Effects of visual feedback training using transient Fresnel prism glasses on balance ability in stroke patients without hemispatial neglect

The center of mass of the body in patients with stroke was oriented toward the nonparetic side. Abnormal weight shift increases the risk of falls. Therefore, many therapists make an effort to help their functional recovery through balance training. Our aim was to investigate the effect of visual feedback intervention using a Fresnel prism on static and dynamic balance in stroke patients without hemispatial neglect. Participants were assigned to control group (n= 10) and experimental group (n=9). In the control group, neurodevelopmental therapy was performance for 30 min. In the experimental group, Fresnel prism glasses were applied with neurodevelopmental therapy for 30 min. We executed motor-free visual perception test for visual perception, balancia for static balance ability, and functional reach test and Berg balance test for dynamic balance ability, respectively. All tests were measured immediately after intervention. The visual perception function showed significant difference between unaffected side performance behaviors and visual perceptual processing time (P<0.05). In the static balance, there was a significant difference in sway velocity and sway distances (P<0.05). Dynamic balance was also significant different between groups (P<0.05). Visual feedback using Fresnel prism helps to control the static and dynamic balance ability by inducing weight shift toward the affected side in stroke patients. Therefore, a Fresnel prism may be suggested as an intervention tool to assist weight training for patients with stroke.