This study was conducted to identify how a flexi-bar exercise influences body alignment and balance in adults who have asymmetry in their right or left body. In total, 20 participants were separated into the experimental group and the comparison group. Those in the experimental group participated in a flexi-bar exercise for 6 weeks and based on the coronal plane before and after exercise, their body alignment and balance were measured behind the body. The result was those who had participated in a flexi-bar exercise significantly improved their angle of acromion on both sides, the difference in the angle and height of the posterior superior iliac spine on both sides(p<.05), and the balance of the center sagittal plane(p<.05). Through this study, it could be said that participating in a flexi-bar exercise would improve postural alignment and balance of the shoulder and pelvis in adults with asymmetric posture.

In this study, an asymmetric lifting posture prediction model was developed, which was a three-dimensional model with 12 links and 23 degrees of freedom open kinematic chains. Although previous researchers have proposed biomechanical, psychophysical, or physiological measures as cost functions, for solving redundancy, they lack in accuracy in predicting actual lifting postures and most of them are confined to the two-dimensional model. To develop an asymmetric lifting posture prediction model, we used the resolved motion method for accurately simulating the lifting motion in a reasonable time. Furthermore, in solving the redundant problem of the human posture prediction, a moment weighted Joint Range Availability (JRA) was used as a cost function in order to consider dynamic lifting. However, it is known that the moment weighted JRA as a cost function predicted the lower extremity and L5/S1 joint motions better than the upper extremities, while the constant weighted JRA as a cost function predicted the latter better than the former. To compensate for this, we proposed a hybrid moment weighted JRA as a new cost function with moment weighted for only the lower extremity. In order to validate the proposed cost function, the predicted and real lifting postures for various lifting conditions were compared by using the root mean square(RMS) error. This hybrid JRA reduced RMS more than the previous cost functions. Therefore, it is concluded that the cost function of a hybrid moment weighted JRA can be used to predict three-dimensional lifting postures. To compare with the predicted trajectories and the real lifting movements, graphical validations were performed. The results also showed that the hybrid moment weighted cost function model was found to have generated the postures more similar to the real movements.