The fallout from the sight of the great Australian batsman Steve Smith being felled by a 92.4 mph bouncer, which led to him being withdrawn on Sunday from the second Ashes Test at Lord’s, has reignited the debate about whether sport is wary enough about the dangers of concussion.

On Saturday Smith had looked groggy and disorientated as he left the pitch after being hit by England’s Jofra Archer – yet he was soon given the all clear to continue after being checked by the Australian team doctor. However, when Smith woke up on Sunday he was suffering from dizzy spells and was quickly pulled out of the team with concussion.

The brain injury charity Headway said Smith should not have returned to the pitch after his “brutal” injury, because a quick off-field test by a team doctor was not always able to diagnose a concussion and a second blow to the head could have led to extremely severe consequences.

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“What this incident highlights is that no test for concussion is foolproof,” Headway’s deputy chief executive Luke Griggs said. “The signs can be delayed for several hours and sometimes even a couple of days. You cannot take any risks with concussion, which is why we have always said that all sports have to take an ‘if in doubt, sit it out’ approach.”

That approach is backed up by Cricket Australia statistics, which show that 30% of concussions in Australian cricket are delayed. In a statement the organisation acknowledged that “it is not uncommon for players to pass their tests and feel well on the day of an injury and then display symptoms 24-48 hours later”.

However, Smith went back out to bat after initial tests flagged up no issues – even though he had needed lengthy treatment on the pitch. “When I came off the ground the results were normal,” he said. “I passed all the tests and felt fine. I felt normal. I was allowed to go back out and bat. Upon discussions with the team doctor and coach as well, they were both happy and I was comfortable as well. We were all happy and I was able to go and continue batting.”

Cricket has recently changed its rules to bring it more in line with other sports, such as football and rugby, which require any player suspected of having concussion to be assessed by a doctor before returning.

The International Cricket Council has also allowed concussion replacements for the first time, with Smith becoming the first concussed player ever to be substituted out of a Test match after being replaced by Marnus Labuschagne.

Headway believes far more should have been done by the sport’s governing bodies earlier, given the inherent risks of the game and the tragic death of the Australian batsman Phillip Hughes after he was hit on the neck in 2014.

“Cricket has been caught on the back foot a little bit with concussion,” said Griggs. “We thought it was an American football, rugby or football issue, but we are slowly beginning to realise that it affects all sports.

“The reaction time of a batsman facing a 90 mph-plus delivery is incredibly small and yet it is absolutely vital they are fully concentrated. But with concussion the vision can be blurred, and the brain can be slow at processing information. That leads to delayed reaction times, and that is just incredibly dangerous.”

Another issue is that players often want to keep going, and if they are star players, managers and coaches are often only too happy to let them. “But if there is even an hint of concussion when someone is bowling at 90 mph, there is absolutely no way a player should be on the pitch,” added Griggs.

Scientists have begun to understand much more about concussions in recent years, including the dangers of a “second impact”, a second concussion when someone has continued to play on after an initial concussion. That is partly why the ICC’s guidelines now suggest that a typical recovery process takes about seven days to complete – which means Smith is likely to miss the third Ashes Test at Headingley on Thursday.

However, Headway believes that all sports need to use independent doctors to make the decisions about concussions at all levels of sport. “Cricket may need to consider this, while making it abundantly clear that players should have absolutely no say in the decision,” added Griggs.

In the longer term, scientists are hoping to use molecules in the blood, saliva or urine, known as microRNAs, to allow them to better detect brain injuries. The hope is for a simple test that could use such biomarkers to detect concussion, using an instrument at the side of the pitch, possibly by taking saliva samples from athletes. But although the football Premier League and rugby union Premiership and Championship are currently undergoing pilot studies, such technology is still some way off.

“I liaise closely with key researchers in this area, and they are all very positive that in the medium term there could be more reliable sideline diagnostic tools available, such as saliva tests or blood biomarkers for different proteins to indicate there could be an issue going on in the brain,” said Griggs. “But we have got to be realistic and say these are some way away from coming to fruition and actually being put into action.”