why my daughter locks her legs in a strange possition

My daughter is 2 years and 4 months and since she was about 1 year she started locking her legs together and some times she standing is her hands like if she is doing push ups, except that she locks her legs and while she does this she sweats as if she is holding her breath, she does talk some but she is not able to tell me what is going on... I ask her if she is on pain but she does not respond, also she is very aware of what is going on around her and if I get her attention wile she does this she responds. It is usually her right keg on top of the left. Can someone knows what is going on? thanks.