i think i have an ankle issue???

can someone answer me why sometimes i feel like my Achilles tendon is not in the right place so that it feels like my leg is jamming into my ankle . . .kinda like its collapsing in . .i have no clue how else to describe it . . . should i just get an ankle brace iv been thinking about it because i have tendinitis in the same knee so i have a knee brace . . .