Padding & protection is a fundamental aspect of the preventative approach to sports medicine. Pads provide protection from injury, or from further injury, for the athlete during training or competition. Athletes in a wide variety of sports routinely employ padding & protection equipment. It can range from the use of a simple piece of foam to reduce friction and blisters inside footwear all the way to a football helmet to protect against head injuries.
Pads are classified as belonging to either soft, low density materials or hard, high density materials. Soft, low density materials are more comfortable on the body as a result of the presence of air in the material. On the other hand, hard, high density materials offer less comfort but greater protection from high impact forces. They are more able to absorb energy through deformation and this results in less force at the point of impact with the body.
Some sports require at least minimum levels of padding & protection as part of rules governing practice and competition. In some cases, these rules also prohibit the use of certain materials (e.g. fibreglass, metal or other nonpliable materials) unless they are covered by high density closed cell foam or other similar material.