Two-way repeated measures analysis of variance for comparisons between the direction of shoulder arm movement and the center of foot pressure (CFP) position while standing in each muscle.

<p>DM, Deep fibers of lumbar multifidus; SM, Superficial fibers of lumbar multifidus; RA, Rectus abdominis</p><p>Two-way repeated measures analysis of variance for comparisons between the direction of shoulder arm movement and the center of foot pressure (CFP) position while standing in each muscle.</p

The center of foot pressure position in the anteroposterior direction (% foot length [%FL]) during quiet standing (QS), extreme forward leaning (EFL), and extreme backward leaning (EBL).

<p>Data are shown as mean ± SEM.</p><p>*The %FL of QS, EFL, and EBL were significantly different (all comparisons, <i>P</i> < 0.01)</p><p>The center of foot pressure position in the anteroposterior direction (% foot length [%FL]) during quiet standing (QS), extreme forward leaning (EFL), and extreme backward leaning (EBL).</p

Mean+SEM (ms) EMG onset of each trunk muscle relative to that of the deltoid.

<p>Data during flexion (open squares) and extension (close squares) are shown. The dashed vertical line represents the APA phase or CPA phase. APA, Anticipatory postural adjustments; CPA, Compensatory postural adjustments; DM, Deep fibers of the lumbar multifidus; SM, Superficial fibers of the lumbar multifidus; RA, Rectus abdominis; Flex, Arm flexion; Ext, Arm extension; QS, Quiet standing; EFL, Extreme forward leaning; EBL, Extreme backward leaning; EMG, Electromyography.</p

Raw electromyographic data for shoulder movements in three standing positions (QS, EFL, and EBL).

<p>The left panels show data for shoulder flexion, and right panels show data for shoulder extension. Panels show electromyographic data for anterior or posterior deltoid as focal muscle, deep (DM) and superficial (SM) fibers of lumbar multifidus and rectus abdominis (RA). The dashed vertical lines represent the EMG onset of deltoid, and the arrows represent the EMG onset of each muscle.</p