Comparison of the intramuscular circulation of the lumbar multifidus in subjects with and without low back pain in trunk extension and trunk extending exercise (<i>koredake-exercise</i>)

<p>Low back pain (LBP), a common symptom experienced by all age groups, has been reported to be the primary cause of disability worldwide. The aim of this study was to investigate changes in relative circulation over time in the lumbar multifidus in different trunk extension exercises between subjects with and without LBP.</p><p>Twelve subjects (mean age, 21.2±0.4 years) with LBP (LBP group) for the past three months and 18 healthy subjects (mean age, 21.1±0.3 years) without LBP (non-LBP group) were recruited. They received a full explanation of the study, and all agreed to participate. Near-infrared spectroscopy (NIRS) was used to non-invasively measure oxygenated hemoglobin (Oxy-Hb), deoxygenated hemoglobin (Deoxy-Hb), and total hemoglobin (Total-Hb) of the lumbar multifidus at the L5-S1 segment. All measurements were obtained in the neutral position, at trunk extension of 20 degrees, and during trunk extending exercise while standing. The subjects were asked to move into either the trunk extended position or extending exercise movement from the starting (neutral) position in 3 seconds, timed by a metronome, and to maintain the position for 10 seconds. The angles of the extended positions were measured with a goniometer, and self-made devices were used for extending exercise movement to properly maintain these positions. All participants received education and practice time to be able to perform the proper body movements and positions prior to assessment. The measurements were obtained at −3 seconds (neutral position), 0, and 10 seconds in each extended and extending exercise position while standing and compared between the LBP and non-LBP groups.</p><p>In extension, there were no significant interactions in both the LBP and non-LBP groups. In both groups, significant increases were noted in Deoxy-Hb and Total-Hb.</p><p>In extending exercise, there were no significant interactions in both the LBP and non-LBP groups in Oxy-Hb and Total-Hb. In the non-LBP group, significant increases were noted in Deoxy-Hb.</p><p>The results of this study showed that the intramuscular circulation of lumbar multifidus increased with trunk extension, but the circulation increased more with extending exercise in both the LBP and non-LBP groups.</p>