Applied Neuromechanics Group, Universidade Federal do Pampa, Uruguaiana, RS, Brazil.
Phys Ther Sport. 2010 Nov;11(4):136-42. doi: 10.1016/j.ptsp.2010.06.005. Epub 2010 Jul 23.
This review summarizes the effects of bilateral asymmetry on running and cycling performance and risk of injury in healthy subjects and the influence of leg preference. We define the term leg preference derived from lateral preference as representative of the choice for one side of the body to perform a motor action. Useful information is provided for biomechanical and physiological research and coaching with relevance to an understanding regarding the occurrence of lower limb asymmetry.
To provide a synopsis of what is known about bilateral asymmetry in human running and cycling and its relationship to limb preference, especially in the context of competitive sport performance and risk of injury.
Structured narrative review.
The relationship between asymmetry and lower limb preference was reviewed using Medline(®), Sciencedirect(®), and Scopus(®) search engines considering studies published in English until June 2009.
The environment characteristics may influence running asymmetries, which are more frequent in angular parameters. Environment characteristics are related to ground irregularities requiring compensatory movements changing the mechanical workload on joints and bones, which may influence asymmetries in biomechanical parameters between lower limbs. The relationship between asymmetry and injury risk should be assessed with caution since running speed may influence asymmetry in injured and non-injured subjects who often show similar asymmetry levels. Symmetry can be improved with increasing running speed. In addition to running speed, coaches and athletes interested in minimizing lateral difference should consider a training regime aimed at correcting asymmetry which may negatively affect running technique by influencing the compensatory movements that an athlete usually performs. During cycling, bilateral differences are frequently found and vary with the competitive situation, pedaling cadence, exercise intensity and exercise duration. Regardless of the variability of asymmetry index between subjects, few suggestions are available to overcome lateral differences. Most of the research suggests that bilateral pedaling asymmetries decrease as the workload increases, however the relationship to injury risk was not clearly addressed. For both running and cycling, few investigations examined the central mechanisms of neuromuscular control, and no study addressed the effect of asymmetry on performance.
Collectively, the volume of studies supporting symmetry is small and to a large extent research considered unilateral assessment. Preferred limb performance can differ from the contralateral limb. In the context of biomechanical and physiological investigations, we believe that further studies should address the role of lower limb symmetry on human motor performance and injury risk focusing on the energetic cost, muscle efficiency and the neuromuscular aspects such as muscle activation and motor units firing rate.
本综述总结了双侧不对称对健康受试者跑步和骑行表现和受伤风险的影响，以及腿部偏好的影响。我们将由侧方偏好衍生的术语“腿部偏好”定义为对身体一侧执行运动动作的选择。这为生物力学和生理学研究以及教练提供了有用的信息，有助于了解下肢不对称的发生。
概述人体跑步和骑行中的双侧不对称及其与肢体偏好的关系，特别是在竞技运动表现和受伤风险方面。
结构化叙述性综述。
使用 Medline®、Sciencedirect® 和 Scopus®搜索引擎，检索截至 2009 年 6 月以英文发表的研究，回顾不对称与下肢偏好之间的关系。
环境特征可能会影响跑步的不对称性，这种不对称性在角度参数中更为常见。环境特征与地面不规则性有关，需要进行补偿性运动，从而改变关节和骨骼的机械工作量，这可能会影响下肢生物力学参数的不对称性。由于受伤和未受伤的受试者的跑步速度可能会影响不对称性，而他们通常表现出相似的不对称性水平，因此应谨慎评估不对称性与受伤风险之间的关系。随着跑步速度的增加，对称性可以得到改善。除了跑步速度之外，教练和运动员如果希望将侧方差异最小化，还应考虑采用旨在纠正不对称性的训练方案，因为这可能会通过影响运动员通常进行的补偿性运动来影响跑步技术。在骑自行车时，双侧差异经常出现，并且随竞技情况、踩踏频率、运动强度和运动持续时间而变化。无论受试者之间的不对称性指数差异如何，都很少有建议可以克服侧方差异。大多数研究表明，随着工作量的增加，双侧踩踏不对称性会减小，但与受伤风险的关系尚未明确。对于跑步和骑自行车，很少有研究调查神经肌肉控制的中枢机制，也没有研究涉及不对称性对表现的影响。
总的来说，支持对称性的研究数量较少，而且在很大程度上研究都只考虑了单侧评估。优势腿的表现可能与对侧腿不同。在生物力学和生理学研究方面，我们认为，进一步的研究应该关注下肢对称性对人类运动表现和受伤风险的作用，重点关注能量成本、肌肉效率以及肌肉激活和运动单位放电率等神经肌肉方面。
