Surgeon, Department of Orthopedic Surgery, Saiseikai Nara Hospital, Nara City, Japan.
Professor, Faculty of Sport Sciences, Waseda University, Tokorozawa, Japan.
J Foot Ankle Surg. 2021 Jul-Aug;60(4):753-756. doi: 10.1053/j.jfas.2021.02.008. Epub 2021 Mar 6.
Impingement between the Achilles tendon and the posterosuperior prominence of the calcaneus is considered to be a cause of insertional Achilles tendinopathy. The corresponding treatment intends to reduce tensile stress from calf muscles and avoid hyper-dorsiflexion of the ankle joint for decreasing the contact pressure; however, no study has reported on whether these treatments can decrease impingement. Thus, this study investigated the hypothesis that the tensile stress of the Achilles tendon and ankle motion affect the contact pressure between the Achilles tendon and the posterosuperior prominence of the calcaneus. Six fresh-frozen cadaveric lower leg specimens were procured. Each specimen was set to a custom foot-loading frame and loaded with a ground reaction force of 40 N and a tensile load of 70 N along the Achilles tendon. The contact pressure between the Achilles tendon and the posterosuperior prominence of the calcaneus was measured using a miniature pressure sensor under different tensile loadings of the Achilles tendon at the neutral ankle position. Similarly, the contact pressures during the ankle motion from a neutral position to maximum dorsiflexion were measured. The tensile load of the Achilles tendon and ankle motion affected the contact pressure between the Achilles tendon and the posterosuperior prominence of the calcaneus. The contact pressure increased with tensile load or ankle dorsiflexion. Conditions with increasing the tensile load of the Achilles tendon or under ankle dorsiflexion increase the contact pressure between the Achilles tendon and the posterosuperior prominence of the calcaneus.
跟腱与跟骨后上突之间的撞击被认为是跟腱止点病的一个病因。相应的治疗旨在减少小腿肌肉的拉伸应力，避免踝关节过度背屈，以降低接触压力；然而，尚无研究报道这些治疗方法是否可以减少撞击。因此，本研究假设跟腱的拉伸应力和踝关节运动影响跟腱和跟骨后上突之间的接触压力。本研究使用定制的足加载框架，将 6 个新鲜冷冻的小腿标本固定在框架上，分别施加沿跟腱方向的 40N 的地面反作用力和 70N 的拉伸力。在中立踝关节位置下，测量不同跟腱拉伸力下跟腱和跟骨后上突之间的接触压力，使用微型压力传感器进行测量。同样，测量从中立位置到最大背屈的踝关节运动过程中的接触压力。跟腱的拉伸力和踝关节运动影响跟腱和跟骨后上突之间的接触压力。接触压力随拉伸力或踝关节背屈而增加。增加跟腱拉伸力或踝关节背屈的条件会增加跟腱和跟骨后上突之间的接触压力。
