The true emergency lameness occurs when the signs appear suddenly and are often linked to an identifiable incident as a fall, misstep, injury or kick. Your first task is to identify what area of the leg has been injured; whether it's hoof, lower leg, or upper leg. Don't let the horse continue to hobble around in the hope that he'll "walk out of it." Ideally, while you're working on your horse, he'll be restrained by a trusted assistant at his head. If you're working on a hind limb, the assitant should stand on the same side, ready to pull the horse's head toward himself and lever the hindquarters away from you if problems arise. If you're working on a forelimb, the assistant should stand on the opposite side, ready to pull the forequarters toward himself, away from you. Physical restrain devices, such as a twitch, lip chain or rope, chain chain or rope, war bridle, etc., can be both potentially helpful and dangerous depending on the horse and on your own experience; use these tools only if you're well versed in their proper use.
If it's necessary to tie the horse, don't cross-tie him; he can rear and lunge forward when in cross-ties. And avoid close quarters so you can get out of harm's way should the horse lash out in pain or fall or otherwise make a sudden change of position. Never attempt to examine an injured horse in a standing tie-stall or in a horse trailer.
The use of chemical restraint; tranquillizers, sedatives and pain killers; is unwise in the field lameness situation. Such drugs can mask the signs, making your horse detective work more difficult, and they can also affect the horse's balance, making it less likely that he'll be able to stand during your examination without risk of stumbling or falling; in addition to being hazardous to your health. Furthermore, when under the influence of a mood-altering sedative ot tranquillizer, some horses seem oblivious to pain, but can suddenly overreact in an excessive and illogical manner.
If you see that a foreign body ("poker") is still in place in the horse's hoof, you can only guess where the tip of the poker reached inside the hoof. At this moment, your horse's freshly wounded hoof is not infected; it's just contaminated. Quick action might be able to prevent infection.
After meticulously cleaning the foot and carefully excavating and irrigating the puncture wound, a plastic hoof boot is invaluable for preserving the clean environment. Bandages and duct tape are fine if the horse is to be confined to a stall with soft bedding, but if he must walk any distance to get to veterinary assistance, tha bandage is likely to wear through and expose the foot to dirt, mud, grit, and a whole host of contaminants. The boot should be water tight (the plastic models seem to hold better than the rubber ones), tall enough to encompass the pastern, large enough to put on over the foot bandage, and somewhat contoured to the shape of the foot. It should be removed and cleaned daily along with the bandage.
It's a good idea, within 24 hours of the initial injury, unless you're positive that the poker penetrated less than one-half inch. In that case, cleaning the foot thoroughly, carefully excavating and irrigating the puncture wound, plugging the hole, applying water-proof and air-proof bandages and boots and giving anti-inflammatory drugs would probably be enough. Nevertheless, it shouldn't be difficult for you to get to a competent equine veterinarian in 24 hours. In doing so, you'll benefit from getting a second, experienced opinion, backed by x-rays and ultrasound. And if the horse becomes more, rather than less, sore over next few days, take that as a sign that there's trouble brewing, and get to a vetrinarian right away.