Drop Arm Test and External Rotation Lag Signs: Clinical Examination for Cuff Tears
In short
Special physical examination tests identify full-thickness rotator cuff tears with high diagnostic accuracy. Learn how clinicians perform and interpret these clinical markers.
In this guide (4 sections)
Accurate clinical diagnosis of rotator cuff pathology begins with targeted physical examination special tests that assess the structural continuity and contractile capacity of individual tendons. While imaging modalities like magnetic resonance imaging and diagnostic ultrasound provide anatomical visualization, bedside physical tests demonstrate real-time biomechanical function. Among the most specific clinical examination maneuvers are the Drop Arm Test, the External Rotation Lag Sign (ERLS) described by Hertel, and the Hornblower Sign (Patte Test). Unlike sensitivity-focused impingement maneuvers that frequently elicit non-specific bursal pain, these lag signs detect full-thickness tendon detachment and significant fatty muscle infiltration with exceptional clinical specificity.
Everyday Manifestations of Shoulder Drop and Lag in Indian Homes
In Indian daily life, patients exhibiting positive lag signs demonstrate characteristic functional compensations that family members readily observe. When trying to lower an umbrella after walking through a monsoon downpour, the affected arm may suddenly drop uncontrollably from a ninety-degree position, striking the side of the body. In the dining room, when eating rice and curry with the right hand, a patient with a positive Hornblower sign will excessively flare their elbow outward and upward to bring food to the mouth because the arm cannot externally rotate. Homemakers notice that they can no longer reach behind to hook a brassiere or hold a hair dryer steady during personal grooming. Identifying these clear clinical signs enables physiotherapists to establish realistic rehabilitation goals and arrange timely orthopaedic consultations.
Biomechanical Mechanics and Diagnostic Accuracy Parameters
The biomechanical basis of lag signs relies on the inability of a torn muscle to maintain a passively placed joint position against gravity. The Drop Arm Test specifically evaluates the supraspinatus: the examiner passively elevates the arm to ninety degrees of abduction and asks the patient to lower it slowly. A sudden uncontrolled drop accompanied by severe pain signifies complete supraspinatus disruption, exhibiting a specificity of ninety-eight percent. The External Rotation Lag Sign evaluates the infraspinatus: the shoulder is positioned in twenty degrees of abduction and ninety degrees of elbow flexion, and passively rotated externally to near-maximal range. When released, an inability to maintain the position (a lag or spring-back greater than five to ten degrees) indicates an infraspinatus tear, boasting ninety-four percent specificity. The Hornblower sign examines the teres minor at ninety degrees of abduction; failure to hold external rotation indicates advanced teres minor atrophy.
Post-Diagnostic Rehabilitation Staging and Compensatory Retraining
The presence of a positive lag sign indicates substantial structural disruption that dramatically alters the therapeutic strategy. In acute cases following trauma in younger patients, a positive drop arm or lag sign warrants urgent orthopaedic surgical referral for primary tendon repair before irreversible retraction occurs. In chronic elderly presentations, rehabilitation focuses on compensatory neuromuscular training. The physiotherapist develops an anterior deltoid re-education protocol to compensate for supraspinatus failure, while training the posterior deltoid to assist in maintaining functional external rotation. Rhythmic stabilization drills in supported, closed-chain environments build joint proprioception and prevent sudden involuntary limb drops during daily activities.
Seated Supported External Rotation Isometric with Wall Biofeedback
Objective: Stimulate dormant posterior rotator cuff motor units without allowing compensatory lag or joint shear
- 1Sit upright on a stable chair placed sideways next to a solid wall, maintaining good posture.
- 2Place a rolled towel between your ribcage and operative elbow to maintain twenty degrees of abduction.
- 3Bend your elbow to ninety degrees, resting the back of your wrist lightly against the wall surface.
- 4Without shifting your body, gently push the back of your wrist outward into the wall with ten to twenty percent effort.
- 5Hold the gentle pressure for 5 seconds while focusing on breathing normally, then relax for 3 seconds.
| Special Test Maneuver | Targeted Tendon & Biomechanical Execution | Diagnostic Accuracy & Clinical Interpretation |
|---|---|---|
| Drop Arm Test (Codman) | Supraspinatus; arm passively abducted to 90 degrees; patient asked to lower limb slowly in smooth control. | Sensitivity ~35%, Specificity ~98%; sudden drop or severe pain indicates full-thickness supraspinatus tear. |
| External Rotation Lag Sign (Hertel) | Infraspinatus & Supraspinatus; arm at 20 degrees abduction, 90 degrees elbow flexion; externally rotated. | Sensitivity ~70%, Specificity ~94%; spring-back or angular lag > 5 degrees indicates full-thickness infraspinatus tear. |
| Hornblower Sign (Patte Test) | Teres Minor; arm placed at 90 degrees abduction and 90 degrees flexion; patient holds maximal external rotation. | Sensitivity ~85%, Specificity ~93%; inability to maintain external rotation (forearm falls forward) indicates teres minor tear. |
| Internal Rotation Lag Sign | Subscapularis; hand placed behind back in maximal internal rotation and lifted away; examiner releases wrist. | Sensitivity ~89%, Specificity ~96%; hand dropping back against lumbar spine confirms full-thickness subscapularis tear. |
Never evaluate a suspected rotator cuff tear in an acute post-traumatic patient without first excluding acute glenohumeral dislocation or proximal humerus fracture. Forcing external rotation or abduction in an unreduced dislocation can cause severe neurovascular injury.
Frequently Asked Questions
What does a positive drop arm test mean for my shoulder recovery?
A positive drop arm test strongly suggests that the supraspinatus tendon is completely torn across its full thickness. In active individuals, this finding usually warrants an urgent MRI and orthopaedic consultation to discuss surgical repair. In older or medically frail individuals, structured physiotherapy can train surrounding muscles to compensate successfully.
Do I need a doctor referral to see a rotator cuff physiotherapist on BookPhysio.in?
BookPhysio.in does not require a physician prescription. Under the National Commission for Allied and Healthcare Professions (NCAHP) Act 2021, patients across India enjoy direct access to autonomous registered physiotherapists. Through BookPhysio.in, you connect directly with verified clinicians and pay per session with transparent fees, completely free from advance package commitments, commission markups, or platform subscription charges.
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