Stretching programs to increase muscle flexibility are
frequently used by physical therapists in the management
of patients.24 Therefore, if muscle stretching
methods differ in effectiveness, then elucidating which
methods are most effective would enable clinicians to
better manage patients with muscle tightness. Based on
the results of our study, we believe that both passive and
active stretching are effective methods to increase muscle
flexibility. Active stretching may improve the function
of the antagonist muscles, although we have no data
to support that assertion. We did not measure isometric
muscle torque or endurance in our study. In future
studies, researchers should investigate the changes in
antagonist muscle function associated with active stretching,
whether an active stretching regimen results in
fewer subsequent injuries, and whether muscle length is
maintained after the stretching program is stopped.