title: The effects of neuromuscular electrical stimulation at different frequencies on the activations of deep abdominal stabilizing muscles.
abstract: BACKGROUND
  Low back pain is associated with transversus abdominis (TrA) dysfunction. Recently, it was proposed that Neuromuscular Electrical Stimulation (NMES) could be used to stimulate deep abdominal muscle contractions and improve lumbopelvic stability.
  
  
  OBJECTIVE
  The purpose of this study was to determine the optimal stimulation frequency required during NMES for the activation of deep abdominal muscles.
  
  
  METHODS
  Twenty healthy volunteers between the ages of 24 and 32 were included. The portable research-stimulator was applied using a 10 second contraction time, and a 10 second resting time at 20 Hz, 50 Hz, and 80 Hz. Changes in muscle thicknesses were determined for the TrA, obliquus internus (OI), and obliquus externus (OE) by real time ultrasound imaging.
  
  
  RESULTS
  Significant thickness increases in the TrA, OI, and OE were observed during NMES versus the resting state (p < 0.05). Of the frequencies examined, 50 Hz NMES produced the greatest increase in TrA thickness (1.33 fold as compared with 1.22 fold at 20 Hz and 1.21 fold at 80 Hz) (p < 0.05).
  
  
  CONCLUSIONS
  Our results indicate that NMES can preferentially stimulate contractions in deep abdominal stabilizing muscles. Most importantly, 50 Hz NMES produced greater muscle thickness increases than 20 or 80 Hz.
authors.affiliation: Department of Physical Medicine and Rehabilitation, College of Medicine, Catholic University, Daegu, Korea.
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Cho
authors.affiliation: Medical Devices Clinical Trial Center, Yeungnam University, Daegu, Korea.|Department of Rehabilitation Science, Graduate School, Daegu University, Gyeongsan, Korea.
authors.forename: Gil Su
authors.initials: GS
authors.lastname: Jung
authors.affiliation: Department of Physical Medicine and Rehabilitation, Bogang Hospital, Daegu, Korea.
authors.forename: Eun Hyuk
authors.initials: EH
authors.lastname: Kim
authors.affiliation: Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Yun Woo
authors.initials: YW
authors.lastname: Cho
authors.affiliation: Department of Neurosurgery, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Medical Devices Clinical Trial Center, Yeungnam University, Daegu, Korea.|Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Daegu, Korea.
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Ahn
mesh_terms: D000009:Abdominal Muscles / Q000000981:diagnostic imaging* / Q000502:physiology*; D000328:Adult; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D014463:Ultrasonography; D055815:Young Adult
keywords: Neuromuscular electrical stimulation; abdominal muscle thickness; frequency; low back pain; real time ultrasound imaging; transversus abdominis