Ude-kujiki
(straight armlock from astride)
"Uke attempts to hold you off with his right arm, 
as
he does so grasp his wrist with both hands and pull his arm out
to full extent. At the same time slide your left leg out at an
angle to his body and imobilise his arm against your thigh. 
It
is important that his thumb should be uppermost and the fulcrum
provided by your thigh should be nearer to his shoulder than his
elbow. 
If
your thigh is below his elbow he will brace his arm against it
and escape."
