Excessive engagement in a particular sport may give rise to permanent physical damage. Familiar examples are tennis elbow, football knee, and basketball back injuries. Sensitive areas in these cases are joints and the spine. More serious hazards are brain and eye damages from boxing; and damage to the groin, pelvis, uterus, kidneys and other internal organs can occur from riding horses or motorcycles. Professional athletes suffering continuous pain from injuries, or experiencing excessive stress due to the competitive nature of their games, may seek relief in drugs, leading to drug abuse and narcotic addiction. Competitors pressured into use of steroids may develop cancer.
Accidents resulting from sports most often affect limbs (80% of all cases), particularly the lower limbs (50%); while the small proportion of injuries to the skull, thorax or abdomen results in the low mortality rates. But, depending on the country, damage to the spinal cord in sporting accidents accounts for between 3 and 12% of spinal cord damage. The most frequent causes are shallow water diving, rugby football, horse-riding, mountaineering, and gymnastics.
In the USA, one quarter of all emergency room injuries to people ages 5 to 24 are caused by sports. Data from 1987/98 show that the most common sports injuries for young people were from basketball (447,000 emergency room visits per year) cycling (421,000 visits); football (271,000) and baseball/softball (245,000). Other sports that resulted in frequent emergency room visits were ice skating, roller skating, skateboarding, gymnastics and water and snow sports.
Youth team sports are run mostly by volunteers.