Magnetic Resonance Imaging-Measured Adductor Muscle Volume and 100 m Sprint Running Performance in Female Sprinters

The purpose of this study was to determine the specific muscles that may contribute to sprint performance. Eleven female 100-m sprinters and nine non-sprinters volunteered. Thigh muscle volume (MV) was measured using magnetic resonance imaging (MRI) images obtained from the spina iliaca anterior-superior to below the distal end of the femur. The MV of the adductors, quadriceps and hamstrings was calculated. Evidence for the null/alternative hypothesis was provided thorough the calculation of Bayes Factors (BF10). Differences represented as median δ (95% credible interval). Absolute MVs in the quadriceps [1.287 (0.315, 2.39), BF10: 14.3], hamstrings [3.032 (1.886, 4.482), BF10: 9487.4] and adductors [3.22 (1.994, 4.654), BF10: 23,360.2] were greater in sprinters than in non-sprinters. This was also observed when MV was normalized to body mass (cm3/kg). Absolute and relative MVs in the adductor longus, the adductor brevis, the adductor magnus, pectineus, and gracilis were also greater in the sprinters. However, percentage of component adductor relative to total adductors MV appeared similar between the two groups. There was no evidence for a correlation between sprint time and quadriceps, hamstrings and adductors MV relative to body mass. Within the adductors, there was evidence for a correlation between sprint time and adductor brevis MV relative to body mass [r = −0.652, BF10: 3.028, δ −0.548 (−0.870, 0.040)]. Although the credible interval was wide, our results suggest that the adductor brevis may contribute to sprint running performance in female sprinters. This may be related, in part, to supporting the flexion and medial rotation of the thigh.