title: High eccentric hip abduction strength reduces the risk of developing patellofemoral pain among novice runners initiating a self-structured running program: a 1-year observational study.
abstract: METHODS
  Observational prospective cohort study with 1-year follow-up.
  
  
  OBJECTIVE
  To investigate the relationship between eccentric hip abduction strength and the development of patellofemoral pain (PFP) in novice runners during a self-structured running regime.
  
  
  BACKGROUND
  Recent research indicates that gluteal muscle weakness exists in individuals with PFP. However, current prospective research has been limited to the evaluation of isometric strength, producing inconsistent findings. Considering that hip muscles, including the gluteus maximus and medius, activate eccentrically to control hip and pelvic motion during weight-bearing activities such as running, the potential link between eccentric strength and PFP risk should be evaluated.
  
  
  METHODS
  Eight hundred thirty-two novice runners were included at baseline, and 629 participants were included in the final analysis. Maximal eccentric hip abduction strength was measured using a handheld dynamometer prior to initiating a self-structured running program. The diagnostic criteria to classify knee pain as PFP were based on a thorough clinical examination. Participants were followed for 12 months and training characteristics were gathered with a global positioning system.
  
  
  RESULTS
  Results from the unadjusted generalized linear regression model for cumulative risk at 25 and 50 km indicated differences in cumulative risk of PFP between high strength, normal strength, and low strength (P<.05), with higher strength associated with reduced risk.
  
  
  CONCLUSIONS
  Findings from this study indicate that, among novice runners, a level of peak eccentric hip abduction strength that is higher than normal may reduce the risk of PFP during the first 50 km of a self-structured running program.
authors: Department of Public Health, Section of Sport Science, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark.
authors: Daniel
authors: D
authors: Ramskov
authors: Christian
authors: C
authors: Barton
authors: Rasmus O
authors: RO
authors: Nielsen
authors: Sten
authors: S
authors: Rasmussen
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D046788:Patellofemoral Pain Syndrome / Q000517:prevention & control*; D010806:Physical Education and Training; D011446:Prospective Studies; D012307:Risk Factors; D012420:Running / Q000502:physiology*
keywords: anterior knee pain; chondromalacia; patella