Abstract
The purpose of this study was to investigate differences in the acute effects of passive
knee extension (PKE) and active knee extension (AKE) stretching on the shear elastic
modulus of the hamstrings. In 20 healthy men, maximum knee extension (maximum range
of motion [ROM]) and shear elastic modulus of the hamstrings (biceps femoris long
head, semitendinosus, semimembranosus) were measured before (Pre) and after (Post)
AKE and PKE stretching. The maximum ROM during stretching was measured. In both stretching
methods, maximum ROM increased and the shear elastic modulus decreased (p<0.01), but
no difference was found between the procedures. No significant difference was observed
in the maximum ROM during stretching between the procedures (p=0.06). The shear elastic
modulus was significantly lower in the biceps femoris long head and semimembranosus
than in the semitendinosus muscle (p<0.05). Static stretching with PKE and AKE stretching
showed an increase in maximum ROM and a decrease in hamstring elasticity, but no difference
was found between the methods. Both stretching protocols were effective for reducing
elasticity of the biceps femoris long head and semimembranosus.
Key words
muscle strain - flexibility - range of motion - shear wave elastography