Department of Medical Imaging of Domestic Animals and Orthopaedics of Small Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
Human Movement Biomechanics Research Group, Faculty of Movement and Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
J Anat. 2018 Oct;233(4):460-467. doi: 10.1111/joa.12845. Epub 2018 Jul 9.
Although the form-function relation of muscles and tendons has been studied extensively, little in vivo data exist on the musculotendon properties of the gastrocnemius complex in dogs. Using a combination of ultrasound and 3D motion tracking, musculotendon parameters were obtained in vivo from the lateral gastrocnemius muscle and the gastrocnemius tendon in nine healthy Labrador Retrievers. These parameters include musculotendon length and excursion potential, tendon slack length, muscle belly length, muscle fibre length, pennation angle and architectural index. This study also examined the variation of muscle and tendon length contributions to musculotendon length, as well as the relation between musculotendon excursion potential and muscle fibre length or tendon length. To facilitate comparison between dog breeds, the femur length as a potential scaling parameter was examined. In the Labrador gastrocnemius musculotendon complex, the tendon contributes 41% (± 9%) of musculotendon length. In longer musculotendon complexes, the contribution of the muscle belly increases while the tendon contribution decreases. Longer muscle belly and musculotendon complexes were, however, associated with shorter muscle fibres. No significant relations were found between musculotendon excursion potential and muscle fibre length or tendon slack length, and femur length did not prove to be a reliable scale factor for the length-related musculotendon parameters examined in this study. Longer musculotendon complexes exhibit relatively longer muscle bellies, which are in turn associated with shorter muscle fibre lengths. This trade-off between gastrocnemius muscle belly length and muscle fibre length might have the advantage that muscle volume stays constant regardless of the length of the limbs.
尽管肌肉和肌腱的形态-功能关系已经得到了广泛的研究，但关于犬类腓肠肌复合体的肌肉-肌腱特性的体内数据却很少。本研究采用超声和 3D 运动跟踪相结合的方法，从 9 只健康的拉布拉多猎犬的外侧腓肠肌和腓肠肌腱中获得了体内的肌肉-肌腱参数。这些参数包括肌肉-肌腱长度和拉伸潜力、肌腱松弛长度、肌腹长度、肌纤维长度、羽状角和结构指数。本研究还检查了肌肉和肌腱长度对肌肉-肌腱长度的贡献变化，以及肌肉-肌腱拉伸潜力与肌纤维长度或肌腱长度之间的关系。为了便于比较不同犬种，还检查了股骨长度作为潜在的比例参数。在拉布拉多猎犬的腓肠肌-肌腱复合体中，肌腱占肌肉-肌腱长度的 41%（±9%）。在较长的肌肉-肌腱复合体中，肌腹的贡献增加，而肌腱的贡献减少。然而，较长的肌腹和肌肉-肌腱复合体与较短的肌纤维有关。肌肉-肌腱拉伸潜力与肌纤维长度或肌腱松弛长度之间没有显著的关系，股骨长度也不能作为本研究中检查的与长度相关的肌肉-肌腱参数的可靠比例因子。较长的肌肉-肌腱复合体表现出相对较长的肌腹，而肌腹又与较短的肌纤维长度有关。这种腓肠肌肌腹长度和肌纤维长度之间的权衡取舍可能具有优势，即无论四肢的长度如何，肌肉体积都保持不变。
