My new horse was 10 years old when I got her and had never been ridden. She was quite shy around people and therefor difficult to catch. We have been working together now for about a year, and each day I love her more than I did the day before. She has gotten over her shyness, due to very quiet, slow, gentle handling on the part of all who have worked with her. She actually is quite affectionate now that the shyness is behind her.
When I first began riding her, after she had spent 6 weeks at the trainer's facility, I remembered what I had forgotten since it had been so many years: totally green horses present very special challenges. With all green horses it's important to remember to go very slowly and patiently. Each time I alight in the saddle, I am reminded again what it's like to ride a horse who needs to learn all about communicating with a rider. In addition, an older horse is likely to be a bit more stiff. It's important then to work on developing a more supple horse - both laterally and longitudinally, as the lessons progress. How to supple? Spiraling in and out on a circle is great! Gentle turns on the forehand, even from the ground is excellent. And doing half-turns and reverse half-turns , as well as broken lines are all excellent ways to develop a more supple horse.
It is so true that we have to treat the older green horses differently! However, even though there may be more stiffness, I also find that they aren't as frisky (in general) as their younger counterparts. They have grown up and matured a bit, for the most part!