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...
Mechanism
Synthesis from 1 study
When you curl a weight with your arm in different positions but keep the same effort, weight, and elbow movement, every part of your biceps gets pulled the same way. Because all parts feel the same force, they all grow at the same rate — no part gets bigger than the others.
Most probable mechanism
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.
The resistance profile and elbow range of motion are held constant, resulting in identical length-tension relationships across the entire length of the elbow flexor muscles during each repetition.
Muscle fibers throughout the proximal and distal regions experience comparable levels of mechanical tension due to uniform load transmission along the muscle-tendon unit.
Mechanical tension triggers identical intracellular signaling pathways in all regions of the muscle, including mTOR activation and protein synthesis rates, leading to balanced myofibrillar accretion.
Over 10 weeks of consistent training, the absence of regional differences in tension results in symmetrical hypertrophy across proximal and distal segments of the elbow flexors.
Evidence from Studies
Supporting (1)
Community contributions welcome
The effects of shoulder extension angle on elbow flexor hypertrophy in the cable curl exercise
Contradicting (0)
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Gold Standard Evidence Needed
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