a Department of Kinesiology and Physical Education , Wilfrid Laurier University , Waterloo , Ontario , Canada.
b Department of Health Sciences , Wilfrid Laurier University , 75 University Ave West, Waterloo , Ontario , Canada.
Eur J Sport Sci. 2019 Jun;19(5):603-611. doi: 10.1080/17461391.2018.1537379. Epub 2018 Oct 26.
Rugby Union scrumming puts the spine under a high degree of loading. The aim of the current study was to determine how sagittal hip range of motion and quadriceps fatigue influence force output, spinal posture, and activation of the trunk and quadriceps muscles in rugby scrumming. Measures of sagittal hip flexion/extension range of motion were collected from 16 male varsity and club first XV level participants. Sagittal spine motion (electromagnetic motion capture), trunk and quadriceps activation (electromyography), and applied horizontal compressive force (force plate) were measured during individual machine scrumming. Participants performed a 5-trial scrum block involving 5 s of contact with 1-2 min recovery between each trial. They then performed a fatiguing protocol (wall sit to failure) and immediately returned to the scrum machine to perform another five trials. Though there was no significant influence of fatigue on the horizontal compressive force applied during contact (P = .83), there was a 52% increase in cervical flexion (P < .001), as well as decreased (18-23% lower) abdominal and erector spinae muscle activation (P < .05). Furthermore, quadriceps activation decreased (12-25% lower) over the course of the initial scrum block but increased (13-15% higher) in the post fatigue block (P < .05). Although athletes were able to maintain force output following the fatiguing wall sit task, there is the potential that they may be at an increased risk of spinal injury due to the combination of increased flexion and high-applied compressive force; a combination which has been shown to increase the likelihood of intervertebral disc herniation.
橄榄球争边球会对脊柱造成高度负荷。本研究旨在确定矢状髋关节活动范围和股四头肌疲劳如何影响橄榄球争边球中的力量输出、脊柱姿势以及躯干和股四头肌肌肉的激活。从 16 名男性校队和俱乐部一线队级别的参与者中收集矢状髋关节屈伸活动范围的测量值。在个体机器争边球中测量矢状脊柱运动（电磁运动捕捉）、躯干和股四头肌激活（肌电图）和施加的水平压缩力（测力板）。参与者进行了 5 次争边球试验，每次接触持续 5 秒，每次试验之间有 1-2 分钟的恢复期。然后，他们进行了疲劳协议（靠墙深蹲至力竭），并立即返回争边球机器进行另外 5 次试验。尽管疲劳对接触时施加的水平压缩力没有显著影响（P = .83），但颈椎前屈增加了 52%（P < .001），同时腹部和竖脊肌的激活减少了（低 18-23%）（P < .05）。此外，股四头肌的激活在初始争边球试验过程中降低（低 12-25%），但在疲劳后试验中增加（高 13-15%）（P < .05）。尽管运动员在疲劳的靠墙深蹲任务后能够保持力量输出，但由于前屈增加和高应用压缩力的组合，他们可能有更高的脊柱受伤风险；这种组合已被证明会增加椎间盘突出的可能性。
