[1] This condition is commonly observed among gamekeepers and Scottish fowl hunters, as well as athletes (such as volleyballers and soccer goalkeepers).

It also occurs among people who sustain a fall onto an outstretched hand while holding a rod, frequently skiers grasping ski poles.

[citation needed] Characteristic signs include pain, swelling, and ecchymosis around the thenar eminence, and especially over the MCP joint of the thumb.

[citation needed] The patient will often manifest a weakened ability to grasp objects or perform such tasks as tying shoes and tearing a piece of paper.

Other complaints include intense pain experienced upon catching the thumb on an object, such as when reaching into a pants pocket.

In addition to skiing, this injury (resulting from forced abduction or hyperextension of the proximal phalanx of the thumb) is seen in a wide variety of other athletic endeavors.

[citation needed] In most cases of a complete tear, the aponeurosis of the adductor pollicis muscle may be interposed between the bones of the MCP joint and the torn ligament.

Radiographs are helpful in determining the possible presence of an avulsion fracture of the proximal phalanx insertion site of the ulnar collateral ligament.