Postural Sway and Motor Control in Trans-Tibial Amputees
The balance involved in keeping upright is related to proprioception signals from the foot. With amputation of the lower limb the receptors available for the creation of these signals are reduced.
Factors that affect balance include: stability of surface, foot position (base of support) and eyes open or closed.
Standing with one foot in front on the other on an unstable surface with eyes closed was the highest level of balance challenged in this experiment.
Prosthetics users showed up to 4 times as much sway in the most difficult balance tasks as well as increased corticospinal excitability. The band power of beta and sigma brain waves (16-31Hz and 12-14 Hz signals respectively,) increased significantly at central and parietal lobe areas as task difficulty increased.
The reduced somatosensory input for an amputee means there is more reliance on the brain. Poor balance is contributed to by delays in central balance processing to activate leg muscles.
> From: Petrofsky et al., Med Sci Monit 20 (2015) 2695-2704(Epub ahead of print). All rights reserved to International Scientific Literature, Inc.. Click here for the Pubmed summary.
Lower body balance and proprioception exercises:
Article on balance in amputees:
Scientific article "Postural sway and rhythmic electroencephalography analysis of cortical activation during eight balance training tasks":