Original Article: PDF OnlyQuantification of Lumbar Function Part 2: Sagittal Plane Trunk Strength in Chronic Low-Back Pain PatientsMAYER, TOM G. MD*; SMITH, SUSAN S. MS, PT*; KEELEY, JANICE PT†; MOONEY, VERT MD* Author Information *From the University of Texas Health Science Center at Dallas, Texas †From the Productive Rehabilitation Institute of Dallas for Ergonomics, Dallas, Texas Spine: October 1985 - Volume 10 - Issue 8 - p 765-772 Buy Abstract A prototype sagittal plane trunk strength tester was used to measure trunk strength in 286 chronic low-back pain patients. Initial data for this patient group are compared with data acquired previously from a group of controls, adjusted for age, sex, and body weight. Distinct patterns characterize the patient sample as opposed to the controls: (1) Patient values for both flexors and extensors were markedly decreased, with greater variability; (2) Extensor strength was affected more significantly than flexor strength; (3) Discrepancies between patients and controls were greater for females than for males; (4) Highspeed dropoff ratios were much lower for patients, both in flexion and extension. These results demonstrate that strength deficits are a major factor in the deconditioning syndrome associated with chronic low-back pain. © Lippincott-Raven Publishers.