کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6210419 | 1266217 | 2013 | 8 صفحه PDF | دانلود رایگان |
Greater fatigability across lumbar extensors has been reported in persons with chronic low back pain (LBP), however, extensor atrophy tends to be local to the site of pain. Therefore, specific ultrasound guided local and remote intramuscular electromyographic recordings were undertaken during an isometric horizontal trunk hold in two carefully matched cohorts; persons with and without LBP. The test was performed to self-determined maximal hold time, and the control group held the horizontal position longer (PÂ <Â 0.001). A power spectral analysis was performed to calculate the normalized median frequency (NMF) slope for both the first and last 30Â s of the fatigue test due to the group difference in hold times. There were no significant group differences in NMF slope at the first 30Â s of testing (PÂ =Â 0.650). The NMF slope for the first and last 30Â s was not different in healthy subjects (PÂ =Â 0.688), but was different in persons with LBP, illustrated by shallowing of the slope at the last 30Â s of the test (PÂ =Â 0.008). A between muscle comparison in the LBP group showed greater non-linear behavior in the deep multifidus (painful region) in contrast to T10 longissimus thoracis (nonpainful region) (PÂ =Â 0.013). Possible explanations for these findings are discussed.
Journal: Journal of Electromyography and Kinesiology - Volume 23, Issue 1, February 2013, Pages 70-77