This turns the ground under the target's feet into a big hand that reaches out to grab their legs and hold them in place. The hand has a DR of 5 and skill 14 to attack with.

This is a variation of Earthen Grasp.

Binding (Gaze) 15 [18] 
    Homing (Vibration Sense (Universal)) [+65%] 
    Accurate 1 [+5%] 
    Maximum Duration (10 minutes) [-50%] 
    Environmental (Stone Ground/Floor Under Target, Occasional) [-20%] 
    Magical [-10%] 
    Spell Components [-30%] 
        Must say "earth" in Latin 
        Must gesture with hands 
        Must hold a miniature hand sculpted from clay ($3) 
Levels 2+ [+3/level] 
    Add an extra pass to Homing [+10%]