石川さんの研究がPLoS Oneに掲載

石川さんの研究がPLoS Oneに掲載されました。

運動学的な観点から胚子期-胎児初期における下肢筋骨格構造の発達を明らかにし、筋と骨格の発達過程を比較することを目的にしました。29例の標本を位相CT, MRIを用いて得た画像から、膝関節構成要素の形態形成、滑車溝角度、および大腿筋の仮想的な関節運動を3次元で分析しました。関節形態の安定化がスムーズな関節運動を可能にし、それが筋量および関節運動の増加につながることを示唆する結果が得られました。

Ishikawa A, Nagai-Tanima M, Ishida K, Imai H, Yoneyama A, Yamada S, Otani H, Aoyama T, Takakuwa T. Morphogenetic development of trochlear groove and thigh muscles from embryo to fetus in humans, PLOS ONE 21(2): 2026, e0339167. https://doi.org/10.1371/journal.pone.0339167

Mechanical forces caused by fetal movements are essential for normal musculoskeletal development. However, the relationship between skeletal development and knee joint motion in utero remains unclear. We aimed to clarify the development of lower limb musculoskeletal structures during the embryonic and early fetal stages from a kinematic perspective and to compare muscle and skeletal developmental processes. We analyzed 29 human embryonic and fetal specimens. Using phase-contrast X-ray computed tomography and magnetic resonance imaging, we analyzed the morphogenesis of the knee joint components, trochlear groove angle, and hypothetical joint motion of the thigh muscles in three dimensions. The trochlear groove angle on the plane vertical to the femoral axis decreased from approximately 160° to 130° until 120 mm Crown-rump length (CRL) and remained constant until 185 mm CRL. All hypothetical joint motions increased slowly between 30 and 100 mm CRL, whereas rapidly after approximately 100 mm CRL. The protrusions of the lateral femoral condyle became more pronounced from fetal stage as they grew. The timing of the onset of fetal movement and the increase in muscle mass and joint motion during early pregnancy were consistent with those of previous studies, and the timing of the angle stabilization occurred almost simultaneously with the rapid increase in femoral muscle mass and hypothesized joint motion. It suggested that stabilization of joint morphology enables smooth joint motion, which leads to an increase in muscle mass and joint motion.