The fractal dimension approach in posture: a comparison between Down and Prader-Willi syndrome patients.
The suitability of new dynamic system analysis was investigated to compare postural control in Prader-Willi syndrome (PWS) and Down syndrome (DS) patients. Time-domain, frequency-domain parameters and fractal dimension (FD) of centre of pressure (CoP) were computed in maintaining normal standing on a force platform in 20 DS and 13 PWS patients, compared to 26 obese (obese control group, OCG) and 20 healthy individuals (healthy control group, HCG). DS and PWS showed greater displacements along both directions and longer sway path (SP) parameter than HCG and OCG, with statistical differences between PWS and DS for anteroposterior displacement and SP. DS used higher frequency strategy when compared to PWS, OCG and HCG. Both DS and PWS were characterised by greater values of FD than OCG and HCG, with higher values in DS. The analyses in frequency domain and of the dynamic nature of CoP suggest that DS patients are characterised by a more complex and irregular signal than PWS patients.
a Dipartimento di Elettronica , Informazione e Bioingegneria , Politecnico di Milano , Italy.
Veronica
V
Cimolin
Manuela
M
Galli
Chiara
C
Rigoldi
Graziano
G
Grugni
Luca
L
Vismara
Shirley Aparecida Fabris
SA
de Souza
Luca
L
Mainardi
Giorgio
G
Albertini
Paolo
P
Capodaglio
D000328:Adult; D004314:Down Syndrome / Q000503:physiopathology*; D005260:Female; D017709:Fractals; D006801:Humans; D008297:Male; D009765:Obesity / Q000503:physiopathology; D011187:Posture; D011218:Prader-Willi Syndrome / Q000503:physiopathology*
Down syndrome; Prader-Willi syndrome; centre of pressure; fractal dimension analysis; posture evaluation