Why are so many British players injured?

But Boulter, who has climbed back into the top 60, told BBC Sport: "I think it's impossible as a tennis player to be like, 'I'm going to take the week off because my wearable [device] says that I'm in red'.

"Financially, there might be people that don't have that luxury to stop a week out of their schedule and not play - the majority of us are still trying to make a living.

"I've played through many injuries, I've also stopped through many injuries. Ultimately you have to make the best judgement call you can.

"It's good to have that information, but it doesn't necessarily marry up sometimes."

The LTA has refreshed its entire physiotherapy staff over the past 18 months and believes it now has the right expertise to support the modern player. The next task is to consider how best to upgrade its recovery facilities.

British players have a lot more resources at their disposal than many other nationalities. An LTA physio was sent to Miami in March as Kartal started to realise the extent of her back problem, but the emphasis is also on players building their own support network.

'No-one should feel forced to play if hurt'

Image caption,

Jessica Pegula has played the third-most matches of any WTA player this season

There is wide consensus that an 11-month season is too long - and with it comes the extra risk of injury.

World number five Jessica Pegula is chair of the WTA Tour Architecture Council, which has been tasked with recommending changes that could be brought in as soon as next season.

"Right now it feels like you have to play every single week for 10 months and if you miss out, it can come back and bite you," Pegula told BBC Sport in Indian Wells.

"I don't think anyone should be forced to play if they are hurt or feel like they are forced to play, which it sometimes does."

Pegula would like to see more penalty-free withdrawals from the top events to avoid players having to perform injured or hurt.

It is mandatory for the top players to play all 10 WTA 1000 events and six 500-level tournaments - and there are four Grand Slams on top of that.

As well as recording zero ranking points at any event they miss, players also run the risk of points being deducted from their tally at the end of the season.

World number one Aryna Sabalenka can easily shoulder the penalties involved, but not all players can.

After playing 12 matches in Australia in January - winning the title in Brisbane and finishing runner-up at the Australian Open - Sabalenka skipped both of February's WTA 1000 events in the Middle East.

Pegula can also afford to be selective, and missing the Qatar Open paid immediate dividends when she won the Dubai title the following week.

"Doing so well in Australia, making the semis, I had always planned to go home before the Middle East so I was only going to have maybe three days at home," added the 32-year-old American.

"To fly from Australia back to Florida, and then fly 12 or 13 hours three days later to Doha, was something I'm not interested in at my age."