I am male 17. A few weeks ago I was playing football (soccer) and for shooting the ball I planted the other foot on the ground. When I planted the foot, I felt instant pain right from the moment of impact of foot on the ground at the back of an ankle especially on the inner sided back of the ankle (flexor retinaculum) and at the back (Achilles tendon) I think. After that my ankle was kind of stiff and a painful so I rested 1 and a half week but still it has stiffness. The pain was less even in running like on toes (not using these effected muscles) but whenever I tried to kick the ball and planted the whole foot on ground or stand on one leg, applying all muscles to work and it would trigger the pain and stiffness more. The pain and stiffness does become less when I message the effected area using thumb.