A competitor at the annual UK wife-carrying contest was stretchered off the Surrey course after being dropped on her head mid-race.

Footage posted online captured the painful moment the unidentified woman’s partner slipped on a muddy patch running on a downhill section of the 380-metre obstacle course in Dorking.

The unidentified pair tackled the treacherous course using the Estonian carry - where the 'wife' hangs upside-down on the carrier's back, with her legs positioned over his shoulders.

Shocked spectators let out a collective gasp as the pair tumbled to the ground on the course's 'splash zone', where volunteers armed with buckets of water and water guns gleefully soak competitors.

“Ow, my back!” the woman exclaimed while writhing around in agony on the muddy ground as her concerned partner checked she was OK.