Saeterbakken Atle H, Andersen Vidar, Jansson June, Kvellestad Ann C, Fimland Marius S
1Faculty of Teacher Education and Sport, Sogn og Fjordane University College, Sogndal, Norway; 2Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway; and 3Hysnes Rehabilitation Center, St. Olavs University Hospital, Trondheim, Norway.
J Strength Cond Res. 2014 Dec;28(12):3515-22. doi: 10.1519/JSC.0000000000000565.
The objective of this study was to assess the electromyographic activity of the rectus abdominis (upper and lower part) and external oblique during sit-ups performed on BOSU ball(s). Twenty-four men participated in a familiarization session, and in the next session, they performed the experimental tests in randomized order. The sit-ups were performed with 10 repetitions with body weight and with 10 repetition maximum (10RM) using elastic bands as external resistance under 4 different conditions: (a) on a stable surface, (b) with the BOSU ball under their feet (dome side down, lower-body instability), (c) BOSU ball under the low back (dome side up, upper-body instability), and (d) with BOSU balls under both feet and the low back (dual instability). The feet were not attached to the surface. We observed that with body weight, external oblique activation was decreased by upper-body instability and dual instability by 22-24% (p = 0.002-0.006), whereas the rectus abdominis was not affected by the surface. Using 10RM loads, the upper and lower rectus abdominis activities were increased by upper body and dual instability by 21-24% compared with that for a stable surface (P ≤ 0.001-0.036). Further, lower-body instability did not affect muscle activities significantly with either load for any condition. Hence, BOSU balls under the low back can increase and decrease abdominal muscle activation depending on the load, whereas placing a BOSU ball under the feet with the dome side down had little impact.
本研究的目的是评估在BOSU球上进行仰卧起坐时腹直肌（上半部分和下半部分）和腹外斜肌的肌电活动。24名男性参加了一次熟悉训练课程，在下一次课程中，他们以随机顺序进行了实验测试。仰卧起坐分别在4种不同条件下进行，每种条件下均进行10次自重重复以及使用弹力带作为外部阻力的10次最大重复量（10RM）：（a）在稳定表面上；（b）双脚置于BOSU球上（圆顶侧朝下，下半身不稳定）；（c）下背部置于BOSU球上（圆顶侧朝上，上半身不稳定）；（d）双脚和下背部均置于BOSU球上（双重不稳定）。双脚未固定在表面。我们观察到，在进行自重训练时，上半身不稳定和双重不稳定会使腹外斜肌的激活降低22%-24%（p = 0.002-0.006），而腹直肌不受表面条件的影响。使用10RM负荷时，与稳定表面相比，上半身不稳定和双重不稳定使腹直肌上半部分和下半部分的活动增加了21%-24%（P≤0.001-0.036）。此外，在任何条件下，下半身不稳定对两种负荷下的肌肉活动均无显著影响。因此，下背部放置BOSU球可根据负荷增加或减少腹部肌肉的激活，而圆顶侧朝下将BOSU球置于脚下的影响很小。
