title: Comparison of 2D and 3D kinematic changes during a single leg step down following neuromuscular training.
abstract: OBJECTIVE
  Evaluate the effects of a weight-bearing neuromuscular training program on 2D and 3D lower extremity kinematics during a single leg step down.
  
  
  METHODS
  Pre-test, post-test quasi experimental.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Sixty nine healthy females performed a single leg step down. The 20 females with the most medial knee orientation during this task participated in this study (20.0 yr (1.6 yr), 167.9 cm (6.0 cm), 63.2 kg (8.3 kg)).
  
  
  METHODS
  2D knee frontal plane projection angle (FPPA) and 3D lower extremity joint (hip and knee) and segment (pelvis and femur) angles during a single leg step down before and after training were compared using paired t-tests. Pearson correlation coefficients were used to measure the association of 2D and 3D kinematic changes following training.
  
  
  RESULTS
  Knee FPPA decreased 4.6° after training (P < 0.001). Hip flexion (P < 0.001) and hip adduction (P = 0.04) increased after training. However, no other 3D joint kinematic changes were observed. Segment angle changes included decreased femoral internal rotation (P = 0.008) and adduction (P = 0.08) and increased anterior pelvic tilt (P < 0.001) and contralateral pelvic drop (P = 0.02). The association between changes in 2D and 3D joint kinematics ranged from 0.12 to 0.34.
  
  
  CONCLUSIONS
  Exercises intended to improve altered lower extremity kinematics may reduce medial knee 2D FPPA values during a single leg step down. However, this 2D change may not be linked with any specific change in 3D joint kinematics.
authors.affiliation: La Crosse Institute for Movement Science, Department of Health Professions-Physical Therapy Program, University of Wisconsin-La Crosse, 1725 State Street, LaCrosse, WI 54601, United States. thomas.olson@vvmc.com
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Olson
authors.forename: Christian
authors.initials: C
authors.lastname: Chebny
authors.forename: John D
authors.initials: JD
authors.lastname: Willson
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Kernozek
authors.forename: J Scott
authors.initials: JS
authors.lastname: Straker
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000517:prevention & control*; D035002:Lower Extremity / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D010806:Physical Education and Training / Q000379:methods*; D012399:Rotation; D016896:Treatment Outcome; D016474:Weight-Bearing / Q000502:physiology