The horse I ride is very stiff- I know this because of a NH session with him lol, anyway. usually at the begining of the lesson we are free to warm up how we like (in walk) whilst every sorts their girths, stirrups and mounts etc. Is there anything I can do to make him flex more? Before I get on I do some neck stretch things (hard to explain) which the NH lady said worked well. What else could I do?