The purpose of this study was to investigate the short-term effects of lumbar rotational mobilization under the single-leg standing (SLS) position. Fifteen healthy individuals were recruited, and randomized to agroup of trunk rotational exercise (TRE) and lumbar rotational mobilization (LRM). Trunk twist rotational exercise was performed to the TRE group, and mobilization was applied to the LRM group on the lumbar spine. Velocity of the center of pressure (VCOP) and center of pressure (COP) for each participant were measured through SLS. COPs were not significantly increased or decreased after treatment in both groups. VCOPs also did not change considerably except on the right side when the eye was closed. There was no significant difference between COPs and VCOPs in two groups. This study suggests that trunk rotation exercise and lumbar rotation mobilization would have similar effects on balance ability.

The aim of this study was to investigate the effects of lumbar stabilization on both trunk and lower limb muscle activity and center of pressure (COP) in single leg standing. Surface electromyography (EMG) was used to collect muscle activity data, the mean velocity of COP was measured using a force plate, and a pressure biofeedback unit was used for lumbar stabilization training. The findings of this study are summarized as follows: 1) The EMG activity of the erector spinae decreased significantly and the activity of the rectus abdominis, internal oblique, external oblique, gluteus maximus, and gluteus medius increased significantly with lumbar stabilization single leg standing. 2) No differences in activity in the tibialis anterior, medial gastrocnemius, rectus femoris, and medial hamstrings were found with single leg standing. 3) The mean velocity of COP in the antero-posterior and medio-lateral directions in the lumbar stabilization single leg standing decreased significantly compared with the preferred single leg standing. The findings of this study therefore indicate that lumbar stabilization can facilitate the co-activation of deep stabilization and global muscles that improve postural control capability during single leg standing.