Agility, dock diving, obedience, IPO/Schutzhund/French Ring, and flyball all have something in common. These dog sports require the dogs participating in them to execute at least one jump while training and competing in their sport.
Jumping is a high-impact exercise that exponentially increases the force on the body, the joints, and the muscles. This increases the risk of injury, especially if your dog is not strong enough (read here to find out if your dog is strong enough to participate in high-impact sports) or has poor technique.
Understanding the biomechanics of the canine jump is crucial to training proper jumping form. Proper jumping form is important for efficient and safe jumping. Jumping is a complicated sequence of movements.
Jumping is a full body exercise. The front assembly, consisting of the shoulders, chest, and the front legs, provides the lift, or upward thrust, and absorbs the landing. The rear assembly, consisting of the back legs and pelvic area, provides the forward propulsion. The spine and the core muscles are also heavily involved.
The jump, broken down into its most basic components, looks like this:
Phase 1 - Take Off:
1. Your dog must approach the jump at a canter or gallop.
2. Your dog plants the front feet, one slightly ahead of the other, at the calculated take-off spot.
3. The head lowers and the front leg joints slightly flex, effectively loading the front assembly muscles.
4. The spine flexes as the rear legs are brought forward and the rear feet are planted slightly ahead of the front feet.
5. The shoulders and elbows extend, pushing the front end up and the head lifts to aid in this upward thrust.
6. The rear leg joints then extend to propel your dog forward (and up) and the tail goes down.
Phase 2 - Transition
7. In the air, the head lowers close to the extended front limbs to help with forward momentum (and this helps to slightly reduce drag, although aerodynamics play only a tiny role.)
8. At the apex of the jump arc, your dog lowers his head, and the tail (if present) goes up so that his body rotates forwards and downwards.
Phase 2 - Transition Phase - Your dog is airborne
Phase 3 - Landing
9. The outstretched front legs, with shoulders extended, hit the ground, one slightly in front of the other, and the head rises.
10. The spine flexes again as the rear legs are pulled forward under the body to absorb some of the impact of landing and to continue forward running movement upon landing.
Phase 3 - Landing Phase - The front assembly absorbs the landing
Phase 3 - Ends and the forward running movement continues.
Center of Gravity
Your dog’s center of gravity, when standing, is just behind the shoulders. To jump successfully, your dog must raise its center of gravity high enough for the entire body to clear the height and width of the jump. The ability of your dog to change its center of gravity is determined by your dog’s conformation, level of physical fitness, as well as, jumping experience, and confidence in their ability. The front assembly is primarily responsible for shifting the center of gravity for lift. A strong front end will help your dog shift its center of gravity. (Read here for how your dog's muscles actually get bigger and stronger.)
Once your canine athlete’s feet have left the ground, the trajectory around your dog’s center of gravity is set. The only thing to be altered is your dog’s body position around that center of gravity. Your dog may raise or lower its head, kick out its back legs, or move its tail to influence its ability to clear the jump.
For instance, a dog that raises its head just past the apex will have the effect of shifting the center of gravity backward, causing the back legs to land either at the same time or very shortly after the front legs. Landing on all four feet helps to minimize the impact on the front end but causes the landing forces to travel up all four feet and meet in the spine. Forward thrust to continue running is also reduced.
Jumping style tends to vary with breed and the individual, but the sequence of events is essentially the same. Changes in your dog's jumping style could indicate weakness or possible injury. Improving your dog's overall fitness level and specifically strengthening will lower the risk of an injury occurring while jumping.