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Human Senses TV Programmes

Programme 6 - Balance

Balance is our true sixth sense - it enables us to sense how our bodies are moving around in the world and keep us upright. There are only two kinds of animal that spend their whole lives performing the tricky balancing act of walking on two legs – humans and some flightless birds, like ostriches.

Organs in our ears help us keep our balance

Balancing can be a deceptively complex business. Nigel Marven joins stunt co-ordinator Marc Cass for a dramatic drive and experiences how the balance organs let us know how we're being yanked around and even turned upside down.

For really fine balance, we need our eyes. They help us to work out exactly what the body is doing relative to the outside world. A troupe of acrobats at the Circus School in San Francisco illustrate this when they perform a human tower in darkness.

Nigel reveals why spinning round in circles makes you dizzy. And, under the guidance of Dr Ros Davies from the National Hospital for Neurology and Neurosurgery, he discovers why drinking alcohol makes it hard to walk in a straight line and can make your head spin.

Our sense of balance is so complex that even if all components are working fine – the balance organs, the feedback from our limbs, and our eyes – if there there's any disagreement about what's going on, the result can be unpleasant. Dr Frank Golden of the Royal National Lifeboat Institution explains that sea sickness is caused when the central nervous system receives conflicting messages from these three systems.

The ultimate test for our sense of balance is a trip into space – or even worse, a trip on board the infamous Russian Vomit Comet. This ride is so unpleasant that first-timers can sometimes end up in hospital on a drip because they have to vomit so much. Nigel gives it a go. At first his brain is deeply confused, but gradually he gains control of his body again. It's the ultimate triumph of the human senses - to survive in a situation which no animal was designed for.