Abdominal viscera are vulnerable in contact sport and, although the ribs and pelvis provide some protection, the main protection is by the abdominal musculature. In addition, superficial structures such as skin, subcutaneous tissues, and muscle may be injured. Diagnosis is usually obvious, and management is as for skin and SC wounds elsewhere in the body. Nevertheless, rectus abdominus muscle rupture with damage of epigastric artery may produce a large haematoma. The swelling may first be thought of as arising from an abdominal organ, but the later bluish discoloration gives a clue that it does not. The swelling will not cross the midline or extend beyond the lateral border of the muscle. It is relatively immovable due to the rectus sheath. US or MRI will confirm if required.

The spleen lies on the 9th to 11th ribs on the posterior wall of the abdomen and thus is unusually injured in sport unless enlarged. US is the most convenient means to assess splenic enlargement beyond clinical examination. The most common cause of splenomegaly in athletes is glandular fever (infectious mononucleosis), and this causes the spleen to be vulnerable in blows to the left upper quadrant. Consequently, athletes should be advised against contact sport whilst the spleen is enlarged. The exact time period following the onset of glandular fever is controversial, although 5 weeks is the minimum. FBC, liver enzymes, and abdominal examination should have normalized. Some practitioners recommend 6 months off contact sport and, even then, athletes should be warned to report any abdominal discomfort for thorough assessment.

The spleen may also be ruptured by a fractured rib. The athlete will have persistent aching in the left flank following the initial acute pain. Sometimes there is an intervening period with no pain. Some have referred pain to the shoulder.

Clinicians should be alert to splenic bleeds. CT scan can confirm the diagnosis. Though minor splenic injuries can be treated conservatively and with ongoing observation, rapid blood loss demands splenectomy.

Lacerations of the liver are rare in sport, although subcapsular haemorrhage may occur and give rise to right upper quadrant pain and tenderness. US or CT scan may confirm the diagnosis.

The pancreas lies deep at the back of the abdomen and is rarely injured in sport. Epigastric pain radiating to the back after severe blunt trauma, with midline tenderness, distension, and loss of bowel sounds due to reflex ileus, should lead the clinician to consider pancreatic damage. Serum amylase will be elevated and CT will confirm the diagnosis.

The kidneys have some protection from blunt trauma from the 11th and 12th ribs, psoas muscle, and surrounding fat. However, renal contusions do occur, particularly in the young where the relative size of the kidney is larger. The kidneys are the most commonly injured abdominal organ in sport and result in many hospitalizations. The kidneys are vulnerable when the abdominal muscles are relaxed, and typically this might occur when leaping high and reaching for a ball, whilst taking a blow from another athlete, e.g. during basketball or at the rugby line-out.