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.
Biological Altruism. In evolutionary biology, an organism is said to behave altruistically when its behaviour benefits other organisms, at a cost to itself. The costs and benefits are measured in terms of reproductive fitness, or expected number of offspring.