Psoas sign
Encyclopedia
The psoas sign is a medical sign
that indicates irritation to the iliopsoas group of hip flexors
in the abdomen, and consequently indicates that the inflamed appendix is retrocaecal in orientation (as the iliopsoas muscle is retroperitoneal). It is elicited by performing the psoas test by passively extending the thigh of a patient lying on his side with knees extended, or asking the patient to actively flex his thigh at the hip. If abdominal pain
results, it is a "positive psoas sign". The pain results because the psoas borders the peritoneal cavity
, so stretching (by hyperextension at the hip) or contraction (by flexion of the hip) of the muscles causes friction against nearby inflamed tissues. In particular, the right iliopsoas muscle lies under the appendix
when the patient is supine
, so a positive psoas sign on the right may suggest appendicitis
. A positive psoas sign may also be present in a patient with a psoas abscess.
Medical sign
A medical sign is an objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient....
that indicates irritation to the iliopsoas group of hip flexors
Hip flexors
In human anatomy, the hip flexors are a group of skeletal muscles that act to flex the femur onto the lumbo-pelvic complex, i.e., pull the knee upward....
in the abdomen, and consequently indicates that the inflamed appendix is retrocaecal in orientation (as the iliopsoas muscle is retroperitoneal). It is elicited by performing the psoas test by passively extending the thigh of a patient lying on his side with knees extended, or asking the patient to actively flex his thigh at the hip. If abdominal pain
Abdominal pain
Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem...
results, it is a "positive psoas sign". The pain results because the psoas borders the peritoneal cavity
Peritoneal cavity
The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum, that is, the two membranes that separate the organs in the abdominal cavity from the abdominal wall...
, so stretching (by hyperextension at the hip) or contraction (by flexion of the hip) of the muscles causes friction against nearby inflamed tissues. In particular, the right iliopsoas muscle lies under the appendix
Vermiform appendix
The appendix is a blind-ended tube connected to the cecum , from which it develops embryologically. The cecum is a pouchlike structure of the colon...
when the patient is supine
Supine position
The supine position is a position of the body: lying down with the face up, as opposed to the prone position, which is face down, sometimes with the hands behind the head or neck. When used in surgical procedures, it allows access to the peritoneal, thoracic and pericardial regions; as well as the...
, so a positive psoas sign on the right may suggest appendicitis
Appendicitis
Appendicitis is a condition characterized by inflammation of the appendix. It is classified as a medical emergency and many cases require removal of the inflamed appendix, either by laparotomy or laparoscopy. Untreated, mortality is high, mainly because of the risk of rupture leading to...
. A positive psoas sign may also be present in a patient with a psoas abscess.