This study investigates the effectiveness of visual feedback in reducing trunk compensation during one-arm reaching exercises using an end-effector robot. Results suggest that visual feedback is more effective than verbal feedback in suppressing trunk compensation, as evidenced by lower trunk movements. Synchronized target position with respect to trunk motion exhibited a suppressive effect on trunk motion, as observed by a reduction in trunk standard deviation, trunk root mean square, and trunk difference between the starting and ending positions. These findings have important implications for developing feedback techniques to address unnatural upper limb reach movements in stroke survivors during rehabilitation programs. However, the study's limitations, such as small sample size, should be considered. Future research should explore feedback techniques in different patient populations and exercise types and evaluate their long-term effects.