Milgrom Charles, Voloshin Arkady, Novack Lena, Milgrom Yael, Ekenman Ingrid, Finestone Aharon S
Military Track, Hadassah Hebrew University Medical School, Jerusalem 911200, Israel.
Department of Bioengineering, Lehigh University, Bethlehem, PA, USA.
Bone Rep. 2022 Feb 5;16:101170. doi: 10.1016/j.bonr.2022.101170. eCollection 2022 Jun.
There is a known variance in the incidence and anatomical site of tibial stress fractures among infantry recruits and athletes who train according to established uniform training programs. To better understand the biomechanical basis for this variance, we conducted axial strain measurements using instrumented bone staples affixed in the medial cortex, aligned along the long axis of the tibia at the level of the mid and distal third of the bone in four male subjects. Strain measurements were made during treadmill walking, treadmill running, drop jumps from a 45 cm height onto a force plate and serial vertical jumps on a force plate. Significance levels for the main effects of location, type of activity and their interaction were determined by quasi-parametric methodologies. Compared to walking, running and vertical jumping peak axial tensile strain (με) was 1.94 (p = 0.009) and 3.92 times (p < 0.001) higher, respectively. Peak axial compression strain (με) values were found to be greater at the distal third than at the mid tibia for walking, running and vertical jumping (PR = 1.95, p-value<0.001). Peak axial compression and tension strains varied significantly between the subjects (all with p < 0.001), after controlling for strain gauge location and activity type. The study findings help explain the variance in the anatomical location of tibial stress fractures among participants doing the same uniform training and offers evidence of individual biomechanical susceptibility to tibial stress fracture. The study data can provide guidance when developing a generalized finite element model for mechanical tibial loading. For subject specific decisions, individualized musculoskeletal finite element models may be necessary.
在按照既定统一训练计划进行训练的步兵新兵和运动员中，胫骨应力性骨折的发生率和解剖部位存在已知差异。为了更好地理解这种差异的生物力学基础，我们对四名男性受试者进行了轴向应变测量，使用固定在内侧皮质的仪器化骨钉，在胫骨中、远三分之一交界处沿胫骨长轴排列。在跑步机行走、跑步机跑步、从45厘米高度跳到测力板以及在测力板上连续垂直跳跃过程中进行应变测量。通过准参数方法确定位置、活动类型及其相互作用的主要效应的显著性水平。与行走相比，跑步和垂直跳跃时的峰值轴向拉伸应变（με）分别高出1.94倍（p = 0.009）和3.92倍（p < 0.001）。发现在行走、跑步和垂直跳跃时，远三分之一处的峰值轴向压缩应变（με）值高于胫骨中部（PR = 1.95，p值<0.001）。在控制应变片位置和活动类型后，受试者之间的峰值轴向压缩和拉伸应变存在显著差异（均p < 0.001）。研究结果有助于解释在进行相同统一训练的参与者中胫骨应力性骨折解剖位置的差异，并提供了个体对胫骨应力性骨折生物力学易感性的证据。该研究数据可为开发胫骨机械负荷的通用有限元模型提供指导。对于特定受试者的决策，可能需要个体化的肌肉骨骼有限元模型。
