The Inferior Sulcus Test, also called the Sulcus Sign, assesses inferior glenohumeral translation by applying a downward traction force to the relaxed arm and observing for a visible or palpable sulcus below the acromion. It is commonly used to support assessment reasoning around inferior shoulder laxity and multidirectional instability.
A positive finding may include a visible sulcus, increased inferior translation, apprehension or familiar instability symptoms. However, laxity is not the same as symptomatic instability. Some asymptomatic people demonstrate inferior laxity, so the result must be interpreted with history, symptoms, apprehension, functional instability reports and other shoulder tests.
The Inferior Sulcus Test is a shoulder special test used to assess inferior translation of the humeral head. When downward traction is applied to the arm, a visible dimple or gap may appear below the acromion. This is called the sulcus sign.
The test is commonly associated with inferior glenohumeral laxity and multidirectional instability. However, inferior laxity can be present in people without symptoms. This makes interpretation important: a sulcus sign alone does not confirm a clinically significant instability problem.
The test is most useful when the visible sulcus is associated with apprehension, familiar symptoms, functional instability reports, a history of subluxation or dislocation, or positive findings on other instability tests.
For Measurz, the key is to record the size of the sulcus, side tested, arm position, pain or apprehension, symptom familiarity, comparison side and whether the finding appears symptomatic or incidental.
Test name: Inferior Sulcus Test / Sulcus Sign
Region: Shoulder / glenohumeral joint
Primary purpose: Assess inferior glenohumeral translation and shoulder laxity
Commonly associated presentation: Inferior laxity, multidirectional instability, symptomatic shoulder instability
Positive finding: Visible sulcus below the acromion, increased inferior translation, apprehension or familiar instability symptoms
Negative finding: No visible sulcus, no apprehension and no meaningful side-to-side difference
Main limitation: Laxity may be present without symptoms; the test does not confirm instability on its own.
The Inferior Sulcus Test is a shoulder laxity test.
The client sits or stands with the arm relaxed by the side. The professional applies a downward traction force to the humerus. A positive sulcus sign is observed when a visible indentation appears below the acromion as the humeral head translates inferiorly.
The sulcus may be graded by the amount of inferior displacement, commonly using:
Grade 0: no visible sulcus
Grade 1: less than 1 cm
Grade 2: 1–2 cm
Grade 3: more than 2 cm
Grading should be interpreted carefully because laxity can be normal for some people.
The Inferior Sulcus Test may be used to support assessment reasoning around:
Inferior glenohumeral laxity
Multidirectional shoulder instability
Generalised shoulder laxity
History of shoulder subluxation or dislocation
Apprehension or instability symptoms
Shoulder symptoms in overhead athletes
Shoulder instability after trauma
Side-to-side laxity comparison
Baseline and retest documentation in Measurz
It is most useful when the test reproduces familiar symptoms or is part of a broader instability pattern.
The Inferior Sulcus Test assesses inferior translation of the humeral head relative to the glenoid.
It may provide information about:
Inferior shoulder laxity
Sulcus size
Side-to-side difference
Apprehension
Symptom reproduction
Possible multidirectional instability pattern
Shoulder capsule laxity
Instability-type assessment reasoning
It does not directly assess:
Symptomatic instability with certainty
Labral integrity
Capsular lesion with certainty
Rotator cuff integrity
Imaging findings
Shoulder strength
Scapular control
Readiness for sport or work
Treatment need
The Inferior Sulcus Test may be useful for clients with:
Shoulder instability symptoms
Recurrent subluxation sensations
Multidirectional instability-type presentation
A feeling that the shoulder slips or drops
Overhead sport symptoms
Generalised joint laxity
Shoulder apprehension
A history of dislocation or subluxation
A need for baseline and retest documentation
It may also be useful for professionals learning the difference between laxity and symptomatic instability.
Consider using the Inferior Sulcus Test when:
Shoulder instability is part of the assessment reasoning
The client reports slipping, subluxation or giving way
Multidirectional instability is being considered
You want to compare inferior laxity side to side
Apprehension is relevant
You are building a broader shoulder instability profile
It should be combined with apprehension, relocation, load-and-shift, Gagey or other instability tests where appropriate and within scope.
Use caution or avoid the test when:
Recent acute dislocation or major trauma is suspected
Fracture is possible
The shoulder is highly irritable
The client is apprehensive before testing
There is severe pain before testing
Neurological symptoms are present
The professional cannot safely support the arm
The test would not change assessment reasoning
Stop if pain increases sharply, apprehension becomes high, neurological symptoms occur, the client feels the shoulder is slipping, or the client asks to stop.
The Inferior Sulcus Test usually requires no equipment.
Optional equipment includes:
Measurz app
Pain rating scale
Notes field for sulcus grade and apprehension
Shoulder instability test records
Video or image record only where appropriate
Generalised joint laxity screening where relevant
Ask the client to sit or stand comfortably with the tested arm relaxed by the side.
Explain the test:
“I am going to gently apply downward pressure through your arm and observe whether the top of the shoulder shows increased movement. Tell me if this feels painful, unstable or familiar.”
Test the less symptomatic side first where appropriate.
The client sits or stands with:
Trunk upright
Shoulder relaxed
Arm by the side
Elbow relaxed
Forearm relaxed
No active shoulder shrugging or bracing
The professional stands beside or slightly behind the tested shoulder.
The professional should be able to observe the space below the acromion while applying a controlled downward force.
Hold the client’s distal humerus, elbow, forearm or wrist depending on comfort and control.
Apply traction downward through the arm.
Avoid gripping painfully.
The shoulder girdle should remain relaxed.
Do not forcefully depress the scapula unless using a specific modified variation and recording it clearly.
Apply an inferior traction force to the humerus.
The force should be:
Gradual
Controlled
Symptom-limited
Compared with the other side where appropriate
Observe for a sulcus below the acromion.
Tell the client:
“Stay relaxed. Let me know if this causes pain, apprehension, slipping, or your familiar shoulder symptoms.”
A positive finding may include:
Visible sulcus below the acromion
Increased inferior translation compared with the other side
Sulcus greater than expected
Apprehension
Familiar instability symptoms
Feeling of slipping or dropping
Symptoms that match the client’s history
Record sulcus size and symptom response separately.
A negative finding may include:
No visible sulcus
No meaningful inferior translation
No apprehension
No familiar symptoms
Similar response to the opposite side
A negative result does not fully exclude shoulder instability.
Stop the test if:
Pain increases sharply
Apprehension becomes high
The client reports slipping or instability that feels unsafe
Neurological symptoms occur
The client asks to stop
The professional cannot control the arm safely
The test should be gentle and controlled. Avoid repeated strong traction, especially in irritable or recently unstable shoulders.
A positive Inferior Sulcus Test may suggest inferior glenohumeral laxity. It is more meaningful when it reproduces the client’s familiar instability symptoms, apprehension, slipping sensation or matches a broader pattern of multidirectional instability.
However, a positive sulcus sign does not confirm symptomatic instability. Some asymptomatic clients have visible inferior laxity. Laxity is a physical finding; instability is usually related to symptoms, control, apprehension and function.
A negative Inferior Sulcus Test may reduce suspicion of marked inferior laxity, especially if other instability tests and history are also negative. However, it does not exclude anterior, posterior or functional instability.
The finding is more meaningful when interpreted with:
History of dislocation or subluxation
Apprehension
Direction of symptoms
Load-and-shift testing
Apprehension/relocation testing
Generalised joint laxity
Shoulder strength
Scapular control
Sport or work demands
Functional instability reports
Diagnostic accuracy varies depending on the sulcus size threshold and target condition.
Commonly cited evidence from Tzannes and Murrell reported:
Condition or presentation: Shoulder instability / inferior laxity assessment
Population: Shoulder instability assessment population
Test variation: Sulcus sign / Inferior Sulcus Test
Reference standard: Clinical instability assessment and related reference criteria
Sensitivity: Approximately 28% for a sulcus sign greater than 2 cm
Specificity: Approximately 97% for a sulcus sign greater than 2 cm
Positive likelihood ratio: Potentially useful when the sign is large and clinically relevant
Negative likelihood ratio: Limited usefulness because sensitivity is low
Key limitations: Laxity can be observed in asymptomatic people, and sulcus size alone does not define symptomatic instability.
Some summaries also describe a lower threshold, such as more than 1 cm, as more sensitive but less specific. This reinforces the importance of recording the size of the sulcus and the client’s symptom response rather than using a simple yes/no result.
Plain-language interpretation:
A large sulcus sign may increase suspicion of inferior laxity when symptoms fit.
A negative test does not exclude instability.
A visible sulcus without symptoms may represent laxity rather than clinically relevant instability.
The test is most useful when combined with history and other instability findings.
Reliability evidence for the sulcus sign is mixed and standardisation remains important.
A study of shoulder instability and laxity testing reported that several shoulder instability tests showed better intertester reliability than the sulcus sign, and concluded that the sulcus sign needs further standardisation before acceptable evidence can be assumed.
Reliability may be affected by:
Force magnitude
Arm position
Client relaxation
Shoulder guarding
Definition of sulcus size
Visual versus palpated grading
Examiner experience
Whether symptoms or only translation are recorded
Validity is limited if the test is used alone. It has practical value as an inferior laxity observation but does not directly prove symptomatic multidirectional instability.
Reliability improves when the professional records:
Arm position
Force direction
Sulcus grade
Symptom response
Apprehension
Comparison side
Client relaxation
Test confidence
Common errors include:
Confusing laxity with symptomatic instability
Applying inconsistent force
Not recording sulcus grade
Not recording apprehension
Not comparing sides
Testing when the client is guarding
Treating asymptomatic laxity as pathology
Not considering generalised joint laxity
Using the test alone to make decisions
Ignoring shoulder strength and scapular control
Limitations include:
Low sensitivity at higher sulcus thresholds
Laxity may be normal in some clients
Reliability can be limited
Force is difficult to standardise manually
It does not identify labral or capsular pathology with certainty
It does not assess dynamic shoulder control
It should not be used alone for sport or work decisions
The Inferior Sulcus Test may be useful for:
Inferior shoulder laxity assessment
Multidirectional instability assessment reasoning
Side-to-side comparison
Recording apprehension or instability symptoms
Baseline and retest documentation
Client education about laxity versus instability
Deciding whether further shoulder assessment is needed
In Measurz, it can be recorded alongside apprehension/relocation testing, load-and-shift, Gagey test, shoulder range of motion, rotator cuff strength, scapular control and functional shoulder testing.
Record:
Test name: Inferior Sulcus Test / Sulcus Sign
Side tested
Arm position
Result: positive, negative, unclear or unable to test
Sulcus grade: none, less than 1 cm, 1–2 cm, greater than 2 cm
Pain score
Symptom location
Apprehension
Feeling of slipping or instability
Whether symptoms were familiar
Force direction
Comparison side
Generalised laxity notes if relevant
Guarding or compensations
Reason for stopping if relevant
Related instability findings
Confidence in interpretation
Further assessment or referral notes if appropriate
Retest date if relevant
Recording these details improves repeatability, communication, client education, assessment reasoning, monitoring over time, team consistency and reporting quality.
Apprehension Test
Relocation Test
Load-and-Shift Test
Gagey Test
Posterior Apprehension Test
Jerk Test
Scapular Assistance Test
Shoulder Range of Motion
Shoulder Strength Testing
Drop Arm Test
Cervical Quadrant Test
It assesses inferior translation of the humeral head and may support reasoning around inferior laxity or multidirectional instability.
A positive finding is a visible or palpable sulcus below the acromion when inferior traction is applied to the arm.
No. It may indicate laxity, but symptomatic instability requires symptoms, apprehension, functional reports and other assessment findings.
Yes. Some asymptomatic people have inferior laxity, so the result must be interpreted in context.
A sulcus greater than 2 cm has been reported with high specificity but low sensitivity in commonly cited evidence. Size should be recorded, not overinterpreted.
No. A negative sulcus sign does not exclude anterior, posterior, inferior or functional instability.
Yes. Side-to-side comparison is important.
History, instability symptoms, apprehension testing, load-and-shift, generalised laxity assessment, strength testing and scapular control assessment.
The Inferior Sulcus Test assesses inferior shoulder laxity.
A visible sulcus may indicate inferior translation, but laxity is not the same as symptomatic instability.
A sulcus greater than 2 cm has been reported with low sensitivity and high specificity in commonly cited evidence.
A negative test does not exclude instability.
The test should be interpreted with history, apprehension, functional instability symptoms and other shoulder tests.
Measurz recording should include side, sulcus grade, pain, apprehension, symptom familiarity and comparison side.
Blonna, D., Bellato, E., Caranzano, F., Assom, M., Rossi, R., Castoldi, F., & Marmotti, A. (2018). Intertester reliability of clinical shoulder instability and laxity tests in subjects with and without self-reported shoulder problems. BMJ Open, 8(3), e018472. https://doi.org/10.1136/bmjopen-2017-018472
Hegedus, E. J., Goode, A. P., Cook, C. E., Michener, L., Myer, C. A., Myer, D. M., & Wright, A. A. (2012). Which physical examination tests provide clinicians with the most value when examining the shoulder? Update of a systematic review with meta-analysis of individual tests. British Journal of Sports Medicine, 46(14), 964–978. https://doi.org/10.1136/bjsports-2012-091066
Jaggi, A., & Lambert, S. (2010). Rehabilitation for shoulder instability. British Journal of Sports Medicine, 44(5), 333–340. https://doi.org/10.1136/bjsm.2009.059311
Tzannes, A., & Murrell, G. A. C. (2002). Clinical examination of the unstable shoulder. Sports Medicine, 32(7), 447–457. https://doi.org/10.2165/00007256-200232070-00004
