physics

Jobe's test

Jobe's test is a physics 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 Jobe's test rather than just read about it. In short: Jobe's test, also known as the empty can test, is an orthopedic examination used to test stability of the shoulder. Purpose The purpose of this test is to determine instability for the shoulder.

Key takeaways

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

Reference excerpt

Jobe's test, also known as the empty can test, is an orthopedic examination used to test stability of the shoulder.

Purpose The purpose of this test is to determine instability for the shoulder. This test should be performed bilaterally to compare stability of both right and left shoulder joints.

Procedure The patient is to lie supine on the table. They are to place their shoulder at 90° abduction. The elbow should be flexed at 90°. The examiner should stand beside the patient with their distal hand holding the patient's wrist and hand. The examiner's proximal hand is to be placed over the patient's humeral head. The examiner applies a posterior force to the humeral head and externally rotates the patients humerus.

Mechanism The examiner applies a posterior force to the humeral head and externally rotates the patients humerus.

Results A decrease in pain or apprehension or an increase in range of motion is a positive sign for anterior instability. Anterior pain may be caused by laxity in anterior ligaments or capsular structures or a tear of the labrum. Posterior pain may be caused from internal impingement of the posterior capsular or labrum.

History Jobe's test is a physical exam test that is used to detect anterior shoulder instability. It is used to distinguish between anterior instability and primary shoulder impingement. This test should be performed after the Apprehension test. This test was named for Christopher Jobe.

References

Worked examples

Example 1 — a first encounter with Jobe's test

Start with the simplest possible case. Write down what Jobe's test claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 Jobe's test 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 Jobe's test 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 Jobe's test

In research: Jobe's test appears in physics 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 Jobe's test 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: Jobe's test is common in secondary-school and first-year university syllabi. It links to neighbouring topics Physical examination, Shoulder, so understanding it makes those chapters shorter.
In everyday life: Look for Jobe's test 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Jobe's test” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Jobe's test in 20 minutes

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

Frequently asked questions

What is Jobe's test in simple terms?

Jobe's test, also known as the empty can test, is an orthopedic examination used to test stability of the shoulder. Purpose The purpose of this test is to determine instability for the shoulder.

Why does Jobe's test matter?

Because it connects several physics 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 Jobe's test?

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 Jobe's test.