Okamura Kazunori, Kanai Shusaku, Fukuda Kengo, Tanaka Satoshi, Ono Takeya, Oki Sadaaki
Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, 1-1 Gakuen-cho, Mihara-shi, Hiroshima 723-0053, Japan; Department of Physical Therapy, Faculty of Health and Welfare, Prefectural University of Hiroshima, 1-1 Gakuen-cho, Mihara-shi, Hiroshima 723-0053, Japan.
Department of Physical Therapy, Faculty of Health and Welfare, Prefectural University of Hiroshima, 1-1 Gakuen-cho, Mihara-shi, Hiroshima 723-0053, Japan.
Foot (Edinb). 2019 Mar;38:19-23. doi: 10.1016/j.foot.2018.11.002. Epub 2018 Nov 6.
Strengthening exercises of the plantar intrinsic foot muscles (PIFMs) are often prescribed to flat-footed subjects because of the capacity of the PIFMs to support the medial longitudinal arch (MLA). However, it is unclear whether the capacity of the PIFMs to support the MLA is enough to change the foot kinematics in flat-footed subjects. To confirm this, the current study examined changes in foot kinematics in flat-footed subjects during standing and gait accompanied by changes in the activity of the PIFMs.
Eighteen flat-footed subjects were randomly assigned to an electrical stimulation group (ESG) or a control group (CG). In the ESG, electrical stimulation to the PIFMs was applied during standing and gait to simulate reinforcement of the PIFMs. Then, foot kinematics were measured using 3D motion analysis, and the amount of change from baseline (when no electrical stimulation was applied) was compared between the groups.
In the gait analysis, the time at which the MLA height reached its minimum value was significantly later in the ESG, with no reduction in the MLA height at that time. Moreover, forefoot inversion angle and tibial external rotation angle were significantly increased in the ESG at that time. In the standing analysis, there were no significant differences between the groups.
The results revealed that in flat-footed subjects, the PIFMs have the capacity to support the MLA enough to change foot kinematics during gait. Strengthening these muscles may be effective in preventing or treating lower extremity overuse injuries related to flat-foot alignment.
由于足底固有肌（PIFMs）具有支撑内侧纵弓（MLA）的能力，因此常为扁平足受试者开具增强这些肌肉的锻炼处方。然而，尚不清楚PIFMs支撑MLA的能力是否足以改变扁平足受试者的足部运动学。为证实这一点，本研究调查了扁平足受试者在站立和步态期间伴随PIFMs活动变化时的足部运动学变化。
18名扁平足受试者被随机分配至电刺激组（ESG）或对照组（CG）。在ESG中，在站立和步态期间对PIFMs施加电刺激，以模拟增强PIFMs。然后，使用三维运动分析测量足部运动学，并比较两组相对于基线（未施加电刺激时）的变化量。
在步态分析中，ESG中MLA高度达到最小值的时间明显更晚，且此时MLA高度没有降低。此外，此时ESG中的前足内翻角度和胫骨外旋角度显著增加。在站立分析中，两组之间没有显著差异。
结果表明，在扁平足受试者中，PIFMs具有支撑MLA的能力，足以在步态期间改变足部运动学。增强这些肌肉可能对预防或治疗与扁平足姿势相关的下肢过度使用损伤有效。
