Extensibility of the Hamstrings Is Best Explained by Mechanical Components of Muscle Contraction, Not Behavioral Measures in Individuals With Chronic Low Back Pain

Wiley - Tập 1 Số 8 - Trang 709-718 - 2009
Paul W.M. Paul W.M., Jamie Jamie, Bernadette A. Bernadette A.

Tóm tắt

ObjectiveTo examine the relationship between hamstring extensibility by use of the instrumented straight leg raise; mechanical components of muscle contraction, including muscle recruitment, passive torque measures of tissue stiffness, and eccentric strength; and self‐reported measures of pain and disability.DesignCross‐sectional study.SettingUniversity laboratory.ParticipantsTwenty‐one individuals with chronic nonspecific axial lower back pain and 15 healthy control subjects.AssessmentInstrumented straight leg raise, concentric and eccentric hamstring strength, self‐reported measures of pain, disability, fear avoidance, general health and well‐beingMain Outcome MeasurementsObjective measures included hamstring extensibility, hamstring muscle stiffness, absolute and relative concentric/eccentric strength, concentric/eccentric strength ratios. Self‐reported measures included Oswestry disability index, visual analog pain scale, fear avoidance beliefs, and general health and well being.ResultsPatients with lower back pain had lower range of motion, greater changes in muscle stiffness, and impaired concentric‐to‐eccentric strength levels. Stepwise regression identified measures of stiffness as significantly predicting hamstring extensibility (adjusted r2 = 0.58, F = 23.76, P < .001). Self‐reported measures were not associated with extensibility. Gender differences were noted for passive stiffness and absolute strength. For women, later onset of the medial hamstrings also was associated with greater hamstring extensibility.ConclusionsDecreased extensibility of the hamstrings was associated with increased passive stiffness during the common range of motion (20 to 50°). Impaired stretch tolerance is associated with actual mechanical restriction, not behavioral measures indicating increased pain or fear‐avoidant behavior. With no relationship to actual disability and contradictory findings in the literature for the relationship of the hamstrings to the mechanics of the low back, it is unclear whether decreased hamstring extensibility should be targeted in rehabilitation programs for axial lower back pain.

Tài liệu tham khảo

10.1097/00007632-199601010-00017 10.1097/00005768-199806000-00023 Göeken L.N., 1993, Instrumental straight‐leg raising: Results in healthy subject, Arch Phys Med Rehabil, 74, 194 10.1016/j.apmr.2005.03.033 Göeken L.N., 1991, Instrumental straight‐leg raising: A new approach to Lasegue's test, Arch Phys Med Rehabil, 72, 959 10.1053/apmr.2001.19786 10.1016/0268-0033(95)00038-0 10.2519/jospt.2008.2575 Dvir Z., 2003, Trunk extension effort in patients with chronic low back dysfunction, Spine, 28, 685, 10.1097/01.BRS.0000051917.04731.A4 10.1016/S0003-9993(95)80628-8 10.1097/00007632-199611150-00010 10.1016/0304-3959(94)00279-N 10.1016/S0304-3959(98)00229-2 10.1023/A:1026666403039 10.1093/bja/87.1.144 10.1016/S0304-3959(99)00242-0 10.1097/00007632-200011150-00017 10.1016/0304-3959(93)90127-B 10.1097/00005650-199206000-00002 10.1016/j.jneumeth.2003.10.014 10.1177/03635465990270050801 Dvir Z., 2001, Identifying feigned isokinetic trunk extension effort‐in normal subjects: An efficiency study of the DEC, Spine, 26, 1046, 10.1097/00007632-200105010-00011 Kendall F.P., 1993, Muscle Testing and Function Nourbakhsh M.R., 2006, The relationship between pelvic cross syndrome and chronic low back pain, J Back Musc Rehabil, 19, 119, 10.3233/BMR-2006-19403 10.1016/j.apmr.2006.12.021 Pearcy M., 1985, The effect of low‐back pain on lumbar spinal movements measured by three‐dimensional X‐ray analysis, Spine, 10, 150, 10.1097/00007632-198503000-00007 10.1097/00007632-199703010-00019 Blackburn TJ Bell DR Norcross MF Hudson JD Engstrom LA. Comparison of hamstring neuromechanical properties between healthy males and females and the influence of musculotendinous stiffness. J Electromyogr Kinesiol in press. 10.1016/j.clinbiomech.2008.10.001 10.1016/j.jelekin.2004.04.001 10.1016/S1050-6411(02)00002-0 10.1007/BF00235181