Musculoskeletal Injuries and Their Relationship with Training Programs

First, what are MSIs?

MSIs describe any injury involving the bones, joints, muscles, ligaments, and tendons. These could be a fracture, muscle tear, or a bowed tendon to name a few.

So how are they related to the training program?

MSIs result from acute trauma or chronic stress, commonly from exercise. Did you know that approximately 70% of Thoroughbred racehorse fatalities on race days are due to MSIs? Crazy right!

Training programs are designed to prepare horses for the physical demands of performance/ exercise. The program is optimal when the imposition of and stimulatory load is correctly balanced with recovery.

(With the interest of being descriptive, the following examples are based on the bones in relation to MSI's. However, the concepts are transferable to the other Musculoskeletal structures.)

Considering the effects of load:

As strange as this sounds, micro-damage is essential for growth. To keep up with the workload, bones, for example, need to increase in size and density. Bone density and size are increased during the bone remodeling process which is stimulated via bone micro-damage. Where things can go wrong is in the event of excessive loads or insufficient rest periods, for example, high-speed exercise introduced too rapidly. In this situation the accumulation of bone damage exceeds structural capacity, leading to an MSI. In the opposite direction, insufficient load or excessive rest periods can lead to little to no long-term tissue response, leaving the bone unprepared or naïve to the load. When bone is not stimulated or used, it will be reabsorbed in the bone remodeling process. The same as if the muscles are not put under stress, the muscle fibers will not undergo the remodeling process and thus the strength will remain the same or less even. Reiterating the importance of the balance of load and recovery in exercise preparation.

Considering the recovery aspect:

Age is important for consideration of bone turnover rates. Mature horses’ skeletons are less adaptable with a slower bone turnover rate, meaning they require longer rest periods. Younger horses have a faster bone turnover rate, thus requiring shorter rest periods while still frequent. Rest periods should also be based on the previous training program and developmental stage, more specifically, the projected micro-damage accrued. Allowing better estimation of the required time for the structures to heal and remodel.

Prevention of MSIs is multifaceted, the relation of the training program is only one aspect. However, if I were to include every factor, I’d be delivering a textbook to you! Some other important factors to mention regarding the prevention of MSI’s are the importance of nutrition, hoof care, housing environments as well as alternative therapies.

Thanks for reading! I hope you have learnt something new from this post!