Aeroplanes rely on them to record flight data and now New Zealand Rugby's "black box" is one measure being pushed in the fight to prevent further incidents of concussion.

For the past three weeks, a sturdy black box has been pitch side at each Super Rugby match in New Zealand. Inside a video review system allows match day doctors to pause and rewind footage via a remote control and touch screen laptop in order to get a second look at suspected concussions.

It's effectively a safe net, should team doctors and on-field officials fail to spot a player who is knocked out, or takes a serious blow to the head.

After reviewing footage match day doctors have the power to make decisions about whether a player should leave the field immediately for further head injury assessment or remain on the field.

The ugly incident involving Highlanders prop Josh Hohneck, who was allowed to return to play despite losing consciousness in a match against the Crusaders, saw the video review system fast tracked. It was originally due to be introduced in New Zealand from June.

Australia has adopted the system for some time but have a match day doctor reviewing footage in a box similar to the TMO, as opposed to the sideline, while South Africa have received the hardware and will start the process next month.

New Zealand currently have one black box in circulation, however, a second is under construction and three should be available for the start of the NPC season in August.

It's not the only precaution being taken as concussion continues to cause officials headaches at all levels of the game. A blue card policy that places responsibility on referees to send amateur players from the field after a head knock, and then consult a doctor before being cleared to play, has now been accepted by nine of New Zealand's 26 unions, including those involved in the Heartland Championship.

The scheme, first used successfully in Northland, was founded by National MP Mike Sabin after his son, Darryl, suffered a catastrophic brain injury that almost claimed his life following repeated head knocks attained when playing rugby.

New Zealand Rugby chief executive Steve Tew said at a media briefing in Auckland on Friday he wanted all provincial unions to adopt the blue card protocol but at present there were "resourcing" issues in some areas.

Globally, science and conclusive evidence around the long-term effects of concussion remains in its infancy. While some feel NZR aren't doing enough on the issue these steps show the issue is being taken seriously.