Figure 2From: Lumbar segmental instability: a criterion-related validity study of manual therapy assessment The passive physiological intervertebral motion (PPIVM) test in flexion. The patient is positioned side-lying. The clinician palpates the interspace between the adjacent spinous processes of the target motion segment with one finger, while moving the lumbar spine from neutral into flexion via the patient's uppermost limb.Back to article page