John Terry was back at Stamford Bridge on Wednesday night - the first time in an official capacity since leaving Chelsea at the end of the 2016/17 season.The Blues legend currently works as Aston Villa’s assistant manager and watched his side lose 2-1 against his former employers.Tammy Abraham broke the deadlock midway through the first half before the visitors levelled shortly before half-time through Trezeguet. Mason Mount’s superb volley shortly after the restart, however, sealed all three points for the hosts.Mateo Kovacic played the full 90 minutes for Chelsea and emerged unscathed - until he encountered Terry by the tunnel.The midfielder was left seriously regretting his decision to go in for a handshake with the former footballing hardman.

Terry left Kovacic in agony after a particularly hard handshake which the Croatia international obviously wasn’t expecting.

Kovacic, clearly in pain, looked back at Terry, who waved his hand semi-apologetically.

A lesson for everyone: never shake hands with JT!

According to a report published by the Guardian back in 2007, there are many different types of handshakes - including the ominous-sounding ‘Bone Crusher’.

Terry clearly brought out a Bone Crusher for Kovacic - but what does this mean about the retired defender’s personality?

“The message of squeezing your hand until you cringe is clearly designed to intimidate you,” the Guardian’s report states. “Even when the person may not know how strong they are, there is still a message of intimidation and power behind the grip.

“You don’t have to pretend to be a wimp with them, and, in fact, they may respond positively to you if you present yourself with strength. Just don’t get into a hand-squeezing contest when you shake because then it becomes a competition and even if you win, you’ll lose.”

So, there you have it: the Bone Crusher is a weapon used by competitive people, which explains why Terry has it in his locker.

Most footballers are extremely competitive and you don’t scale the heights Terry has during his career unless you despise losing.

And the fact he’d just watched Villa lose to Chelsea increased the chances of Terry dishing out a few post-match Bone Crushers.