Back at it again with squat mechanics, a new study looked the biomechanical differences between wide- and narrow-stance squats.
For background, changing bar placement can also change the mechanics of the squat, though it’s not clear that this has a ton of practical importance, e.g. how big or strong someone gets from picking a particular variant.
In this study, a Europe-based research group took young dudes who could squat at least 1.5x their bodyweight, and had them squat a 3-repetition max (3RM) with both wide and narrow stances. Stance widths were defined as 1.7-times shoulder* width for wide, and 0.7-times shoulder width* for narrow.
- Refers to acromion to acromion distance, not really shoulder width. My anatomy background won’t let this slide
As predicted, the narrow squat showed more knee and ankle flexion than the wider squat during the 3RM test. However, the hip flexion was about the same between both squats. Typically, a wider stance results in less hip flexion/forward lean compared to a narrow stance, particularly in low bar variants. Finally, the average 3RM was ~ 295 pounds, with the wide stance being about 3 pounds heavier than the average narrow stance.
The authors go on to use these observed differences to model forces on the individual muscles during each style of squat, concluding that a narrow stance squat likely puts more force on the quads. They did not go further and extrapolate this to greater strength or hypertrophy, which is good, because neither EMG nor modeling of net joint moments correlate well with these outcomes.
So, what was the point of the study? Honestly, I don’t know. The authors said they wanted to “compare joint angles, NJMs, and lower extremity muscle forces between a wide vs. narrow stance width”, though not any particular reason why. An outcome-based study, e.g. hypertrophy and/or strength would be more useful for assessing the practical implications of a wide or narrow stance squat, though admittedly this can be challenging to do.
Overall, I think that squat stance width, like bar position, toe angle, and so on, should mostly be determined by personal preference, demonstrated efficiency, and trainability. I would not predict a low- or high-bar squat to routinely drive more strength or size gain than the other, which is similar to how I feel about stance width. I think future studies should look at outcomes between different styles in addition biomechanics, as biomechanic-only studies are of limited utility.