Print Email Facebook Twitter Balance asymmetry in Parkinson's disease and its contribution to freezing of gait Title Balance asymmetry in Parkinson's disease and its contribution to freezing of gait Author Boonstra, T.A. Van Vugt, J.P.P. Van der Kooij, H. Bloem, B.R. Faculty Mechanical, Maritime and Materials Engineering Department Biomechanical Engineering Date 2014-07-17 Abstract Balance control (the ability to maintain an upright posture) is asymmetrically controlled in a proportion of patients with Parkinson’s disease. Gait asymmetries have been linked to the pathophysiology of freezing of gait. We speculate that asymmetries in balance could contribute to freezing by a) hampering the unloading of the stepping leg and/or b) leading to a preferred stance leg during gait, which then results in asymmetric gait. To investigate this, we examined the relationship between balance control and weight-bearing asymmetries and freezing. We included 20 human patients with Parkinson (tested OFF medication; nine freezers) and nine healthy controls. Balance was perturbed in the sagittal plane, using continuous multi-sine perturbations, applied by a motion platform and by a force at the sacrum. Applying closed-loop system identification techniques, relating the body sway angle to the joint torques of each leg separately, determined the relative contribution of each ankle and hip joint to the total amount of joint torque. We also calculated weight-bearing asymmetries. We determined the 99-percent confidence interval of weight-bearing and balance-control asymmetry using the responses of the healthy controls. Freezers did not have larger asymmetries in weight bearing (p = 0.85) nor more asymmetrical balance control compared to non-freezers (p = 0.25). The healthy linear one-to-one relationship between weight bearing and balance control was significantly different for freezers and non-freezers (p = 0.01). Specifically, nonfreezers had a significant relationship between weight bearing and balance control (p = 0.02), whereas this relation was not significant for freezers (p = 0.15). Balance control is asymmetrical in most patients (about 75 percent) with Parkinson’s disease, but this asymmetry is not related to freezing. The relationship between weight bearing and balance control seems to be less pronounced in freezers, compared to healthy controls and non-freezers. However, this relationship should be investigated further in larger groups of patients. To reference this document use: http://resolver.tudelft.nl/uuid:77ed9363-9abe-4a8a-8aee-ae3d3c34e071 DOI https://doi.org/10.1371/journal.pone.0102493 Publisher Public Library of Science ISSN 1932-6203 Source PLoS One, 9(7), 2014 Part of collection Institutional Repository Document type journal article Rights (c) 2014 The Author(s)This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Files PDF 307510.pdf 1.1 MB Close viewer /islandora/object/uuid:77ed9363-9abe-4a8a-8aee-ae3d3c34e071/datastream/OBJ/view