Johnson Caleb D, Davis Irene S
Spaulding National Running Center, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA.
Spaulding National Running Center, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA.
Clin Biomech (Bristol). 2021 Apr;84:105334. doi: 10.1016/j.clinbiomech.2021.105334. Epub 2021 Mar 23.
Acute hamstring injuries during sprinting have been attributed, in part, to the ground reaction forces experienced during early stance. However, no studies have investigated the factors associated with overuse hamstring injuries in endurance runners. Our purpose was to compare early stance ground reaction forces and step length between runners with overuse hamstring injuries and healthy controls.
23 runners (5 men/ 18 women) who presented to a running clinic with an overuse hamstring injury were matched with healthy controls for sex, running speed and age. All participants ran on an instrumented treadmill, embedded with force plates. A 3-min warm-up was given, at a self-selected training pace, followed by 16-s of ground reaction force data collection (≈20 strides). Statistical parametric mapping was used to compared ground reaction force waveforms. Additionally, discrete force variables were calculated, including vertical average/instantaneous. Mean comparisons for discrete ground reaction force variables and step length were performed.
Differences in ground reaction force waveforms did not reach statistical significance (p > 0.05). However, mean vertical loading rates were found to be higher in the Hamstring Injury group compared to Controls (p = 0.03-0.04) with small to moderate effect sizes (d = 0.47-0.52). No differences were found in mean step length.
These results provide evidence that vertical loading rates may be associated with overuse hamstring injuries. However, further research is needed to identify the contribution of joint kinematics/kinetics and muscle activity.
短跑过程中的急性腘绳肌损伤，部分原因是在初始支撑阶段所承受的地面反作用力。然而，尚无研究调查耐力跑运动员中与过度使用性腘绳肌损伤相关的因素。我们的目的是比较过度使用性腘绳肌损伤的跑步者与健康对照组之间的初始支撑阶段地面反作用力和步长。
23名因过度使用性腘绳肌损伤而前往跑步诊所就诊的跑步者（5名男性/18名女性），在性别、跑步速度和年龄方面与健康对照组进行匹配。所有参与者在装有测力板的仪器化跑步机上跑步。先以自选的训练速度进行3分钟热身，随后收集16秒的地面反作用力数据（约20步）。使用统计参数映射来比较地面反作用力波形。此外，计算离散力变量，包括垂直平均力/瞬时力。对离散地面反作用力变量和步长进行均值比较。
地面反作用力波形的差异未达到统计学显著性（p>0.05）。然而，发现腘绳肌损伤组的平均垂直负荷率高于对照组（p = 0.03 - 0.04），效应大小为小到中等（d = 0.47 - 0.52）。平均步长未发现差异。
这些结果表明垂直负荷率可能与过度使用性腘绳肌损伤有关。然而，需要进一步研究来确定关节运动学/动力学和肌肉活动的作用。
