A normal reaction for most people is to outstretch their arms and hands when faced with a threat. For example, if a ball were moving toward your head, you would likely extend your arms to block the ball and protect your face. Similarly, when falling to the ground, a normal reaction is to break your fall by putting your hands out in front of your body. This reaction makes the hands and fingers especially susceptible to some types of injuries, including finger jams.
Finger jams occur during impact with a person or object. Any forceful impact or sudden stretching of a finger may result in injury. Common causes of this type of impact include falls into hard surfaces, being hit with a ball or by a teammate during sports, or smashing a finger into a hard surface such as a wall or door.
A jammed finger is one that is sprained, strained, or dislocated. Sudden or forceful impact may cause the ligaments between the finger bones to tear or may result in dislocation of finger joint. Typically, impact forces the joints in the finger together, and causes twisting of the joints at the same time. The resulting dislocation may be resolved without medical intervention, or may require correction by a doctor. Sometimes, jammed fingers may actually be fractured. For this reason, it is crucial to seek medical advice any time you suffer an injury to a finger that results in swelling, severe pain, or discoloration.
Once a finger has become jammed, even if the damage has corrected itself, a number of symptoms may persist. A jammed finger may appear crooked, swollen, discolored, and may be severely painful. Sometimes, the resulting swelling and inflammation caused by the initial injury can hold a dislocation in place, worsening the injury.