When I think of horses that balk—or refuse to move forward, I recall the ponies I had as a child that seemed to have this behavior down to a fine art. I vaguely remember drumming my heels on their sides while pulling back and forth on the reins, frantically trying to get the pony to move forward (helmet-less and with bare feet no less). Now, more than forty-five years later I know better, although I still encounter horses that balk. My mare is very insecure about going out trail riding alone and will start to balk if we head towards the barn door opposite to the one that leads to the arena or field where she's happy. Thankfully, because she is very obedient, it only takes some assertive seat and leg aids to send her down the trail.
Horses balk for many reasons. Like my mare, they may be nervous about certain situations and rather than spook and try to flee, they freeze. These horses lack confidence and need to be ridden by a rider who they trust. A horse may balk because they are feeling physical pain. I can only imagine that my childhood ponies wore ill-fitting saddles or perhaps had foundered – a condition that will cause hoof pain. Poor saddle fit, teeth issues, vision problems, hoof pain and chiropractic issues may cause a horse to balk or spook. Most ponies are very clever, so once mine learned they didn't have to obey a not-so-smart little girl, it became an ingrained response. A horse may balk because you are giving it conflicting aids—pulling on the reins inappropriately while urging it on with your leg aids.
Horses don't balk because they are lazy. It actually takes more energy to balk than to be obedient. Some people suggest backing up a balking horse up, but I feel this may be a mistake, especially with a horse that may be inclined to rear. Simply pushing them forward is sometimes counterproductive. Unless your horse is very obedient, it may only resist more assertively. Some horses will respond to a tap on the haunches with a crop or whip, but you need to time your aid well and be consistent. This can be difficult for a beginner who may not know when to apply both natural and artificial aids at the same time.
One exercise that is useful for dealing with a balking horse is the Tteam method that includes the “Dingo” cue. By teaching the horse to respond to the touch of a wand (whip) on its haunches when in hand, the cue can then be used in the saddle. It's more fun to be in the saddle, but working on problems in the ground can often be the shorter road.
Another way to work through a balk is too busy the horse's mind with something else. If your horse doesn't go forward, you can turn it in a small circle, asking it to obey with your rein, seat and leg aids. The idea is not to spin the horse so it becomes disoriented, but to take its mind off of balking. Like you and I, horses can only think of one thing at a time! Alternatively, if your horse and you understand how to do a leg yield, a half or full pass, you may 'practice' these for a few moments to distract the horse. During these exercises, you need to stay relaxed and confident, remembering to breathe and look where you want to go, not at the horse.
Breaking the habit of balking can take time. Just like the process of de-spooking your horse, you may need the help of a coach or instructor who will help you learn the appropriate aids and timing. Certainly, if your horse seems inclined to balk and rear, it's time to get professional help..