body under crash conditions. (See "Further reading" below.) This work led to the formation of the International Board for Research into Aircraft Crash Events (IBRACE) on 21 November 2016. The brace position as set out to airlines in the UK for passengers in forward-facing seats is based on extensive analytical work arising from Kegworth. It is subtly different from that in the United States and some other countries. Passengers should place their feet and knees together with their feet firmly on the floor (either flat or on the balls of their feet) and tucked behind the knees to prevent shins and legs from being broken against the base of the seat in front. They should bend as far forward as possible, resting their head against the seat in front if it is within reach and place their hands on the back of their head, with the hands one on top of another (rather than interlocked). Their elbows should then be brought in. This prevents both flailing of the arms in the crash sequence and protects the head from flying debris. The head should be as far below the top of the seats as possible to prevent injury from any collapsing overhead compartments. The brace procedure for the forward-facing seat in the United States is similar to that of the UK, but rather than placing the hands on the back of the head, passengers are advised to place them on the top of the seat in front, one hand holding the other wrist and resting the head in the space between the arms. If the seat in front is not within reach then passengers are advised to either grab their ankles or place their hands under their legs and grab the opposite forearm. Jumpseats Flight attendant brace positions are somewhat different due to the design of aircraft jumpseats. So far, there has been little research into the best brace position for flight attendants, though airlines have adopted positions that are very similar to one another. In rear-facing seats, the attendant should be sitting with their back and head firmly against the back of the jumpseat, their knees and feet together and slightly in front of or behind the knee (depending on the individual airlines procedures)—commonly referred to as "toes to tail". In European carriers, the hands can be placed behind the head and hands one on top of the other and