title: The acute effects of targeted abdominal muscle activation training on spine stability and neuromuscular control.
abstract: BACKGROUND
  Targeted activation of the transversus abdominis (TrA) muscle through the abdominal drawing-in maneuver (ADIM) is a frequently prescribed exercise for the prevention and rehabilitation of low back pain. However, there is still debate over the role the ADIM plays in maintaining a stable spine during movement. Thus, a single cohort pre/post-intervention protocol was used to examine whether 5 min of ADIM training prior to a dynamic movement task alters dynamic spine stability and control.
  
  
  METHODS
  Thirteen healthy participants performed a repetitive spine flexion task twice, once before and once after they received biofeedback training on how to correctly perform the ADIM in standing. Abdominal and back muscle activation (indwelling and surface electromyography, EMG) and 3D kinematic data were recorded during all trials. EMG activation (percent maximum) and local dynamic stability of spine movement [maximum finite-time Lyapunov exponent (λmax)] were compared before and after the training using Friedman's rank test and repeated-measures ANOVA, respectively. To assess the moderating effects of absolute changes in EMG (∆EMG) of each muscle after training on changes in stability, the ∆EMG (peak and mean) were added to the ANOVA as separate covariates (ANCOVA).
  
  
  RESULTS
  Following ADIM training, there were greater peak and mean levels of activation in all tested abdominal muscles, including TrA, (p < 0.05), but not in the back muscles. The ANOVA showed no significant change in λmax following training (p = 0.633). However, after considering the moderating effects of the ∆EMG seen in each muscle with training, it was found that only changes in TrA EMG significantly influenced stability. The ANCOVA revealed a significant main effect of training on stability as well as a significant interaction effect between training and ∆EMG recorded from TrA (p < 0.05); those with larger increases in TrA activation demonstrated larger improvements in stability.
  
  
  CONCLUSIONS
  As a group, 5 min of ADIM training did not change spine stability during dynamic movement. However, those who were most successful in improving TrA activation with a 5-min ADIM training session showed the greatest improvements in local dynamic spine stability after training. As such, dynamic spine stability in some individuals may benefit from ADIM training.
authors.affiliation: School of Physical and Health Education, Nipissing University, 100 College Drive, Box 5002, North Bay, ON, P1B 8L7, Canada. djsouthwell736@community.nipissingu.ca.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Southwell
authors.affiliation: School of Rehabilitation Therapy, Queen's University, 31 George Street, Kingston, ON, K7L 3N6, Canada. 8nh4@queensu.ca.
authors.forename: Nicole F
authors.initials: NF
authors.lastname: Hills
authors.affiliation: School of Rehabilitation Sciences, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada. linda.mclean@uottawa.ca.
authors.forename: Linda
authors.initials: L
authors.lastname: McLean
authors.affiliation: School of Physical and Health Education, Nipissing University, 100 College Drive, Box 5002, North Bay, ON, P1B 8L7, Canada. rgraham@uottawa.ca.|School of Human Kinetics, University of Ottawa, 125 University Private, Ottawa, ON, K1N 6N5, Canada. rgraham@uottawa.ca.
authors.forename: Ryan B
authors.initials: RB
authors.lastname: Graham
mesh_terms: D000009:Abdominal Muscles / Q000294:innervation / Q000502:physiology*; D000328:Adult; D064131:Back Muscles / Q000503:physiopathology; D001676:Biofeedback, Psychology; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D010806:Physical Education and Training / Q000379:methods*; D013131:Spine / Q000502:physiology*