Chronic low back pain-associated paraspinal muscle dysfunction is not the result of a constitutionally determined 'adverse' fiber-type composition
| Autor: | Mike Mahon, Paul J. Watson, Kim Crossman, Jacqueline Oldham, Robert G. Cooper |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Adult
Male medicine.medical_specialty Biopsy Isometric exercise Electromyography Central nervous system disease Internal medicine Isometric Contraction medicine Humans Orthopedics and Sports Medicine Prospective cohort study Muscle Skeletal medicine.diagnostic_test business.industry Case-control study Middle Aged medicine.disease Low back pain Surgery Muscle Fibers Slow-Twitch Case-Control Studies Muscle Fatigue Muscle Fibers Fast-Twitch Cardiology Female Neurology (clinical) medicine.symptom business Low Back Pain Paraspinal Muscle |
| Zdroj: | Spine. 29(6) |
| ISSN: | 1528-1159 |
| Popis: | STUDY DESIGN: Investigative case control study. OBJECTIVES: To determine whether excessive paraspinal muscle fatigue in chronic low back pain results from a paucity of muscle type I fiber content. SUMMARY OF BACKGROUND DATA: Paraspinal muscle function is vital for spinal protection. Prospective studies suggest that excessive paraspinal muscle fatigability may increase risk of first-time low back pain. As contractile performance of the paraspinal muscles is governed by their constitutionally determined fiber composition, the question arises whether a constitutionally determined "adverse" composition could predispose to low back pain through impaired spinal protection. METHODS: Thirty-five male patients with chronic low back pain were compared with 32 male control patients of similar age and anthropometry. During Sorensen and 60% of maximum voluntary isometric contraction fatigue tests, median frequency declines in the paraspinal muscle surface electromyograph signal were monitored and correlated with muscle histomorphometry. RESULTS: Patients were weaker than controls during maximum voluntary isometric contractions (84.47 [28.44]vs. 98.74 [18.11] kg, respectively; P = 0.02) and more fatigable during their Sorensen tests (endurance time 105.29 [28.53]vs. 137.50 [40.38] sec, respectively; P < 0.01). There were no between-group differences in median frequency declines during the Sorensen (-0.37 [0.16]vs. -0.36 [0.12]%.sec) or 60% maximum voluntary isometric contraction (-0.42 [0.31]vs. -0.51 [0.29]%.sec) tests, for patients and controls, respectively. There were no between-group differences in the percent number of paraspinal muscle type I fibers (64 [11]vs. 64 [9]%) or the percent area occupied by type I fibers (67 [11]vs. 69 [9]%), for patients and controls, respectively. Type I and II muscle fiber narrow diameters were similar for both groups. CONCLUSION: In the patients with chronic low back pain tested, their associated paraspinal muscle dysfunction was not the result of a constitutionally determined "adverse" fiber type composition. |
| Databáze: | OpenAIRE |
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