Harnesses and why some are more appropriate for performance dogs than others

Dog's are quadruped, meaning that they use four limbs in locomotion. Because of this, their forelimbs are different in some ways from ours.

The bony structure of human and dog's forelimbs are similar. Both forelimbs are composed of phalanges, metacarpals, carpals, a radius, and ulna in the forearm, joining to the humerus at the elbow joint, and then the humerus joining in a ball and socket joint to the scapula (shoulder joint).  Now we have some differences. Because dog's bear 60% of their body weight on their front limbs, the bony structures (and associated musculature) are comparatively larger than a human, and similar in size to their rear limb. Human's shoulders are attached to their thorax (chest) by muscles around the scapula, and a small joint on the end of the clavicle (collar bone) that attaches to the sternum, and again more musculature. In contrast dog's have no clavicle, only the musculature around their scapula, to attach their forearm to their thorax. This gives dogs a greater range of motion, and movement required for fast and fluid running, however less structure in the shoulder meaning it can be easier to injure. 

Tendons, ligaments, and muscles are similar between humans and dogs, however, there are some orientation, size, and attachment point differences. 

This video (from the excellent book / DVD set 'Dogs in Motion') shows which muscles are being used, as the dog walks. In particular, note the muscles that are active when the dog extend their forearm forwards. 

So there are a lot of harnesses around, right? So which are more suitable for performance dogs? We are looking for harnesses that allow full range of motion, and don't cut across large muscle groups. 

So which of the ones below fit these specifications? 

Dr. Chris Zink notes that there are some muscles involved in shoulder extension, that are common sporting injuries. These are the supraspinatus, and biceps brachii. 

If we look at one popular style of harness, and where this cuts across muscle groups, we can see that it cuts across the biceps brachi, along with other large shoulder and chest muscles. 

This style of harness work's by restricting the dog's range of motion, therefore making it harder for the dog to pull forwards. Whilst this may make walking pulling dog's easier, it is also likely to affect not only range of motion, but possibly cause injury. 

Obviously, not all harnesses will fit all dog's perfectly, what you need to consider for your performance dog, is what is the best pieces of equipment to use with them, to meet your needs as well as minimise injury. Dog's can injure themselves on a flat collar and lead, or head halter, with incorrect fitting and use.

My top suggested harnesses are: 

• The Balance Harness (https://www.blue-9.com/products/100000000000061-balance-harness-over-head) 
• The Ruffwear harness (https://www.furtherfaster.co.nz/collections/ruffwear/products/front-range-2017) 
• The Perfect Fit harness (https://www.dog-games-shop.co.uk/perfect-fit-fleece-dog-harness.html) 
• The Hurtta Active harness (http://www.dogmechanics.co.nz/hurtta-active-harness.html) 

Some related reading:

• https://www.whole-dog-journal.com/issues/16_7/features/the-no-pull-debate_20782-1.html 
• https://www.whole-dog-journal.com/issues/20_4/features/Best-Dog-Harnesses-2017_21622-1.html