The current study aimed to verify whether or not passive static stretching affects balance control capacity. Thirty-eight participants (19 women and 19 men) underwent a passive static stretching session, involving the knee extensor/flexor and dorsi/plantarflexor muscles, and a control session (no stretching, CTRL). Before (PRE), immediately after (POST), after 15 (POST15) and 30 min (POST30) from stretching (or rest in CTRL), balance control was evaluated under static and dynamic conditions, with open/closed eyes, and with/without somatosensory perturbation (foam under the feet). During tests, centre of pressure (CoP) sway area and perimeter and antero-posterior and medio-lateral sway mean speed were computed. Surface electromyography root mean square (sEMG RMS) was calculated from the vastus lateralis, biceps femoris, gastrocnemius medialis, and tibialis anterior muscles during MVC and during the balance tests. Hip flexion/extension and dorsi/plantarflexion range of motion (ROM), maximum voluntary contraction (MVC) and sEMG RMS during MVC were measured at the same time points. After stretching, ROM increased (≈6.5%; P<0.05), while MVC and sEMG RMS decreased (≈9% and ≈7.5%, respectively; P<0.05). Regardless of the testing condition, CoP sway area and the perimeter remained similar, while antero-posterior and medio-lateral sway mean speed decreased by ≈8% and ≈12%, respectively (P<0.05). sEMG RMS during the balance tests increased in all muscles in POST (≈7%, P<0.05). All variables recovered in POST30. No changes occurred in CTRL. Passive static stretching did not affect the overall balance control ability. However, greater muscle activation was required to maintain similar CoP sway, thus suggesting a decrease in muscle efficiency.

中文翻译：

---

被动拉伸会降低肌肉在平衡任务中的效率。

目前的研究旨在验证被动静态拉伸是否影响平衡控制能力。38 名参与者（19 名女性和 19 名男性）接受了被动静态拉伸训练，涉及膝伸肌/屈肌和背/跖屈肌，以及控制训练（无拉伸，CTRL）。在（PRE）之前，立即（POST）之后，在拉伸（或在 CTRL 状态下休息）15 分钟（POST15）和 30 分钟（POST30）之后，在静态和动态条件下评估平衡控制，睁眼/闭眼，和/没有体感扰动（脚下的泡沫）。在测试期间，计算了压力中心 (CoP) 摇摆面积和周长以及前后和中间横向摇摆平均速度。表面肌电图均方根 (sEMG RMS) 由股外侧肌、股二头肌、腓肠内侧肌、MVC 和平衡测试期间的胫骨前肌。在相同时间点测量 MVC 期间的髋关节屈曲/伸展和背/跖屈运动范围 (ROM)、最大自主收缩 (MVC) 和 sEMG RMS。拉伸后，ROM增加（≈6.5%；P<0.05），而MVC和sEMG RMS降低（分别≈9%和≈7.5%；P<0.05）。无论测试条件如何，CoP 摇摆面积和周长保持相似，而前后和中间横向摇摆平均速度分别降低 ≈8% 和 ≈12%（P<0.05）。POST 中所有肌肉的平衡测试期间的 sEMG RMS 均增加（≈7%，P<0.05）。在 POST30 中恢复的所有变量。CTRL 中没有发生任何变化。被动静态拉伸不影响整体平衡控制能力。然而，