Cause
A sprain of the hand is caused by an external force acting on the joint which exceeds the physiological level and overstretches structures in the joint. In the case of a sprain, the joint surfaces involved are lifted out of their normal position for a short moment by overstretching or twisting, but then immediately jump back. This overloads ligaments, tendons and joint capsule and can lead to injuries.
The wrist is a functional unit composed of several small joints. In addition to the bones of the forearm and wrist involved, it consists of the joint capsule, cartilage and a large number of stabilizing ligaments. The normal range of motion of the wrist comprises two axes of movement.
Bending towards the palm of the hand is possible up to about 80°, stretching towards the other side is 70°. In addition, the wrist can be extended by 20° to the thumb side and by 40° to the little finger side. Any movement beyond this can only be achieved passively by external force and will overload the joint.
The typical cause of a sprained hand is a fall, in which the hand is supported by the body and the entire body weight is applied to the wrist, as happens especially when stumbling, but also often during sports. To be mentioned here are mainly cyclists and snowboarders, but theoretically of course all conceivable sports. The ligaments are overstretched to such an extent that they cause pain and must be protected.
Since the ligaments provide stability, they are only stretchable to a limited extent. The more the wrist is stretched beyond the normal extent, the greater the risk of a torn ligament or fracture. In addition to falls, which are by far the most common cause of sprains in the hand, other causes include a soccer being shot at the hand.
A previously damaged wrist due to previous frequent sprains or overstretching is at increased risk because the ligaments are already worn out to a certain extent. The diagnosis of a sprained hand is primarily a clinical diagnosis. A sprained hand can also be correctly diagnosed for the layperson if the symptoms are appropriate.If the symptoms are severe or long lasting and do not get better, a doctor should be consulted.
The nature of the accident and the symptoms described by the person affected give the doctor sufficient information to investigate further in the direction of the sprain of the hand. Slight palpation causes a pressure pain and confirms that the wrist is injured. An important measure is to check the movement of the hand in order to distinguish a sprain from a more serious injury such as a torn ligament or fracture.
As long as active movement of the hand by the patient is also possible, this is a good sign. Only clinical examination and observation of the swollen wrist, however, cannot provide a reliable diagnosis of a sprained hand. In order to rule out more serious injuries, an X-ray of the affected region should be ordered.
Computer tomography (CT) is also a good method for assessing bony structures. In case of doubt, magnetic resonance imaging (MRI) can be helpful for imaging ligaments and tendons. CT and MRI are not routinely used in cases of sprains of the hand. For safety’s sake, the X-ray should be ordered even in cases of minor injuries and persistent complaints.