Strength and fatigability of the dominant and nondominant hip abductors.
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.
Jacobs
Cale
C
University of Kentucky, Lexington, KY, USA. cjaco@lexclin.com
Uhl
Timothy L
TL
Seeley
Matt
M
Sterling
Wes
W
Goodrich
Larry
L