. 2023 Apr 1;18(2):493–512. doi: 10.26603/001c.73797

Table 2. Example of a quadriceps muscle/tendon load-progression after anterior cruciate ligament reconstruction with an all soft-tissue quadriceps tendon autograft fixated with suspensory fixation.

Postoperative Month	Single-Leg Progression	Split-Squat Progression	Open-Kinetic-Chain Progression
Month 0-1	Banded TKE (Sitting at Edge of Surface) Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 3-4 times/day I: Elastic resistance band exercise (light to heavy) T: Isotonic (concentric/eccentric phase) T: 10-15 minutes each exposure V: 2-4 sets of 10-20 repetition with a 1-3 second isometric contraction in TKE P: Progression of elastic resistance band level; superimposition of NMES with exercise; progression onto blood flow restriction exercise (1-2 times/day, 3-4 set to volitional fatigue at 80% LOP)	Quadriceps Setting (Straight Leg Raise) Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 3-6 times/day I: Progressive increase in contraction intensity onto the straight leg raise exercise T: Isometric quadriceps contraction training T: 8-10 minutes each exposure V: 2-4 sets of 10-20 repetition with a 1-3 second isometric contraction in TKE P: Progression of body position and/or onto the straight leg raise exercise (with/without external resistance at the ankle); superimposition of NMES with exercise; progression onto blood flow restriction exercise (1-2 exposures/day, 3-4 set to volitional fatigue at 80% LOP)	Short/Long-Arc Quad (AROM) Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 3-4 times/day I: Weight of lower leg T: Isotonic (concentric/eccentric phase) T: 10-15 minutes each exposure V: 2-4 sets of 10-20 repetition with a 1-3 second isometric contraction in TKE P: Progression of contraction intensity and knee flexion angle during exercise; superimposition of NMES with exercise; progression onto blood flow restriction exercise (1-2 times/day, 3-4 set to volitional fatigue at 80% LOP)
Month 1-2	Banded TKE (Standing) Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 2-3 times/day I: Elastic resistance band (light to heavy) T: Isotonic (concentric/eccentric phase) T: 10-15 minutes each exposure V: 3-4 sets of 10-20 repetition with a 1-3 second isometric contraction in TKE P: Progression of elastic resistance band level; progression onto blood flow restriction exercise (1-2 times/day, 3-4 set to volitional fatigue at 80% LOP)	Double-Leg Squat (0-60 Degrees of Knee Flexion) Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 2-3 times/day I: Body weight (0-60 degrees of knee flexion) T: Isotonic (concentric/eccentric phase) or Isometric T: 10-15 minutes each exposure V: 3-4 sets of 10-15 repetition followed by a 45-90 second isometric contractions in 45-60 degrees of knee flexion \| 30-90-second rest periods between sets P: Progression of knee flexion angle, positive shin angle and duration of isometric contraction; redistribution of weight toward the surgical limb	Long-Arc Quad (AROM with Blood Flow Restriction) Prescription Type: Cell Swelling/Atrophy Mitigation/Hypertrophy F: 1-2 times/day I: Weight of lower leg, blood flow restriction at 80% LOP T: Isotonic (concentric/eccentric phase) \| 0-90+ degrees of knee flexion T: 10-20 minutes each exposure V: 3-4 sets to volitional fatigue \| 30-90-second rest periods between sets P: Addition of progressive isometric contractions at 45-90 degrees of knee flexion with/without the superimposition of NMES
Month 2-3	Double-Leg Wall Squat (60-90+ Degrees of Knee Flexion) Prescription Type: Extensor Mechanism Load-Tolerance/Hypertrophy F: 3-5 times/week I: Body weight (60-90+ degrees of knee flexion) T: Isometric T: 5-10 minutes each exposure V: 3-4 sets of 45-90 second isometric contractions \| 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle, or duration of isometric contraction; pressure redistribution of additional weight onto the surgical limb	Split-Squat (0-60 Degrees of Knee Flexion) Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 2-3 times/day I: Body weight (0-60 degrees of knee flexion) on involved limb T: Isotonic (concentric/eccentric phase) or Isometric T: 5-10 minutes each exposure V: 3-4 sets of 10-15 repetition followed by a 45-60 second isometric contractions in shallow knee flexion \| 30-90-second rest periods between sets P: Progression of knee flexion angle, positive shin angle or duration of isometric contraction; redistribution of weight onto the surgical limb	Knee Extension Machine (Single-Leg with Blood Flow Restriction) Prescription Type: Hypertrophy/Strength F: 3-5 times/week I: 15-30 RM (<40-65% 1-RM) of involved limb, blood follow restriction at 80% LOP T: Isotonic (concentric/eccentric phase) \| 45-90+ degrees of knee flexion T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue \| 2-5-minute rest periods between sets P: Progression of external resistance at the distal tibia
Month 3-4	Leg Press Machine (Single-Leg with Blood Flow Restriction) Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 10-20 RM (40-75% 1-RM) on the involved limb, blood follow restriction at 80% limb occlusion pressure T: Isotonic (concentric/eccentric phase) T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue \| 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle or external resistance	Split -Squat (60-90+ Degrees Knee Flexion) Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: Body weight (60-90+ degrees of knee flexion) on the involved limb T: Isometric T: 5-10 minutes each exposure V: 3-4 sets of 45-90 second isometric contractions in progressively deeper knee flexion \| 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive	Knee Extension Machine (Single-Leg with Blood Flow Restriction) Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 15-20 RM (40-65% 1-RM) of involved limb, blood follow restriction at 80% limb occlusion pressure T: Isotonic (concentric/eccentric phase) \| 0-90+ degrees of knee flexion T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue \| 2-5-minute rest periods between sets P: Progression of external resistance at the distal tibial
Month 4-6	Leg Press (Single-Leg with Increasing Load) Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 6-15 RM (65-85% 1-RM) on the involved limb T: Isotonic (concentric/eccentric phase) T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue \| 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle or external resistance	Split-Squat (Rearfoot-Elevated Position) Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 6-15 RM (65-85% 1-RM) on the involved limb T: Isotonic (concentric/eccentric phase) T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue \| 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle or external resistance	Knee Extension Machine (Single-Leg with Increasing Load) Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 6-15 RM (65-85% 1-RM) on the involved limb T: Isotonic (concentric/eccentric phase) \| 0-90+ degrees of knee flexion T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue \| 2-5-minute rest periods between sets P: Progression of external resistance at the distal tibial
Month 6+	Eccentric Leg Press (2-Legs Up Concentric / 1-Leg Down Eccentric) Prescription Type: Hypertrophy/ Eccentric Strength F: 2-3 times/week I: 1-5 RM (85-100% 1-RM) on the involved limb T: Eccentric resistance training T: 5-10 minutes each exposure V: 3-4 sets of 8-15 eccentric repetitions \| 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle or external resistance greater than a 1-RM (e.g., 120% 1-RM)	Split-Squat Jumps (Lunge or Rearfoot-Elevated Position) Prescription Type: Power F: 2-4 times/week I: Body weight to 40-60% 1-RM on the involved limb T: Isotonic (concentric/eccentric phase), emphasis on speed/effort during the concentric phase of the movement T: 5-10 minutes each exposure V: 4-5 sets of 3-5 reps \| 2-5-minute rest period between sets P: Progression of knee flexion angle, positive shin angle, contraction speed or external load	Eccentric Knee Extension Machine (2-Legs Up Concentric / 1-Leg Down Eccentric) Prescription Type: Hypertrophy/ Eccentric Strength F: 2-3 times/week I: 1-5 RM (85-100% 1-RM) on the involved limb T: Eccentric resistance training \| 0-90+ degrees of knee flexion T: 5-10 minutes each exposure V: 3-4 sets of 8-15 eccentric repetitions \| 2-5-minute rest periods between sets P: Progression of external resistance greater than a 1-RM (e.g., 110% 1-RM)

Postoperative Month

Single-Leg
Progression

Split-Squat
Progression

Open-Kinetic-Chain
Progression

Month 0-1

Banded TKE (Sitting at Edge of Surface)

Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 3-4 times/day I: Elastic resistance band exercise (light to heavy) T: Isotonic (concentric/eccentric phase) T: 10-15 minutes each exposure V: 2-4 sets of 10-20 repetition with a 1-3 second isometric contraction in TKE P: Progression of elastic resistance band level; superimposition of NMES with exercise; progression onto blood flow restriction exercise (1-2 times/day, 3-4 set to volitional fatigue at 80% LOP)

Quadriceps Setting (Straight Leg Raise)

Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 3-6 times/day I: Progressive increase in contraction intensity onto the straight leg raise exercise T: Isometric quadriceps contraction training T: 8-10 minutes each exposure V: 2-4 sets of 10-20 repetition with a 1-3 second isometric contraction in TKE P: Progression of body position and/or onto the straight leg raise exercise (with/without external resistance at the ankle); superimposition of NMES with exercise; progression onto blood flow restriction exercise (1-2 exposures/day, 3-4 set to volitional fatigue at 80% LOP)

Short/Long-Arc Quad (AROM)

Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 3-4 times/day I: Weight of lower leg T: Isotonic (concentric/eccentric phase) T: 10-15 minutes each exposure V: 2-4 sets of 10-20 repetition with a 1-3 second isometric contraction in TKE P: Progression of contraction intensity and knee flexion angle during exercise; superimposition of NMES with exercise; progression onto blood flow restriction exercise (1-2 times/day, 3-4 set to volitional fatigue at 80% LOP)

Month 1-2

Banded TKE (Standing)

Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 2-3 times/day I: Elastic resistance band (light to heavy) T: Isotonic (concentric/eccentric phase) T: 10-15 minutes each exposure V: 3-4 sets of 10-20 repetition with a 1-3 second isometric contraction in TKE P: Progression of elastic resistance band level; progression onto blood flow restriction exercise (1-2 times/day, 3-4 set to volitional fatigue at 80% LOP)

Double-Leg Squat (0-60 Degrees of Knee Flexion)

Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 2-3 times/day I: Body weight (0-60 degrees of knee flexion) T: Isotonic (concentric/eccentric phase) or Isometric T: 10-15 minutes each exposure V: 3-4 sets of 10-15 repetition followed by a 45-90 second isometric contractions in 45-60 degrees of knee flexion | 30-90-second rest periods between sets P: Progression of knee flexion angle, positive shin angle and duration of isometric contraction; redistribution of weight toward the surgical limb

Long-Arc Quad (AROM with Blood Flow Restriction)

Prescription Type: Cell Swelling/Atrophy Mitigation/Hypertrophy F: 1-2 times/day I: Weight of lower leg, blood flow restriction at 80% LOP T: Isotonic (concentric/eccentric phase) | 0-90+ degrees of knee flexion T: 10-20 minutes each exposure V: 3-4 sets to volitional fatigue | 30-90-second rest periods between sets P: Addition of progressive isometric contractions at 45-90 degrees of knee flexion with/without the superimposition of NMES

Month 2-3

Double-Leg Wall Squat (60-90+ Degrees of Knee Flexion)

Prescription Type: Extensor Mechanism Load-Tolerance/Hypertrophy F: 3-5 times/week I: Body weight (60-90+ degrees of knee flexion) T: Isometric T: 5-10 minutes each exposure V: 3-4 sets of 45-90 second isometric contractions | 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle, or duration of isometric contraction; pressure redistribution of additional weight onto the surgical limb

Split-Squat (0-60 Degrees of Knee Flexion)

Prescription Type: Neuromuscular Reeducation and Muscle Activation F: 2-3 times/day I: Body weight (0-60 degrees of knee flexion) on involved limb T: Isotonic (concentric/eccentric phase) or Isometric T: 5-10 minutes each exposure V: 3-4 sets of 10-15 repetition followed by a 45-60 second isometric contractions in shallow knee flexion | 30-90-second rest periods between sets P: Progression of knee flexion angle, positive shin angle or duration of isometric contraction; redistribution of weight onto the surgical limb

Knee Extension Machine (Single-Leg with Blood Flow Restriction)

Prescription Type: Hypertrophy/Strength F: 3-5 times/week I: 15-30 RM (<40-65% 1-RM) of involved limb, blood follow restriction at 80% LOP T: Isotonic (concentric/eccentric phase) | 45-90+ degrees of knee flexion T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue | 2-5-minute rest periods between sets P: Progression of external resistance at the distal tibia

Month 3-4

Leg Press Machine (Single-Leg with Blood Flow Restriction)

Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 10-20 RM (40-75% 1-RM) on the involved limb, blood follow restriction at 80% limb occlusion pressure T: Isotonic (concentric/eccentric phase) T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue | 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle or external resistance

Split -Squat (60-90+ Degrees Knee Flexion)

Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: Body weight (60-90+ degrees of knee flexion) on the involved limb T: Isometric T: 5-10 minutes each exposure V: 3-4 sets of 45-90 second isometric contractions in progressively deeper knee flexion | 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive

Knee Extension Machine (Single-Leg with Blood Flow Restriction)

Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 15-20 RM (40-65% 1-RM) of involved limb, blood follow restriction at 80% limb occlusion pressure T: Isotonic (concentric/eccentric phase) | 0-90+ degrees of knee flexion T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue | 2-5-minute rest periods between sets P: Progression of external resistance at the distal tibial

Month 4-6

Leg Press (Single-Leg with Increasing Load)

Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 6-15 RM (65-85% 1-RM) on the involved limb T: Isotonic (concentric/eccentric phase) T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue | 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle or external resistance

Split-Squat (Rearfoot-Elevated Position)

Knee Extension Machine (Single-Leg with Increasing Load)

Prescription Type: Hypertrophy/Strength F: 2-4 times/week I: 6-15 RM (65-85% 1-RM) on the involved limb T: Isotonic (concentric/eccentric phase) | 0-90+ degrees of knee flexion T: 5-10 minutes each exposure V: 3-4 sets to volitional fatigue | 2-5-minute rest periods between sets P: Progression of external resistance at the distal tibial

Month 6+

Eccentric Leg Press (2-Legs Up Concentric / 1-Leg Down Eccentric)

Prescription Type: Hypertrophy/ Eccentric Strength F: 2-3 times/week I: 1-5 RM (85-100% 1-RM) on the involved limb T: Eccentric resistance training T: 5-10 minutes each exposure V: 3-4 sets of 8-15 eccentric repetitions | 2-5-minute rest periods between sets P: Progression of knee flexion angle, positive shin angle or external resistance greater than a 1-RM (e.g., 120% 1-RM)

Split-Squat Jumps (Lunge or Rearfoot-Elevated Position)

Prescription Type: Power F: 2-4 times/week I: Body weight to 40-60% 1-RM on the involved limb T: Isotonic (concentric/eccentric phase), emphasis on speed/effort during the concentric phase of the movement T: 5-10 minutes each exposure V: 4-5 sets of 3-5 reps | 2-5-minute rest period between sets P: Progression of knee flexion angle, positive shin angle, contraction speed or external load

Eccentric Knee Extension Machine (2-Legs Up Concentric / 1-Leg Down Eccentric)

Prescription Type: Hypertrophy/ Eccentric Strength F: 2-3 times/week I: 1-5 RM (85-100% 1-RM) on the involved limb T: Eccentric resistance training | 0-90+ degrees of knee flexion T: 5-10 minutes each exposure V: 3-4 sets of 8-15 eccentric repetitions | 2-5-minute rest periods between sets P: Progression of external resistance greater than a 1-RM (e.g., 110% 1-RM)

F, frequency; I, intensity; T, type; T, time; V, volume; P, progression; AROM, active range-of-motion; TKE, terminal knee extension; LOP, limb occlusion pressure, RM, repetition maximum, 1-RM, 1-repetition maximum