Background

Backward walking and fast walking have distinctive gait patterns in adults; however, there is minimal literature describing these gait modifications in typically developing children. Additionally, most of previous research focused on overground backward walking, but not on a treadmill.

Research question

How do typically developing children adapt their gait patterns, including spatiotemporal parameters, joint kinematics, and muscle activation, to changes in direction and speed during treadmill walking?

Methods

We recruited 19 children (10 M/9 F) aged 6–12 years. Treadmill conditions included forward and backward walking at three speeds: slow (75 % of normal speed), normal speed, and fast (125 % of normal speed). Subjects completed a 2-minute trial under each condition. Spatiotemporal, kinematic, kinetic and electromyography data were collected and analyzed. Correlations between forward and time-reversed backward walking were calculated for joint angles and vertical ground reaction force.

Results

During backward walking, children (a) decreased step lengths and increased step widths and foot clearance, (b) decreased peak hip and knee flexion and increased peak ankle dorsiflexion, and (c) increased muscle activity at the vastus lateralis, rectus femoris, and tibialis anterior. At faster speeds, children increased step lengths and inconsistently increased overall muscle activity. Both the hip and knee showed high correlation between forward and time-reversed backward walking, while correlation at the ankle was low.

Significance

Overall, children adapt their gait to changes in direction and speed of treadmill walking in similar ways to adults. However, notable differences emerged in that children limited their ankle range of motion. Our results suggest that, while many aspects of gait are mature enough by this age to adapt to backward walking on a treadmill, neuromuscular control at the ankle may still be lacking in children while walking backward on a treadmill.

中文翻译：

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方向和速度对典型发育儿童的跑步机行走的影响

背景

成年人的向后走动和快速走动具有独特的步态模式。然而，很少有文献描述典型发育中儿童的这些步态改变。此外，以前的大多数研究都集中在地面向后行走，而不是在跑步机上。

研究问题

通常，发育中的孩子如何在跑步机行走过程中适应其步态模式（包括时空参数，关节运动学和肌肉激活）以适应方向和速度的变化？

方法

我们招募了19个年龄在6-12岁之间的儿童（10 M / 9 F）。跑步机的状况包括以三种速度向前和向后行走：慢速（正常速度的75％），正常速度和快速（正常速度的125％）。受试者在每种情况下均完成了2分钟的试验。收集并分析时空，运动学，动力学和肌电图数据。计算了关节角度和垂直地面反作用力之间向前和向后时间倒退步行的相关性。

结果

在向后行走过程中，儿童（a）减少步长，增加步幅和脚部间隙，（b）降低臀部和膝盖的最大屈曲度和增加峰值的踝背屈度，以及（c）外侧股骨，股直肌和胫前肌。以更快的速度，儿童增加步长，并不一致地增加整体肌肉活动。髋部和膝盖都显示出向前和时间反向后向行走之间的高度相关性，而脚踝处的相关性很低。

意义

总体而言，儿童的步态以与成年人相似的方式适应跑步机行走的方向和速度的变化。但是，显着的差异在于儿童限制了脚踝的运动范围。我们的研究结果表明，虽然步态的许多方面在这个年龄之前已经足够成熟，可以适应在跑步机上向后走，但是在跑步机上向后走时儿童的脚踝仍可能缺乏神经肌肉控制。