If your horse does not take a left or right lead there may be a back subluxation and or rib issue.
Subluxations in the back specifically the upper back ie.withers will also affect the shoulder and lower neck.
If a rib is subluxated at its thoracic junction then bending will be difficult and your horse may feel stiff to that side or tend to throw his hind end out to make the turn.
Please contact me if these issues are present. Dr Bruce at 781-337-1180 or indekchiropractic@gmail.com