The causes of leg pain can be musculoskeletal, neurological, or vascular. Shin splints and stress fractures can result from repetitive sports, such as running. Leg pain can sometimes indicate a serious vascular problems.
Noun. 1. altruism-the quality of unselfish concern for the welfare of others. selflessness. unselfishness-the quality of not putting yourself first but being willing to give your time or money or effort etc. for others; rural people show more devotion and unselfishness than do their urban cousins.
In biology, altruism refers to behaviour by an individual that increases the fitness of another individual while decreasing the fitness of the actor. Altruism in this sense is different from the philosophical concept of altruism, in which an action would only be called altruistic if it was done with the conscious intention of helping another. In the behavioural sense, there is no such requirement.