Originally Posted by saraandgalaxy
... who was on break and not used at all over the winter.....
The root cause of many 'evils' (no fault implied). You would be surprised at how many people I know that send their horse to a trainer, get it back, ride it and say it's a wonderful horse, put it in the pasture for 6 months, and then wonder why their wonderful horse is almost unrideable (and then blame the trainer).
Just go back to basics like you are starting fresh. Your horse hasn't forgotten, just needs reinforcement and work to get back in the groove.