title: Strength and fatigability of the dominant and nondominant hip abductors.
abstract: BACKGROUND
  Contralateral muscular imbalances have been suggested to increase the risk of lower extremity injury. Previous groups have assessed strength of the quadriceps and hamstring muscle groups; however, no previous authors have compared bilateral hip-abductor muscular performance.
  
  
  OBJECTIVE
  To examine the strength and fatigability of the hip abductors in the dominant and nondominant legs.
  
  
  METHODS
  Single-group, repeated-measures design.
  
  
  METHODS
  Musculoskeletal laboratory.
  
  
  METHODS
  Forty-two healthy subjects (23 males, 19 females; age = 24.3 +/- 2.7 years, height = 173.4 +/- 9.8 cm, mass = 73.7 +/- 11.6 kg).
  
  
  METHODS
  Subjects performed three 5-second maximal voluntary isometric contraction (MVIC) trials of the hip abductors with the dominant and nondominant legs. Following the maximal strength trials, subjects performed a submaximal (50% of MVIC) 30-second fatigue trial with each leg.
  
  
  METHODS
  Peak torque (PT) was recorded from each MVIC trial. Surface electromyography was used to record muscle activity during the fatigue trials. Power spectral analysis was used to determine the median frequency of each 0.512-second portion of the fatigue trials. Median frequencies were plotted against time, and linear regression was used to determine the median frequency slope (MF(slope)). Data were analyzed using 2-tailed, paired t tests.
  
  
  RESULTS
  Hip-abduction PT of the dominant leg (81.0 +/- 23.7 Nm) was significantly larger than that of the nondominant leg (76.1 +/- 9.9 Nm, P = 0.02). There was no difference in MF(slope) between the dominant (-0.37 +/- 0.29) and nondominant limbs (-0.35 +/- 0.34, P = 0.84). The PT and MF(slope) were not significantly correlated (r = -0.07, P = 0.53).
  
  
  CONCLUSIONS
  Hip-abduction strength differences exist between the dominant and nondominant legs. Measures of strength and fatigability were poorly related; therefore, clinicians may opt to assess hip strength and fatigability independent of each another.
authors.affiliation: University of Kentucky, Lexington, KY, USA. cjaco@lexclin.com
authors.forename: Cale
authors.initials: C
authors.lastname: Jacobs
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Uhl
authors.forename: Matt
authors.initials: M
authors.lastname: Seeley
authors.forename: Wes
authors.initials: W
authors.lastname: Sterling
authors.forename: Larry
authors.initials: L
authors.lastname: Goodrich