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.

The purpose of this research is to find the effect of motor learning if quantitative knowledge of results and qualitative knowledge of results are presented according to task natures. As the experimental method, I execute a kind of linear positioning task adopting 36 college students as objects of this study. After measuring movement time and distant error using a touch pad adhered a circuit and a programmed personal computer system, I calculate the mean of distant error and standard deviation. I come to get these results as followings to perform factorial ANOVA with repeated measures providing a basis for this computation. The task natures and forms of knowledge of results have not influences on the effect of motor learning. The performance effect according to task natures makes a meaningful difference, that is students show high accuracy of motion when they have enough time to perform the task voluntarily than under the condition that they have to do the task as soon as possible.