Stenroth Lauri, Thelen Darryl, Franz Jason
Department of Applied Physics, University of Eastern Finland, Finland.
Faculty of Sport and Health Sciences, University of Jyvaskyla, Finland.
Transl Sports Med. 2019 Mar;2(2):73-81. doi: 10.1002/tsm2.61. Epub 2018 Dec 1.
The Achilles tendon is a common tendon for the medial and lateral gastrocnemius and soleus muscles. Non-uniform Achilles tendon regional displacements have been observed which may result from non-uniform muscle loading and intra-tendinous shearing. However, prior observations are limited to the sagittal plane. This study investigated Achilles tendon tissue displacement patterns during isometric plantarflexor contractions in the coronal and sagittal planes. Fourteen subjects (5 female, 9 male, 26±3 yr) performed maximal isometric plantarflexor contractions with the knee in full extension and flexed to 110°. An ultrasound transducer positioned over the free Achilles tendon collected beam formed radio frequency (RF) data at 70 frames/s. Localized tissue displacements were analyzed using a speckle tracking algorithm. We observed non-uniform Achilles tendon tissue displacements in both imaging planes. Knee joint posture had no significant effect on tissue displacement patterns in either imaging plane. The non-uniform Achilles tendon tissue displacements during loading may arise from the anatomical organization of the sub-tendons associated with the three heads of the triceps surae. The biplanar investigation suggests that greatest displacements are localized to tissue likely to belong to soleus sub-tendon. This study adds novel information with possible implications for muscle coordination, function and muscle-tendon injury mechanisms.
跟腱是腓肠肌内侧头、外侧头和比目鱼肌的共同肌腱。已观察到跟腱区域位移不均匀，这可能是由于肌肉负荷不均匀和腱内剪切力所致。然而，先前的观察仅限于矢状面。本研究调查了在等长跖屈收缩过程中跟腱组织在冠状面和矢状面的位移模式。14名受试者（5名女性，9名男性，26±3岁）在膝关节完全伸展和屈曲至110°时进行最大等长跖屈收缩。一个置于游离跟腱上方的超声换能器以70帧/秒的速度采集波束形成的射频（RF）数据。使用斑点追踪算法分析局部组织位移。我们在两个成像平面中均观察到跟腱组织位移不均匀。膝关节姿势对任一成像平面中的组织位移模式均无显著影响。负荷过程中跟腱组织位移不均匀可能源于与小腿三头肌三个头相关的子腱的解剖结构。双平面研究表明，最大位移集中在可能属于比目鱼肌子腱的组织上。本研究增加了新信息，可能对肌肉协调、功能和肌腱损伤机制具有启示意义。
