The Achilles tendon is in a very special position at the back of the heel. When a person stands, the whole Achilles tendon is in a tense state, because it needs to use muscle power to maintain the balance of the human body, so the whole Achilles tendon is in a tense state when touched by hand, and it can be felt like a bowstring when touched by hand. If there is a secondary rupture of the Achilles tendon, there will be a noticeable depression in the area, with no sense of tension, especially when compared to the Achilles tendon that has not been ruptured, which can be clearly detected. In addition, when the heel is lifted up while standing, the Achilles tendon is in pain, and there is a lack of strength, and the depression is even more pronounced, which is a clinical symptom. This can be further confirmed by an MRI or ultrasound, which shows a complete disruption of the continuity of the Achilles tendon.