title: The influence of hip strength on lower-limb, pelvis, and trunk kinematics and coordination patterns during walking and hopping in healthy women.
abstract: METHODS
  Cross-sectional laboratory study.
  
  
  OBJECTIVE
  To compare peak lower-limb, pelvis, and trunk kinematics and interjoint and intersegmental coordination in women with strong and weak hip muscle performance.
  
  
  BACKGROUND
  Persons with lower extremity musculoskeletal disorders often demonstrate a combination of weak hip musculature and altered kinematics during weight-bearing dynamic tasks. However, the association between hip strength and kinematics independent of pathology or pain is unclear.
  
  
  METHODS
  Peak hip extensor and abductor torques were measured in 150 healthy young women. Of these, 10 fit the criteria for the strong group and 9 for the weak group, representing those with the strongest and weakest hip musculature, respectively, of the 150 screened individuals. Kinematics of the hip, knee, pelvis, and trunk were measured during the stance phases of walking and rate-controlled hopping. Hip/knee and pelvis/trunk coordination were calculated using the vector coding technique.
  
  
  RESULTS
  There were no group differences in peak hip, knee, or pelvis kinematics. Participants in the weak group demonstrated greater trunk lateral bend toward the stance limb during hopping (P = .002, effect size [d] = 1.88). In the transverse plane, those in the weak group utilized less inphase coordination between the hip and the knee during walking (P = .036, d = 1.45) and more antiphase coordination between the hip and knee during hopping (P = .03, d = 1.47).
  
  
  CONCLUSIONS
  In the absence of pain or pathology, poor hip muscle performance does not affect peak hip or knee joint kinematics in young women, but is associated with significantly different lower-limb and trunk/pelvis coordination during weight-bearing dynamic tasks. J Orthop Sports Phys Ther 2014;44(7):525-531. Epub 10 May 2014. doi:10.2519/jospt.2014.5028.
authors.affiliation: Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA.
authors.forename: Jo Armour
authors.initials: JA
authors.lastname: Smith
authors.forename: John M
authors.initials: JM
authors.lastname: Popovich
authors.forename: Kornelia
authors.initials: K
authors.lastname: Kulig
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D006615:Hip / Q000502:physiology*; D006801:Humans; D008124:Locomotion / Q000502:physiology*; D035002:Lower Extremity / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D010388:Pelvis / Q000502:physiology*; D060726:Torso / Q000502:physiology*; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: coordination; gait; hopping; muscle performance