Table 1. Progression criteria and training exercises (examples, SM_ Fig. 3+4).

Level	Progression criteria into the level	Training exercise (examples)
1: Proprioception	AFS>40/100 Pass the clinical examination Pass proprioceptive performance tests (modified Stork Balance Test; Y-Balance Test)	Weight bearing exercises (proprioceptive); progession model; principles of motor learning (e.g. external focus strategies) Closed-chain strength training (e.g. peroneal) Stationary bicycle Crosstrainer Alter G
2: Running	AFS>60/100 Pass the clinical examination Pass Heel Rise Test and qualitative running analysis	Linear running Progression in linear running speed Hops and bounds (progression)
3: Jump abilities	AFS>75/100 Pass the clinical examination Pass hop tests (Side Hop Test; Triple Hop Test)	Ladder training (short reactive impacts) Extensive interval running
4: athletic skills (rehabilitation)	AFS>85/100 Pass the clinical examination Pass hop tests (Square Hop Test; Crossover Hop Test; mod. 6m-timed Crossover Hop Test)	Athletic skills Multidirectional movement patterns Sprinting
RTS: football-specific	AFS>95/100 Pass the test battery	High-intensity runs Cutting, change of direction Dribbling, passing, shooting from the short to the long distance (progression model)
RTP: re-integration (team training)	lack of criteria; experienced-based; subjective	Re-integration into team training Team warm-up Training forms without opponents No tackling (protected player)
RTC: team training	VBG test battery Lack of evidence	Team training

Only new exercises for each level added. Exercises from previous levels can be applied.

AFS, Ankle Function Score; RTP, Return to Play; RTS, Return to Sports; VBG,Verwaltungs Berufsgenossenschaft (German elite sports insurance)