Q: I just noticed yesterday when I was playing Simon Says with my five-year-old that I can no longer stand on my left leg without falling over. I did have surgery on that side two years ago for a badly sprained ankle. But I went through Physical Therapy and everything seemed fine back then. Is this normal? Should I be worried?
A: What you are describing might be something referred to as functional instability. More formal testing would be needed to know for sure -- and to advise you what to do. Functional instability just means the ankle holds up for you during daily activities. It doesn't give out when standing, walking, or otherwise challenged (e.g., on hills or uneven surfaces). But when you try to balance on it, there are some obvious deficits that show up.
One of the problems may be a lack of normal proprioception. This refers to the joint's sense of its own position. Receptors in the joint that signal the brain where the joint is and when a shift in position occurs aren't firing properly. The signals may be absent, delayed, or too weak to allow the joint to stay stable under stress or challenge.
One thing you can try is to stand on the other (uninjred) leg and see if this is a general balance problem or just specific to the post-surgical side. In either case, some remedial work is advised to prevent future injuries or reinjuries.
Your Physical Therapist is the best one to re-evaluate you and set up a plan for functional rehabilitation. The therapist has the advantage of reviewing your discharge notes to see what the status of your balance was at that time and compare it to now. This may help you understand what happened, what is going on now, and what to do about it. You are fortunate that a simple children's game brought this to your attention now. Simon says: you can do something about it!
Reference: John G. Kennedy, MD, MCh, MMSc, FRCS (Orth), et al. Anatomic Lateral Ligament Reconstruction in the Ankle. In The American Journal of Sports Medicine. October 2012. Vol. 40. No. 10. Pp. 2309-2317.