Use of ultrasound to monitor biceps femoris mechanical adaptations after injury in a professional soccer player

This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (bf) architecture of aprofes-sional soccer player with acute first-time hamstring strain. the player followed a 14 session physiotherapy treatment until return to sport. the pennation angle and aponeurosis strain of the long head of the biceps femoris (bf) were monitored at 6 occasions (up until 1 year) after injury. the size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. the pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. in contrast,pennation angle of fascicles located away from the injury site were relatively unaffected. the treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of mvc moment and remained similar one year after the intervention. this study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. © journal of sports science and medicine.