) during the sit-stand and stand-sit movements, as well as the average SI of VGRF, AP-COP and ML-COP for sit-stand and stand-sit movements.