If gill maybury will cover your area then highly reccommend her!!!!! She has worked wonders on my horse and is an experienced horsewoman who has competed at badminton.
Jane Pennick aka 'the blind lady' to many. She's a qualified human and equine physio, she's been doing my horse for nearly 10 years (way before I got him!).
Gill is a chiro ( physio is same thing ) she needs to see how the horse moves and then will manipulate it ( my horse has electrodes and laser treatemt too ).
I have a lady called Stephanie Appleton, she was highly recommended to me by several people. She covers Essex aswell. PM me if you would like her number.