title: Increased sliding of transverse abdominis during contraction after myofascial release in patients with chronic low back pain.
abstract: OBJECTIVE
  Recent evidence suggested the significance of integrity of the tension balance of the muscle-fascia corset system in spinal stability, particularly the posterior musculofascial junction which is adjacent to dorsal located paraspinal muscles joining each other at lateral raphe (LR). The purpose of this study was to compare the contraction of the transversus abdominis (TrA) at both anterior and posterior musculofascial muscle-fascia junctions in patients with low back pain (LBP) and asymptomatic participants before and immediately after a sustained manual pressure to LR.
  
  
  METHODS
  The present observational cohort study used a single-instance, test-retest design. The outcome variables included the resting thickness (Tr), the thickness during contraction (Tc), change in thickness (ΔT), sliding of musculofascial junction (ΔX), muscle length at rest (L) and displacement pattern (ΔD) of the TrA using ultrasonography. Vertical tolerable pressure at the LR was applied manual for 1 min. Tr, Tc, ΔT, and ΔX were analyzed by three-way ANOVA (musculofascial junction sites*group* pre-post manual release). ΔL and ΔD were analyzed by two-way ANOVA (group* pre-post manual release).
  
  
  RESULTS
  Participants with LBP revealed less Tc, ΔT and ΔX at both sites (p < 0.005). After myofascial release, LBP group demonstrated a positive ΔD of the musculofascial junctions at both end (p < 0.001). Nevertheless, both groups increased the ΔT and ΔX at both sites (p < 0.001 and 0.001, respectively).
  
  
  CONCLUSIONS
  The result indicated immediately effect of sustained manual pressure on musculofascial junction of TrA and supported the concept that the possible imbalanced tension of the myofascia corset of TrA in patients with LBP.
authors.affiliation: Division of Physical Therapy, Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Hsin-Chu Branch, HsinChu, Taiwan.
authors.forename: Yen-Hua
authors.initials: YH
authors.lastname: Chen
authors.affiliation: School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan; Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Huei-Ming
authors.initials: HM
authors.lastname: Chai
authors.affiliation: Institute of Applied Mechanics, College of Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Yio-Wha
authors.initials: YW
authors.lastname: Shau
authors.affiliation: Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: chungli@ntu.edu.tw.
authors.forename: Chung-Li
authors.initials: CL
authors.lastname: Wang
authors.affiliation: School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address: sfwang@ntu.edu.tw.
authors.forename: Shwu-Fen
authors.initials: SF
authors.lastname: Wang
mesh_terms: D000009:Abdominal Muscles / Q000502:physiology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D009209:Myofascial Pain Syndromes / Q000628:therapy*
keywords: Abdominal drawing-in maneuver; Lateral raphe; Musculofascial junction; Tensegrity; Transversus abdominis