title: Low back pain development response to sustained trunk axial twisting.
abstract: OBJECTIVE
  To investigate if there is an effect of sustained trunk axial twisting on the development of low back pain.
  
  
  METHODS
  Sixteen male pain-free university students volunteered for this study. The trunk axial twisting was created by a torsion moment of 50 Nm for 10-min duration. The axial rotational creep was estimated by the transverse camera view directly on the top of the head. The visual analog scale in low back area was examined both in the initial and at the end of twisting. Each performed three trials of lumbar flexion-extension with the cycle of 5 s flexion and 5 s extension in standing before and after twisting. Surface electromyography from bilateral erector spinae muscles as well as trunk flexion performance was recorded synchronously in video camera. A one-way ANOVA with repeated measures was used to evaluate the effect of twist.
  
  
  RESULTS
  The results showed that there was a significant (p < 0.001) twist creep with rotational angle 10.5° as well as VAS increase with a mean value 45 mm. The erector spinae was active in a larger angle during flexion as well as extension after trunk axial twisting.
  
  
  CONCLUSIONS
  Sustained trunk axial twisting elicits significant trunk rotational creep. It causes the visual analog scale to have a significant increase, and causes erector spinae muscles to become active longer during anterior flexion as well as extension, which may be linked to the decrease of the tension ability of passive tissues in low back area, indicating a higher risk in developing low back pain.
authors.affiliation: Biomechanics Laboratory, College of Physical Education, Shandong Normal University, 88 Wenhua East Road, Jinan, 250014, Shandong, China, xhshan_jn@aliyun.com.
authors.forename: Xinhai
authors.initials: X
authors.lastname: Shan
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Ning
authors.forename: Zhentao
authors.initials: Z
authors.lastname: Chen
authors.forename: Meng
authors.initials: M
authors.lastname: Ding
authors.forename: Weifei
authors.initials: W
authors.lastname: Shi
authors.forename: Shulong
authors.initials: S
authors.lastname: Yang
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D064368:Healthy Volunteers; D006801:Humans; D007403:Intervertebral Disc / Q000293:injuries* / Q000503:physiopathology; D017116:Low Back Pain / Q000209:etiology* / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000502:physiology; D008161:Lumbosacral Region / Q000503:physiopathology; D008297:Male; D010147:Pain Measurement; D016059:Range of Motion, Articular / Q000502:physiology; D014102:Torsion Abnormality / Q000150:complications* / Q000503:physiopathology*; D060726:Torso / Q000503:physiopathology; D055815:Young Adult