No abstract

Upright standing and walking tasks require the integration of several sources of sensory information. In a normal and highly predictable environment, locomotor synergies involving several muscles may take place at lower spinal levels with neural circuitry tuned by local loops of assistance or self-organizing processes generated in coordinative networks. When ongoing regulation of gait is necessary (obstacles, changes in direction) supraspinal involvement is necessary to perform movements adapted to the environment. Using a classical information processing framework and a dual-task methodology, it is possible to evaluate the attentional demands for performing static and dynamic equilibrium tasks. The present experiment evaluates whether the attentional requirements for a control sitting condition and for standing and walking conditions vary with the intrinsic balance demands of the tasks. The results show that standing and walking conditions required more attention than sitting in a chair. The attentional cost for walking was also significantly greater than for standing. For the walking task, reaction times when subjects were in single-support phase (small base of support) were significantly longer than those in double-support phase, suggesting that the attentional demands increased with an increase in the balance requirements of the task. Balance control requires a continuous regulation and integration of sensory inputs; increasing balance demands loads the higher level cognitive system.

Virtual reality (VR) training has been used successfully to rehabilitate functional balance and mobility in both traumatic brain injury (TBI) survivors and elderly subjects. Similarly, computer-based biofeedback (BF) training has resulted in decreased sway during quiet stance and decreased reaction times during a dual-task reaction time paradigm in elderly subjects. The objective of this study was to determine the effect of VR and BF training on balance and reaction time in older adults. Two groups of twelve healthy older adults completed 10-week training programs consisting of two 30-min sessions per week. VR training required that participants lean sideways to juggle a virtual ball. Participants in the BF group viewed a red dot representing their center of gravity on a screen and were required to move the dot to the four corners of the monitor. Measures of functional balance and mobility (Community Balance and Mobility Scale [CB&M]), sway during quiet stance, and reaction time during a dual task paradigm were recorded before training, as well as 1 week and 1 month after the end of the program. Both groups showed significant improvements on the CB&M, as well as decreased reaction times with training. Postural sway during quiet stance did not change significantly.

This study evaluates attentional requirements for maintaining an upright posture and for walking among young and elderly persons to determine if, with normal aging, there is a deficit and/or a modification in the allocation of the attentional resources necessary for balance control. Eight young adults and 8 elderly persons were asked to respond to an auditory reaction time (RT) task (secondary task) while in a seated position, while in a broad-support or narrow-support upright standing position, and while walking (primary tasks). Reducing the base of support yielded slower RTs for the elderly than for the young persons. When walking, the elderly persons adopted a slower speed than young persons. They also had a shorter stride length. These adaptations have been reported to produce a more secure gait. Even so, they responded to the probe RT task with greater delays than young adults. Together, the results suggest that normal aging requires that a greater proportion of attentional resources be allocated to the balance demands of postural tasks.

No abstract

Postural training in combination with a feedback fading protocol seems to improve the automaticity of posture significantly.

Study design: A group of people with incomplete spinal cord injuries (SCI) were evaluated and compared with able-bodied individuals during several walking conditions. Objectives: To evaluate the functional community ambulation and estimated energy expenditure in persons with incomplete SCI and able-bodied individuals. Methods: A list of criteria was used to evaluate functional community ambulation among participants. Physiological variables, such as the heart rate, oxygen uptake and the lactate concentration, were also measured. Results: Three of nine incomplete SCI subjects and all able-bodied subjects were able to meet all the criteria measured. The required velocity to safely cross an intersection was the criterion that the incomplete SCI group had the most di culty reaching. The able-bodied subjects had a comfortable walking velocity twice that of the incomplete SCI subjects' preferred velocity. When walking at the same velocity (incomplete SCI subjects' preferred velocity), the incomplete SCI subjects had a rate of oxygen uptake 26% greater than the healthy subjects and were 200% less e cient. The lactate concentration also proved to be a useful tool when evaluating the incomplete SCI subjects' walking e ciency. The incomplete SCI subjects lactate concentration increased after walking at their preferred velocity, meaning that the anaerobic pathways were used to meet energy demands. Conclusion: Rehabilitation centers should adapt their evaluation forms and increase their criteria requirements to more suitable criteria that are found in the SCI patient's community. The physiological cost should also be taken into consideration when evaluating the SCI patient's functional ambulation.

Gamesbased balance biofeedback training using a range of training postures can significantly improve functional balance in exercise trained older adults by reducing the attentional demands of postural control.