Disc degeneration affects the multidirectional flexibility of the lumbar spine.
ABSTRACT An in vitro biomechanical investigation using human lumbar cadaveric spine specimens was undertaken to determine any relationship between intervertebral disc degeneration and nonlinear multidirectional spinal flexibility.
Previous clinical and biomechanical studies have not established conclusively such a relationship.
Forty-seven discs from 12 whole lumbar spine specimens were studied under the application of flexion-extension, axial rotation, and lateral bending pure moments. Three flexibility parameters were defined (neutral zone (NZ), range of motion (ROM), and neutral zone ratio (NZR = NZ/ROM)) and correlated with the macroscopic and radiographic degeneration.
In flexion-extension, the ROM decreased and NZR increased with degeneration. In axial rotation, NZ and NZR increased with degeneration. In lateral bending, the ROM significantly decreased and the NZR increased with degeneration. In all three loading directions, the NZR increased, indicating greater joint laxity with degeneration.
SourceAvailable from: Jia-Hao Chang
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ABSTRACT: Find full article at http://www.jmptonline.org/current Abstract Objective The purpose of this study is to measure the prevalence of graded disc degeneration, spondylolisthesis, transitional segmentation, and the distribution of sacral slope in patients 21 to 65 years of age with chronic low back pain (CLBP). Methods This retrospective study analyzed 247 digital lumbar radiographic series obtained during a randomized controlled trial of chiropractic patients with CLBP. Chronic low back pain was defined as pain in the low back lasting 12 weeks or longer. Radiographic findings of disc degeneration, spondylolisthesis, and lumbosacral transitional segmentation were graded by 2 authors using established classification criteria. Sacral slope was measured with a digital tool contained within imaging software. Results Lumbosacral transitional segments graded I to IV (Castellvi classification) were present in 14% of cases. Lumbar disc degeneration was most prevalent at L3-4 (49%), followed by L4-5 (42%), L2-3 (41%), L5-S1 (37%), and L1-2 (29%). Isthmic spondylolisthesis was present in 5% of cases, with L5 the most common location. Degenerative spondylolisthesis demonstrated a prevalence of 18%, most commonly occurring at L4. The prevalence of degenerative spondylolisthesis was 51% for women aged 50 to 59 years and 24% for men in the same age range. Conclusions Moderate-severe disc degeneration, multilevel disc narrowing, and degenerative spondylolisthesis were common in individuals with CLBP with age more than 40 years. Isthmic spondylolisthesis was not more prevalent than what has been reported in other populations. Transitional segmentation was identified in a minority of participants, with some of these exhibiting accessory joints or fusion. Mean sacral slope in individuals with CLBP was not substantially different from mean slopes reported in other populations. Key Indexing Terms: Low Back Pain, Prevalence, Intervertebral Disc Degeneration, Spondylolisthesis, Radiography, Lumbosacral Region, ChiropracticJournal of Manipulative and Physiological Therapeutics 11/2014; 37(9):678-687. DOI:10.1016/j.jmpt.2014.10.003 · 1.25 Impact Factor
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ABSTRACT: The goal of the current study was to investigate potential differences in back and hip extensor muscle activity and hip extension force during prone hip extension (PHE) in individuals with lumbar segmental instability (LSI) and asymptomatic subjects. Thirty-six subjects with LSI and 26 asymptomatic volunteers participated in this study. Muscle activity of the erector spinae, gluteus maximus, and biceps femoris was recorded using electromyography (EMG), and hip extension force was measured by a digital force gauge. Muscle activity was significantly greater in subjects with LSI than in asymptomatic subjects during PHE (p < 0.05). Hip extension force was significantly lower in the subjects with LSI than in asymptomatic subjects during PHE (p < 0.05). These findings suggest that during PHE, subjects with LSI have differences in back and hip extensor muscle activity and hip extension force compared to asymptomatic individuals.Manual Therapy 11/2014; DOI:10.1016/j.math.2014.11.002 · 1.76 Impact Factor