AC Joint Compression Test | Steps and Indication

AC Joint Compression Test | Steps and Indication

The Acromioclavicular Joint Compression Test which is also referred as cross-body adduction test or scarf test is the common physical examination test used to identify the AC joint pathology. This joint although a little higher than the former is located at the top of the shoulder and is formed by the union of the acromion which is part of the scapula to the clavicle. The test is mainly applied in patients who are suspected to have conditions like arthritis of the AC joint, AC joint sprain or actual separation of the AC joint ligament.

Indication for AC Joint Compression Test 

The ACJ Compression Test is indicated for patients presenting with:

  1. Pain over the AC joint of the shoulder.
  2. Past history of either acute injury or repetitive usage and stress to the shoulder.
  3. Some of the signs that are evident and related to the shoulder joint may include: 
  4. A directly swollen joint An area that is tender and warm often possesses some inflammation
  5. A joint whose range of motion is compromised in some way
  6. Other possible conditions that could be anticipated are OA of the AC joint, AC joint sprain or AC joint dislocation.

Steps to Perform AC Joint Compression test 

Physiotherapists do the AC Joint Compression test in an attempt to diagnose the condition or general state of the acromioclavicular joint. 


The steps involved are:


  1. Positioning the Patient: The position of the patient can also be seated or standing while the position of the physiotherapist can also be in front of the patient or beside.
  2. Arm Placement: To perform this test the patient’s arm on the affected side is brought into 90 degrees of shoulder flexion by the physiotherapist. 
  3. Cross-Body Adduction: The physiotherapist then takes the patient’s arm perpendicular to his/her body, towards the ipsilateral shoulder (horizontal abduction).
  4. Compression: The physiotherapist then places his/staff hand on the patient’s elbow with a view to pressing the AC joint slightly.



Assessment Outcome Of AC Joint Compression Test 


Positive Test: When the exact pain is replicated at the AC joint then it means that the test is positive condemning pathology such as AC joint arthritis, sprain or separation.


Negative Test: Lack of pain in AC joint area means that it is not the cause of the shoulder pain.

Utility for Differential Diagnosis with  AC Joint Compression Test

The ACJ Compression Test is useful for differentiating AC joint pathology from other shoulder conditions such as:The ACJ Compression Test is useful for differentiating AC joint pathology from other shoulder conditions such as: 

  • Rotator cuff injuries
  • Subacromial bursitis
  • Glenohumeral joint disorders


Thus, when only the pain from the AC joint is reproduced during the compression maneuver, the clinician can more easily pinpoint the problem. To understand ACJ Pain, explore our CPD course, become certified in AC Joint assessment, and make an informed diagnosis.

Related Tests For AC Joint Assessment

Other tests related to AC joint assessment include :Other tests related to AC joint assessment include:

  • O’Brien test 

O’Brien test involves active compression, where pressure measured in kiloponds is applied on the patient’s chest aiming at identifying areas of reduced compliance, usually caused by pneumothorax.

  • Paxinos Test
  • AC Joint Shear Test
    Again, this is similar to the ACJ Compression, although it is referred to as the Cross-Body 
  • Adduction Test.

Current research focuses the AC Joint Compression Test

Test in conjunction with clinical examinations and diagnostics imaging modalities for proper identification. Available literature review indicates that physiotherapy treatment, particularly those based on research, entails some components such as joint mobilization, muscle strengthening/Strengthening programmes and patient education when treating AC joint pathologies. The current research is therefore studying the effectiveness of different therapeutic approaches and identification of better diagnostic equipment.


A systematic approach to physiotherapy management requires clinicians to be updated with evidence-based practice guidelines and apply active ingredients’ multimodal approach to enhance the patients’ conditions. Other research also shows the potential of using Patient Reported Outcomes Measures (PROMs) in assessing treatment plans’ suitability for a particular patient and modifying the strategy if needed.


Author : Dr. Khadija Fareed (DPT, MS Pain Management, PPTA)



Rina Pandya

Article by Rina Pandya

Published 29 Jun 2024