Research

Mixed

Performing a maximal isometric back squat at a 90-degree knee joint angle generates the highest overall muscle activation for the quadriceps and gluteus maximus compared to shallower (20 degrees) or deeper (140 degrees) positions.

If you are using isometric squats to maximize quad and glute activation, lock your knees at 90 degrees. Going deeper (140 degrees) actually reduces activation for these muscles, and going shallower (20 degrees) is also suboptimal. Keep your feet hip-width and bar high on your back.

ModerateSupportsMEDIUM confidence
An isometric back squat at 90° generates the highest overall muscle activation of the quadriceps and gluteus maximus muscles.
Paulo Henrique Marchetti et al. · Journal of Sports Medicine · 2016

Why this rating

Small sample size (n=15), healthy resistance-trained men only, and lack of control for hip angles limit generalizability.

Source

Muscle Activation Differs between Three Different Knee Joint-Angle Positions during a Maximal Isometric Back Squat Exercise

Paulo Henrique Marchetti et al. · Journal of Sports Medicine · 2016

DOI 10.1155/2016/3846123

mechanism_only · n=15Cited 69×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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