The Claim
In untrained men, varying the shoulder extension angle during cable curl exercises does not differentially affect proximal or distal elbow flexor muscle hypertrophy when resistance profiles, elbow range of motion, and effort are equated, with both conditions resulting in similar regional muscle growth patterns after 10 weeks of training.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
If you're new to lifting, changing your arm position during cable curls doesn't make one part of your biceps grow more than another — both positions give you the same kind of muscle growth over 10 weeks if everything else is kept equal.
See the scientific wording
In untrained men, altering shoulder extension angle during cable curls does not preferentially influence proximal or distal elbow flexor hypertrophy when resistance profiles, elbow range of motion, and effort are matched, with both conditions producing similar regional growth patterns over 10 weeks.
When you lift a weight with your arm in different shoulder positions but keep the same effort, weight, and elbow movement, the muscles in your upper arm stretch and contract the same amount along their whole length. This means every part of the muscle feels the same pulling force, so all parts grow equally over time.
What the research says
1 studyStudy: The effects of shoulder extension angle on elbow flexor hypertrophy in the cable curl exercise
If you're new to lifting and do cable curls with your arm in different positions, your biceps grow the same amount in both the upper and lower parts — as long as you're lifting the same weight, moving through the same range, and trying just as hard.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.