Background: It is known that hand strength and fingertip force are used as an indicator of muscle strength and are also highly related to the various chronic symptoms and even lifespan. To use the individual fingertip force (IFF) as a quantitative index for clinical evaluation, the IFF should be measured and analyzed with various variables from various subjects, such as the normal range of fingertip force and the difference in its distribution by disease. Objects: We tried to measure and analyze the mean maximum IFF distribution during grasping a cylindrical object in healthy adults and patients with spinal cord injury (SCI). Methods: Five Force-sensitive resistor (FSR) sensors were attached to the fingertips of 24 healthy people and 13 patients with SCI. They were asked to grip the object three times for five seconds with their maximum effort. Results: The mean maximum IFF of the healthy adult group’s thumb, index, and middle finger was similar statistically and showed relatively larger than IFF of the ring and small finger. It is a 3-point pinch grip pattern. All fingertip forces of patients with SCI decreased by more than 50% to the healthy group, and their IFF of the middle finger was relatively the largest among the five fingertip forces. The cervical level injured SCI patients showed significantly decreased IFFs compared to thoracic level injured SCI patients. Conclusion: We expect that this study results would be helpful for rehabilitation diagnosis and therapy goal decision with robust further study.

Background: The Microsoft Kinect which is a low-cost gaming device has been studied as a promise clinical gait analysis tool having satisfactory reliability and validity. However, its accuracy is only guaranteed when it is properly positioned in front of a subject. Objects: The purpose of this study was to identify the error when the Kinect was positioned at a 45˚ angle to the longitudinal walking plane compare with those when the Kinect was positioned in front of a subject. Methods: Sixteen healthy adults performed two testing sessions consisting of walking toward and 45˚ obliquely the Kinect. Spatiotemporal outcome measures related to stride length, stride time, step length, step time and walking speed were examined. To assess the error between Kinect and 3D motion analysis systems, mean absolute errors (MAE) were determined and compared. Conclusion: Based on our study experience, positioning the Kinect directly in front of the person walking towards it provides the optimal spatiotemporal data. Therefore, we concluded that the Kinect should be placed carefully and adequately in clinical settings.

Background: At present time, smartphones have become very popular and powerful devices, and smartphone applications with the good validity have been designed to assess human balance ability. Objects: The purpose of this study is to evaluate the feasibility of smartphone acceleration in the assessment of postural control ability for six different conditions. Methods: Twenty healthy college-aged individuals volunteered. Static balance ability was measured twice with one-day interval using smartphone application and 3D motion capture system under the six different conditions. Results: Dominant frequencies for each test condition did not show significant differences except for two conditions. The intra-rater correlation coefficient between the first and second tests showed high correlations in six conditions(r>.70, p<.05). Smartphone acceleration and the acceleration calculated from the 3D marker position data showed high correlation coefficient(r>.80, p<.001). Conclusion: Acceleration recorded from a smartphone could be useful assessment variables for balance test in the clinical field.

Background: There are insufficient objective or quantitative evidence for the better intervention to improve proprioception particularly for the application of external load. There are conflicting opinions whether the external load is effective for proprioception improvement or not. Objects: The purpose of this study was to investigate effects of external load on proprioception of shoulder joint quantitatively using 3D motion capture system. Methods: Nine healthy adults joined for this study. They were asked to perform scapular plane abduction motion with attaching reflective markers on the trunk and upper limb. The 3D positions of finger marker, while they performed the same task with and without external load, were recorded and analyzed. Results: All participants showed decreased variable errors in the vertical direction when the external load was applied (p<.02). Even though other directions (y, z) and absolute errors increased, they did not have statistical significances. Conclusion: Based on this study results, the external load application would be effective for shoulder joint position sense improvement.