On Gaited Horses' website they give this little tidbit about heavier riders which considers bone mass to some extent by measuring cannon bones. Here is what they say... I feel this is a another option and a viable way (pun intended) to determine more closely how much weight a horse can carry during equestrian travel.
The Heavier Riders’ Guide
to Comfort and Safety with Gaited Horses
By Beverly Whittington and Rhonda Hart-Poe
The U.S. Calvary published “The Cavalry Manual of Horse Management”, by Frederick L. Devereux, Jr., in 1941. He recommended that the collective weight of rider and gear not exceed 20% of the total weight of the horse. These were horses in top condition whose riders’ very lives depended on the horse's ability to carry them long miles, often at speed. It stands to reason that if they were to incorporate a margin of error, it would be on the side of the horse being overly capable of carrying its rider, rather than less so.
Comparably, a study of 374 competitive trail riding horses compared horse/rider weight relationships. They concluded that these horses can easily carry over 30% of their body weight for 100 miles and not only compete, but compete well. As would be expected, good body condition and bone structure were found to be paramount. Bone structure was evaluated using the front leg cannon bones as representative of general structure.
|Measurement Test |
Values near 75 are great, below 75, even better.
Values from 75/80 are acceptable.
Values over 80 indicate weaker legs and a need to train carefully, especially downhill.
Values over 85 suggest you need a horse with more substance.
Damascus rates near the end of the acceptable range, but should still be able to carry Lady comfortably.
*Note that cannon bone circumference (as overall bone substance) increases with the horse's fitness level, so if he is borderline, like Damascus, it doesn't necessarily mean you're too big for him. By “racking” up Long - slow - distance (LSD) miles, which builds up bone over time, he may measure up yet. Be patient: it can take up to three years for bone to remodel. But don't expect a miracle either. This is a slight variance from the original bone mass. Just as if a person where doing bone mass building exercises the changes are small overall.
Condition Your Horse
Obviously no horse should be ridden if he is unsound or in pain. Add a heavy load on his back and the horse must be more than just sound, he should be fit.
The overweight or out-of-shape horse must be conditioned, slowly, prior to carrying a heavy load. Consult with your trainer or vet for the best way to condition your individual horse. Unfortunately, the average “back yard horse” is generally not in any better condition than the average “weekend rider”, which includes a lot of us. Such horses should not be expected to carry more than 20 to 25% percent of their body weight. Add a rider who is heavier, and possibly less balanced and/or athletic, and it becomes obvious that the stouter and/or better conditioned horse will be more able to carry the load comfortably, safely, with less chance of injury.
Have your veterinarian perform a thorough “soundness” exam. Explain that the horse will be carrying extra weight and ask him or her to be especially thorough in his evaluation of the horses back structure and the suspensory ligaments in the legs.
Next, have a qualified farrier look at the horse's hooves. Be sure he watches the horse travel at a walk and in gait, moving straight and in a circle. The hoof should be balanced, as odd angles or heights increase the stress on his feet, legs and back. Many horses need to be shod to maintain a balanced foot, as they wear their hooves unevenly if left unshod.
Be sure you can mount a horse fairly quickly without hanging on the side of the horse or "plopping" down into the saddle. Any rider who gets their foot in the stirrup then struggles up the side of the horse, puts undue stress on the horse's shoulder and back. Use a stable mounting block when possible to reduce strain to the horse, however, don't consider it the ultimate answer. Unless you have a physical handicap that precludes it, for safety and convenience sake, you should be able to get on your horse.
Make sure you are mounting the horse correctly. DO NOT pull yourself into the saddle. Place your left foot into the stirrup, toes pointing towards the horse's head so as not to “jab” him in the side, push off on the right leg and raise yourself up in one smooth motion by straightening the left knee. Then swing your right leg over the horse’s rump and settle gently into the saddle.
To dismount slip both feet from the stirrups, turn in the saddle and hop down. This requires some finesse on your part, but is much easier on the horse’s back that pulling all your weight to one side as you climb down.
Improve Your Seat
A balanced seat means having your weight distributed equally on either side of the horse, while having your body aligned along the points of gravity. A plumb line dropped from your ear should intersect the point of your shoulder, the second sacral vertebrae, hip and ankle.
One of the easiest ways to adjust your leg position to keep the proper muscle groups of the inner thigh in contact with the saddle is to 'roll' your thighs. Sitting with the ball of your foot in the stirrup, reach down and grab the fleshiest part of the back of your thigh and pull it back and out. This rolls the flattest muscles of the inner thigh against the saddle resulting in a much more secure seat. If it feels uncomfortable at first, persevere. Your muscles are not used to being used properly and may protest. With practice you will find that the aches will go away and a more secure seat becomes easier to maintain.
Balance is Key
Proper balance dictates that you carry your weight evenly distributed through the buttocks and thighs. Do not carry excessive weight in the stirrup. An old Calvary rider that I was fortunate enough to have as a riding instructor when I was very young, stressed that the stirrup was not there for me to stand in. He said to visualize a raw egg placed between the bottom of my foot and the stirrup. Keep your stirrups without breaking the egg. Use this visualization the next time you ride; you might find that you place too much weight in your stirrups.
Stirrup length strongly affects balance. You cannot achieve a balanced seat if your stirrups are too long or too short. Allow your feet to hang out of the stirrups, then pretend you are Fred Flintstone. Yup. Remember how Fred stopped his car? He had to push his heels down and straight below him. Push your legs straight down, heel towards the ground, as if to touch it. The stirrups should hit you in the ankle bones, if not, adjust them.
Balance is the difference between a good rider and a poor one, a safe rider and one in peril. It is also the division between a horse comfortably carrying a heavier rider and a horse straining under the load. Make sure you have your weight evenly distributed from one side of the saddle to the other, sit straight (but relaxed) and keep your shoulders even. A dropped shoulder often means a more heavily weighted seatbone on the same side.
Weight and Gaited Horses
Often a heavier rider will cause a horse to become pacey. The extra weight causes the horse to ventroflex, pushing his back down and head up, a factor of the pace and to some extent at the rack (paso llano, tolt, paso corte, etc.). One trainer laments of a pacey horse which she had trained into a good fox trot for her owner, a fairly light weight man, only to see him give the horse to his wife, who outweighed him by a good 100 lbs. The extra weight coupled with the lack of expertise of the new rider, made the horse instantly revert to a hard pace.
One of the reasons people seek out gaited horses is that they think they are easier to ride. Often these are people who are injured, not very athletic or merely overweight. However, to get and keep, many horses in gait requires skill, flexibility and athleticism.