Liss Cameron M, Sanni Adeola A, McCully Kevin K
Department of Kinesiology, University of Georgia, Athens, GA 30602, USA.
J Funct Morphol Kinesiol. 2020 Jul 8;5(3):47. doi: 10.3390/jfmk5030047.
Endurance of the muscles of the neck are rarely studied. This study measured the endurance index (EI) of the sternocleidomastoid (SCM) and upper trapezius muscles of the neck (trap). The vastus lateralis (VL) was used for comparison. Skeletal muscle endurance of twelve healthy subjects, age 19-22 years, were tested on their SCM and trap in random order on one day, VL was tested on a separate day. Participants were tested in the supine position for the SCM and VL muscles and the prone position for the trap. Muscle contractions consisted of a 5 Hz twitch electrical stimulation for 5 min. Muscle acceleration (resultant vector) was measured using a triaxial accelerometer. EI was the ending acceleration as a percentage of the maximal acceleration. The endurance index (EI) for the SCM, trap, and VL was 42.3 ± 13.0%, 42.3 ± 20.2%, and 92.9 ± 11.0%, respectively. The EI of the VL was significantly higher than the EI of the SCM ((2,22) = 10.33, < 0.001) and the trap ((2,22) = 7.625, < 0.001). The EI was not different between the SCM and the trap muscle ((2,22) = 0.004, = 0.997). In conclusion, the neck muscles had much less endurance than the muscles in the leg and could make fatigued athletes more susceptible to concussions caused by head impacts.
颈部肌肉的耐力很少被研究。本研究测量了胸锁乳突肌（SCM）和颈部上斜方肌（斜方肌）的耐力指数（EI）。使用股外侧肌（VL）作为对照。对12名年龄在19 - 22岁的健康受试者的SCM和斜方肌进行骨骼肌耐力测试，测试顺序随机，在一天内完成，VL在另一天进行测试。受试者在仰卧位测试SCM和VL肌肉，在俯卧位测试斜方肌。肌肉收缩采用5Hz的抽搐电刺激，持续5分钟。使用三轴加速度计测量肌肉加速度（合成矢量）。EI是以最终加速度占最大加速度的百分比来表示。SCM、斜方肌和VL的耐力指数（EI）分别为42.3±13.0%、42.3±20.2%和92.9±11.0%。VL的EI显著高于SCM的EI（(2,22)=10.33，<0.001）和斜方肌的EI（(2,22)=7.625，<0.001）。SCM和斜方肌之间的EI没有差异（(2,22)=0.004，=0.997）。总之，颈部肌肉的耐力远低于腿部肌肉，这可能使疲劳的运动员更容易受到头部撞击导致的脑震荡。
