We discuss the force-velocity relations obtained in a two-state crossbridge
model for molecular motors. They can be calculated analytically in two lim
iting cases: for a large number and for one pair of motors. The effect of t
he strain-dependent detachment rate on the motor characteristics is studied
. It can lead to linear, myosin-like, kinesin-like and anomalous curves. In
particular, we specify the conditions under which oscillatory behavior may
be found.