@article {Schlenstedt2065_2016,
	year = {2016},
	author = {Schlenstedt, Christian and Muthuraman, Muthuraman and Witt, Karsten and Weisser, Burkhard and Fasano, Alfonso and Deuschl, Guenther},
	title = {Postural control and freezing of gait in Parkinson's disease},
	journal = {PARKINSONISM \& RELATED DISORDERS},
	volume = {24},
	DOI = {10.1016/j.parkreldis.2015.12.011},
	ISSN = {1353-8020},
	publisher = {ELSEVIER SCI LTD},
	keywords = {Postural control; Postural balance; Posture; Parkinson's disease;   Freezing of gait; Fullerton advanced balance scale; Asymmetry},
	abstract = {Introduction: The relationship between freezing of gait (FOG) and
   postural instability in Parkinson's disease (PD) is unclear. We analyzed
   the impact of FOG on postural control.
   Methods: 31 PD patients with FOG (PD+FOG), 27 PD patients without FOG
   (PD-FOG) and 22 healthy control (HC) were assessed in the ON state.
   Postural control was measured with the Fullerton Advanced Balance (FAB)
   scale and with center of pressure (COP) analysis during quiet stance and
   maximal voluntary forward backward leaning.
   Results: The groups were balanced concerning age, disease duration and
   disease severity. PD+FOG performed significantly worse in the FAB scale
   (21.8 +/- 5.8) compared to PD-FOG (25.6 +/- 5.0) and HC (34.9 +/- 2.4)
   (mean +/- SD, p < 0.01). PD+FOG had impaired ability to voluntary lean
   forward, difficulties to stand on foam with eyes closed and reduced
   limits of stability compared to PD-FOG (p < 0.05). During quiet stance
   the average anterior posterior COP position was significantly displaced
   towards posterior in PD+FOG in comparison to PD-FOG and HC (p < 0.05).
   The COP position correlated with severity of FOG (p < 0.01). PD+FOG and
   PD-FOG did not differ in average COP sway excursion, sway velocity, sway
   regularity and postural control asymmetry.
   Conclusions: PD+FOG have reduced postural control compared to PD-FOG and
   HC. Our results show a relationship between the anterior posterior COP
   position during quiet stance and FOG. The COP shift towards posterior in
   PD+FOG leads to a restricted precondition to generate forward
   progression during gait initiation. This may contribute to the
   occurrence of FOG or might be a compensatory strategy to avoid forward
   falls. (C) 2015 Elsevier Ltd. All rights reserved.}
}