The University of Queensland, School of Biomedical Sciences, Brisbane, QLD 4072, Australia.
The University of Queensland, School of Health and Rehabilitation Sciences, Brisbane, QLD 4072, Australia.
Clin Biomech (Bristol). 2021 Mar;83:105254. doi: 10.1016/j.clinbiomech.2020.105254. Epub 2020 Dec 25.
Shear wave elastography can measure shear wave speed in muscles, which is used to estimate shear modulus. Normative values and standardized methodology are needed for children. Study aims were to: estimate shear modulus behavior of lower limb muscles of typically developing children; and establish a profile of reference data and recommendations for clinical assessment.
Forty-one typically developing children (mean 9.7 y, SD 1.9 y) completed assessment of resting shear modulus of rectus femoris, biceps femoris, gastrocnemius lateralis and tibialis anterior at short and long lengths using shear wave elastography. Effects of muscle length, age, sex and BMI were examined. Then, our data and data from a scoping review for typical individuals were collated according to Net-Longitudinal Tension Angle (net proximal and distal joint angles).
Shear modulus was: higher at long versus short muscle lengths for all four muscles (P < 0.001); correlated with increasing age for tibialis anterior at short (r = 0.39) and long lengths (r = 0.42) (both P = 0.01); but not related to sex or BMI. Shear modulus: tended to increase with increasing Net-Longitudinal Tension Angle for 18 lower limb muscles; and was higher for children than adults for some muscles (e.g. tibialis anterior and gastrocnemius lateralis, both P < 0.001).
In typically developing children, shear modulus of lower limb muscles increases with increasing Net-Longitudinal Tension Angle. Recommendations enable comparison of values across different test positions and populations. Some relation between shear modulus and age was identified, but more research is needed.
剪切波弹性成像可测量肌肉中的剪切波速度，用于估计剪切模量。儿童需要有规范值和标准化方法。本研究旨在：估计正常发育儿童下肢肌肉的剪切模量行为；并建立参考数据和临床评估建议的概况。
41 名正常发育的儿童（平均 9.7 岁，标准差 1.9 岁）使用剪切波弹性成像完成股直肌、股二头肌、腓肠外侧肌和胫骨前肌在短缩和伸长长度时的静息剪切模量评估。研究了肌肉长度、年龄、性别和 BMI 的影响。然后，根据净纵向张力角（近端和远端关节角度），将我们的数据和典型个体的综述范围数据进行整理。
所有 4 块肌肉的伸长长度的剪切模量均高于缩短长度（均 P < 0.001）；胫骨前肌的缩短长度（r = 0.39，P = 0.01）和伸长长度（r = 0.42，P = 0.01）与年龄呈正相关；但与性别或 BMI 无关。18 个下肢肌肉的剪切模量：随着净纵向张力角的增加而增加；对于一些肌肉（例如胫骨前肌和腓肠外侧肌，均 P < 0.001），儿童的剪切模量高于成人。
在正常发育的儿童中，下肢肌肉的剪切模量随净纵向张力角的增加而增加。建议可用于比较不同测试位置和人群之间的数值。虽然确定了剪切模量与年龄之间的某些关系，但仍需要进一步研究。
