Fernando Alonso "optimistic" Aston Martin has fixed cockpit issue for Monaco GP

Aston Martin driver had to quit in Montreal owing to back pain brought on by extreme seating position in the AMR26 chassis

The world championship began 76 years ago, so it's rare indeed for a new reason for a car's retirement to enter the record books. But a withdrawal for back pain induced by seating position – Fernando Alonso's reason for parking his AMR26 in the garage after 23 laps of the Canadian Grand Prix two weeks ago – is more unusual than you might imagine, given the cramped confines of a Formula 1 car's cockpit.

Alonso suffered throughout the weekend in Montreal but the team was unable to improve the situation for him despite modifying the seat. It's understood the issue is a consequence of the seat's position within the car as well as its shape.

"We worked a little bit last week – online meetings, trying to get a different position in the car," said Alonso on Thursday ahead of this weekend's Monaco Grand Prix. "And then on Tuesday, I live here, so it was very easy for me to pass by the garage and work a little bit in the afternoon. And, yeah, we have like four different positions.

"We changed a lot since Canada. So I think I'm very relaxed, optimistic, that the problem of Canada – where I was very uncomfortable with pain – it's not anymore there. We went back nearly to the 2025 seat position. So basically, we are in a known baseline now. It's nothing experimental."

The seat in an F1 car is carefully custom-moulded to the driver's body, based on an initial casting of them sitting in a bag containing a polyurethane foam mixture. This then forms the basis of the carbon composite moulding of the final seat shell.

It's understood that for the AMR26, managing technical partner Adrian Newey pushed for a much more greatly reclined seating position than in previous Aston Martin F1 chassis. This was done to lower the centre of gravity and reduce the tendency of the driver's helmet to generate wake turbulence around the airbox.

Car of Fernando Alonso, Aston Martin Racing

Photo by: Marcel van Dorst / EYE4images / NurPhoto via Getty Images

This has been a direction of travel for grand prix car design since the early 1960s, when constructors had to respond to engine size being slashed to 1.5 litres. Among the possibilities unlocked by migrating from spaceframe chassis construction to monocoque was to lean the driver back in the car, creating less of an obstruction to airflow.

Newey himself took this philosophy a step further for his Williams FW17 design in 1995, which raised the driver's legs above hip level so the entire nose cone could be elevated, boosting airflow to the underfloor region. Achieving this required a great amount of detail work around the mandatory crash structures, and came at a cost to comfort because it introduced new pressure points around the hips.

Nevertheless it became the de facto standard seating position because of the performance advantages it conferred.

"There are small differences always in new seats that you make, in new cockpit space," said Alonso. "One or two millimetres of different angle or different pressure point underneath your hip area or whatever, it can press some nerves and then you start losing sensitivity.

"And that was the case. So no, it's not a big change. I think if I sit in the garage in different seats from the last three or four years, I will not notice anything, because they are so similar. But then, after 20 or 30 laps, you can start feeling the difference.

"But as I said, I think that should be resolved now."