Crash-test dummies and head cases
There are some well-documented cases of players having suffered heavy head knocks and being sidelined for lengthy periods – this despite the progress made in the last decade through protection and care.
Greenwood – who played more than 250 first class games for Harlequins and Leicester Tigers, was capped 55 times by England and twice by the British and Irish Lions – knows all about the dangers of massive collisions on the international stage.
During the British and Irish Lions tour to South Africa in 1997, Greenwood swallowed his tongue on the pitch after a collision and stopped breathing for several minutes.
Not surprising then he feels the 'vogue topic' in player welfare is the constant appraisal and reappraisal of what is going on with the head in the game of Rugby Union.
Greenwood readily admits there was a time when players – especially at school level where it wasn't monitored as vigorously – players would hide the fact that they were concussed on order to avoid the mandatory three-week lay-off.
In some cases, players were instructed to conceal concussion.
"It has now gone the full circle to head injury assessments, and making use of rolling substitutes, as well as the constant work being done on developing protective head gear," he told rugby365 in an exclusive interview.
"Then there is the huge amount of work being done on tackle techniques, to make sure children are learning at an early age about body positions and angles to put themselves into and look after themselves," he said, adding that concussion remains the biggest concern.
"You can go to a gym and put on [big] big biceps, pectorals and quads – build your body up to almost be like a crash-test dummy.
"However, there is not a lot you do to the scull.
"That is why it is something that is being monitored very closely."
Greenwood said there are the situations are vastly different at school level and in the professional arena.
"It always depends on who you have at your disposal," he told rugby365.
"In an England Test, if you go for a head injury assessment, you have some of the finest brains and resources at your disposal.
"The following week you will be monitored hourly.
"Clearly if you are at a junior club or at a school match, young Jack will just follow the three-week protocol. He could be fine to play soon, but we won't know that. It could actually be that he is not fine to play for eight weeks. He has to work or go to school and during the day you just can't monitor him.
"It comes in two shapes.
"The velocity at Test match level is so much higher. You worry about the force going through your head. The aftercare is so much greater.
"At junior level, the forces are not quite as much, but you have to do your best with doctors and physios on voluntary time, with young men who go back to work or school. You are not able to monitor that situation."
* In Part Two of our Player Welfare interview Greenwood looks at the amount of game time players play and the approach of coaches looking at the 2019 World Cup in Japan.
By Jan de Koning
@king365ed
@rugby365com
* Canterbury's British & Irish Lions Training Range is now available to buy via www.canterbury.com
