**4.1 Graduated return to play protocol**

*Sports, Health and Exercise Medicine*

movement [36, 37].

evaluation [40, 44, 45].

**4. Clinical management**

has been reported and may improve outcomes.

are we at today? (2) Which half is it now? (3) Who scored last in this match? (4) What team did you play last week or last game? (5) Did your team win the last game? Users are instructed to remove athletes from play if one or more of these indicators

The *King-Devick Test in association with Mayo Clinic* (K-D Test) is a rapidnumber naming test used to evaluate for impairments in saccadic eye movements, attention, concentration, and language, which involve integration of functions of the brainstem, cerebellum, and cerebral cortex [36]. The K-D test assesses over half of brain pathways and several cortical areas are involved in saccadic eye

The K-D test requires subjects to read a series of 120 single single-digit numbers aloud from left to right across three test screens that progress in difficult as quickly but as accurately as possible. There are several versions of the test to prevent memorization. The total time to complete the test and the errors are recorded. An individualized pre-injury baseline is determined ideal at pre-season and used for comparison during an acute sideline post-injury evaluation. Extensive research has demonstrated worsening in performance in concussed athletes with high sensitivity and specificity [36, 38–41]. A study by the University of Florida found that the K-D test complements components of the SCAT 5, increasing the concussion detection rate in collegiate athletes when using a combination of testing components that include the K-D test, symptoms checklist and balance assessment [38]. Additionally, the K-D test is resistant to the effects of fatigue, showing no worsening of time when athletes were tested in game-like physical fatigue situations [36, 42, 43]. Although athletic trainers or medical professionals are present on the sidelines of professional and collegiate sporting events, most youth and high school sports lack these resources. However, parents, coaches, and laypersons can administer the King-Devick test in less than 2 minutes, making it realistic for sideline concussion

Multiple studies have also demonstrated the utility of the K-D test in screening

The majority of sports-related concussion symptoms typically resolve spontaneously within 2 weeks [50]. Younger athletes typically require longer recovery within 4 weeks [51]. The International Concussion in Sport Group currently promotes and supports physical and cognitive rest following concussive injury until acute symptoms resolve [9]. Once symptoms are abated, individuals should then undergo a stepwise, graded program of exertion. Athletes should be symptom free at rest as well as during and after exertion prior to complete medical clearance and full return to play. Recent research supporting the inclusion of active concussion rehabilitation

for "unwitnessed" concussive events [41, 47–49]. In a large prospective observational cohort study of New Zealand rugby, routine post-match screening was completed with the K-D test and in doing so aiding in identifying 44 unwitnessed, unreported concussions over the duration of the study. This totaled 6 times more than the 8 witnessed concussions, which were identified pitch-side [46]. Researchers reported that by using a composite of rapid brief tests such as the K-D test, the SAC and BESS are likely to provide a series of effective clinical tools to assess players on the sideline with suspected concussive injury [41, 47–49].

are present or if a memory question is answered incorrectly.

**3.6 King-Devick test in association with Mayo Clinic**

**10**

The graduated return to play protocol is a stepwise process in which the athlete may continue to proceed to the next level if asymptomatic at the previous level. It is outlined that each step should be 24 hours and therefore the athletes would generally take approximately 1 week to complete all levels of the protocol. If any symptoms arise during any of the levels, the athlete should return to the previous level until asymptomatic and 24 hours of rest has occurred [9, 44].

Rehabilitation stage 1: no activity. Symptom limited physical and cognitive rest. Objective: recovery. Rehabilitation stage 2: light aerobic exercise. Walking, swimming or stationary cycling keeping intensity <70% maximum permitted heart rate. No resistance training. Objective: increase heart rate. Rehabilitation stage 3: sport-specific exercise. Skating drills in ice hockey, running drills in soccer. No head impact activities Objective: add movement. Rehabilitation stage 4: non-contact training drills. Progression to more complex training drills (i.e. passing drills in football and ice hockey). May start progressive resistance training. Objective: exercise, coordination and cognitive load. Rehabilitation stage 5: full-contact practice. Following medical clearance participate in normal training activities. Objective: restore confidence and assess functional skills by coaching staff Rehabilitation stage 6: return to Play. Normal game play
