%0 Journal Article
%T Abnormalities of the First Three Steps of Gait Initiation in Patients with Parkinson's Disease with Freezing of Gait
%A Yohei Okada
%A Takahiko Fukumoto
%A Katsuhiko Takatori
%A Koji Nagino
%A Koichi Hiraoka
%J Parkinson's Disease
%D 2011
%I Hindawi Publishing Corporation
%R 10.4061/2011/202937
%X The purpose of this study was to investigate abnormalities of the first three steps of gait initiation in patients with Parkinson's disease (PD) with freezing of gait (FOG). Ten PD patients with FOG and 10 age-matched healthy controls performed self-generated gait initiation. The center of pressure (COP), heel contact positions, and spatiotemporal parameters were estimated from the vertical pressures on the surface of the force platform. The initial swing side of gait initiation was consistent among the trials in healthy controls but not among the trials in PD patients. The COP and the heel contact position deviated to the initial swing side during the first step, and the COP passed medial to each heel contact position during the first two steps in PD patients. Medial deviation of the COP from the first heel contact position had significant correlation with FOG questionnaire item 5. These findings indicate that weight shifting between the legs is abnormal and that medial deviation of the COP from the first heel contact position sensitively reflects the severity of FOG during the first three steps of gait initiation in PD patients with FOG. 1. Introduction Disturbance of gait initiation is common in patients with Parkinson＊s disease (PD) [1每9]. In particular, the postural phase, defined as the phase between the onset of weight shifting to the initial swing side and the onset of the heel off in the initial swing limb, is abnormal in PD patients [1每9]. Duration of the postural phase is prolonged [2, 4, 5]. The displacement of the center of pressure (COP) [5每8] and motoneuron pool excitability of the soleus muscle [9] are abnormal in this phase. Furthermore, electromyographic activities in the tibialis anterior muscle, vastus lateralis muscle, and gastrocnemius muscle are decreased in this phase [2]. The decreased step length during gait initiation [2, 5, 6] may reflect some of these abnormalities in the postural phase. Gait abnormalities in PD patients were reported not only during gait initiation, but also during steady-state gait [10每14]. Step length and step velocity are reduced [10每13], double limb support duration is prolonged [10每13], and stride-to-stride variability of gait cycle timing is increased [13]. Furthermore, movement amplitude of the legs and pelvis and the push-off peak of the vertical ground reaction force are reduced [11, 14]. Given the existing findings about gait abnormality in PD patients, we hypothesized that the transition phase between gait initiation and steady-state gait may also be abnormal in PD patients. This transition phase
%U http://www.hindawi.com/journals/pd/2011/202937/