Hi Marcelo

have a look at the publication of Salavati, M. and  Mazaheri, M. in LBP patients in 2009 and 2010 and also on the work by G. Wulf, Attention and Motor skill learning.

As far as I know, the more you concentrate on your posture, the worse you perform, distraction by a cognitive task might lead to better postural control, as you let the "automatic" control system work

Good luck

Markus

This could help you...

Effect of chewing on postural stability during quiet standing in healthy young males.

Somatosens Mot Res. 2015;32(2):72-6

http://www.ncbi.nlm.nih.gov/pubmed/25356855

 All the best!

Marcelo,

My project for my Masters dealt with peroneus longus reflex response to sudden ankle inversion under 2 overlapping conditions of cognitive information, anticipation and cognitive loading. We are still waiting for the manuscript to be accepted, but if you send me a message, I would be happy to show you some of the data. I know this is a static task, and not really a dynamic or unstable surface in terms of maintaining stance balance, but hopefully my results can inform you.

I identified a trend suggesting that the later components of the stretch reflex, believed to have more cortical control, were more affected when a more difficult cognitive task was added. While not a strong trend, this may suggest that at minimum our protective strategies for balance recovery stay intact under a cognitive load, but your proposed study will hopefully add to this growing field. 

Additionally, this may help you, J Orthop Sports Phys Ther. 2010 Mar;40(3):180-7 - not healthy participants, but they utilized a biodex stability platform and manipulated surface stability.

http://www.ncbi.nlm.nih.gov/pubmed/20195021

Regards,

Hi Christopher,

Firstly, Thanks for your reply. I would like to receive this data material. I'm sure that your material will be enriching. Currently, I'm running a study or project which deal with the cognitive coasts applied to coordination posture and movement, during a precision task of lower limbs. In this project, we producted two interesting papers, both have been submitted.

Sincerely yours.

Dear Marcelo,

Usually young adults will prayoritize motor performance over cognitive performance unlike older adults. meaning your subjects might be concintrating on the motor task of staying stable and make misstakes in the cognitive dual task you give them.

Therefore I would recomend you to monitor cognitive task errors and when you give the instuctons ask the subjects to try and do their best on the cognitive task.

Good luck,

Uri  

Unstable surface training is one of the most commonly used protocols. Proprioception on an unstable surface leads to an efficient weighting capacity of sensory signals that down-weights the proprioceptive signals from the ankle and up-weights the proprioceptive signals from more proximal segments of the paraspinals thus not targeting ankle proprioception and in the process reinforcing the temporary neuroplastic changes that lead to chronic instability.................. "Results show that on foam, the effect of triceps surae vibration on mean CoP velocity was significantly smaller than on a solid surface, while for paraspinal musculature vibration the effect was bigger on foam than on solid surface. Similar effects were seen for mean CoP displacement as outcome. Exercises on unstable surfaces appear not to target peripheral ankle proprioception. Exercises on an unstable surface may challenge the capacity of the central nervous system to shift the weighting of sources of proprioceptive signals on balance"

http://www.ncbi.nlm.nih.gov/pubmed/21858665

"Ten healthy subjects were instructed to stand as still as possible on a force plate during 40 secs on three different surfaces: (1) stable, (2) unstable-unspecific (foam), and (3) unstable-specific (inspired from rearfoot anatomy). Muscular vibration was applied on the paraspinals and fibularis muscles. The unstable-specific support surface was associated with higher fibularis muscular activity and greater postural perturbations when fibularis muscles were vibrated than the unspecific-unstable surface. Balance control on unstable-specific support surface maintains the relevance on muscular proprioceptive signals originating from ankle and increases ankle evertor muscle activity"http://www.ncbi.nlm.nih.gov/pubmed/24919080

Up-weighing the proprioceptive signals from more proximal segments of the paraspinals will further reinforce the neuroplastic changes that occur rapidly in response to injury and then become chronic..............."There are associated changes also found in the meso-limbic pre-frontal areas in subjects with chronic MSD some which may pre-dispose the injury. The neuroplastic changes may occur rapidly in response to injury causing adaptive changes that may help in the protection and healing response. However, these changes may persist and no longer perform their intended function contributing to the development of chronic disability and dysfunctional pain with enduring neuroplastic changes along the neuroaxis of pain resulting in peripheral and central sensitization, in the sensorimotor areas affecting perception and motor behavior, and in the meso-limbic prefrontal areas influencing emotional, attentional and cognitive processes. In some musculoskeletal conditions the responsiveness and somatotopic organization in S1 and M1, including changes in excitability, the blurring of the representation of anatomical structures and a shift in the representation of muscles within somatotopic representations are present. These changes in properties, function and organization within the CNS often correlate with the severity and duration of pain, functional changes including aspects of motor control, psychological traits associated with the chronic pain states, and can be predictive of prognosis"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4331171/

Here it is shown that training on one balance device only improved performance on that specific balance device - there was virtually no transfer to another balance challenge....."In summary, 2weeks of balance training resulted in highly task-specific effects, no transfer even to very similar tasks was observed. Therefore, we recommend identifying and training exactly those tasks that need improvement"http://www.ncbi.nlm.nih.gov/pubmed/26298214

Also, vestibular contributions to body orientation and to spatial localization of auditory and visual stimuli as well as their processing in the superior cerebellar peduncle being impaired by LAS is something I have not viewed in any literature to date but if you have any I would love to check it out. Now as far as distinguishing the somatosensory and vestibular systems it is a common practice to have the subjects perform the testing with their vision occluded. Balance and postural control is comprised of the somatosensory system (which includes joint proprioception) vision (which is visual proprioception, and tells you your head orientation and motion relative to other objects) and your vestibular system (head relative to gravity/motion). So the study was trying to cut out vision and have the subjects only use their somatosensory (joint proprioception) and vestibular systems, that was the purpose of the authors having the eyes occluded.