Table 2: A plyometric program approach across four stages aligned to the functional recovery framework after ACL reconstruction. Particular training goals, use of plyometrics, progression criteria, training planning considerations, with specific movement exercises and progressions are presented.

Stage		1	2	3	4
Typical weeks*		10-14	15-18	19-22	23-29
General goals of stage		Full recovery of joint R.O.M Restoration of muscle strength imbalances to within 20% of ‘trained’ contralateral limb (or pre-injury strength values) Recovery of basic motor patterning and running gait Avoid physical fitness de-training	Develop functional strength Develop closed chain eccentric strength Develop bilateral power Develop unilateral eccentric control Continue to restore lower limb muscle imbalances	Restore neuromuscular function markers to within at least 10% (knee and adjacent joint specific strength and closed kinetic chain and power) Restore high load movement quality Restore aerobic fitness	Restore sports specific movement quality, fitness, skills and develop movement ‘volumes’ to prepare for RTS
Plyometric use		Low intensity predominantly bilateral plyometrics at sub-maximal intensity to support eccentric/motor control and preparation for running	Moderate intensity bilateral and unilateral plyometrics with view to developing lower limb power and eccentric control, particularly unilateral deceleration capabilities	Higher intensity bilateral and unilateral plyometrics with view to developing lower limb power and multipolar motor control and acceleration capabilities	Optimise lower limb explosive neuromuscular performance and support sport-specific movement re-training. Mindful of load management
Criteria to enter plyometric stage		0-1 pain NRS @ rest <2 pain during activities of daily living Full knee extension Knee flexion > 120° Good BL squat (body weight and loaded) with < 20% asymmetry in loading8 Isometric knee extensor LSI >70%	Ability to run of treadmill for 10 mins @8km/h8 Good BL landing kinematics Good SL squat kinematics Closed chain strength > 1.25 times body mass (8RM) or 1.5 x times body mass (1RM/peak isometric force) Isokinetic LSI knee extensor and flexor >80%	Good BL drop jump mechanics Good SL landing control Closed chain strength > 1.5 times body mass (8RM) or 2 x times body mass (1RM/peak isometric force)	Isokinetic LSI knee extensor and flexor >90%9 Closed chain strength > 1.5 times body mass (8RM) or 2 x times body mass (1RM/peak isometric force)9 Good pre-planned movement quality (UL landing/deceleration/ BL and UL drop jump/ CoD mechanics indoor and/or OF)
Training planning	Intensity	Low	Moderate	High	Very high
	Plyometric type	BL off-set BL asymmetrical BL symmetrical (sub-max)	BL off-set BL asymmetrical BL symmetrical UL (linear)	Bilateral off-set Bilateral asymmetrical Bilateral symmetrical UL (multi-planar)	Bilateral off-set Bilateral asymmetrical Bilateral symmetrical UL (multi-planar)
	Volume (foot contacts)	50	100	150	200
	Plyometric Tasks	Lunge push back SJ to box CMJ to box Skips in place Step up jump (same leg) Step up jump (alternating) Step and hold (forward)	BL SJ (in place, forward) BL CMJ (in place, forward) BL drop jump (30 cm box) Split jump (same leg land) Split jump (alternating) Step and land (forward, lateral, standing and from running on spot) Step-land-push back (forward, lateral, standing and from running on spot)	UL SJ/CMJ to BL landing UL SJ/CMJ to box Rotational jump and land Lateral step-jump-back Tuck jump Step cut (30°/45°/60°/90°) Hop singular (in place/ forward/ lateral/45°/90°) Hop multiple (in place/ forward/ lateral/45°/90°) SL drop jump (box/in place/lateral to box) Advanced bounding OF	CMJ (hurdles) SJ/CMJ weighted BL/UL DJ (increased height to box) Lateral hop (band/rope/ med ball) SL 90 lateral drop jump Step cut (perturbation) OF agility drills OF CoD drills with perturbation/ external focus and sport-specific environment
	Other movement tasks	SL movement progressions (from BL squat to UL squat) Bilateral landing from step Trampoline SL landing Re-integration to treadmill running Stage 2 plyometrics in pool (~60% body height)	Treadmill running (12-20 km/h) Outdoor linear movements (running, ladder drills, lateral shuffle) Stage 3 plyometrics in pool (~60% body height)	Outdoor pre-planned coordination program (multi-directional movement demands) High speed linear running/sprinting	On-field sport-specific training with re-active movements, contact/perturbation drills, as well as skills training

R. O. M, range of motion; NRS, numeric rating scale; BL, bilateral; LSI, limb symmetry index; SJ, squat jump; CMJ, countermovement jump; RM, repetition maximum; SL, single leg; UL, unilateral; OF, on-field; RTS, return-to-sport; CoD, change of direction; DJ, drop jump * time is only indicative, and the protocol should be always customized on patient’s response.