I have a 4 year old mare that's very broke, she had 10 months of reining training in the past with a very good trainer. I am trying to start her on barrels now but I am finding some challenges I haven't had with other horses. 

when I move into a smaller circle especially to the left we wants to lose forward momentum and get stiff in the ribcage and neck. I had her looked at by a great performance vet, he had no concerns. I had a body worker and a chiro/ massage both look at and treat her. She did have a shoulder and hip that needed adjustment they both agreed and she's been treated and will continue to make sure everything is in its proper alignment and not sore. And we have been doing daily stretches. 

I am looking for som drills or things I can do to strengthen the muscles and get her to drive forward with a soft ribcage. I keep the circle larger maybe 15 feet or so and really really  have and push and keep tapping the inside leg. It's exhausting to have to push that hard to keep her moving! She is wanting to stiffen and elevate in the front.

She is cowbred and has a bigger barrel and I do think that makes it harder to bend and bring the inside hind forward perhaps? 

I had a very nice mare, that turns out to have Hi/Low Symptom, and a bad case of it. She struggled greatly turning to the left, and would stiffen, and struggle in any smaller kind of circle. Stand behind your horse, unsaddled, on a bucket or something, and look towards her head, and check and see if her shoulders are even or not. My mare had a bulging right shoulder, and a very flat left shoulder. The saddle had a tendency to want to shift to the left also. Just some things to check out. The reining training may also cause some communications issues??

Counter cantering and counter bending excercises helps my horse, moving her forehand and disengaging her hind end in warm up too. I work both sides equally. Plus riding a lot of long and low out in the pasture.  I feed her on the ground too in a tub.   She is over developed on the left side and wants to be stiff, she also has high low syndrome like the other poster mentioned.  Before I got her they switched her left to right because of the stiffness but with those exercises I have been able to swtich her back to right left.  My veterinarian does body work and rides dressage.  She has a horse with a similar issue so I pick her brain.

Thank you! I will look into that! At first I did think the reining training was the issue since they teach big fast circles and small slow circles and I realized she doesn't really seem to understand to keep moving forward with flexsion so working on that. 

Is the high low syndrome a problem with their feet, specifically the heel height varying? I hadn't heard of it and googled and that's what I am getting?  

The training between the big fast to small slow shouldn't be an issue. They still need to be soft, round and driving from behind on the small slow.

Where I have noticed resistance and stiffening (which will cause the lack of drive) in a small circle is if the horse had been schooled too much in the spin rather than taken out of the spin, corrected then put back in it. Or if they were asked for too much speed in the spin before they were ready and the correctness wasn't there. If that was the case, who knows if the stiffness was the symptom or the problem.

The following might not be appropriate for barrel horses. They are exercises I use on my cow horses.

I'd probably start by isolating the body parts, sometimes a hip or a shoulder in the way can keep the rib from moving over. Like said before, counter arcing. I do a lot it at the trot and in my warm up before I ask for the counter canter to get things broke loose and not picking a fight.

Backing circles can be really telling on where they are stuck out and help get them broke loose. If your horse was reiner he should know how to do it. If you're not sure, take it slow at first, it can scare them.

Spiraling in and out of circles while driving them into the bridle and making them hold the same bend as the circle you're on. When you get to the size of circle where he tends to bow out on you and get stiff only ask for a couple steps with the correctness you're seeking then start pushing back out to bigger circle that is comfortable for him. As he gets better you should be getting more correct steps in the circle you want and soon making a complete circle then multiple.

Yes basically.  It is where one angle on one hoof is higher or lower than the other hoof however you look at it.  I have seen it man made and horses born with it.  I use to run a lot of cowbred running cross horses and saw this more than I would like to but the majority never had an issue with it.  My new mare is the first that I felt it made a noticeable difference.  x-rays suggest it is not man made so we do not try to match the hoofs by trimming, we work with her body as a whole.  Also her teeth were a mess, over floated and since we have worked on those it has helped her as well.

Thank you I will try those things! 

Was it fairly obvious by looking in most cases or do you sometimes need xrays to be able to tell if they have it?

My reiner had a hard time with that too, but to the right. Trying to get her to bend made her nervous. I just deal with it now and she turns nice right turns so I dont fight. I think it was from overschooling on spins.

IMO reining has been ruined by the western pleasure trainers that have run out of old rich women with the 10k outfits on and have now invaded the reiners due to the rich purses and the judges being trainers one week and then contestants the next week.  Judged events have always been political with those in the present cliques winning the high dollar events.  

Think back .. you have never seen a WP horse for sale as a nice riding trail or pasture horse because they have been injured due to how they were forced to carry themselves with nose on the ground and trot, lope in the same place as they were being judged and trained.  The judges are at fault for giving high pts against AQHA Rules for the way reiners now carry themselves.  A horse naturally raises its head when stopping and backing is not a natural movement for a horse loose in a pasture... backing is now used as a punishment along with weighted reins and harsh bits.  I would sure like to see the bit checker make them drop the bits and show what is in that horses mouth .. bit inspection may not be in the reiner rules anymore .. ??? ..  

What you see now are the saddest horses with fear in their bodies and heads standing in the arena during each movement in the chosen reining pattern. Like the famous Last Trail statue of the Indian Sitting on his horse.  

The poster looking at the larger shoulder was actually looking for muscle atrophy in the other shoulder and those looking for rib bending were looking for tendon damage in the sensory in one of the rear feet causing the horse to favor the other leg due to a lead change around a barrel.  This is due to hanging a rear toe in training with sliding plates on the rear.  I bred a barrel bred mare to Automatic Cat that had ended his future with this injury and he has a fantastic pedigree reining/cutting pedigree ...  Automatic Cat Quarter Horse   (allbreedpedigree.com)   This will not affect the red roan filly I had by him ... 

Here are two youtube videos to show what has happened to reiners in the show pen .. https://www.youtube.com/watch?v=DN0zDQLcPk0  

and here is the same horse being corrected for stopping to soon and not high stepping his front end in a sliding stop ... this the first video of Clinton Anderson starting the correction training ... take note of his inspection of the crooked ski tracking due to one rear foot sliding to the outside ...  this another way for a horse to injure the suspensory ligament ...  Clinton Anderson Presents: Titan a Legend in the Making, Lesson 9, Part 4 - Downunder Horsemanship - YouTube  

I know you are looking for a simple means to get your horse to run barrels evenly to the right or left turns ... time and pasture riding is your best friend ... You may find grand entries at rodeos is a great distraction from working in an arena ....Use the lightest smooth mouth snaffle bit possible which CA sells for around $45 with no curb chain ... teach horse to be lazy in the pasture... go back to side passing,,,,, two tracking ... and NO BACKING, SPINNING OR ROLLBACKS  ... listen closely to the CA series when he mentions the horse is trained to stop on his strongest lead ...  etc etc ... therefore ... the horse is going to stiffen up due to training and refuse to move his tight side. 

IMO you can spend the next year totally out of an arena overcoming cues and his previous training with casually learning the cues you use for barrel racing .... try to ride with other horses and play train to get your horse to enjoy himself .... or sell this one and move on to one that has been trained the basics by a good colt starter ... 

I know this sounds harsh but you are having to undo the reining training and the inbuilt anticipation the horse has in order to setup his new career ... GOOD LUCK 

The low headset fad in reining didn't come from western pleasure trainers getting into reining. About 20 years ago a well known and now a million dollar rider/trainer was rewarded a big win on a colt that had a low head set and everyone followed suit by trying to imitate and breed for it. I'm not saying some didn't try to beat it into their horses as there are trainers no matter the discipline that will go that route.

Automatic Cat was bred for and was in training for the NRCHA Futurity, not reining. Nothing in his bloodlines jumps out as a reiner. The dry work/reining portion in reined cow horse is judged differently than reining so I'm not seeing the relevance anyhow.

CA isn't exactly the epitome of the reining horse world. I didn't watch the video but scotching a stop is an anticipation problem and needs to be corrected. Anticipation is the kiss of death in the pattern, you spend most of the time to keep them from anticipating not training it into them.

As far as bits go, bit checks are usually not done by the judges but someone as they come out the gate after their run. So no illegal bits in the show pen.

Not all reining horses trainers are evil nor are the horses ruined and unfit for a different job if they aren't going to make the cut. Many reiner flunk outs make great ranch and versatility horses, that's where I good portion go as the popularity of those classes have grown. I know of many that made good backyard horses. Rope horses and barrel horses depending on the bloodlines. Some of the reining lines aren't quick footed enough.

But beyond that, a know a lot of people who send their barrel or rope prospects to a reining or reined cow horse trainer to get them broke, soft, working from behind and off your leg making the transition to the barrel pattern or the box pretty slick.

If you are going to be an authority on something name names, places and details ... 

Tell us what is the major conformation difference on cutters and reiners ? 

To clarify the stallion AUTOMATIC CAT he got injured practicing sliding stops while the clay was too slick after a summer thunderstorm. 

Have fun reading his loaded pedigree and his credentials ...  Automatic Cat | Facebook  

There are 3 events a NRCHA has to compete in at their events .... and take note of his sires banner at the exit gate .. SMOOTH AS A CAT ..  ARC Sparkin Chics ridden by Doug Williamson - 2019 NRCHA Derby Open Bridle Spectacular cow work - Bing video  HOPE YOU ENJOYED .. 

NRHA reiners are judged differently than NRCHA, you said Automatic Cat was cutter and reining bred. No, he is not.

Both the reined cow horse and obviously reiners do a reining pattern but they are two different styles. You're going on about reiners and wp and then thrown in Automatic Cat blew a suspensory on bad ground while in training for the NRCHA Futurity. Posting a video of Doug Williamson showing...NRCHA. What does it have to do with reiners? And bad ground is bad ground no matter what the training is. It wasn't on purpose. 

I know who Automatic Cat is. I'm familiar with Smooth As A Cat. Still nothing is in his bloodlines for the top 70 in Reining. Cutting, yes. Smooth as a Cat is in the top 10 leading sires for cutting.(I forgot to add Smooth As A Cat is in the top 15 sires reined cow horse- not Reining) Duel Pep is also  still in the top 60(?) Cutting I believe. (Top 10 in reined cow horse- not reining. Edit to add...that was Duel Rey not Duel Pep, nevermind.)

The Wheeling Peppy horse that is in black type is the only horse that sired some offspring with NRHA winnings but it doesn't make Automatic Cat specifically reiner bred.