This works over time, not immediately, which is normal for any injury. My French Bulldog had major spinal surgery due to a congenital defect, he is also very hyper which made his healing challenging. While using the blanket he instinctively knew to remain still. At the same time I had a knee injury and tested it on myself. it also relived my pain and speeded up the healing-not recommending for humans, wanted to test it along with other things I am doing. I am a registered nurse, these types of EM products are not a "cure all" but designed to assist with other treatments, always check with your Doctor or Vet, you will not feel it working "immediately" that is not the mechanism by which EM technology works, but that does not mean it does not work. I read a review that it was taken out of the box and put back in the box because it didn't work, I assume the person did not allow adequate time (days or weeks depending on the injury), or understand the mechanism; you will NOT feel a vibration, heat, like something is happening or instant relief, nothing outside pharmaceuticals or medicine do that, or heal that quickly. Injuries take time. It helped our dog heal post operatively, and we use it prophylactically when needed, his back injury means life long recurrence and monitoring. He did improve his gait however, immediately after each use. Again, can't stress enough this should not be the only therapy one uses on their dog, it is not instant or something you feel like a vibrating massage, it works silently and deeply over time but not a cure all. Hope this helps!