In May 2007, Lomas suffered serious injuries at the Osberton Horse Trials. A collision with a tree left her with a punctured lung and fractures to her neck, back and ribs which ultimately resulted in spinal cord injury.
It is not the first time eventers have been involved in getting their gear off to raise funds, with a similar project in 2007 featuring British riders.
Lomas is determined that she will one day walk again, and aims to do this with the aid of a ReWalk suit, a new robotic suit which will be available in Britain soon. She hopes to have the suit in time for 2012 London Marathon, and plans to walk the 26-mile route.
She has also taken up skiing, and has been selected for the British Disabled Development Squad. She has also set up her own jewellery business, works in a ski office and has married partner Mark and they now have a daughter, Maisie.
"They have been amazing," Lomas said of her former colleagues. "Some took more persuading than others, some ignored me completely, and others were asking to be in it! I can't believe how brave the riders have been, the photos are fantastic. I am so grateful to everyone who has helped with this calendar, and everyone who buys a calendar."
There will be an official launch of the new calendar at next week's Land Rover Burghley Horse Trials in the Celebrity Talk Arena.
Lomas hopes to raise £35,000 for the ReWalk suit, and any other profits over and above that amount will go to Spinal Research.
The riders featured in the calendar:
Eventers: Mary King, Gaby Cooke, Mark Todd, Blyth Tait, Lauren Shannon, Charlotte Agnew, Ginny Howe, Izzy Taylor, Lucinda Green, Piggy French, Francis Whittington, Vitorria Panizzon.
Show Jumpers: Geoff Billington, Claire Robertson, Nathalie Phillips, Jackson Reed Stephenson, Vicky Young.
Dressage: Lucy Miller.
Jockeys: Jimmy McCarthy, Paul Moloney, Andrew Thornton, Mark Grant, Richie McLernon, Charlie Poste, Rhys Flint, James Halliday, Danny Cooke, Ewan Whillans, Sam Jones, Charlie Huxley, Aiden Coleman, Sam Thomas.