Shoulder Instability Evidence: confirmed

Jerk Test (Posterior) Special Test

Orthopedic Physical Examination & Clinical Assessment Guide

Jerk Test (Posterior) Orthopedic Special Test

What is it used for?

  • Diagnosing Posterior Instability.

How to Perform

  • Position: Seated. Arm flexed 90°, Internally Rotated.
  • Action: Apply axial load (push back) while horizontally adducting the arm.

Interpretation of Results

  • Positive Test: A sudden 'clunk' or jerk as the humeral head subluxes posteriorly.

Diagnostic Accuracy

  • Sensitivity: 73%
  • Specificity: 98%

References

  • Magee, D. J. (2021). Orthopedic Physical Assessment.