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Obturator sign

Obturator sign is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Obturator sign rather than just read about it. In short: The obturator sign, also called Cope's obturator test, is an indicator of irritation to the obturator internus muscle. The technique for detecting the obturator sign, called the obturator test, is carried out on each leg in succession.

Obturator sign — main illustration
Obturator sign — illustration

Key takeaways

  • Obturator sign belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Obturator sign to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Obturator sign from memory before moving on to harder problems.

Reference excerpt

The obturator sign, also called Cope's obturator test, is an indicator of irritation to the obturator internus muscle. The technique for detecting the obturator sign, called the obturator test, is carried out on each leg in succession. The patient lies on her/his back with the hip and knee both flexed at ninety degrees. The examiner holds the patient's ankle with one hand and knee with the other hand. The examiner internally rotates the hip by moving the patient's ankle away from the patient's body while allowing the knee to move only inward. This is flexion and internal rotation of the hip. In the clinical context, it is performed when acute appendicitis is suspected. In this condition, the appendix becomes inflamed and enlarged. The appendix may come into physical contact with the obturator internus muscle, which will be stretched when this maneuver is performed on the right leg. This causes pain and is evidence in support of an inflamed appendix. The principles of the obturator sign in the diagnosis of appendicitis are similar to that of the psoas sign. The appendix is commonly located in the retrocecal or pelvic region. The obturator sign indicates the presence of an inflamed pelvic appendix. Evidence shows that the obturator test does not adequately diagnose appendicitis, but can be used in conjunction with other signs and symptoms to make a diagnosis. It was introduced by Zachary Cope (1881–1974), an English surgeon.

See also Markle's sign Psoas sign Rovsing's sign McBurney's point

References

External links Acute appendicitis review in American Family Physician

Illustrations

Obturator sign illustration

Worked examples

Example 1 — a first encounter with Obturator sign

Start with the simplest possible case. Write down what Obturator sign claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Obturator sign before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Obturator sign ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Obturator sign

In research
Obturator sign appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Obturator sign in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Obturator sign is common in secondary-school and first-year university syllabi. It links to neighbouring topics Medical signs, so understanding it makes those chapters shorter.
In everyday life
Look for Obturator sign outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Obturator sign in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Obturator sign means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Obturator sign out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Obturator sign in simple terms?

The obturator sign, also called Cope's obturator test, is an indicator of irritation to the obturator internus muscle. The technique for detecting the obturator sign, called the obturator test, is carried out on each leg in succession.

Why does Obturator sign matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Obturator sign?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Obturator sign.

Tags

  • Medical signs

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