What is a common device used to restrain horses in high-stress situations?

Twitch chains are a common device used to restrain horses in high-stress situations because they provide a means of calming the animal while also allowing for safe handling. The twitch works by applying pressure to the skin of the horse, specifically the upper lip, which has a high concentration of nerve endings. This pressure triggers a natural response that can help distract the horse from stress or pain, making it easier for handlers or veterinarians to perform necessary procedures.

In high-stress environments, such as during veterinary exams or treatments, a twitch can effectively reduce anxiety and make the horse more manageable. It is especially useful because it can be applied quickly and costs little compared to other methods. While leg straps, halters, and head collars are also tools for managing horses, they do not specifically provide the same calming effect in stressful situations that twitch chains offer.