Muscle architecture has a significant influence on the mechanical properties of skeletal muscles. Important parameters include the fascicle length, the angle of pennation, the physiological cross-sectional area (PCSA) as well as aponeurosis and tendon dimensions. During growth, skeletal muscles have to react to an increasing body mass and size demanding adaptations in muscle dimensions. Investigations of muscle architectural changes during growth are sparse, and existing studies often confine their scope to specific parameters or regions of the muscle. For this cross-sectional study, we determined the entire three-dimensional fascicle architecture of rabbit M. soleus via manual digitization. To this end, the investigations covered nine rabbits in the age-range between 29 days and 109 days. Fascicle length, muscle belly length, and aponeurosis length increased by 40%, 107%, and 111%, respectively. As the pennation angle remained almost constant and the contribution of fascicle length growth to muscle belly growth was minor, the increase in muscle mass primarily led to an increase in PCSA (462%), which required a similar increase in aponeurosis area (434%). Results gain new insight into the build-up of rabbit M. soleus and reveal that increases in muscle belly length are primarily connected to increases in aponeurosis length (83%). Contributions from fascicle length increase (17%) only play a minor role.

肌肉结构对骨骼肌的机械性能有重要影响。重要的参数包括束的长度，垂线的角度，生理截面积（PCSA）以及腱膜和肌腱的尺寸。在生长过程中，骨骼肌必须对不断增长的体重和体形做出反应，从而需要适应肌肉尺寸。对生长过程中肌肉结构变化的研究很少，而现有研究通常将其范围限制在特定参数或肌肉区域。对于此横断面研究，我们通过手动数字化确定了比目鱼比目鱼的整个三维分册结构。为此，调查涵盖了29天至109天之间的9只兔。束长度，腹肌长度 和腱膜长度分别增加40％，107％和111％。由于垂度角几乎保持恒定，而束长度的增长对腹部肌肉增长的贡献很小，因此，肌肉质量的增加主要导致PCSA的增加（462％），要求腱膜面积也有类似的增加（434％） 。结果获得了对比目鱼比目鱼肌形成的新见解，并揭示了肌肉腹部长度的增加主要与腱膜长度的增加有关（83％）。束长度增加的贡献（17％）仅起很小的作用。这要求腱膜面积也有类似的增加（434％）。结果获得了对比目鱼比目鱼肌形成的新见解，并揭示了肌肉腹部长度的增加主要与腱膜长度的增加有关（83％）。束长度增加的贡献（17％）仅起很小的作用。这要求腱膜面积也有类似的增加（434％）。结果获得了对比目鱼比目鱼肌形成的新见解，并揭示了肌肉腹部长度的增加主要与腱膜长度的增加有关（83％）。束长度增加的贡献（17％）仅起很小的作用。