Lawrence Michael A, Carlson Lara A
1Department of Physical Therapy, University of New England, Portland, Maine; 2Westbrook College of Health Professions, University of New England, Portland, Maine; and 3Center for Excellence in the Neurosciences, University of New England, Portland, Maine.
J Strength Cond Res. 2015 Oct;29(10):2949-53. doi: 10.1519/JSC.0000000000000955.
Stability training has become commonplace in the strength and conditioning field. Although unstable surface training has been investigated, little is known regarding the efficacy of performing resistance exercises with an unstable load. The purpose of this study was to determine if performing a parallel back squat with an unstable load (weights suspended from the bar by an elastic band) produces greater ground reaction forces (GRFs) and muscle activation in the trunk and lower extremities than a stable condition (a normally loaded barbell). Fifteen resistance-trained males (age: 24.2 ± 3.4 years, mass: 83.4 ± 18.7 kg) completed 10 repetitions of the back squat, with 60% of their 1 repetition maximum in both stable and unstable conditions. Peak vertical GRF and the integrated muscle activity of the rectus femoris, vastus lateralis, vastus medialis, biceps femoris, soleus, rectus abdominis, external oblique, and erector spinae muscles on the right side of the body were determined The unstable load resulted in a small (3.9%) but significant decrease in peak vertical GRF. The unstable load also produced greater muscle activation in the rectus abdominis, external oblique, and soleus. The findings of this study suggest that squatting with an unstable load will increase activation of the stabilizing musculature; and while force decrements were statistically significant, the decrease was so small it may not be relevant to practitioners.
稳定性训练在力量与体能训练领域已变得很常见。尽管对不稳定表面训练进行了研究，但对于使用不稳定负荷进行抗阻训练的效果却知之甚少。本研究的目的是确定进行平行后蹲时，使用不稳定负荷（杠铃上通过弹力带悬挂重物）是否比稳定状态（正常加载的杠铃）能在躯干和下肢产生更大的地面反作用力（GRF）和肌肉激活。15名经过抗阻训练的男性（年龄：24.2±3.4岁，体重：83.4±18.7千克）在稳定和不稳定两种状态下，均以其1次最大重复量的60%完成10次后蹲动作。测定了右侧身体的垂直GRF峰值以及股直肌、股外侧肌、股内侧肌、股二头肌、比目鱼肌、腹直肌、腹外斜肌和竖脊肌的积分肌肉活动。不稳定负荷导致垂直GRF峰值出现了虽小（3.9%）但显著的下降。不稳定负荷还使腹直肌、腹外斜肌和比目鱼肌产生了更大的肌肉激活。本研究结果表明，使用不稳定负荷深蹲会增加稳定肌群的激活；虽然力量下降在统计学上具有显著性，但下降幅度很小，可能对从业者并无实际意义。
