Hi dickwhittington, welcome to the EK forum! No footrests in Economy I'm afraid. You could try and upgrade your flights either by a cash upgrade or by following the steps for an upgrade offer, should you receive an email or prompts at online check in. These are well worth the money as they offer business class for up to 75% off the normal fare.
Failing that, I'd suggest you take something in your hand luggage that can be used as a footrest. I've seen someone blow up a beach ball and use that before. Much cheaper!
Safe travels.