当前位置: X-MOL 学术J. Biomech. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Why highly compliant poles are not energetically beneficial during running: Evidence from an optimization-based biped model
Journal of Biomechanics ( IF 2.4 ) Pub Date : 2021-01-20 , DOI: 10.1016/j.jbiomech.2021.110264
Tong Li , Qingguo Li , Tao Liu

Springy poles are a unique load-carrying tool and inspire novel designs of other load-carrying systems. Previous experiments have shown that highly compliant poles with a natural frequency lower than step frequency are more economical than rigid poles during load carriage in walking and this was successfully explained in later modeling studies. However, an energetic benefit was not observed during running with highly compliant poles. We speculate that gait type (running versus walking) may be a factor accounting for the different observations. An optimization-based biped model is adopted to predict the energy cost of load carriage with poles during running, with the parameters from previous experimental studies. The predicted load motion and load-body interaction force agree well with experimental measurements. Compared to running with rigid poles, the highly compliant pole results in reduced peak ground reaction force, longer stance phase duration, and higher energy cost. The changes in running energetics are further found to depend on the natural frequency of the load-pole system relative to the step frequency, but with an opposite trend compared to the changes in walking energetics during pole carriage. Highly compliant poles cost more energy than rigid poles during running, while stiffer poles with a higher natural frequency may offer energetic benefits. This study indicates that the fundamental difference in gait type has a profound influence on the energetic performance of load-carrying devices and this should be taken into consideration in future device designs.



中文翻译:

为什么高柔顺性杆在跑步过程中不会带来能量上的好处:来自基于优化的Biped模型的证据

弹力杆是一种独特的承载工具,它启发了其他承载系统的新颖设计。先前的实验表明,在行走的负载运输过程中,固有频率低于步进频率的高柔顺性极点比刚性极点更经济,这在以后的模型研究中得到了成功的解释。但是,在使用高柔顺性杆子的情况下,没有观察到能量方面的好处。我们推测步态类型(跑步与步行)可能是解释不同观察结果的一个因素。采用基于优化的两足动物模型,使用先前实验研究中的参数来预测运行过程中带有两极的负载运输的能源成本。预测的载荷运动和载荷-主体相互作用力与实验测量结果非常吻合。相比使用刚性杆,高柔顺性的极点会降低峰值地面反作用力,延长站姿相位持续时间,并增加能源成本。进一步发现,运行能量的变化取决于负载极系统的固有频率相对于步进频率的变化,但是与极运动期间行走能量的变化相比,趋势却相反。高度柔和的杆在行驶过程中比刚性杆消耗更多的能量,而具有较高自然频率的较硬的杆可能会提供有益的好处。这项研究表明,步态类型的根本差异对负载设备的能量性能有深远的影响,这在以后的设备设计中应予以考虑。以及更高的能源成本。进一步发现,运行能量的变化取决于负载极系统的固有频率相对于步进频率的变化,但是与极运动期间行走能量的变化相比,趋势却相反。高度柔和的杆在行驶过程中比刚性杆消耗更多的能量,而具有较高自然频率的较硬的杆可能会提供有益的好处。这项研究表明,步态类型的根本差异对负载设备的能量性能有深远的影响,这在以后的设备设计中应予以考虑。以及更高的能源成本。进一步发现,运行能量的变化取决于负载极系统的固有频率相对于步进频率的变化,但是与极运动期间行走能量的变化相比,趋势却相反。高度柔和的杆在行驶过程中比刚性杆消耗更多的能量,而具有较高自然频率的较硬的杆可能会提供有益的好处。这项研究表明,步态类型的根本差异对负载设备的能量性能有深远的影响,这在以后的设备设计中应予以考虑。但与杆子运输过程中步行能量学的变化相比却有相反的趋势。高度柔和的杆在行驶过程中比刚性杆消耗更多的能量,而具有较高自然频率的较硬的杆可能会提供有益的好处。这项研究表明,步态类型的根本差异对负载设备的能量性能有深远的影响,这在以后的设备设计中应予以考虑。但与杆子运输过程中步行能量学的变化相比却有相反的趋势。高度柔和的杆在行驶过程中比刚性杆消耗更多的能量,而具有较高自然频率的较硬的杆可能会提供有益的好处。这项研究表明,步态类型的根本差异对负载设备的能量性能有深远的影响,这在以后的设备设计中应予以考虑。

更新日期:2021-01-28
down
wechat
bug