I had to run before i could search and post this -
from-
http://www.abchomeopathy.com/r.php/Arn

Arnica Montana
Leopard's Bane, Arnica, Mountain Arnica

[ ignore this part - Produces conditions upon the system quite similar to those resulting from injuries, falls, blows, contusions. Tinnitus aurium. Putrid phenomena. Septic conditions; prophylactic of pus infection. Apoplexy, red, full face.]


It is especially suited to cases when any injury, however remote, seems to have caused the present trouble.
After traumatic injuries, overuse of any organ, strains.
Arnica Montana is disposed to cerebral congestion.

this part is what it helps, is good for-
Acts best in plethoric{Florid, red-faced}, feebly in debilitated with impoverished blood, cardiac dropsy with dyspnoea{shortness of breath}. A muscular tonic. Traumatism of grief, remorse or sudden realization of financial loss. Limbs and body ache as if beaten; joints as if sprained. Bed feels too hard. Marked effect on the blood. Affects the venous system inducing stasis{slowdown in the flow of blood (or other body fluid such as lymph).}. Ecchymosis and Hemorrhages. Relaxed blood vessels, black and blue spots. Tendency to hemorrhage and low-fever states. Tendency to tissue degeneration, septic conditions abscesses that do not mature. Sore, lame, bruised feeling. Neuralgias originating in disturbances of pneumogastric. Rheumatism of muscular and tendinous tissue, especially of back and shoulders. Aversion to tobacco. Influenza. Thrombosis. Haematocele.