title: Cruciate ligament force during the wall squat and the one-leg squat.
abstract: OBJECTIVE
  To compare cruciate ligament forces during wall squat and one-leg squat exercises.
  
  
  METHODS
  Eighteen subjects performed the wall squat with feet closer to the wall (wall squat short), the wall squat with feet farther from the wall (wall squat long), and the one-leg squat. EMG, force, and kinematic variables were input into a biomechanical model using optimization. A three-factor repeated-measure ANOVA (P < 0.05) with planned comparisons was used.
  
  
  RESULTS
  Mean posterior cruciate ligament (PCL) forces were significantly greater in 1) wall squat long compared with wall squat short (0 degrees -80 degrees knee angles) and one-leg squat (0 degrees -90 degrees knee angles); 2) wall squat short compared with one-leg squat between 0 degrees -20 degrees and 90 degrees knee angles; 3) wall squat long compared with wall squat short (70 degrees -0 degrees knee angles) and one-leg squat (90 degrees -60 degrees and 20 degrees -0 degrees knee angles); and 4) wall squat short compared with one-leg squat between 90 degrees -70 degrees and 0 degrees knee angles. Peak PCL force magnitudes occurred between 80 degrees and 90 degrees knee angles and were 723 +/- 127 N for wall squat long, 786 +/- 197 N for wall squat short, and 414 +/- 133 N for one-leg squat. Anterior cruciate ligament (ACL) forces during one-leg squat occurred between 0 degrees and 40 degrees knee angles, with a peak magnitude of 59 +/- 52 N at 30 degrees knee angle. Quadriceps force ranged approximately between 30 and 720 N, whereas hamstring force ranged approximately between 15 and 190 N.
  
  
  CONCLUSIONS
  Throughout the 0 degrees -90 degrees knee angles, the wall squat long generally exhibited significantly greater PCL forces compared with the wall squat short and one-leg squat. PCL forces were similar between the wall squat short and the one-leg squat. ACL forces were generated only in the one-leg squat. All exercises appear to load the ACL and the PCL within a safe range in healthy individuals.
authors.affiliation: Department of Physical Therapy, California State University, Sacramento, CA 95819-6020, USA. rescamil@csus.edu
authors.forename: Rafael F
authors.initials: RF
authors.lastname: Escamilla
authors.forename: Naiquan
authors.initials: N
authors.lastname: Zheng
authors.forename: Rodney
authors.initials: R
authors.lastname: Imamura
authors.forename: Toran D
authors.initials: TD
authors.lastname: Macleod
authors.forename: W Brent
authors.initials: WB
authors.lastname: Edwards
authors.forename: Alan
authors.initials: A
authors.lastname: Hreljac
authors.forename: Glenn S
authors.initials: GS
authors.lastname: Fleisig
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Wilk
authors.forename: Claude T
authors.initials: CT
authors.lastname: Moorman
authors.forename: James R
authors.initials: JR
authors.lastname: Andrews
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000502:physiology*; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D016119:Posterior Cruciate Ligament / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D055070:Resistance Training; D055815:Young Adult