Two factors:
Range of Motion – how much knee flexion you allow
Tension – how much tension you are putting through the quad, connective tissue of the knee
Progression
Progress ROM first, then tension
0 – no ROM, no tension
Zone 1-2 Biking
Daily
1 – some ROM, micro tension
Reverse sled drag / backwards walking
Daily
2 – full ROM, mini tension
Heel sits
Daily
3 – full ROM, low tension
Front foot elevated, knees over toes split squat
Banded cyclist squats
Banded sissy squats
2-3x per week
4 – full ROM, moderate tension
KOT split squat
Cyclist squat
2x per week
5 – full ROM, high tension
20-15-10-5-1 Reps
1-2x per week
Common mistakes
1. Avoidance – avoiding using the knee altogether
2. Assuming it will heal completely with rest. 0 to 60 – “I just need to rest it.” Going from complete rest to full ROM, high tension.
3. Not enough frequency – micro and mini tension needs to be daily
4. Stopping movement prep/accessories altogether once the knee feels good. Keep one step down from wherever you are in the progression in your program if you’ve experienced knee pain in the past.