Want more quad work?
A more upright torso and more knee travel shift demand toward the knees and quads.
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BIOMECHANICS LAB / INTERACTIVE MODEL
Squat Lab
Step through a squat one phase at a time and watch the model move with you. See the bar path, your depth, your torso angle, and where the work goes — the same things a coach watches every rep.
New to squatting? Start at Setup and tap through in order. This is a teaching model, not a diagnosis.
INTERACTIVE MODEL
Move through the rep
Pick a phase to see the lifter move into that position. The red line is the load through the middle of the foot; the arrows show how much leverage the hips and knees are fighting. Turn layers on or off to focus.
Setup phase: Set your stance and find the bar.
- Dashed vertical = bar path over midfoot
- Crimson dashed = load line through midfoot
- Red arrow = hip moment arm
- Clay arrow = knee moment arm
SETUP
Same every repSet your stance and find the bar.
Feet about shoulder-width, toes slightly out, bar settled on your back. The same setup every rep makes every rep easier to repeat.
Common mistake
Rushing the setup and standing a little different every time.
Coaching fix
Take the exact same setup each rep — feet, grip, and bar position.
Relative demand
- QuadsLow
- Hips / glutesLow
- Back / erectorsModerate
- Trunk braceModerate
Qualitative only — this shows why position changes demand, not exact muscle activation.
Your torso angle changes the demand
A muscle works harder when the load gets more leverage around the joint it controls. In a squat, the same bar can feel different depending on where your knees, hips, and torso sit relative to that vertical load line.
More leverage at the knee usually feels more quad-biased. More leverage at the hip usually shifts work toward the glutes, adductors, back, and trunk.
No squat isolates one muscle. These are relative biases — not clean on/off switches.
COACHING TAKEAWAYS
Use the squat that fits the goal
Want more hip and glute work?
A controlled forward lean with hips traveling back shifts demand toward the hips, glutes, and back.
Want general strength?
A balanced squat you can repeat with the same positions is the easiest to progress over time.
Want to stay comfortable?
Match the squat to your body — your limb lengths, mobility, and history all change what feels good.
Learn it here. Apply it in training.
Track it in the Forge app.
Take what you see here to the bar, then log every set and watch your numbers move.
Explore the Forge App