title: The association of dorsiflexion flexibility on knee kinematics and kinetics during a drop vertical jump in healthy female athletes.
abstract: OBJECTIVE
  While previous studies have examined the association between ankle dorsiflexion flexibility and deleterious landing postures, it is not currently known how landing kinetics are influenced by ankle dorsiflexion flexibility. The purpose of this study was to examine whether ankle dorsiflexion flexibility was associated with landing kinematics and kinetics that have been shown to increase the risk of anterior cruciate ligament (ACL) injury in female athletes.
  
  
  METHODS
  Twenty-three female collegiate soccer players participated in a preseason screening that included the assessment of ankle dorsiflexion flexibility and lower-body kinematics and kinetics during a drop vertical jump task.
  
  
  RESULTS
  The results demonstrated that females with less ankle dorsiflexion flexibility exhibited greater peak knee abduction moments (r = -.442), greater peak knee abduction angles (r = .355), and less peak knee flexion angles (r = .385) during landing. The range of dorsiflexion flexibility for the current study was between 9° and 23° (mean = 15.0°; SD 3.9°).
  
  
  CONCLUSIONS
  Dorsiflexion flexibility may serve as a useful clinical measure to predict poor landing postures and external forces that have been associated with increased knee injury risk. Rehabilitation specialists can provide interventions aimed at improving dorsiflexion flexibility in order to ameliorate the impact of this modifiable factor on deleterious landing kinematics and kinetics in female athletes.
  
  
  METHODS
  II.
authors.affiliation: Department of Physical Therapy, Marquette University , Milwaukee, WI, USA. philip.malloy@marquette.edu.
authors.forename: Philip
authors.initials: P
authors.lastname: Malloy
authors.affiliation: Department of Physical Therapy, Marquette University , Milwaukee, WI, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Morgan
authors.affiliation: Department of Physical Therapy, Marquette University , Milwaukee, WI, USA.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Meinerz
authors.affiliation: Department of Physical Therapy, Marquette University , Milwaukee, WI, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Geiser
authors.affiliation: Department of Physical Therapy, Marquette University , Milwaukee, WI, USA.
authors.forename: Kristof
authors.initials: K
authors.lastname: Kipp
mesh_terms: D000293:Adolescent; D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007700:Kinetics; D007717:Knee / Q000502:physiology; D007719:Knee Joint / Q000502:physiology*; D011187:Posture; D016059:Range of Motion, Articular; D012916:Soccer / Q000293:injuries / Q000502:physiology*; D055815:Young Adult
keywords: ACL injury; Ankle flexibility; Kinematics; Kinetics; Landing mechanics
references.citation: Behav Res Methods. 2009 Nov;41(4):1149-60
references.pmid: 19897823
references.citation: Knee. 2014 Mar;21(2):563-6
references.pmid: 23290175
references.citation: Knee Surg Sports Traumatol Arthrosc. 2009 Jul;17(7):705-29
references.pmid: 19452139
references.citation: Am J Sports Med. 2005 Apr;33(4):492-501
references.pmid: 15722287
references.citation: Clin J Sport Med. 2016 Nov;26(6):518-523
references.pmid: 27315457
references.citation: J Orthop Sports Phys Ther. 2008 Nov;38(11):661-667
references.pmid: 18978451
references.citation: J Athl Train. 2007 Apr-Jun;42(2):311-9
references.pmid: 17710181
references.citation: Am J Sports Med. 2006 Feb;34(2):269-74
references.pmid: 16260464
references.citation: Am J Sports Med. 2006 Sep;34(9):1512-32
references.pmid: 16905673
references.citation: J Orthop Res. 2006 Oct;24(10):1991-2000
references.pmid: 16894592
references.citation: J Athl Train. 2012 Sep-Oct;47(5):525-36
references.pmid: 23068590
references.citation: Am J Sports Med. 2014 Jan;42(1):177-86
references.pmid: 24124198
references.citation: Clin Biomech (Bristol, Avon). 2004 Jul;19(6):617-21
references.pmid: 15234486
references.citation: Am J Sports Med. 2005 Jul;33(7):1003-10
references.pmid: 15888716
references.citation: Am J Sports Med. 2013 Feb;41(2):385-95
references.pmid: 23144366
references.citation: Am J Sports Med. 2000 Jan-Feb;28(1):98-102
references.pmid: 10653551
references.citation: Clin Biomech (Bristol, Avon). 2006 Nov;21(9):977-83
references.pmid: 16790304
references.citation: J Strength Cond Res. 2013 Jul;27(7):1813-23
references.pmid: 23096063
references.citation: J Orthop Res. 1995 Nov;13(6):930-5
references.pmid: 8544031
references.citation: Am J Sports Med. 2015 Feb;43(2):482-90
references.pmid: 24569703
references.citation: Med Sci Sports Exerc. 2010 Mar;42(3):535-45
references.pmid: 19952814
references.citation: Br J Sports Med. 2014 May;48(9):779-83
references.pmid: 23258848
references.citation: J Sport Rehabil. 2012 May;21(2):144-50
references.pmid: 22100617
references.citation: J Athl Train. 2011 Jan-Feb;46(1):5-10
references.pmid: 21214345
references.citation: Am J Sports Med. 1999 Nov-Dec;27(6):699-706
references.pmid: 10569353
references.citation: J Biomech Eng. 1983 May;105(2):136-44
references.pmid: 6865355
references.citation: Arch Phys Med Rehabil. 2008 Jul;89(7):1323-8
references.pmid: 18586134
references.citation: Am J Sports Med. 1995 Nov-Dec;23(6):694-701
references.pmid: 8600737
references.citation: Clin J Sport Med. 2003 Mar;13(2):71-8
references.pmid: 12629423
references.citation: Br J Sports Med. 2009 Jun;43(6):417-22
references.pmid: 19372088