Execution
- 1Position the patient standing with the back exposed and stand behind the patient to view both scapulae.
- 2Give the patient dumbbells: 1.4 kg / 3 lb if body weight is less than 68 kg / 150 lb, or 2.3 kg / 5 lb if body weight is greater than 68 kg / 150 lb.
- 3Ask the patient to simultaneously abduct both arms to full elevation with thumbs up over a 3-second count, then lower over a 3-second count, repeating three times.
- 4Ask the patient to repeat the same 3-second up and 3-second down sequence through forward flexion, again for three repetitions.
- 5Rate each scapula as normal, subtle dyskinesis, or obvious dyskinesis based on winging or dysrhythmia, especially during the lowering phase.
Positive outcome
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| McClure et al. (2009) | % agreement 75-82; weighted κ = 0.48-0.61 | NA | NA | NA | NA |
| Tate et al. (2009) — validity vs 3D kinematics | validity study | NA | NA | NA | NA |
| Wright et al. (2013) — for AC dislocation only | NA | 71 | NA | NA | NA |
CommentSDT has the best reliability of the scapular dyskinesis observational tests (McClure 2009: weighted κ 0.48-0.61, agreement 75-82%). Tate 2009 confirmed kinematic differences (less upward rotation, less clavicular elevation, greater protraction) between obvious dyskinesis and normal scapulae using 3D motion capture, but did NOT report Sn/Sp/LR for clinical diagnosis. Wright 2013 systematic review noted only Sn 71% for SDT in detecting acromioclavicular dislocation — an off-label finding, not for impingement / cuff disease. Treat SDT as a movement-pattern descriptor, not a diagnostic test for any specific shoulder pathology. Tate 2009 also found no symptom difference between normal and obvious-dyskinesis scapulae (OR 0.79, 95% CI 0.33-1.89), reinforcing that dyskinesis is not necessarily the pain generator.