Center of pressure palindromes reveals a wobbling standing balance in scoliotic girls.

Abstract

This study characterized the center of pressure planar displacement by palindromic strings. The objective is to test if the center of pressure pathway of able-bodied girls and those with a moderate and severe scoliosis displayed similar palindromic tendencies. The center of pressure excursions of 21 able-bodied girls were compared to 14 girls with a moderate scoliosis and 14 girls with severe one. Each girl was asked to stand upright on a force platform for 64s. A crisscross grid of nine areas was centered around the mean center of pressure position (G) to define three other zones to use the MATLAB built-in nucleotide sequence analysis function. These were the antero-posterior extremities A, the coronal extremities C and the tilted or the four corners of the crisscross grid, T. The center of pressure positions were associated to any of the 4 zones using the GATC acronym. For all groups center of pressure pattern in decreasing order was A, G, T and C. Able-bodied girls favored the A zones. Girls with moderate scoliosis displaced their center of pressure mostly in the A zones with shifts in the T sections (P≤0.001). Girls with severe scoliosis, additionally displaced their center of pressure in the C zones (P≤0.001). An ankle modality characterized able-bodied girl's standing balance. Girls with a moderate scoliosis privilege the palindromic zones in the antero-posterior extremities with excursions in the corners of the base of support, girls with severe scoliosis further relied on the medio-lateral zones, suggesting a wobbling standing balance.