Jaebum Son

Unsupervised Virtual Reality-Based Exercise Program Improves Hip Muscle Strength and Balance Control in Older Adults: A Pilot Study

OBJECTIVE To assess the effects of an unsupervised virtual reality (VR)-based exercise program on hip muscle strength and balance control in older adults. DESIGN Controlled cohort repeated-measures experimental design, a pilot study. SETTING University research laboratory. PARTICIPANTS Ambulatory older adults (N=32) from a local community. INTERVENTION The VR group (n=18; mean ± SD, 68.28±3.74y; 4 men) completed the VR-based exercise program, whereas the remaining subjects in the control group (n=14; mean ± SD, 66.21±3.87y, 1 man) were asked to continue their daily routine for 8 weeks. MAIN OUTCOME MEASURES Hip muscle strength was measured using a multimodal dynamometer, and ground reaction force using the backward stepping test and the results of the crossover stepping test were recorded using a force platform. RESULTS The VR group showed significant improvement in hip muscle strength of the extensors, flexors, adductors, and abductors after 8 weeks (all P≤.001). However, no significant improvement was observed in the control group. The VR group had significantly greater ground reaction force on the backward stepping test (with eyes opened and closed) (all P<.005) and the crossover stepping test (with eyes opened and closed) (all P≤.001) compared with those at baseline. However, no significant improvement was observed in the control group. CONCLUSIONS The VR-based exercise program includes the role of supervisor and feedback, which is important for older adults. Therefore, a VR-based exercise program may be a useful tool to improve decreased physical function in older adults as a home-based exercise.

A neuromuscular strategy to prevent spinal torsion: Backward perturbation alters asymmetry of transversus abdominis muscle thickness into symmetry

Symmetric co-contraction of the transversus abdominis (TrA) muscle is beneficial in terms of increasing trunk stability. The aim of this study was to investigate the symmetry of lateral abdominal muscle thickness during static and dynamic conditions. Fifteen male subjects (27.13 ± 5.51 years old) were instructed to sit on a chair and maintain upright posture. Every individual subject wore a jacket harness that could be backwardly attached to a 9-kg weight through a pulley system. An unexpected drop of the weight induced the transition from static to dynamic condition. The thickness of external oblique, internal oblique, and TrA muscles was measured with ultrasonography. Our results revealed more symmetry of TrA thickness during the dynamic condition (21% vs. 13%, p = 0.019) compared with the static. The symmetric muscle thickness of TrA during the dynamic condition is considered a result of more contraction on the non-dominant side. This phenomenon could be a possible strategy of deep abdominal muscles to prevent spinal torsion during sudden trunk perturbation.

Individualized feedback-based virtual reality exercise improves older women's self-perceived health: A randomized controlled trial

OBJECTIVES Individualized feedback-based virtual reality (IFVR) exercise is gaining attention as a cost-effective self-management strategy, however little is known about whether older adults themselves perceive IFVR exercise effective in improving their health. Therefore, we studied the effect of IFVR exercise on health-related quality of life (HRQoL) in older women. METHODS Fifty-four older women aged ≥65 years were randomized to either IFVR exercise group (IFVRG, n=26) or group-based exercise group (GG, n=28). Both groups received a 60-min intervention three times a week for eight weeks. The Short-Form Health Survey (SF-36) was administered. To identify the possible placebo effect, 30-Second Chair Stand Test (30SCST), 8-Foot Up-and-Go Test (8FUGT), and 2-Minute Step Test (2MST) were also administered. RESULTS intention-to-treat analysis with adjustment for baseline levels revealed that IFVRG showed greater improvement in mental health (p=0.029) and lower body strength (p=0.042), compared to GG. Within-group analysis for HRQoL revealed that IFVRG showed an increase in role-physical (p=0.015), bodily pain (p=0.017), general health (p=0.004), vitality (p=0.010), role-emotional (p=0.007), and mental health (p<0.001), whereas GG showed an increase in role-physical (p=0.022), general health (p=0.023), and social functioning (p = 0.023). Both groups showed an increase in 30SCST, 2MST and 8FUGT (all p<0.001). CONCLUSION IFVR exercise improved HRQoL in older women, in addition to improving physical fitness. Therefore, it might be recommended to older women as an effective self-management strategy.