Conley M S, Stone M H, Nimmons M, Dudley G A
Department of Exercise Science, University of Georgia, Athens 30602, USA.
Eur J Appl Physiol Occup Physiol. 1997;75(5):443-8. doi: 10.1007/s004210050186.
This study examined hypertrophy after head extension resistance training to assess which muscles of the complicated cervical neuromuscular system were used in this activity. We also determined if conventional resistance exercises, which are likely to evoke isometric action of the neck, induce generalized hypertrophy of the cervical muscle. Twenty-two active college students were studied. [mean (SE) age, weight and height: 21 (1) years, 71 (4) kg and 173 (3) cm, respectively]. Subjects were assigned to one of three groups: RESX (head extension exercise and other resistance exercises), RES (resistance exercises without specific neck exercise), or CON (no training). Groups RESX (n = 8) and RES (n = 6) trained 3 days/week for 12 weeks with large-muscle mass exercises (squat, deadlift, push press, bent row and mid-thigh pull). Group RESX also performed three sets of ten repetitions of a head extension exercise 3 days/week with a load equal to the 3 x 10 repetition maximum (RM). Group CON (n = 8) was a control group. The cross-sectional area (CSA) of nine individual muscles or muscle groups was determined by magnetic resonance imaging (MRI) of the cervical region. The CSA data were averaged over four contiguous transaxial slices in which all muscles of interest were visible. The 3 x 10 RM for the head extension exercise increased for RESX after training [from 17.9 (1.0) to 23.9 (1.4) kg, P < 0.05] but not for RES [from 17.6 (1.4) to 17.7 (1.9) kg] or CON [from 10.1 (2.2) to 10.3 (2.1) kg]. RESX showed an increase in total neck muscle CSA after training [from 19.5 (3.0) to 22.0 (3.6) cm2, P < 0.05], but RES and CON did not [from 19.6 (2.9) to 19.7 (2.9) cm2 and 17.0 (2.5) to 17.0 (2.4) cm2, respectively]. This hypertrophy for RESX was due mainly to increases in CSA of 23.9 (3.2), 24.0 (5.8), and 24.9 (5.3)% for the splenius capitis, and semispinalis capitis and cervicis muscles, respectively. The lack of generalized neck muscle hypertrophy in RES was not due to insufficient training. For example, the CSA of their quadriceps femoris muscle group, as assessed by MRI, increased by 7 (1)% after this short-term training (P < 0.05). The results suggest that: (1) the splenius capitis, and semispinalis capitis and cervicis muscles are mainly responsible for head extension; (2) short-term resistance training does not provide a sufficient stimulus to evoke neck muscle hypertrophy unless specific neck exercises are performed; and (3) the postural role of head extensors provides modest loading in bipeds.
本研究检测了头部伸展抗阻训练后的肌肉肥大情况，以评估复杂的颈部神经肌肉系统中哪些肌肉参与了该活动。我们还确定了可能引发颈部等长动作的传统抗阻训练是否会导致颈部肌肉普遍肥大。对22名活跃的大学生进行了研究。[平均（标准误）年龄、体重和身高分别为：21（1）岁、71（4）千克和173（3）厘米]。受试者被分为三组之一：RESX组（头部伸展运动和其他抗阻训练）、RES组（无特定颈部运动的抗阻训练）或CON组（无训练）。RESX组（n = 8）和RES组（n = 6）每周进行3天训练，共12周，训练内容为大肌肉群运动（深蹲、硬拉、推压、俯身划船和大腿中部提拉）。RESX组还每周进行3天头部伸展运动，每组10次重复，共3组，负荷为3×10次重复最大值（RM）。CON组（n = 8）为对照组。通过颈部区域的磁共振成像（MRI）确定九块个体肌肉或肌肉群的横截面积（CSA）。CSA数据在四个连续的轴位切片上进行平均，在这些切片中所有感兴趣的肌肉都可见。RESX组训练后头部伸展运动的3×10 RM增加[从17.9（1.0）千克增至23.9（1.4）千克，P < 0.05]，而RES组[从17.6（1.4）千克增至17.7（1.9）千克]和CON组[从10.1（2.2）千克增至10.3（2.1）千克]未增加。RESX组训练后颈部肌肉总CSA增加[从19.5（3.0）平方厘米增至22.0（3.6）平方厘米，P < 0.05]，而RES组和CON组未增加[分别从19.6（2.9）平方厘米增至19.7（2.9）平方厘米以及从17.0（2.5）平方厘米增至17.0（2.4）平方厘米]。RESX组的这种肌肉肥大主要是由于头夹肌、头半棘肌和颈半棘肌的CSA分别增加了23.9（3.2）%、24.0（5.8）%和24.9（5.3）%。RES组颈部肌肉未普遍肥大并非由于训练不足。例如，通过MRI评估，他们的股四头肌肌群CSA在这种短期训练后增加了7（1）%（P < 0.05）。结果表明：（1）头夹肌、头半棘肌和颈半棘肌主要负责头部伸展；（2）除非进行特定的颈部运动，短期抗阻训练不足以引发颈部肌肉肥大；（3）头部伸肌的姿势作用在双足动物中提供了适度的负荷。
