This is probably the best and most simple exercise to train your iliospoas. Most exercises for the illiospoas have two drawbacks. 1. they focus on the lifting of the knee in front of the body. 2. the extension of the hip is preventing a good load on the illiospoas.
With this exercise only the illiospoas is trained and the heaviest load is where it matters most, pulling the leg forward. And in this excersice only the illiospoas is trained. You have to keep in mind the illiospoas is one of the 'big' muscles in the body which are best trained separately.
In this exercise the athlete lies on his back on a high bench, here a massage bench is used its high and wide which is very pleasant in this case. One leg is pulled up, this way it is preventing the athlete from putting lots of strain on his back while lifting and it is handy to stabilize.
A dumbell is attach to the foot using a rope or some powerstraps. The knee has to be slightly extended while lifting. Lift slowly to maximum high.
Some athletes can not bare any weight when starting out with this exercise while some can lift up to 20kg. For hurdlers, with more flexible hips, the lowering of the leg can be some what unpleasant, in most cases this can be avoided by tilting the pelvis in a direction.