Leg Extension
Reviewed by Bryan Cortez, MS
The only move that isolates the quad with zero hip help — squeeze, don't swing.
Coaching profile
quad isolation. This page is the practical coaching layer: use it for setup, cues, programming, pain-free adjustments, and substitutions. The complete biomechanics tier list lives on the muscle page.
How the rankings are built →Demonstration
Demonstration production queue
The written coaching card is ready. The owned video is next.
Physique Skool is filming one canonical demonstration per exercise. Until this movement is published, use the setup, execution, common errors, programming, and substitutions below.
Browse Physique Skool on YouTubeHow to do it
Setup
- Back into the pad, knee aligned with the machine pivot, shin pad on the lower shin.
Execution
- Extend fully and squeeze at the top, control the way down; recline the seat to bias the rectus femoris.
Common Errors
- Swinging/kicking the weight up with momentum
- Hips lifting off the seat
- Knee not aligned with the machine pivot
- Half reps that skip the squeeze or the stretch
Cues That Work
- Drive the shin pad up; squeeze the quads; lower until the knee is comfortably flexed
No-Fly Zone
under 6 reps (heavy partials just stress the knee)
Programming
Sequence priority
Late
Low fatigue, single-joint — slots late as a quad finisher, or first as a deliberate pre-exhaust / knee primer.
Progression
Model — Triple
Fallback model — Double
Triple progression: add reps toward ~20, then add a pin (or a micro-plate, since stack jumps are coarse).
Best program fit
Legs, Lower
Load increments
If it hurts
Pain is information, not a challenge to push through. Stop the set if pain is sharp, worsening, or changes how you move. These are exercise-selection options, not medical diagnosis or rehabilitation advice.
Work down this list in order. Stop at the first change that removes the pain.
Step 1
Setup tweaks
Seat-back angle (reclined = rectus femoris); toe angle in/out for vastus bias.
Step 2
ROM / tempo / bias
Pause and squeeze at the top; slow eccentric; lengthened partials at the bottom.
Step 3
Implement swap
Sissy squat or reverse Nordic for a stretch-biased quad isolation.
Substitutions
Approved fallback
Sissy squat or reverse Nordic for a stretch-biased quad isolation.
Compare all quadriceps optionsThe Evidence
Isolates and builds the quads (esp. rectus femoris). Does NOT train glutes, hams, or any functional pattern.
SFR — 4
Put the exercise inside a system.
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