The effects of a valgus collapse knee position on in vivo ACL elongation.

Journal Article (Journal Article)

There are conflicting data regarding what motions increase ACL injury risk. More specifically, the mechanical role of valgus collapse positions during ACL injury remains controversial. Our objective was to evaluate ACL elongation in a model that mimics knee movements thought to occur during ACL injury. Eight healthy male subjects were imaged using MR and biplanar fluoroscopy to measure the in vivo elongation of the ACL and its functional bundles during three static knee positions: full extension, 30° of flexion, and a position intended to mimic a valgus collapse position described in the literature. For this study, the valgus collapse position consisted of 30° of knee flexion, internal rotation of the hip, and 10° of external tibial rotation. ACL length decreased significantly from full extension (30.2 ± 2.6 mm) to 30° of flexion (27.1 ± 2.2 mm). ACL length further decreased in the valgus collapse position (25.6 ± 2.4 mm). Both functional bundles of the ACL followed similar trends with regards to decreases in length in each of the three positions. Since strain would follow patterns of ACL length, landing on an extended knee may be a more relevant risk factor for ACL injuries than the valgus collapse position in males. Future studies should evaluate the effects of dynamic motion patterns on in vivo ACL strains.

Full Text

Duke Authors

Cited Authors

  • Utturkar, GM; Irribarra, LA; Taylor, KA; Spritzer, CE; Taylor, DC; Garrett, WE; Defrate, LE

Published Date

  • January 2013

Published In

Volume / Issue

  • 41 / 1

Start / End Page

  • 123 - 130

PubMed ID

  • 22855117

Pubmed Central ID

  • PMC3647681

Electronic International Standard Serial Number (EISSN)

  • 1573-9686

Digital Object Identifier (DOI)

  • 10.1007/s10439-012-0629-x


  • eng

Conference Location

  • United States