Glad to hear you are doing well.
Have you ever looked into the specs of homeopathic Arnica Montana ? The common formula is so diluted that it is equal to an Olympic size pool of water with a single molecule of Arnica Montana.
Never discount the value of the placebo effect. Some studies show that the placebo effect can benefit 60% of patients.
Wiki explains homeopathic dilutions at
http://en.wikipedia.org/wiki/Homeopathic_dilutions
The placebo effect can be strong with concussion since belief in healing can reduce stress levels that leads to the brain having a better chance to heal.