title: Normative values of eccentric hip abduction strength in novice runners: an equation adjusting for age and gender.
abstract: OBJECTIVE
  Low eccentric strength of the hip abductors, might increase the risk of patellofemoral pain syndrome and iliotibial band syndrome in runners. No normative values for maximal eccentric hip abduction strength have been established. Therefore the purpose of this study was to establish normative values of maximal eccentric hip abduction strength in novice runners.
  
  
  METHODS
  Novice healthy runners (n = 831) were recruited through advertisements at a hospital and a university. Maximal eccentric hip abduction strength was measured with a hand-held dynamometer. The demographic variables associated with maximal eccentric hip abduction strength from a univariate analysis were included in a multivariate linear regression model. Based on the results from the regression model, a regression equation for normative hip abduction strength is presented.
  
  
  RESULTS
  A SIGNIFICANT DIFFERENCE IN MAXIMAL ECCENTRIC HIP ABDUCTION STRENGTH WAS FOUND BETWEEN MALES AND FEMALES: 1.62 ± 0.38 Nm/kg (SD) for males versus 1.41 ± 0.33 Nm/kg (SD) for females (p < 0.001). Age was associated with maximal eccentric hip abduction strength: per one year increase in age a -0.0045 ± 0.0013 Nm/kg (SD) decrease in strength was found, p < 0.001. Normative values were identified using a regression equation adjusting for age and gender. Based on this, the equation to calculate normative values for relative eccentric hip abduction strength became: (1.600 + (age * -0.005) + (gender (1 = male / 0 = female) * 0.215) ± 1 or 2 * 0.354) Nm/kg.
  
  
  CONCLUSIONS
  Normative values for maximal eccentric hip abduction strength in novice runners can be calculated by taking into account the differences in strength across genders and the decline in strength that occurs with increasing age. Age and gender were associated with maximal eccentric hip abduction strength in novice runners, and these variables should be taken into account when evaluating eccentric hip abduction strength in this group of athletes.
  
  
  METHODS
  2A.
authors.forename: D
authors.initials: D
authors.lastname: Ramskov
authors.affiliation: Orthopaedic Surgery Research Unit. Science and Innovation Center, Aalborg University Hospital, DK-9000.
authors.forename: M B
authors.initials: MB
authors.lastname: Pedersen
authors.affiliation: Orthopaedic Surgery Research Unit. Science and Innovation Center, Aalborg University Hospital, DK-9000.
authors.forename: K
authors.initials: K
authors.lastname: Kastrup
authors.affiliation: Department of Public Health, Section for Sport Science, Faculty of Health Sciences, Aarhus University, DK-8000.
authors.forename: S
authors.initials: S
authors.lastname: Lønbro
authors.affiliation: Department of Physiotherapy and Occupational Therapy, Aarhus University Hospital, DK-8000.
authors.forename: J S
authors.initials: JS
authors.lastname: Jacobsen
authors.affiliation: Arthroscopic Centre Amager, Copenhagen University Hospital, Hvidovre, DK-2300.
authors.forename: K
authors.initials: K
authors.lastname: Thorborg
authors.forename: R O
authors.initials: RO
authors.lastname: Nielsen
authors.affiliation: Orthopaedic Surgery Research Unit. Science and Innovation Center, Aalborg University Hospital, DK-9000.
authors.forename: S
authors.initials: S
authors.lastname: Rasmussen
keywords: Eccentric hip abduction strength; novice runners