Execution
- 1Screen the history for lumbar catching, giving way, painful locking, or need to self-manipulate.
- 2Ask whether symptoms worsen with sustained postures and improve with external support or bracing.
- 3Observe active lumbar movement for aberrant motion, painful arc, instability jog, or difficulty returning from flexion.
- 4Assess segmental mobility and motor-control findings that may support clinical instability.
- 5Integrate subjective and objective identifiers rather than treating any single sign as diagnostic.
Positive outcome
The screen is positive when several subjective instability features are present together with objective signs such as aberrant motion, painful catch, instability jog, or poor segmental control. It suggests a clinical instability construct rather than radiographic instability by itself. Red flags or progressive neurological signs require separate medical evaluation.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Cook et al. (2006) — Delphi consensus | NA | NA | NA | NA | NA |
CommentCook’s lumbar instability descriptors were consensus-derived, not validated as a diagnostic test with Sn / Sp against imaging. Magee describes instability as loss of control, catch, apprehension, or sudden movement shift, but also notes structural instability may be different. Use this construct to guide further examination and caution, not to label radiographic instability.
Low Clinical Value