title: The Effect of Current Low Back Pain on Volitional Preemptive Abdominal Activation During a Loaded Forward Reach Activity.
abstract: A volitional preemptive abdominal contraction (VPAC) supports trunk stability during functional activity. Pain-free individuals can sustain VPAC during function, but such has not been reported for individuals with current low back pain (cLBP).
  
  
  
  To examine whether cLBP affects VPAC performance during a loaded forward reach (LFR) task.
  
  
  
  Observational crossover study.
  
  
  
  Laboratory.
  
  
  
  A total of 18 controls and 17 subjects with cLBP with pain ratings of 1/10 to 4/10 on a visual analog scale.
  
  
  
  Transverse abdominis (TrA) thickness measurements were recorded by blinded researchers from M-mode ultrasound imaging during 4 conditions: (1) quiet standing without abdominal drawing-in maneuver (ADIM); (2) quiet standing with ADIM; (3) LFR without ADIM; and (4) LFR with ADIM. A physical therapist with 29 years of experience collected historical and examination data.
  
  
  
  TrA muscle thickness (mm).
  
  
  
  A 2 (group) × 2 (contraction) × 2 (reach) analysis of variance demonstrated a significant group × contraction interaction (F [1, 31] = 4.499, P = .04) where ADIM produced greater TrA thickness increases in PLBP subjects (2.18 mm) versus controls (1.36 mm). We observed a significant main effect for reach (F [1, 31] = 14.989, P < .001), where LFR activity produced a greater TrA thickness (6.15 ± 2.48 mm) versus quiet standing (5.30 ± 2.12 mm).
  
  
  
  Subjects with cLBP demonstrated a greater increase in TrA activation during ADIM versus controls.
authors.affiliation: Center for Rehabilitation Research, SAHS, Texas Tech University Health Sciences Center, Lubbock, TX; Department of Physical Medicine and Rehabilitation, University of Kentucky, Lexington, KY(∗).
authors.forename: Vittal R
authors.initials: VR
authors.lastname: Nagar
authors.affiliation: Center for Rehabilitation Research, SAHS, Texas Tech University Health Sciences Center, Lubbock, TX(†).
authors.forename: Troy L
authors.initials: TL
authors.lastname: Hooper
authors.affiliation: Doctor of Physical Therapy Program, Campbell University, Buies Creek, NC(‡).
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Dedrick
authors.affiliation: Center for Rehabilitation Research, SAHS, Texas Tech University Health Sciences Center, Lubbock, TX(§).
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Brismée
authors.affiliation: Center for Rehabilitation Research, SAHS, Texas Tech University Health Sciences Center, Lubbock, TX; Doctor of Physical Therapy Program, Harding University, Searcy, AR(¶).
authors.forename: Michael K
authors.initials: MK
authors.lastname: McGalliard
authors.affiliation: Center for Rehabilitation Research, SAHS, Texas Tech University Health Sciences Center, 3601 4th St., Stop 6280, Lubbock, TX 79430-6280(#). Electronic address: phil.sizer@ttuhsc.edu.
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Sizer
mesh_terms: D000009:Abdominal Muscles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D000328:Adult; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D014463:Ultrasonography / Q000379:methods*