Vision and Eye Research Unit (VERU), Postgraduate Medical Institute, Anglia Ruskin University, Cambridge, UK; Sport and Exercise Sciences Research Group (SESRG), Life Sciences, Anglia Ruskin University, Cambridge, UK.
Gait Posture. 2014 Jan;39(1):252-7. doi: 10.1016/j.gaitpost.2013.07.115. Epub 2013 Aug 13.
Vision is of paramount importance in regulating adaptive gait. Using three-dimensional motion analysis, the current study investigated how central visual field loss (CFL) affects step ascent. Ten patients with chronic CFL (77 ± 10 years) and 13 visual normal participants (72 ± 6 years) walked up to and ascended a single step (of varying height). Movement kinematics assessed the period immediately prior to and during step ascent. Compared to visual normal participants, patients with CFL exhibited a lower lead foot horizontal crossing velocity, increased lead limb swing time and increased head flexion (looking down at more immediate areas of the ground/step). They also took longer to initiate the step up, transfer weight to the lead foot upon landing on the upper level and increased trail limb swing time when negotiating the medium and high step height. Increased variability was also shown in a number of dependent measures. Data indicate that during step ascent, patients with CFL exhibit a cautious stepping strategy when compared to visual normal participants. This cautious strategy becomes increasingly evident when negotiating higher step heights, as shown by an increased planning time prior to entering the relatively unstable period of single support during the step up. The increased variability among CFL patients increases their likelihood of experiencing dynamic instability and falling during step ascent.
视觉在调节适应性步态中至关重要。本研究采用三维运动分析方法，探讨了中央视野缺损（CFL）如何影响步上抬。10 名慢性 CFL 患者（77±10 岁）和 13 名视觉正常的参与者（72±6 岁）走上并步上抬一个台阶（台阶高度不同）。运动运动学评估了步上抬前后的阶段。与视觉正常的参与者相比，CFL 患者的前导脚水平穿越速度较低，摆动时间增加，头部前屈（低头看更接近地面/台阶的区域）。他们也需要更长的时间来开始上步，在上步到上一级时将重心转移到前导脚，在跨过中高台阶时增加摆动时间。在一些依赖指标中也显示出更大的可变性。数据表明，与视觉正常的参与者相比，CFL 患者在步上抬时表现出谨慎的步行动作策略。当跨越更高的台阶时，这种谨慎的策略变得更加明显，因为在上步进入相对不稳定的单足支撑期之前，需要更长的计划时间。CFL 患者之间的可变性增加，增加了他们在步上抬过程中出现动态不稳定和跌倒的可能性。
