title: An electromyographical evaluation of the validity of the 2-minute sit-up section of the Army Physical Fitness Test in measuring abdominal strength and endurance.
abstract: OBJECTIVE
  The aim was to evaluate electromyographically the validity of the sit-up section of the Army Physical Fitness Test as a way to assess abdominal endurance.
  
  
  METHODS
  Twenty-eight Reserve Officer Training Corps students at the University of Scranton (Scranton, PA) performed the test while eight electromyography surface electrodes picked up the activity of the rectus abdominus and rectus femoris muscles. The researchers analyzed three groups of five contractions from the beginning, middle, and the end of the test. The percentage area of each group of five contractions for each channel and for each of the 28 participants was averaged.
  
  
  RESULTS
  Two paired sample t tests were used to analyze the change in area for the left hip flexor and left abdominal muscle (t = 5.951, p < 0.001) and right hip flexor and right abdominal muscle (t = 5.025, p < 0.001). Results for both right and left sides indicate a statistically significant increase in the use of hip flexors as compared with abdominal muscles.
  
  
  CONCLUSIONS
  Hip flexors can compensate for fatigued abdominal muscles, causing sit-ups to be performed unsafely, yet are still counted as correct according to Army Physical Fitness Test standards.
authors.affiliation: Department of Physical Therapy, University of Scranton, PA 18510, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Szasz
authors.forename: Amy
authors.initials: A
authors.lastname: Zimmerman
authors.forename: Erin
authors.initials: E
authors.lastname: Frey
authors.forename: Danielle
authors.initials: D
authors.lastname: Brady
authors.forename: Robert
authors.initials: R
authors.lastname: Spalletta
mesh_terms: D000009:Abdominal Muscles / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008889:Military Personnel; D010809:Physical Fitness; D015203:Reproducibility of Results