Execution
- 1Screen for localized AC joint pain, step deformity, swelling, or pain with horizontal adduction / full elevation.
- 2Palpate the AC joint line and record localized tenderness.
- 3Perform at least two AC provocation tests such as cross-body adduction, Paxinos, O’Brien, or AC resisted extension.
- 4Count the cluster positive when history, palpation, and provocation reproduce local AC pain.
- 5Distinguish AC pain from sternoclavicular pain, subacromial pain, and deep intra-articular labral pain.
Positive outcome
A positive cluster is reproduction of the patient’s familiar pain localized to the AC joint across palpation and AC-specific provocation. Diffuse shoulder pain without joint-line localisation should not be counted as a positive AC pain cluster.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Walton et al. (2004) | NA | NA | NA | NA | NA |
| Krill et al. (2018) — systematic review | NA | NA | NA | NA | NA |
CommentThis generic AC pain cluster is an editorial / app grouping, not one named Magee diagnostic study. It should be used to organise local signs rather than to claim a precise LR. When precision is needed, use the Chronopoulos or Krill clusters separately.
Moderate Clinical Value