23.08.2018

SEATING PAINS: HOW MEDICAL RESEARCH IS IMPROVING SEAT DESIGN

Red Bull Ring, Spielberg, Austria. Friday 29 June 2018. Robert Kubica, Williams Martini Racing, settles into his seat. Photo: Glenn Dunbar/Williams F1 ref: Digital Image _31I8962

While this year’s Spanish Grand Prix might have been a straightforward lights-to-flag victory for Lewis Hamilton, Williams driver Sergey Sirotkin described it as “the toughest race” of his life.

After threading his way through the wreckage of Romain Grosjean’s opening-lap crash, he started to feel discomfort from his seat. “I was really struggling with seat comfort and just staying in the car,” he said after the race. “It was a very painful feeling I was getting.”

Sirotkin was in fact struggling with posture-related problems in the cockpit of his Williams, particularly with the angle of the shoulder pads that go towards his HANS device. Rather than holding him in place, they were pushing him down into the seat, which caused significant discomfort through the corners.

“Seating position is one of the most underestimated performance and safety items,” says Grand Prix Drivers Association chairman Alex Wurz. “Sometimes even in a small accident, a bad seat can actually cause a lot of damage in relation to the crash or off itself.”

It is not an uncommon problem. Over the years, a number of drivers have suffered due to seat-related issues and often the correct posture within a seat can be the difference between getting injured in an accident and escaping unscathed.

Finnish driver Valtteri Bottas had a similar issue in 2015 when he missed the Australian Grand Prix because of a back injury he sustained during qualifying. He traced the problem back to his seat position in the Williams car, with the bumpy nature of the track in Melbourne compounding the injury.

“It was the seat and pedal position,” he said at the time. The team made changes to put his back in a more neutral position, which put less pressure on his discs and this solved the issue. However, Bottas admits he was surprised to have the problem in Australia, with no signs that his seat position wasn’t right.“I’ve never had any problems before with the lower back. That kind of thing normally takes a bit of time to build up. But there was no warning, it just went suddenly.”

This is not just an issue in F1 but across motor racing – single seaters, sports cars and rallying.

Controlling Force

When making a race seat, a team’s main goal is to replicate the driver’s body shape in the car but it is difficult to replicate the G-Forces a driver will face. So it can be a challenge to ensure that the seat works in conjunction with the other safety systems on the car.

“When you just sit in an empty monocoque your body is not protected left and right, and that means your spine is not in the correct shape,” says Wurz. “So I can only recommend to all the young professional drivers out there to be extremely accurate, and go into great detail when you are making your seat. Make sure it’s your seat and not just some foam insert, and that it’s a really good seating position in relation to the seat belts, the HANS device, safety points like the headrest and so on.”

This is especially important for lower-level single seater racing where there may not be a budget for a specially-moulded seat for the driver.

“I see drivers sitting in a Formula 3 or Formula 4 car with just foam all around them and they aren’t sitting in the proper seat,” adds Wurz. “You will hardly be able to feel what the car does and if you have an impact, all of the safety devices which are designed around the seat will then work with much less efficiency.”

Audi R18 e-tron quattro - cut

Replicating the cockpit

To help prevent these issues some teams are consulting experts to ensure that the seating position of a driver does not create unnecessary strain on his body.

UK-based consultancy F1 Spinal Solutions, which works with the Mercedes F1 team, uses a special upright MRI scanner to scan a driver’s spine and muscles whilst sitting in the race position. This offers greater insight rather than using a conventional tunnel-type MRI scan, and gives them the opportunity to advise drivers and teams on how to mitigate for potential issues.

“The MRI machine is clever enough that it can pick up the driver, the skin, the muscles, and the shape of the spine,” says radiologist Dr Steven Morgan, one of the founders of the company. “The upright scanner is essentially weight bearing and we can load a driver sitting, bending forwards and backwards, which allows us to tell if the (spinal) disc is stable and physiological as opposed to normal loading where they are lying down.”

Since launching the company two years ago, Morgan has worked with a number of F1 drivers, including one who was suffering from pain during rapid decelerations. By analyzing an MRI scan with the driver in his normal racing position, they were able to identify the cause of the problem.

They found that when the muscle groups were working hard, the blood flow increased dramatically, resulting in muscle engorgement. In a tight-fitting seat, there was no space to accommodate this swelling, which therefore resulted in pain. So the seat design, which seemed to fit the driver perfectly when the car was stationary, had to be changed to allow for muscle changes in a racing environment.

Quite often teams will put padding in the driver’s cockpit, which is designed to help with any discomfort and stop the driver ‘submarining’ under braking. But these can be misplaced or not the right type of material, meaning it could be subjected to increased degradation over time due to the high temperature and G-Forces that drivers are subjected to.

“You can easily tell by looking at the seat that the padding is in the wrong place,” says Morgan. “With the drivers’ recurrent (G-Force) loading they often put a foam insert down the center of the seat to give them a little bit of padding. That’s often not in the correct place, or offline. There are different kinds of cushions for different kinds of spines, and we try to glean most of what their problems are and how to fix them.”

Morgan explains how they were able to see this information after conducting a series of experiments when drivers still complained they found back pain returned, even when they were happy with the inserts. “From this we could infer that there was significant foam degradation within the hostile driving environment,” says Morgan. “We advised the teams to fit new inserts every 2-3 races, solving the issue.”

Even minimal compression of foam inserts can make a huge difference to the driver. “We can go down to a millimeter if we need to and see how different foams compress under weight bearing,” adds Morgan. “If you have a two-centimeter foam insert for the driver and tell them it compresses to 50 per cent, that’s quite important even in the virgin state of the foam because it will incur quite a lot of degradation over a few races.”

Scuderia Ferrari SF71H, seat details during the 2018 Formula One World Championship, Grand Prix of Monaco from on May 24 to 27 in Monaco - Photo Florent Gooden / DPPI

Scope for evolution

Whereas drivers in F1 have the luxury of making seats to suit their body shape, in sportscar racing it is a different affair. They often have to share the car with two other drivers, with the seat itself changing every time they do a driver change.

“In my case, because I’m the tallest I have the carbon seat, which is shaped to me and then the smaller team mates will have the foam inserts,” says Wurz. “It’s the same story for the foam inserts, but also for the safety of the positioning of the steering, that has to be the best compromise possible where always the number one priority is safety, two is performance and three is comfort.”

Following Anthony Davidson’s heavy crash during the 2012 running of Le Mans, when he crushed two vertebrae in his lower back after his LMP1 car was launched into the air, the FIA conducted an investigation into how he was injured.

While it was not clear whether it was the vertical landing or frontal impact with the barriers that caused the injury, it was a concern for the FIA, which was already investigating Guillaume Moreau’s head-on crash in an LMP2 car at the Le Mans Test Day, when he also sustained an injured vertebra.

As such, the FIA teamed up with Toyota Motor Company to use its Total Human Model For Safety (THUMS) software, which is a computer model that represents the human body. This enabled them to recreate body parts using their Finite Element modelling and simulate how individual bones and organs react in the event of an accident.

From there, they were able to recreate Davidson’s crash and compare it to Wurz in the same scenario for a smaller and taller driver. They found that the smaller driver (Davidson) ended up moving around in the cockpit more during an impact, whereas for the taller driver (Wurz) there is less distance for them to travel because they are rested against the monocoque.

This technology has been used to analyze other impacts such as Toyota driver Jose Maria Lopez’s accident during the 2017 Silverstone race where he sustained “minor damage” to two vertebrae, and Daniel De Jong’s crash at Spa Francorchamps in which he fractured the T6 vertebrae during a GP2 race after colliding with Pierre Gasly and slamming into the barrier, head-on at high speed.

“This is actually resulting in a rule change, because we had a few accidents where we had broken spines from compression break” explained Wurz, referring to the next LMP1 regulations that will be introduced in 2020/21. “We will have a slightly different seating position to ensure that the pressure between each vertebra is spread out as equal as possible to not have one weak link in your back. This will help to prevent injuries that we’ve seen in the past where either a rearwards or forwards impact compression breaks the vertebrae.”

It is all part of a move to ensure that teams take a safety first (rather than performance first) approach when designing drivers’ seats. The FIA and its safety research partner the Global Institute are one year into a four-year research project using Toyota’s THUMS software to further improve this aspect of motor sport.

The joint project covers research on collisions across motor sport disciplines, and will include analysis of safety elements such as seat structures and seatbelt positioning, with a focus on minimising spinal injury. The results will be used to put forward proposals to update motor sport regulations and safety equipment.

Drivers can rest assured that motor sport safety researchers are not sitting still on this important issue.

auto+ med cover for GI websiteThis article has
been republished
with permission
from AUTO+ Medical,
the FIA’s Journal of
motor sport medicine.