Are attentional instruction and feedback type affect on learning of postural and supra-postural tasks?

Optimum postural control and balance is dependent on the individual, the environment, and the task limitations. Thus, the present study investigated the effect of attentional instruction and feedback type on postural and supra-postural tasks. The 96 participants aged 11-19 years with attention deficit hyperactivity disorder (ADHD) were randomly assigned to one of the eight groups such as attentional instruction (internal and external), feedback (external and internal), and task (postural and supra-postural). Following a pre-test, the participants underwent four training sessions. Each session included 20 trials of 30 s with 20 s of rest between trials. Twenty-four hours after the training session, they performed two trials of warm-up and then took part in a retention test. Twenty-four hours after the retention test, they again performed two trials of warm-up and then participated in the transfer test. The result showed that the external attentional feedback and external attentional instruction groups performed better on supra-postural and postural tasks than the other experimental groups (P > 0.05). The external attentional instruction group performed better on postural and supra-postural tasks in the delayed retention and transfer tests (P > 0.05). Also, the external feedback group scored highest on postural and supra-postural tasks in the delayed retention and transfer tests. The results suggest that external attentional feedback and instruction is more effective than internal attention when learning supra-postural tasks to maintain balance.

Visual Information and Support Surface for Postural Control in Visual Search Task

When standing on a reduced support surface, people increase their reliance on visual information to control posture. This assertion was tested in the current study. The effects of imposed motion and support surface on postural control during visual search were investigated. Twelve participants (aged 21 ± 1.8 years; six men and six women) stood on a reduced support surface (45% base of support). In a room that moved back and forth along the anteroposterior axis, participants performed visual search for a given letter in an article. Postural sway variability and head-room coupling were measured. The results of head-room coupling, but not postural sway, supported the assertion that people increase reliance on visual information when standing on a reduced support surface. Whether standing on a whole or reduced surface, people stabilized their posture to perform the visual search tasks. Compared to a fixed target, searching on a hand-held target showed greater head-room coupling when standing on a reduced surface.

The effect of actual and imaginary handgrip on postural stability during different balance conditions

The stabilizing effect of holding an object on upright posture has been demonstrated in a variety of settings. The mechanism of this effect is unknown but could be attributed to either additional sensorimotor activity triggered by a hand contact or cognitive efforts related to performance of a supra-postural task. A potential mechanism was investigated by comparing postural stability in young healthy individuals while gripping a custom instrumented wooden stick with a 5N force and while imagining holding the same stick in the hand. Twenty subjects were tested during three standing balance conditions: on a stationary surface, on a freely moving rockerboard, and with an unexpected perturbation of 10° forward rockerboard tipping. Postural stability was evaluated as velocity of the center of mass (COM) and center of pressure (COP) compared across all experimental conditions. COM and COP velocities were equally reduced when subjects gripped the stick and imagined gripping while standing stationary and on the rockerboard. When perturbed, subjects failed to show any postural stability improvements regardless of handgrip task. Results indicate a stabilizing effect of focusing attention on motor task performance. This cognitive strategy does not appear to contribute any additional stabilization when subjects are perturbed. This study adds to the current understanding of postural stabilization strategies.