Execution
- 1Position the patient prone and place the pressure biofeedback unit under the lower abdomen.
- 2Inflate the PBU to the selected baseline pressure, commonly 40 mmHg in this protocol.
- 3Ask the patient to gently draw in the lower abdomen without pelvic tilt, spinal movement, breath holding, or global muscle bracing.
- 4Ask the patient to hold the contraction for repeated timed holds while keeping the pressure change steady.
- 5Record endurance, pressure-control quality, substitution, breath holding, and symptom response.
Positive outcome
The test is positive as an impairment finding when the patient cannot produce or maintain the target pressure change without substitution. Loss of pressure control, pelvic movement, breath holding, or rapid fatigue indicates poor local stabilizer performance. The test does not diagnose structural instability.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Storheim et al. (2002) — reproducibility study | NA | NA | NA | NA | NA |
| von Garnier et al. (2009) — reliability study | NA | NA | NA | NA | NA |
CommentPBU testing is a motor-control and endurance measure for local stabilizers, not a diagnostic test for pain source. Results depend strongly on instruction, baseline pressure, breathing, and examiner cueing. Use it as a training and reassessment tool rather than a pathology classifier.
Low Clinical Value