Delval A, Krystkowiak P, Blatt J-L, Labyt E, Destée A, Derambure P, Defebvre L
Service de neurophysiologie clinique, hôpital Roger-Salengro, CHRU de Lille, 59037 Lille cedex, France.
Neurophysiol Clin. 2005 Nov-Dec;35(5-6):180-90. doi: 10.1016/j.neucli.2006.01.002. Epub 2006 Jan 26.
Preparation of upper-limb movements differs between self-paced and triggered conditions. This study analyzed the anticipatory postural adjustments (APAs) of gait initiation in normal subjects in 2 conditions: self-generated and triggered by a "beep" sound.
We recorded kinematic, spatiotemporal parameters of the first two steps by means of video motion analysis (6 infrared cameras), and kinetic parameters (using a force platform and the optoelectronic system) in 20 normal subjects. Two conditions: 1) self-generated initiation; and 2) initiation triggered by a "beep" sound were studied to evaluate the APA phase, by recording kinetic data (duration of the APAs, trajectory of the center of pressure, speed and trajectory of the center of mass). Kinematic data (first and second step speed, length and duration) were also recorded.
First step speed and length were increased in self-paced gait initiation compared to triggered gait initiation in controls. We found no difference between the 2 conditions in terms of second step kinematic data. It was caused by a significant difference between the 2 conditions for the temporal characteristics of anticipatory postural adjustments (APAs) in the initiation of the first step, which was longer when normal subjects performed self-generated gait initiation. The trajectory of center of pressure and center of mass remained the same in the 2 conditions.
APAs of gait initiation process are delayed under self-paced condition, although they do not differ qualitatively between reaction time and self-paced condition. Neuphysiological support of self-generated movement could explain these differences.
在自主节奏和触发条件下，上肢运动的准备情况有所不同。本研究分析了正常受试者在两种条件下步态起始的预期姿势调整（APA）：自主产生和由“哔”声触发。
我们通过视频运动分析（6台红外摄像机）记录了20名正常受试者前两步的运动学和时空参数，以及动力学参数（使用测力平台和光电系统）。研究了两种条件：1）自主产生起始；2）由“哔”声触发起始，通过记录动力学数据（APA的持续时间、压力中心轨迹、质心速度和轨迹）来评估APA阶段。还记录了运动学数据（第一步和第二步的速度、长度和持续时间）。
与对照组中触发式步态起始相比，自主节奏步态起始时第一步的速度和长度增加。我们发现两种条件在第二步运动学数据方面没有差异。这是由于第一步起始时预期姿势调整（APA）的时间特征在两种条件之间存在显著差异，当正常受试者进行自主产生的步态起始时，该时间更长。压力中心和质心的轨迹在两种条件下保持相同。
在自主节奏条件下，步态起始过程的预期姿势调整（APA）会延迟，尽管它们在反应时间和自主节奏条件之间在质量上没有差异。自主产生运动的神经生理学支持可以解释这些差异。
