Your horse should easily yield its feet. This allows you, your vet or farrier to assess this area for injury or illness, as well as safely and effectively perform treatments on their feet and lower limbs.
All horses should stand with their feet raised without resistance. You should be able to touch the entire limb, all the way to the coronet without the horse moving or kicking before you start.
For the left forelimb: With an assistant at the head of your horse, stand on left side of your horse at their flank and facing toward their rear end. Make contact with your horse and move your hand down the upper limb and down to the flexor tendons.
Some horses will raise their foot at this point. Hold it or put it between your knees depending on what you need to accomplish. If the horse does not raise its foot on cue, pinch the flexor tendons above the fetlock between the left thumb and fingers.
Start with little pressure and gradually apply pressure until a yield or "try" is felt and the horse begins to comply. Immediately release the pinch and lift the limb. Hold it only as long as necessary and then reward the horse by letting it down.
If your horse tries to bear weight again with the limb, increase the pressure on the tendons until you again feel the release. Once you have the foot raised, if the horse tries to pull the limb away, grasp the toe with the fingers of the left hand, put the fetlock in flexion and lift straight up. This gives you the best mechanical advantage and puts the horse in an uncomfortable position. You do this only as long as he is resisting.
When your horse relaxes, immediately relax your grasp too, providing your horse with comfort.
Tips for safety & Success
Practice this skill before you need to use it. Your vet and farrier will appreciate your efforts.