Intragenic Polymorphisms of the Vitamin D Receptor Gene Associated With Intervertebral Disc Degeneration
Tapio Videman, Jenni Leppävuori, Jaakko Kaprio, Michele C. Battié, Laura E. Gibbons, Leena Peltonen, and Markku Koskenvuo

Two vitamin D receptor alleles were associated with intervertebral disc degeneration, demonstrating for the first time the existence of genetic determinants for disc degeneration, as identified through magnetic resonance imaging disc signal intensity. These results provide a starting point from which to study the effects of gene-environment interactions on disc degeneration.

Compression-Induced Degeneration of the Intervertebral Disc: An in Vivo Mouse Model and Finite-Element Study
Jeffrey C. Lotz, Olivier K. Colliou, Jennie R. Chin, Neil A. Duncan, and Ellen Liebenberg

An in vivo mouse tail model was used to demonstrate that static compression results in biologic and biomechanical alterations of the intervertebral disc. Finite element analysis suggested that the anulus fibrosus may remodel in response to altered tissue stress in a manner similar to other oriented fibrous tissues.

Psychosocial Job Factors, Physical Workload, and Incidence of Work-Related Spinal Injury: A 5-Year Prospective Study of Urban Transit Operators
Niklas Krause, David R. Ragland, June M. Fisher, and S. Leonard Syme

This 5-year prospective study of 1449 transit vehicle operators shows that physical workload and psychosocial job factors independently predict work-related spinal injury.

Acute Effects of Nucleus Pulposus on Blood Flow and Endoneurial Fluid Pressure in Rat Dorsal Root Ganglia
Shoji Yabuki, Shinichi Kikuchi, Kjell Olmarker, and Robert R. Myers

Application of autologous nucleus pulposus to nerve root simultaneously increased endoneurial fluid pressure and decreased blood flow in rat dorsal root ganglia. These acute pathophysiologic changes may have a role in lumbar pain caused by disc herniation.

The Effect of Compressive Force Applied to the Intervertebral Disc in Vivo: A Study of Proteoglycans and Collagen
William C. Hutton, Yasumitsu Toribatake, William A. Elmer, Timothy M. Ganey, Katsuro Tomita, and Thomas E. Whitesides

Pairs of stainless steel coil springs were stretched and attached to produce a compressive force across L1-L2 and L3-L4 in 16 dogs. The dogs were killed between 13 and 27 weeks later. A compressive force applied to the disc over time initiated changes in proteoglycans and collagen.

Changes in Collagen Cross-Linking in Degenerative Disc Disease and Scoliosis
Victor C. Duance, John K. G. Crean, Trevor J. Sims, Nicholas Avery, Sharon Smith, Janis Menage, Stephen M. Eisenstein, and Sally Roberts

The collagen cross-link profile was investigated in intervertebral disc tissue samples from patients with degenerative disc disease or scoliosis. Changes in the cross-link profile were found in both diseases, which are indicative of increased matrix turnover and tissue remodelling and likely to have implications for the progression of these disorders.

The Ligamento-Muscular Stabilizing System of the Spine
Moshe Solomonow, Bing-He Zhou, Mitchel Harris, Yun Lu, and Richard V. Baratta

The synergistic relationship between the supraspinous ligament and the multifidus muscles in maintaining spinal stability was studied experimentally. The electromyographic discharge from the multifidus muscles in the lumbar level was recorded in two separate experimental procedures in which the supraspinous ligament was stimulated.

Estimation of Trunk Muscle Forces and Spinal Loads During Fatiguing Repetitive Trunk Exertions
Patrick J. Sparto and Mohamad Parnianpour

Trunk muscle recruitment patterns were studied in 16 healthy subjects during repetitive dynamic trunk extension endurance tests performed at two load levels and two repetition rates. Using an electromyographic-assisted model, trunk muscle forces and spinal loading were estimated. Elevations in latissimus dorsi and external oblique muscle forces were offset by reductions in erector spinae forces, so that there was no systematic net change in spine compression force. It is suggested that the muscular loading of the spine does not directly increase risk of injury during repetitive lifting.

Intramuscular Pressure in the Erector Spinae and Intra-abdominal Pressure Related to Posture and Load
Gerd Mueller, Michael M. Morlock, Matthias Vollmer, Matthias Honl, Ekkehard Hille, and Erich Schneider

Intramuscular and intra-abdominal pressures were measured during different lifting tasks. Intramuscular pressures were dependent on posture, load, lifting task, and position of the weight. Results suggest that intramuscular pressure measurements may become a valuable tool for evaluating trunk muscle function in vivo.

The Reduction of Chronic Nonspecific Low Back Pain Through the Control of Early Morning Lumbar Flexion: A Randomized Controlled Trial
Stover H. Snook, Barbara S. Webster, Raymond W. McGorry, Maxwell T. Fogleman, and Kathleen B. McCann

The results of previous studies have indicated an increased risk of low back pain with forward bending in the early morning. It was hypothesized that the control of lumbar flexion in the early morning significantly reduces chronic, nonspecific low back pain. An 18-month, randomized, controlled trial produced significant reductions in pain intensity (P less than 0.01).

Efficiency and Costs of Medical Exercise Therapy, Conventional Physiotherapy, and Self-Exercise in Patients With Chronic Low Back Pain: A Pragmatic, Randomized, Single-Blinded, Controlled Trial With 1-Year Follow-Up
Tom Arild Torstensen, Anne Elisabeth Ljunggren, Helge Dyre Meen, Ellen Odland, Petter Mowinckel, and Svante af Geijerstam

A multicenter, randomized, single-blinded controlled trial with 1-year follow-up was conducted to evaluate the efficacy of progressively graded medical exercise therapy, conventional physiotherapy, and self-exercise by walking in patients with low back pain.

Range of Motion and Motion Patterns in Patients With Low Back Pain Before and After Rehabilitation
Marianne L. Magnusson, Jeffrey B. Bishop, Leif Hasselquist, Kevin F. Spratt, Marek Szpalski, and Malcolm H. Pope

Trunk kinematic data were obtained from patients with chronic low back pain in a rehabilitation program. The data were analyzed to extract features from the motion patterns. These features showed marked improvement after the patients had participated in the rehabilitation program.