Department of Teacher Education, Nord Trøndelag University College, Levanger, Norway.
J Strength Cond Res. 2012 Nov;26(11):2962-9. doi: 10.1519/JSC.0b013e3182443430.
The purpose was to investigate the effect of 3 chest-press exercises with different degrees of freedom upon the sticking region and muscle activity in maximal attempts. It was hypothesized that, with increasing degrees of freedom, the sticking region (the weakest region during the lift) would be longer because the muscles need to use a part of their ability to control these increasing degrees of freedom during the exercise. Furthermore, the prime movers would have the same muscle activity, but the biceps muscle activity would increase when the degrees of freedom increases because of the enhanced control of the upward movement. Eleven male subjects (age 22.6 ± 1.7 years, body mass 78.6 ± 8.0 kg, stature 1.80 ± 0.07 m) with at least 1 year of bench press training experience participated in this study. Every subject was tested in 1 repetition maximum (1RM) in the 3 chest-press exercises. During the attempts, kinematics and muscle activity were recorded and analyzed in 4 different regions (downward, presticking, sticking, and poststicking). The participants achieved the highest 1RM strength using the free barbell (106.4 ± 15.5 kg), followed by the Smith machine (103.6 ± 14.8 kg) and dumbbells (89.5 ± 13.7 kg). Furthermore, muscle activity differences (electromyographic) between the 3 different exercises and the muscle activation between the 4 different regions were found. The length of the different lifting regions together with muscle activity was different between the exercises. However, the differences found did not follow the line of increasing degrees of freedom that would result in a longer sticking region. Therefore, it is possible to choose to train a particular chest press exercise with the purpose of training a particular muscle more than the others.
目的是研究三种不同自由度的卧推练习对最大试举中的粘着区和肌肉活动的影响。假设自由度增加时，粘着区（举重过程中最薄弱的区域）会变长，因为肌肉在运动过程中需要动用一部分能力来控制这些不断增加的自由度。此外，主动肌的肌肉活动应该是相同的，但随着自由度的增加，二头肌的肌肉活动会增加，因为对向上运动的控制增强了。11 名男性受试者（年龄 22.6±1.7 岁，体重 78.6±8.0kg，身高 1.80±0.07m），有至少 1 年的卧推训练经验，参加了这项研究。每位受试者都在 3 种卧推练习中进行了 1 次最大重复（1RM）测试。在尝试过程中，记录并分析了运动学和肌肉活动，共分析了 4 个不同区域（下降、预粘滞、粘滞和粘滞后）。参与者使用自由杠铃（106.4±15.5kg）达到了最高的 1RM 力量，其次是史密斯机（103.6±14.8kg）和哑铃（89.5±13.7kg）。此外，还发现了 3 种不同练习之间的肌肉活动差异（肌电图）和 4 个不同区域之间的肌肉激活差异。不同练习的不同提升区域的长度以及肌肉活动都不同。然而，发现的差异并没有遵循自由度增加导致粘着区变长的趋势。因此，可以选择进行特定的卧推练习，以有针对性地训练特定的肌肉，使其比其他肌肉更发达。
