The AC Joint is the small joint on top of the shoulder, which connects the end of the collarbone to the shoulder (ie the clavicle to the acromion, thus the" AC joint"). In theory, football players wear shoulder pads to protect injury to the AC joint. However, if a player falls on the tip of his shoulder with a heavy lineman on top of him, the forces can exceed that of the shoulder pads.
At this time of the season, the toll of injuries start to mount and it is common to see several AC joint injuries being treated in the training room at Iowa State.
Severity of the injury varies:
● Grade I injury sprains the ligaments but no actual tearing occurs. This can be quite painful.
● Grade II injuries partially tear some of the ligaments, allowing the end of the collarbone to shift upwards slightly, usually less than one centimeter. This injury is also painful, and the player is inhibited from blocking and tackling because of the resultant pain.
● Grade III injuries are associated with rupture of one or more of the supporting ligaments and the collarbone protrudes upward to a significant degree.
Usually grade I injuries result in minimal loss of playing time. Treatment involves restoration of shoulder range of movement (ROM) and strength before returning to action with special orthoplast pad which protects the AC joint under the shoulder pads.
Grade II injuries may result in a short loss of practice or games, depending on position of the player. Special padding again is usually needed under the shoulder pads. It may take a week or two to restore basic shoulder function.
Grade III injuries can also involve muscle injury or occasion damage to the larger ball and socket joint of the shoulder. Although most of these injuries are treated without surgery, some will need ligament repair and reconstruction. A third degree AC injury in the dominant shoulder of the quarterback is likely to need surgery to regain full use. Without surgery, a football player usually returns in six week.
These injuries are common and can have significant psychologic effects in players until a pain free shoulder is achieved. Imagine tackling a fast moving running back if you knew it would cause killer pain in your shoulder.
Rarely do AC joint injuries cause permanent problems, but they sure can make life miserable for the player until the season ends.