This is the moment Irish model Pippa O'Connor was thrown off an army horse during a glamorous photo shoot to promote a top equestrian event.

Ms O'Connor, a sister of equestrian star Cian, was brought to hospital with suspected concussion at lunchtime, following the incident during the media launch of the Dublin Horse Show.

The Irish Army said no investigation is planned after Ms O'Connor, wearing a summer dress and no helmet, was thrown from the horse which then fell on top of her.

Fortunately, after a number of tests were carried out, it emerged last night that the 23-year-old had been lucky enough to escape more serious injury.

"She is actually grand," her brother Cian said yesterday evening. "I've just been on the phone to my father who is with her at the moment and she is okay, she's fine. She'll be out of hospital in an hour."

Ireland's Sports Minister Martin Cullen and the chief executive of Failte Ireland, Shaun Quinn, had earlier had their photos taken near the horses, rode by Lieutenant Michael Kelly and Captain Brian Curran-Cournane in Ring Two of the RDS.

When the Assets model arrived, she was asked by a photographer if she would sit on Captain Curran-Cournane's horse while he walked towards a group of photographers leading the horse.

Ms O'Connor, who was wearing a short dress, slipped off her stiletto shoes and sat side-saddle on Ballymoney while holding the reins.

"I haven't been up on a horse for over a year," she said.

What happened next is unclear, but it is thought that Ms O'Connor may have pulled sharply on the reins for balance as the horse took its first steps forward, causing it to rear up on its hind legs. Captain Curran-Cournane tried to hold the horse down but it was too powerful.

As our pictures show, the model kept hold of the reins as she fell off the horse before the horse itself fell backwards and rolled over Ms O'Connor as she lay on the ground.

The eventing horse was quickly on its feet again and, as photographers and onlookers rushed to aid Ms O'Connor, she rose briefly before being persuaded to lie back down.

It was initially thought she had just been badly winded in the incident.

But an ambulance was quickly called when the model began to complain about her vision and a pain in her chest, and started to drift in and out of consciousness.

She was rushed to nearby St Vincent's Hospital and was quickly joined by her father Tadhg and later by her partner, RTE presenter Brian Ormonde.

A spokesperson for the hospital declined to comment on the model's condition, but it is understood that she suffered concussion, heavy bruising and shock.

"It's an unfortunate incident and we wish Pippa a full and speedy recovery from her injuries," an Army spokesman said last night. "But we are talking about a horse. Perhaps after being photographed for 15 minutes or so, it just got spooked."

The spokesman said that an investigation into the incident was not planned at present, but that a senior officer from the Army Equitation School would visit the model.

"The horses would have been specifically selected from the Equitation School as their temperament would have been deemed suitable for a photoshoot," he added.

"But unfortunately when you are dealing with animals of this nature there is some element of risk."

A spokesman for the RDS also said that no investigation was planned.

Earlier, Minister Cullen had the help of Sophie Roden (7) to launch the horse show, which begins on August 6. Sophie, from Ballsbridge in Dublin, will compete in the Lead Rein class at this year's event.

"Her name is Dream and I like the way she goes fast," Sophie said of her pony.

This is the 135th Dublin Horse Show and will include 12 international jumping competitions and a prize fund of nearly €800,000.

Longford show-jumper Eddie Macken (58), will be seen competing in the RDS for the first time since 2000.

Model Pippa O'Connor and her mother spoke to The Herald about the fall. Click here to read more.