Soft tissue vibrations (STV) can generate discomfort during running. Recent research has shown that footwear affects the amplitude of STV differently across runners but no studies have linked human characteristics and footwear construction yet. The purpose of this study was to investigate the runner specific STV responses to various midsole hardness and to identify functional groups, that is, groups of runners responding similarly to a given intervention. A total of 133 runners (56 females) with a wide range of anthropometrics and running habits performed an 8.5‐min trial at a self‐selected speed with three different midsole hardness (soft i.e., 46 Asker C, medium i.e., 58 Asker C and hard i.e., 71 Asker C). STV, kinetics, kinematics and electromyographic activity of gastrocnemius medialis muscle were recorded at minute 8. Mechanical properties of calf muscles were obtained through a standardized impact test on the calf muscles. An ascendant hierarchical clustering was computed to cluster individuals based on their STV amplitudes in the three conditions. Three functional groups with distinctive STV responses were identified. STV amplitude decreased for 61% of runners with the soft condition (SOFT group) and for 11% of runners with the medium condition (MED group), whereas 28% of runners demonstrated greater STV amplitude in the hard condition (HIGH‐HARD group). The findings revealed differences between groups in term of body fat percentage, running volume per week, foot/ground angle at initial contact, ankle plantarflexion and flight time. It provides guidelines to recommend footwear reducing STV amplitude based on anthropometrics, running practice and biomechanical characteristics of the runners.

中文翻译：

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中底硬度对软组织振动的影响：133 名跑步者的上升分层聚类


软组织振动 （STV） 会在跑步过程中产生不适。最近的研究表明，鞋类对跑步者之间 STV 振幅的影响不同，但目前还没有研究将人类特征与鞋类结构联系起来。本研究的目的是调查跑步者对各种中底硬度的特异性 STV 反应，并确定功能组，即对给定干预反应相似的跑步者组。共有 133 名跑步者（56 名女性）具有广泛的人体测量学和跑步习惯，以自选速度使用三种不同的中底硬度（软即 46 Asker C，中等即 58 Asker C 和硬 I.即 71 Asker C）进行了 8.5 分钟的试验。在第 8 分钟记录腓肠肌内侧肌的 STV 、动力学、运动学和肌电活动。通过对小腿肌肉的标准化冲击试验获得小腿肌肉的机械性能。计算上升分层聚类，根据个体在三种条件下的 STV 振幅对个体进行聚类。确定了三个具有不同 STV 反应的功能组。61% 的软条件跑步者 （SOFT 组） 和 11% 的中等条件跑步者 （MED 组） 的 STV 振幅降低，而 28% 的跑步者在硬条件 （HIGH-HARD 组） 表现出更大的 STV 振幅。研究结果揭示了各组在体脂百分比、每周跑步量、初次接触时的脚/地角、踝关节跖屈和飞行时间方面的差异。它提供了根据人体测量学、跑步练习和跑步者的生物力学特性推荐降低 STV 振幅的鞋子的指南。