Is Biceps Femoris Aponeurosis Size an Independent Risk Factor for Strain Injury?

Abstract

This study examined whether professional footballers with previous biceps femoris long head (BF (LH) ) injury in the last 3-years present a smaller proximal aponeurosis (Apo-BF (LH) ) size compared to footballers with no previous injury. We examined the Apo-BF (LH) and BF (LH) size using magnetic resonance imaging and tested the knee flexor maximal isometric strength in 80 thighs of 40 footballers. Apo-BF (LH) size parameters were processed using a semi-automated procedure. Outcomes were compared between thighs with (n=9) vs. without (n=71) previous BF (LH) injury. No differences were observed between injured and non-injured thighs for the Apo-BF (LH) and BF (LH) size parameters (p>0.05) except for Apo-BF (LH) volume, which was higher in the non-injured thighs of athletes with previous injury (3692.1 +/- 2638.4 mm3, p<0.006) compared to the left (2274.1<plus/minus>798.7 mm3) thighs of athletes without previous injury. A higher knee flexor isometric strength was observed in the injured limb of athletes with previous BF (LH) injury (196.5 +/- 31.9 Nm, p<0.003) compared to the left (156.2<plus/minus>31.4 Nm) and right (160.0 +/- 31.4 Nm) thighs of non-injured athletes. The present results suggest that BF (LH) proximal aponeurosis size should not be considered as an independent risk factor for strain injury.