Ironically, the injury occurred in February when he fell from a horse as he finalised preparation for a return to competitive action, following surgery in Germany last November on a long-term back problem.
On his website, Nottinghamshire-based Twomey, a stalwart of the Irish team for many years, outlined how his hopes of competing again last month were dashed by the freak accident.
“The operation went well and has made my back a lot stronger. They cleared me to start riding again and I announced my show plans etc.
“[But] the week before my first show back, in a freak accident at home, one of the young horses spooked and, in what would have in nine-times-out-of-ten been a simple spill, I fractured a vertebrae in my back, which put me back on the injured list.
“Hence my reluctance to publish my plans as, until now, I have not been sure of how the recovery would go.
“I am glad to say that this weekend, I quietly slipped off to the Spanish Sunshine tour at Oliva Nova with Tinka’s Serenade, Tin Tin, Royale Du Rouet and Aminko. They all jumped really well, jumping clear rounds. I have competed for three days and my back feels brand new, so I feel safe to report I am back competing.”