What is the NFL's concussion protocol? Tua Tagovailoa injury puts policy in spotlight

The National Football League's concussion protocol is again in the spotlight after Miami Dolphins quarterback Tua Tagovailoa was injured during Thursday night's game against the Cincinnati Bengals.

The latest hit happened four days after Tagovailoa was injured when he was pushed by Buffalo Bills linebacker Matt Milano, causing his head to hit the turf. The NFL Players Association said it was launching an investigation into what went into the Dolphins' decision to allow Tagovailoa to return to play in that game.

Thursday night, Tagovailoa was stretchered off the field in Cincinnati in the second quarter after again being thrown to the ground and hitting the back of his head on the turf. He was released from the hospital and flew to Miami with the team. "Tua is home and initial tests were negative," a Dolphins spokesperson said, and the quarterback tweeted that he was "feeling much better."

TAGOVAILOA INJURY: What is a 'fencing response position' following head trauma?

OPINION: Tagovailoa's second distressing injury in four days is ugly moment for NFL

NFL NEWSLETTER: Sign up now to get exclusive content in your inbox

Here is how the NFL's concussion protocol works:

What is the concussion protocol?

The league's concussion protocol is designed to make sure players are getting the most valuable information when it comes to the diagnosis and treatment of concussions. The protocol was developed by an independent board and league physicians and scientists, including NFLPA advisers, better known as the head, neck and spine committee.

Once a player is feared to have a head injury, they're mandated to be taken off the field of play immediately and examined in a medical tent to assess the injury. The player can only return to the game if cleared by a doctor after a five-step evaluation.

The player cannot return if he demonstrates “gross motor instability determined by [the] team physician, in consultation with the [unaffiliated neurotrauma consultant], to be neurologically caused.”

In a joint statement released Saturday, the NFL and NFLPA said they both "agree that modifications are needed to enhance player safety" and added that they "anticipate changes to the (concussion) protocol being made in the coming days." 

What are the steps for returning to play?

The steps in which a player can return to play - the protocol was amended in July 2020 - are outlined here.

All decisions for returning to full participation need to be confirmed by the Independent Neurological Consultant, who is an independent neurotrauma doctor.

Phase 1: Symptom-limited activity

The player is prescribed rest, limiting, or if necessary, avoiding activities that increase or aggravate symptoms. Under athletic training staff supervision, limited stretching and balance training can be introduced, progressing to light aerobic exercise, all as tolerated.

If the player doesn't have an increase in symptoms and does not demonstrate signs of a concussion during a neurological examination, they may be cleared to move on to the next phase.

Phase 2: Aerobic exercise

Under the supervision of team staff, players should begin graduated cardiovascular exercise and may also engage in dynamic stretching and balancing training. If the player demonstrates the ability to engage in cardiovascular exercise without an increase or aggravation of symptoms, they move on to next phase.

Phase 3: Football-specific exercise

The player continues supervised cardiovascular exercises that are increased and may mimic sport-specific activities, and supervised strength training is introduced.

Phase 4: Non-contact training drills

The player is encouraged to continue cardiovascular, strength and balance training, team-based sports-specific exercise and participate in non-contact football activities.

Phase 5: Full football activity/clearance

The player is finally cleared by the club doctor for full football activity involving contact. The player must be examined by the independent neurological consultant assigned to his club. If the consultant agrees with the club physician that the player’s concussion has been resolved, then the player can participate in practice and contact without restriction.

This article originally appeared on USA TODAY: NFL concussion protocol: What are the steps for return to play?