Frenkel-Toledo Silvi, Giladi Nir, Peretz Chava, Herman Talia, Gruendlinger Leor, Hausdorff Jeffrey M
Department of Physical Therapy, Sackler School of Medicine, Tel-Aviv University, Israel.
J Neuroeng Rehabil. 2005 Jul 31;2:23. doi: 10.1186/1743-0003-2-23.
The ability to maintain a steady gait rhythm is impaired in patients with Parkinson's disease (PD). This aspect of locomotor dyscontrol, which likely reflects impaired automaticity in PD, can be quantified by measuring the stride-to-stride variability of gait timing. Previous work has shown an increase in both the variability of the stride time and swing time in PD, but the origins of these changes are not fully understood. Patients with PD also generally walk with a reduced gait speed, a potential confounder of the observed changes in variability. The purpose of the present study was to examine the relationship between walking speed and gait variability.
Stride time variability and swing time variability were measured in 36 patients with PD (Hoehn and Yahr stage 2-2.5) and 30 healthy controls who walked on a treadmill at four different speeds: 1) Comfortable walking speed (CWS), 2) 80% of CWS 3) 90% of CWS, and 4) 110% of CWS. In addition, we studied the effects of walking slowly on level ground, both with and without a walker.
Consistent with previous findings, increased variability of stride time and swing time was observed in the patients with PD in CWS, compared to controls. In both groups, there was a small but significant association between treadmill gait speed and stride time variability such that higher speeds were associated with lower (better) values of stride time variability (p = 0.0002). In contrast, swing time variability did not change in response to changes in gait speed. Similar results were observed with walking on level ground.
The present results demonstrate that swing time variability is independent of gait speed, at least over the range studied, and therefore, that it may be used as a speed-independent marker of rhythmicity and gait steadiness. Since walking speed did not affect stride time variability and swing time variability in the same way, it appears that these two aspects of gait rhythmicity are not entirely controlled by the same mechanisms. The present findings also suggest that the increased gait variability in PD is disease-related, and not simply a consequence of bradykinesia.
帕金森病（PD）患者维持稳定步态节奏的能力受损。这种运动控制障碍的方面可能反映了PD患者自动性的受损，可以通过测量步态时间的步幅间变异性来量化。先前的研究表明，PD患者的步幅时间和摆动时间变异性均增加，但这些变化的起源尚未完全了解。PD患者通常也以较慢的步态速度行走，这是观察到的变异性变化的一个潜在混杂因素。本研究的目的是检查步行速度与步态变异性之间的关系。
在36例PD患者（Hoehn和Yahr分期2 - 2.5）和30名健康对照者中测量步幅时间变异性和摆动时间变异性，他们在跑步机上以四种不同速度行走：1）舒适步行速度（CWS），2）CWS的80%，3）CWS的90%，以及4）CWS的110%。此外，我们研究了在平坦地面上缓慢行走（有无助行器）的影响。
与先前的研究结果一致，与对照组相比，PD患者在CWS时步幅时间和摆动时间变异性增加。在两组中，跑步机步态速度与步幅时间变异性之间存在小但显著的关联，即较高速度与较低（较好）的步幅时间变异性值相关（p = 0.0002）。相比之下，摆动时间变异性并未随步态速度的变化而改变。在平坦地面行走时也观察到了类似的结果。
目前的结果表明，至少在所研究的范围内，摆动时间变异性与步态速度无关，因此，它可以用作节奏性和步态稳定性的速度独立指标。由于步行速度对步幅时间变异性和摆动时间变异性的影响不同，似乎步态节奏性的这两个方面并非完全由相同机制控制。目前的研究结果还表明，PD患者步态变异性增加与疾病相关，而不仅仅是运动迟缓的结果。
