Here are a couple pieces of information on magnesium and magnesium oil. As always, this information is intended to be a start for your research, not the end answer.
Dr Sircus on May 14, 2010 “Uses of Magnesium Oil”
Transdermal magnesium therapy offers an exciting breakthrough in sports medicine. Coaches can now treat injuries, prevent them, and increase athletic performance all at the same time. Magnesium Oil enhances recovery from athletic activity or injuries. It reduces pain and inflammation while propagating quicker regeneration of tissues. Topical application of magnesium chloride increases flexibility, which helps avoid injury. It also increases strength and endurance. Transdermal Magnesium Therapy is a boon for athletes, coaches and doctors who practice sports medicine.
Dr. Jeff Schutt says that hamstring injuries can be avoided through nutritional support because contraction and relaxation is dependent on adequate cellular levels of magnesium. “A shortened hamstring is a result of lack of available magnesium,” he says. Liquid magnesium chloride can be simply sprayed and rubbed into a sore Achilles tendon to decrease swelling. And soaking the feet in a magnesium chloride footbath is the single best thing – apart from stretching – that you can do for yourself to protect from, or recover from hamstring and other injuries.