kha-āu-kun跤後筋

Achilles tendon

Achilles tendon (strong tendon in the calf of the leg)

English Wiktionary, “跤後筋” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E8%B7%A4%E5%BE%8C%E7%AD%8B · confidence: Medium (Wiktionary)