my 1yr baby born at 33 week and 3 days ,normal delivery ,birth weight was 2.15kg .was in nicu for 3 days for observation. no other complaints were noted.his all milestone were in normal.but during crawling ,he is using army crawling ,and drag his left leg sometimes.he has developed squint of left eye ,noted at 4 month.power all was normal.ROP screening normal.After birth ultrasonogram was taken 2 times .one after 2 days and one after 1 week.all was normal.now he stand with support.only army crawling and some times drags left leg. not sit by himself.when we put on sitting posture he will sit and pull to stand on. he also have 4 upper teeth and 3 lower teeth.why he drags the leg? may be due to squint?