Overview: The doctors reveal the incredible bit of body kit that keeps you balanced – your vestibular system, and find out what makes Team GB hockey star Shona McCallin so fast in Brilliant Bodies. More medical mysteries are solved on the wards in Ouch and About and find out how to confuse your mates’ digits with a new body trick. Meanwhile, in the Emergency Department Matthea’s broken her arm after running into her friend in the playground and Ben has a sore and swollen eye.