In a dog's forward movement, a harness with a strap crossing its chest from side to side, hinders it in the same way humans would be bothered hiking with a rubber band holding their arms. Physiological movement of the front limb is inhibited. The same way rubber would inhibit the pendulum movement of our arms.
Thanks to the “Study of Dog Movement, Jena University”, we now know that in the dog, the centre of rotation of the front limb is at the top of the scapula, but in the human the centre of rotation in the arm it's in the humour. Jena's study demonstrates, among other things, the importance of scapula movement for dog locomotion. The importance of keeping the dog's shoulder free movement in mind is now understandable when choosing a chest harness.
That means there should be no straps in the scapula area, and not going through the chest side to side either. From the point of view of biomechanics and physiotherapy, it is recommended not to choose walking harnesses that have a tape across the chest laterally, or that have tapes touching or pressing the scapula unless you have a working dog like a detector dog and movement is restricted for a reason and for short times.
Always prefer harness models with an ergonomic Y harness design, to allow maximum freedom of movement of your dog, improve well-being and safety during their walk. Opt for a Y harness that goes over the shoulder blades not a harness that is direct over the shoulder joints restricting your dogs movement and causing discomfort.
Here at Delta Canine we will only make a restrictive harness if there is good reason to do so (i.e for a working dog) and the rest of our harnesses are ergonomic Y harnesses. Feel free to get in touch if you have any questions.
Here is a link to a summary of the study:
The video below of a presentation by Prof Dr Martin S Fischer about dog movement is long but well worth watching.