Attacked By a Beggar

Recently I was in town for a few purchases (actually I was on my way home from the dentist) when a beggar attacked me.

I saw her sitting on the sidewalk from afar but had to pass her because there was no other way to the parking lot. As I passed her, she mumbled something in a foreign language. When I was already a few yards away she jumped on her feet, followed me, grabbed my wheelchair by the push handles and tried to tilt me backward.

I managed to regain my balance, turned around and shouted at her loudly and sharpy. Luckily, she was startled and ran away.

Did something similar happen to you? How can you actually defend yourself if the attacker does not run away?