title: The effect of pain on hip and knee kinematics during running in females with chronic patellofemoral pain.
abstract: OBJECTIVE
  Despite the growing recognition of the role of abnormal hip and knee mechanics in patellofemoral pain (PFP), few studies have assessed if or how these mechanics change when the person experiences pain while running. Therefore, the purpose of this study was to determine if the development of pain while running resulted in altered hip and knee kinematics in female runners with PFP as compared to healthy female runners.
  
  
  METHODS
  Thirty female runners (15 PFP, 15 controls) participated in an instrumented gait analysis while running for 30 min at a self-selected pace. Pain and fatigue were recorded every minute while participants ran. Variables of interest included peak hip adduction, hip internal rotation, knee abduction, knee external rotation, pain, and fatigue.
  
  
  RESULTS
  There were significant group by pain interactions for hip adduction (p<0.01) and hip internal rotation (p<0.01). The healthy group, who did not develop pain had significant increases in both motions compared to the PFP group, who did develop pain. There was also a trend toward less knee external rotation in the PFP group in presence of pain (p=0.059). No differences were found for knee abduction (p=0.32). A group main effect was found for hip internal rotation (p=0.008) in which the PFP group had significantly larger values.
  
  
  CONCLUSIONS
  Runners with PFP did not alter their hip mechanics over the course of the run. This may have resulted in repetitive stress to the same aspect of the patellofemoral joint and contributed to the initial development of pain. However, the PFP group did attempt to make a compensation once in pain by reducing knee external rotation.
authors: Department of Rehabilitation Sciences, College of Health Science, University of Kentucky, United States. b.noehren@uky.edu
authors: Brian
authors: B
authors: Noehren
authors: Zack
authors: Z
authors: Sanchez
authors: Tom
authors: T
authors: Cunningham
authors: Patrick Owen
authors: PO
authors: McKeon
mesh_terms: D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D002908:Chronic Disease; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D008875:Middle Aged; D018763:Muscle Fatigue / Q000502:physiology*; D010147:Pain Measurement; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D012420:Running / Q000502:physiology*; D055815:Young Adult