Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Viewing medium affects arm motor performance in 3D virtual environments | Subramanian and Levin Journal of NeuroEngineering and Rehabilitation 2011 8 36 http content 8 1 36 Iril JOURNAL OF NEUROENGINEERING NCR AND REHABILITATION RESEARCH Open Access Viewing medium affects arm motor performance in 3D virtual environments Sandeep K Subramanian1 2 and Mindy F Levin1 2 Abstract Background 2D and 3D virtual reality platforms are used for designing individualized training environments for post-stroke rehabilitation. Virtual environments VEs are viewed using media like head mounted displays HMDs and large screen projection systems SPS which can influence the quality of perception of the environment. We estimated if there were differences in arm pointing kinematics when subjects with and without stroke viewed a 3D VE through two different media HMD and SPS. Methods Two groups of subjects participated healthy control n 10 aged yrs stroke n 20 yrs . Arm motor impairment and spasticity were assessed in the stroke group which was divided into mild n 10 and moderate-to-severe n 10 sub-groups based on Fugl-Meyer Scores. Subjects pointed 8 times each to 6 randomly presented targets located at two heights in the ipsilateral middle and contralateral arm workspaces. Movements were repeated in the same VE viewed using HMD Kaiser XL50 and SPS. Movement kinematics were recorded using an Optotrak system Certus 6 markers 100 Hz . Upper limb motor performance precision velocity trajectory straightness and movement pattern elbow shoulder ranges and trunk displacement outcomes were analyzed using repeated measures ANOVAs. Results For all groups there were no differences in endpoint trajectory straightness shoulder flexion and shoulder horizontal adduction ranges and sagittal trunk displacement between the two media. All subjects however made larger errors in the vertical direction using HMD compared to SPS. Healthy subjects also made larger errors in the sagittal direction slower movements overall and used less range of