According to Sahrmann’s movement balance system
(MBS) approach, active stretching is purported to
increase the flexibility of the tight muscles while concomitantly
improving function of the antagonistic muscles.
8 Our findings support active stretching as an effective
method for increasing the flexibility of tight hip
flexor muscles. However, we did not assess the effectiveness
of stretch type on the function of the antagonist
muscles (hip extensors). The claim of proponents of the
MBS approach that active stretching improves muscle
function of the antagonist muscles and “balances” the
length and function characteristics of the hip flexors and
extensors, resulting in improved patient function and
decreased tissue trauma, is unsubstantiated and needs to
be investigated.