| Our joints are marvelously designed to allow us to do | | | | This kind of injury will often go together with a |
| the very large number of activities and attain the very | | | | ligamentous injury and will be serious enough to cause |
| large number of postures that we wish to in doing a | | | | a quick swelling of the joint, most commonly the knee |
| variety of functional deeds. Each joint is designed with | | | | due to its vulnerable position in the centre of the chain |
| a particular function in mind for the position it is placed | | | | of the leg. The person will keep the knee bent to |
| in the body and for the forces it has to exert and | | | | around 30 degrees which is the position where most |
| resist. However, our joints are often injured in sport, | | | | of the knee structures are most lax, minimising the |
| leisure activities or just in everyday activities and such | | | | forces through the joint. Cartilage injuries are slow to |
| injuries need good management to settle down | | | | heal and if a piece of it has been bounced off this will |
| completely. | | | | not heal back, leaving a bare area which may scar to |
| Joints may suffer a direct injury to their surface, the | | | | some degree but not be like the previous tissue. |
| articular cartilage which coats the joint surfaces to a | | | | Another type of injury occurs when the joint is strongly |
| depth of several millimetres. This cartilage is slippery | | | | stressed on one side, pushing it out of alignment and |
| and dense, will indent with pressure but spring back | | | | straining the ligamentous structures which hold the joint |
| slowly once the pressure is removed, and is fed by | | | | stable. Ligament injuries can vary from minor strains to |
| the synovial fluid secreted by the joint. One type of | | | | complete ruptures but many will need expert |
| joint injury to get a direct blow across the joint so one | | | | evaluation, often after the acute pain has settled, to |
| joint surfaces impacts heavily on the other. This | | | | ensure that a significant injury has not occurred. Muscle |
| causes a local trauma which can vary from a bruised | | | | injuries are less common than ligamentous ones but |
| cartilage area to a region of the cartilage being | | | | often involve the muscle contracting against a stronger |
| detached by the blow and then becoming a loose | | | | force or when the joint is moving the other way. |
| body within the joint. | | | | |