Research Interest Group of Physical Activity and Human Performance, SMI®, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7D, 9220, Aalborg, Denmark.
Sci Rep. 2017 May 17;7(1):2010. doi: 10.1038/s41598-017-01972-1.
It remains unclear why humans spontaneously shift from walking to running at a certain point during locomotion at gradually increasing velocity. We show that a calculated walk-to-run transition stride frequency (70.6 ± 3.2 strides min) agrees with a transition stride frequency (70.8 ± 3.1 strides min) predicted from the two stride frequencies applied during treadmill walking and running at freely chosen velocities and freely chosen stride frequencies. The agreement is based on Bland and Altman's statistics. We found no essential mean relative difference between the two transition frequencies, i.e. -0.5% ± 4.2%, as well as limits of agreement of -8.7% and 7.7%. The particular two freely chosen stride frequencies used for prediction are considered behavioural attractors. Gait is predicted to be shifted from walking to running when the stride frequency starts getting closer to the running attractor than to the walking attractor. In particular, previous research has focussed on transition velocity and optimisation theories based on minimisation of, e.g., energy turnover or biomechanical loadings of the legs. Conversely, our data support that the central phenomenon of walk-to-run transition during human locomotion could be influenced by behavioural attractors in the form of stride frequencies spontaneously occurring during behaviourally unrestricted gait conditions of walking and running.
目前尚不清楚为什么人类在逐渐增加速度的运动过程中，会在某个特定时刻自发地从行走转变为奔跑。我们表明，计算得出的从行走转变为奔跑的步频（70.6±3.2 步/分钟）与从跑步机上以自由选择的速度和自由选择的步频行走和跑步时应用的两种步频预测出的转变步频（70.8±3.1 步/分钟）一致。这种一致性基于 Bland 和 Altman 的统计数据。我们发现两种转变频率之间没有明显的平均相对差异，即-0.5%±4.2%，以及一致区间的下限为-8.7%和上限为 7.7%。用于预测的两个特定的自由选择步频被认为是行为吸引子。当步频开始更接近跑步吸引子时，步态就会从行走转变为跑步。特别是，以前的研究集中在转变速度和基于最小化能量消耗或腿部生物力学负荷等的优化理论上。相反，我们的数据支持这样一种观点，即在人类运动中的从行走转变为奔跑的中央现象可能会受到行为吸引子的影响，这种行为吸引子以行走和跑步时行为不受限制的步态条件下自发出现的步频的形式出现。
