If the leg position is "not too far" from frame 1 to frame 15, then you have only a modest movement, spread over half a second or a second (I'm not clear at which frame you're rendering), so you aren't going to see much blur (unless you jack the camera shutter speed).

     Try using a starting pose with the leg well back, and eight frames later have the leg at full kick (render at this frame), then eight frames later set the leg in a "recovered" pose.

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5