You can speed up the time by taking Arnica right away (of course, after seeking emergency medical help). This is a great example of how natural and conventional medicine can work together.
You would never use natural remedies instead of professional care. But it would be safe to use Arnica alongside professional care. Arnica will not interfere with medical help – and in most cases, doctors will not offer much treatment besides rest. (You do need to keep your doctor involved, of course, in case the injury is serious.)
You can get Arnica in any natural food store or online, for example from www.homeopathic.com. Get the 30c potency (strength) and dissolve a couple of pellets in your mouth two to four times a day (more frequently if your symptoms are recent and intense, less frequently as time goes on and your symptoms subside).
For more information, see the Bumps and Bruises chapter of my book, A Healer In Every Home.
Find out more about this book:Your Natural Medicine Cabinet: A Practical Guide to Drug-Free Remedies for Common Ailments