Although I do recommend some products (and subsequently earn a little bit of commission off the top of anyone purchasing these products using the links below [thank you guys]), feel free to buy whichever product/ variation you would like. I have gone through a number of reviews and products to try to recommend what I would think is the best combination of value for money and quality product.
Physiotherapy/ rehabilitation devices
Ankle weights:
The reason why I selected these ankle weights over others was because of the reviews - strong D-ring buckles, adjustable velcro and low cost.
Books
101 Dressage exercises for Horse and Rider
One of my favourite quotes is 'When you're not training, you're untraining' - this book is such a good resource to help plan schooling sessions. The thing which I like the most about it is that the book is split into different chapters based on what you are trying to improve in your horse - suppleness, straightness, canter, etc.
NB: The book does have a plastic comb at the top and you therefore have to flip pages over - personally find that kind of weird but it is a really useful book.
Dressage 101
The only thing that I did not like about this book was the fact that Jane Savoie has sadly passed away since it was published. After reading the first few pages, I wanted to meet Jane - her outlook into how a horse stands and moves is well aligned with my own. Helping a horse to develop balance and understand how its body works is essential in developing not only a quality dressage horse, but a healthier horse which holds a better posture.
Although this is not really a book to help with training (albeit there are some tips), I thought that it was really good at helping any owner understand key concepts of dressage and what they are supposed to look like, building on the last chapter to develop a well rounded and balanced horse.