Recommendations for initial examination, differential diagnosis, and management of concussion and other head injuries in highlevel football

Head injuries can result in substantially different outcomes, ranging from no detectable effect to transient functional impairments to life-threatening structural lesions. In high-level international football (soccer) tournaments, on average, one head injury occurs in every third match. Making the diagnosis and determining the severity of a head injury immediately on-pitch or off-field is a major challenge for team physicians, especially because clinical signs of a brain injury can develop over several minutes, hours, or even days after the injury. A standardized approach is useful to support team physicians in their decision whether the player should be allowed to continue to play or should be removed from play after head injury. A systematic, football-specific procedure for examination and management during the first 72 hours after head injuries and a graduated Return-to-Football program for high-level players have been developed by an international group of experts based on current national and international guidelines for the management of acute head injuries. The procedure includes seven stages from the initial on-pitch examination to the graduated Return-to-Football program. Details of the assessments and the consequences of different outcomes are described for each stage. Criteria for emergencyThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

# | introduction
Across all sports, special attention should be given to acute head injuries, since they may be potentially severe and may lead to a prolonged recovery or to long-term consequences. [bib_ref] The role of concussion history and gender in recovery from soccer-related concussion, Chiang Colvin [/bib_ref] The incidence of head injuries and concussions in football has been reported to be lower than in American football, ice hockey, or rugby 2 but higher than in non-contact sports. [bib_ref] Epidemiology of sports-related concussion in NCAA athletes from 2009-2010 to 2013-2014: incidence,..., Zuckerman [/bib_ref] Published incidences are higher in female than male players, [bib_ref] Injury surveillance in the World Football Tournaments 1998-2012, Junge [/bib_ref] [bib_ref] Concussions and heading in soccer: a review of the evidence of incidence,..., Maher [/bib_ref] during matches than during training, [bib_ref] Concussions and heading in soccer: a review of the evidence of incidence,..., Maher [/bib_ref] and highest during international tournaments with about one injury in every third match, and one or two concussions per tournament. [bib_ref] Injury surveillance in the World Football Tournaments 1998-2012, Junge [/bib_ref] As in other sports, the total number of concussions and other head injuries in football appears to be underreported. [bib_ref] Underreporting of concussions and concussion-like symptoms in female high school athletes, Mcdonald [/bib_ref] [bib_ref] Concussion under-reporting and pressure from coaches, teammates, fans, and parents, Kroshus [/bib_ref] [bib_ref] Concussion nondisclosure during professional career among a cohort of former national football..., Kerr [/bib_ref] Head injuries include all injuries caused by a direct or indirect blow against/transmitted to the head and can result in substantially different central and peripheral outcomes, ranging from no detectable functional effects to transient functional impairments, from absent to major structural lesions, and from clinically absent to life-threatening deficits. [bib_ref] Sideline assessment of concussion, Putukian [/bib_ref] [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] [bib_ref] Diagnosis, prognosis, and clinical management of mild traumatic brain injury, Levin [/bib_ref] A differentiation between injuries of the brain, the skull, the face, the cervical spine, or the inner ear (vestibular and cochlear labyrinth) is often not possible on-pitch or off-field, [bib_ref] Brain or strain? Symptoms alone do not distinguish physiologic concussion from cervical/vestibular..., Leddy [/bib_ref] especially since combined injuries of different central and peripheral systems (eg, brain, cervical, vestibular, cochlear, and ophthalmological) are frequent. [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] [bib_ref] Patients with chronic dizziness following traumatic head injury typically have multiple diagnoses..., Arshad [/bib_ref] [bib_ref] Post-traumatic balance disorder, Elziere [/bib_ref] In addition, an athlete may not have or may not report any symptoms immediately after the injury, nor demonstrate any pathological signs; however, he/she might develop symptoms and/or abnormalities on physical examination minutes, hours, or even days later. [bib_ref] Diagnosis, prognosis, and clinical management of mild traumatic brain injury, Levin [/bib_ref] [bib_ref] Mild traumatic brain injury, Vos [/bib_ref] [bib_ref] Advanced trauma life support((R)) update 2019: management and applications for adults and..., Galvagno [/bib_ref] Thus, the diagnosis and estimation of the severity of an injury on-pitch or off-field is a major challenge for the team physician. [bib_ref] Return to play management after concussion in football: recommendations for team physicians, Feddermann-Demont [/bib_ref] Nevertheless, an immediate, targeted assessment and diagnosis is of great importance for the return-to-play decision and the therapeutic approach. [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] [bib_ref] Brain or strain? Symptoms alone do not distinguish physiologic concussion from cervical/vestibular..., Leddy [/bib_ref] The present paper provides practical recommendations for team physicians on the management during the first 72 hours after a head injury in high-level football, and a football-specific Return-to-Sport program.
Our recommendations are based on a review of the literature with regard to the newest findings on concussion, that is, mild traumatic brain injury (mTBI), as well as peripheral injuries (eg, vestibular organ or cervical spine), and are specifically designed for high-level football. We have defined high-level football as participation in international or national competitions. The review of the literature included national and international guidelines for the management of concussion in sports by expert groups (eg, Concussion in Sports Group), [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] [bib_ref] Updated guidelines for the management of sports-related concussion in general practice, Makdissi [/bib_ref] [bib_ref] What are the critical elements of sideline screening that can be used..., Patricios [/bib_ref] [bib_ref] Head injury in soccer: from science to the field; summary of the..., Putukian [/bib_ref] American Academy of Neurology,American Medical Society for Sports Medicine (AMSSM), [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] American Association of Neurological Surgeons,and sport federations (eg, World Rugby, 25 National Football League,National Hockey League,English Ice Hockey Federation,Parachute Canada,Water Polo Canada 30 ) as well as national and international guidelines on the management of mTBI [bib_ref] Diagnosis, prognosis, and clinical management of mild traumatic brain injury, Levin [/bib_ref] [bib_ref] Mild traumatic brain injury, Vos [/bib_ref] and (other) head injuries.All authors are experienced in the management of concussion/TBI and cover different medical areas: Emergency Medicine, Neurology, Neuro-Otology and Neuro-Ophthalmology, Internal Medicine, Football and Sports Medicine, Performance Medicine and Rehabilitation Medicine. Four authors (G.C., C.C., M.P., and T.M.) are team physicians and two (E.K. and G.C.) emergency physicians in high-level football. The authors are from three continents.

## | procedure after head injury
A systematic approach for the initial examination, diagnosis, and management in the first 72 hours after head injury in high-level football has been developed . The procedure can be initiated by the team physician or his/her designee. It consists of seven post-injury phases and includes the emergency management , an initial (on-pitch) examination (phase 1), followed by off-field/quiet area (phase 2/3), post-match examinations (phases 4-6), and a detailed Return-to-Football program (phase 7).
The initial (on-pitch), off-field, and quiet area examinations are not designed to make a specific diagnosis, such as a concussion, but to identify clinical signs and symptoms, which require (temporary) removal from play for a more detailed management (red flags), removal from play (orange flags), and referral to specialists for further diagnosis and treatment (persistent orange flags) are provided. The guidelines for return to sport after concussion-type head injury are specified for football. Thus, the present paper presents a comprehensive procedure for team physicians after a head injury in high-level football. examination. Due to the potential severe neurological consequences of a head injury, any suspicion of abnormal findings should result in initiation of appropriate emergency management in case of red flags , further examination in case of orange flags , and removal from match or training. If the physician is in doubt, the player should be removed from the pitch. Only players without suspected signs or symptoms of a TBI (including concussion) or other significant injury should be allowed to continue to play or train.
The post-match examinations serve to establish a diagnosis to accurately initiate therapeutic strategies and a safe return to football. The physician should be aware that an emergency situation can arise at any time in the first hours and days after the head injury,and therefore, repetitive examinations are required. Ideally, the team physician knows each individual player, their characteristics, medical history, and baseline tests results, if performed, and should be able to communicate with all players appropriately. Observe and recognize (phase 0): Team physicians should observe the match (or training) with a focus on potential head injury, which often happens during aerial duels, [bib_ref] Concussions and heading in soccer: a review of the evidence of incidence,..., Maher [/bib_ref] [bib_ref] A six year prospective study of the incidence and causes of head..., Fuller [/bib_ref] [bib_ref] Time trends of head injuries over multiple seasons in professional male football..., Beaudouin [/bib_ref] and specifically the immediate red and orange flags , such as (suspected) loss of consciousness, convulsion or abnormal posturing, slowness, or imbalance. [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] [bib_ref] International consensus definitions of video signs of concussion in professional sports, Davis [/bib_ref] The injury mechanism and player behavior are best recognized using direct observation, if possible supported by immediate video review. [bib_ref] Head injury in soccer: from science to the field; summary of the..., Putukian [/bib_ref] [bib_ref] International consensus definitions of video signs of concussion in professional sports, Davis [/bib_ref] With respect to concussion, observable signs demonstrated on video, such as lying motionless, motor incoordination, ataxia, staggering gait, no protective action (floppy, tonic), cervical hypotonia, seizure/convulsion, tonic posturing, and blank/vacant look, have been shown to be useful for clinical decision making. [bib_ref] International consensus definitions of video signs of concussion in professional sports, Davis [/bib_ref] Emergency management and red flags for referral to hospital:
It is important to consider the differential diagnoses when examining a deteriorating or collapsed player. [bib_ref] Advanced trauma life support((R)) update 2019: management and applications for adults and..., Galvagno [/bib_ref] Potentially life-threatening emergency concerns after acute head injury include signs or symptoms of cardio-pulmonary arrest or of severe structural injuries to the brain, skull, face, cervical spine, or spinal cord, which have been denoted as red flags . The emergency assessment and management after any acute head injury should be performed according to clear principles and standardized practice, for example, embodied in the Advanced Trauma Life Support (ATLSTM) principles. [bib_ref] Advanced trauma life support((R)) update 2019: management and applications for adults and..., Galvagno [/bib_ref] The first priority is the treatment of the greatest threat to life and the avoidance of further harm.Cardiac arrest is extremely rare and not considered to be a consequence of a head injury. It can be caused by a hit against the chest (commotio cordis) or occur spontaneously. [bib_ref] Failure of commercially available chest wall protectors to prevent sudden cardiac death..., Weinstock [/bib_ref] Full Advanced Cardiac (Life) Support procedures have to be undertaken. [bib_ref] Advanced trauma life support((R)) update 2019: management and applications for adults and..., Galvagno [/bib_ref] [bib_ref] american heart association focused update on advanced cardiovascular life support use of..., Panchal [/bib_ref] [bib_ref] Resuscitation Council Guidelines for Resuscitation 2015 Section 8. Initial management of acute..., Nikolaou [/bib_ref] Any head injury should be regarded as having a concomitant cervical spine injury until excluded by clinical examination or imaging if indicated . [bib_ref] Diagnosis, prognosis, and clinical management of mild traumatic brain injury, Levin [/bib_ref] Any suggestion of a cervical fracture or intraspinal lesion (GCS < 15 on initial assessment, neck pain or tenderness, focal neurological deficit, paresthesia, or weakness in the extremities, any other clinical suspicion of cervical spine injury) should result in immobilization and stabilization of the cervical spine, appropriate removal from pitch, and emergency transport to hospital.Similarly, all players with a suspected fracture of the skull should be removed from the pitch for further examination. This includes also players with a suspected skull fracture who are free of symptoms or have local pain only. In addition to local ocular tenderness to palpation, other significant signs and symptoms of an orbital floor fracture are periorbital hematoma, double vision (diplopia), and abnormalities in eye movements. Any deterioration of signs and symptoms can indicate intracranial bleeding and/or swelling, which can only be diagnosed by tomographic imaging (eg, computerized tomography) of the brain. Therefore, it is also important to continuously observe players even if they are initially symptom-free.
Any red flag mandates removal from play, treatment on site (on-pitch/sideline/medical room) as necessary and consideration of immediate emergency transport to a hospital, if the sign or symptom is confirmed, persists, or deteriorates.
Initial (on-pitch) examination (phase 1):
The outcome of the initial (on-pitch) examination is the basis for the team physician s decision on emergency management, referral to hospital, off-field/quiet area assessment, and removal from or return to match play or training. The physician s decision should be communicated to the referee during match play and to the manager/coach during training. If no physician is present, the principles of "recognize and remove" and "if in doubt, sit them out" should be applied. [bib_ref] The concussion recognition tool 5th edition (CRT5): background and rationale, Echemendia [/bib_ref] During this initial examination, it is essential to focus on red and orange flags. The elements of the initial (on-pitch) inspection and examination are based on the latest version of the Sport Concussion Assessment Tool (eg, SCAT5TM)and the NICE criteria.The inspection concentrates on visible signs (eg, loss of consciousness, vomiting), while the examination assesses core signs and symptoms of neurological impairment of different brain areas (cortical, subcortical, cerebellar, brain stem) [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] [bib_ref] Clinical diagnosis of bilateral vestibular loss: three simple bedside tests, Petersen [/bib_ref] [bib_ref] Assessment of vision in concussion, Akhand [/bib_ref] and of a cervical spine or intraspinal injury. Any period of loss of consciousness or GCS < 15 indicates a concussion/mTBI or a more severe TBI.
The injured player should be removed from the pitch to the off-field location for further assessments , phase 2) if (a) the outcome in one or more criteria of the initial assessment is considered or suspected to be abnormal, (b) additional time for examination is required, or (c) all tests yield normal results, but the team physician suspects that the player is suffering from functional neurological impairment.
Note: Any period of loss of consciousness or GCS < 15 indicates a concussion/mTBI or a more severe TBI, and thus, the player has to be removed from match play or training, albeit he/she might not have other acute or suspected findings.
The player should only be allowed to continue to play or train if all on-pitch examinations reveal no (suspected) signs or symptoms and on explicit confirmation of the player's capability to play by the team physician to the referee during match play and to the manager/coach during training. If the team physician is uncertain, the principle "if in doubt, take him/her out" applies.
The team physician should continue observing the player throughout the match play or training (phase 4) and re-evaluate him/her serially to watch for the delayed onset of signs or symptoms (phase 5). All players after head injury should be observed for the first 24 hours (phase 6).

## | 1853
FEDDERMANN-DEMONT ET Al.

## Off-field assessment (phase 2):
The off-field assessment should focus on red and orange flags . Testing of ocular motor function should be included, since many of the pathways in the brain potentially affected by head injuries are involved in ocular motor control. [bib_ref] Review of vestibular and oculomotor screening and concussion rehabilitation, Kontos [/bib_ref] [bib_ref] A brief vestibular/ocular motor screening (VOMS) assessment to evaluate concussions: preliminary findings, Mucha [/bib_ref] [bib_ref] Sideline concussion assessment: the current state of the art, Yue [/bib_ref] Obvious minor injuries, such as lacerations or bruises, might be treated.
Examination and treatment in a quiet area (phase 3):
Players attributed with any (suspected) orange flag onpitch or off-field should be examined in a quiet area (eg, medical or locker/change room, pop-up tent) using the latest version of a sport concussion assessment tool (eg, SCAT5 TM ) 39,45 and a detailed neurological examination.
The neurological examination should include an examination of cranial nerves, vestibular, balance, and coordinative functions (spontaneous nystagmus, head impulse test, [bib_ref] The video head impulse test, Halmagyi [/bib_ref] vertical eye deviation, dynamic visual acuity, 40 balance (Romberg), positioning maneuvers), [bib_ref] A brief vestibular/ocular motor screening (VOMS) assessment to evaluate concussions: preliminary findings, Mucha [/bib_ref] cervical spine (range of motion, stability, proprioception, strength, muscle tone), motor function of upper/lower extremities, and standardized neurocognitive tests. Based on the outcome of the neurological examination, the team physician decides on further examinations, as recommended by the National Institute of Health and Care Excellence (NICE) for head injuriesand by the European Federation of Neurological Societies (EFNS) guidelines for mTBI [bib_ref] Mild traumatic brain injury, Vos [/bib_ref] as well as other guidelines. [bib_ref] Diagnosis, prognosis, and clinical management of mild traumatic brain injury, Levin [/bib_ref] Players who continued playing or returned to the match or training session where they incurred the head injury, and who have no further signs or symptoms after phase 2 (or 3) can be allowed to participate as usual in the next training and match. Players who are removed from the match or training session and have signs or symptoms of a TBI (including concussion) or of other significant head injury at any time should complete the graduated Return-to-Football program (Stage 7) once their symptoms have resolved.

## Observation and serial re-examination until leaving the sports facilities (phase 4):
The team physician should observe the player until the end of the match or training for worsening or additional signs or symptoms regardless of whether the player had returned to or was removed from match play or training. Medications that may mask or worsen symptoms should be avoided unless a more severe head injury has been ruled out. Any worsening or newly developed signs or symptoms should result in emergency management in the case of red flags or further examinations in the case of orange flags .
Prior to leaving the sports facilities, all injured players should be re-examined for worsening of or new signs and symptoms using the latest version of a sport concussion assessment tool. Before travel without access to emergency care (eg, flight), any worsening of symptoms or concern for any form of brain, skull, or cervical spine injury should be cleared with appropriate diagnostic imaging. Driving a car should not be allowed until medically cleared,which was reported to take about 24 to 48 hours. [bib_ref] Post-concussion driving behaviors and opinions: a survey of collegiate student-athletes, Schmidt [/bib_ref] An initial computerized tomography (CT) scan is recommended on the day of injury, if risk factors for a brain injury (eg, Glasgow Coma Scale < 13 or <15 after 2 hours, suspected skull fracture, more than 1 episode of vomiting, post-injury seizure, loss of consciousness, persistent anterograde amnesia, or focal neurological deficit) are present. [bib_ref] Diagnosis, prognosis, and clinical management of mild traumatic brain injury, Levin [/bib_ref] [bib_ref] Mild traumatic brain injury, Vos [/bib_ref] Observation for 24 hours after head injury (phase 5):
In general, all players after a head injury should be observed for 24 hours either by the team physician or by a reliable adult person instructed to immediately contact the team physician or the emergency department of the closest hospital in case of worsening of or new symptoms (red or orange flags, .Until re-evaluation (phase 6), physical and cognitive rest is recommended, which includes avoidance of using electronic devices.
If a player was allowed to return to play on the day of injury, is free of symptoms, and has a normal neurological examination, the team physician may decide that the observation is not necessary. [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] [bib_ref] Mild traumatic brain injury, Vos [/bib_ref] In any case, the injured player should be informed and instructed to report worsening or new symptoms, and the team physician should contact him/her the following morning with respect to symptom development and further steps.

## Re-evaluation within 18 to 72 hours after head injury (phase 6):
A player who was removed from football and those who continued to play and developed specific signs or symptoms at any time after the head injury should be re-evaluated within 72 hours by a physician, or his/her designee, experienced in head injury assessment according to current international guidelines. [bib_ref] What domains of clinical function should be assessed after sport-related concussion? A..., Feddermann-Demont [/bib_ref] [bib_ref] Acute sport concussion assessment optimization: a prospective assessment from the CARE consortium, Broglio [/bib_ref] The time frame of up to 72 hours has been chosen, since symptoms can develop with latency, and a brief initial period of cognitive and physical rest after brain injury is currently recommended. [bib_ref] Concussion part II: rehabilitation -the need for a multifaceted approach, Schneider [/bib_ref] [bib_ref] Rest and treatment/ rehabilitation following sport-related concussion: a systematic review, Schneider [/bib_ref] Ideally, the team physician, or his/her designee, should assess the injured player daily during this period, if the number or the intensity of signs and symptoms do not improve or even worsen.
In addition to the examination of cranial nerves, cervical spine, motor function of upper/lower extremities, balance, vestibular, ocular motor, vision, coordination, emotions, and neuropsychological tests, a detailed medical history (eg, previous head injuries, pre-existing headache, or sleep problems), and, if indicated, neurocognitive tests should be included. [bib_ref] What domains of clinical function should be assessed after sport-related concussion? A..., Feddermann-Demont [/bib_ref] These examinations provide valuable hints to different head injury diagnoses. [bib_ref] What domains of clinical function should be assessed after sport-related concussion? A..., Feddermann-Demont [/bib_ref] indicates which signs and symptoms might be caused by injuries of the brain, the cervical spine, and the vestibular, cochlear, visual and ocular motor systems and thus helps to choose a medical specialist for further examination and treatment in case of persistence. Results from baseline testing may be helpful for comparison of signs and symptoms in the decision-making process with respect to the most appropriate diagnostic and therapeutic approach.
The aim of the examination in phase 6 is to decide whether 1. The player is medically cleared to start the graduated Return-to-Football program (phase 7) in case of no, minimal, or improving symptoms and a normal outcome of all examinations in phase 6; or 2. The player should be referred to a medical specialist for further examination and treatment in case of persistent orange flags (see .

## Graduated return-to-football (phase 7):
The graduated Return-to-Football program is based on the Return-to-Sports protocol by McCrory et al [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] and intended to ensure a controlled stepwise return to sport activities for high-level adult football players after concussion/mTBI. It adds football-specific detail to the more general recommendations from the Concussion in Sports Group. For players with a structural damage (such as intracranial hemorrhage or skull fracture), the return-to-football procedure should be determined on an individual basis by the physician in charge.
The player should be re-examined by the physician in charge before starting symptom-limited activity (Stage 1), ideally within 18-72 hours after head injury , phase 6) and before returning to "routine/contact training" , Stage 5). The medical re-evaluations should focus on (a) the abnormal diagnostic findings on the day of injury, (b) persisting or additional signs or symptoms or changes in their character, intensity or frequency, and (c) symptom development under increasing physical and cognitive training load. [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] [bib_ref] Physiological, vestibulo-ocular and cervicogenic post-concussion disorders: an evidence-based classification system with directions..., Ellis [/bib_ref] Current guidelines and position statements agree that a player with a (suspected) concussion should not return to sport on the same day. [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] Although there is insufficient scientific evidence on appropriate duration of rest after concussion, an initial phase of cognitive and physical rest (24 to 48 hours) before the graduated return to training and match play is recommended. After this initial period of rest, lowlevel exercise that does not lead to worsening of pre-exercise intensity of symptoms or new symptoms has been identified as meaningful. [bib_ref] Earlier time to aerobic exercise is associated with faster recovery following acute..., Lawrence [/bib_ref] [bib_ref] A preliminary study of the effect of early aerobic exercise treatment for..., Leddy [/bib_ref] [bib_ref] Early subthreshold aerobic exercise for sport-related concussion: a randomized clinical trial, Leddy [/bib_ref] Allowing a player to participate in low-level exertion without exaggeration of symptoms and without the risk for contact or fall may also minimize the players' likelihood for emotional affection as psychological response to the injury. [bib_ref] Mental health in elite athletes: International Olympic Committee consensus statement (2019), Reardon [/bib_ref] [bib_ref] Mental health issues and psychological factors in athletes: detection, management, effect on..., Chang [/bib_ref] Allowing a player, with symptoms to participate in low-level exercise (as part of the treatment plan) should be differentiated from the graduated or accelerated Return-to-Football program. The duration until return to match play varies and might be influenced by player's age or his/her history. [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] A multidisciplinary team approach is recommended especially with respect to return to routine/ contact training.
The standard Return-to-Football program comprises six stages with a graduated increase in physical demands ("aerobic" to "anaerobic," "no resistance" to "resistance"), football-specific exercises ("simple" to "complex"), and the risk of contact ("individualized" to "team training," "non-contact" to "full contact") and head impact ("no heading" to "heading"). Each stage should include at least one training session and should last according to current guidelines for a minimum of 24 hours. [bib_ref] American Medical Society for Sports Medicine position statement on concussion in sport, Harmon [/bib_ref] [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] In case of worsening or recurrence of symptoms during or after a training session of any stage, the player should rest until these symptoms have resolved (for a minimum of 24 hours) and then continue the program at the previous symptom-free stage. [bib_ref] Consensus statement on concussion in sport-the 5(th) international conference on concussion in..., Mccrory [/bib_ref] The player should only be medically cleared to return to football, when each stage has been completed without symptoms. Currently, there are no scientific data on the appropriate duration of absence from match play after a head injury. In the adult players with minimal symptoms, no prior brain or other significant head injury, and no other risk factors, an accelerated Returnto-Football program can be considered, while in younger players and players with certain risk factors, such as a history of repetitive concussive injuries, a more conservative approach is recommended. [bib_ref] What is the difference in concussion management in children as compared with..., Davis [/bib_ref] [bib_ref] Predictors of clinical recovery from concussion: a systematic review, Iverson [/bib_ref] In some leagues, there are more specific, mandated concussion guidelines and the team physician should refer to these where relevant.
The accelerated Return-to-Football program should only be initiated, if (a) any acute post-injury symptoms and signs were classified as not specific for concussion, (b) the duration of these unspecific symptoms was shorter than 24 hours, and (c) the results of the re-evaluation were normal (or similar to pre-injury baseline, if performed). Persisting orange flags or one or more red flags at any time after the head injury disqualify from an accelerated return to football. The accelerated return-to-football approach concentrates on stages 2 and 5 and requires a close cooperation of the player, the coach, and a physician experienced in concussion management. Individual variations between the accelerated and the standard approach are possible; however, no scientific evidence on the effectiveness is currently available. Any individual return-to-football procedure should include a multidisciplinary approach.
Detailed recommendations on Return-to-School/Work were published, for example, by the Concussion Awareness Training Tool (CATT),and are not specific for football.
Medical clearance for return to football, school, work, or other physical activity should always be made by the treating physician/s and based on medical considerations only, regardless of the player's desire to play, dissimulation of symptoms, [bib_ref] At-risk populations in sports-related concussion, Kutcher [/bib_ref] and/or pressure from others including the coaching staff, parents, or media.

# | conclusion
The present paper presents a standardized practical procedure for the initial examination, differential diagnosis, and first 72-hour management after head injury in high-level football and a graduated Return-to-Football program developed by an international group of experts based on review of the literature and current national and international guidelines for the management of head injuries. It should serve as recommendation for team physicians with respect to a consistent procedure after a head injury in football.

## | perspective
Head injuries can result in different outcomes, and signs and symptoms can develop or change rapidly within minutes, hours, and days after head injury. Therefore, a systematic procedure for examination and management of football players after head injuries should be implemented to support team physicians in their decision whether the player should be allowed to continue to play or should be removed from play. The presented procedure can be adapted to other sports. Awareness to the potential severity of a head injury should be raised across sports and responsible medical persons.
Future research should focus on biomechanical aspects, such as severity of impact (threshold), and on the time course of pathophysiological/metabolic changes, that may eventually lead to an energy crises and delayed signs or symptoms. Further development and validation of on-pitch tests and measures to quantify signs and symptoms are needed.
[fig] F: I G U R E 1 Procedure after head injury in high-level football | 1849 EDDERMANN-DEMONT ET Al. [/fig]