Arm Pump – Chronic exertional compartment syndrome (CECS)
Arm pump is a compartment syndrome overuse type injury. In that respect it is quite unusual in motorcycle racing, as the majority of injuries are traumatic in nature. It seems to be more commonplace in motocross, yet the list of Motogp riders who have suffered from this complaint includes:
Toni Elias, Sylvain Guintoli, Nicky Hayden, Chris Vermuelen, John Hopkins, Makoto Tamada, Marco Melandri and Kenny Roberts jnr.
It exists due to the complex coordination necessary at the hands and wrists required to control a high powered motorcycle....more here: http://www.backontrackphysio.org/page7.htm