title: Modulation of frontal-plane knee kinematics by hip-extensor strength and gluteus maximus recruitment during a jump-landing task in healthy women.
abstract: BACKGROUND
  Abnormal lower extremity kinematics during dynamic activities may be influenced by impaired gluteus maximus function.
  
  
  OBJECTIVE
  To examine whether hip-extensor strength and gluteus maximus recruitment are associated with dynamic frontal-plane knee motion during a jump-landing task.
  
  
  METHODS
  Exploratory study.
  
  
  METHODS
  Biomechanics laboratory.
  
  
  METHODS
  40 healthy female volunteers.
  
  
  METHODS
  Isometric hip-extension strength was measured bilaterally with a handheld dynamometer. Three-dimensional hip and knee kinematics and gluteus maximus electromyography data were collected bilaterally during a jump-landing test. Data were analyzed with hierarchical linear regression and partial correlation coefficients (α = .05).
  
  
  RESULTS
  Hip motion in the transverse plane was highly correlated with knee motion in the frontal plane (partial r = .724). After controlling for hip motion, reduced magnitudes of isometric hip-extensor strength (partial r = .470) and peak gluteus maximus recruitment (partial r = .277) were correlated with increased magnitudes of knee valgus during the jump-landing task.
  
  
  CONCLUSIONS
  Hip-extensor strength and gluteus maximus recruitment, which represents a measure of the muscle's neuromuscular control, are both associated with frontal-plane knee motions during a dynamic weight-bearing task.
authors.affiliation: Program in Physical Therapy, Mayo Clinic, Rochester, MN, USA.
authors.forename: John H
authors.initials: JH
authors.lastname: Hollman
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Hohl
authors.forename: Jordan L
authors.initials: JL
authors.lastname: Kraft
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Strauss
authors.forename: Katie J
authors.initials: KJ
authors.lastname: Traver
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006615:Hip / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology*; D016059:Range of Motion, Articular; D055815:Young Adult