i have achilles tendonitis and i’m going to physical therapy for it but when im walking my achilles get very tight which tightens and makes my calves burn and achillse and it makes it difficult to walk if im walking long enough. also when im just sitting here right now and i extend my foot to its like pointing vertical and then relax it again i get a burning pain in my calves. also if i flex my calves this sensation happens also. if i flex my thighs the burning sensation is in my knees. what could this be from? my physical therapist said i had some scar tissue growing on my achilles also if that helps