The muscle underneath your bicep gets just as strong and big whether you curl with your arm in front or behind you.

54

Pro

0

Against

Evidence from Studies

Supporting (1)

54

Community contributions welcome

54

Comparison Between Shoulder Flexed and Extended Positions in Elbow Flexion Resistance Training on Regional Hypertrophy and Maximum Strength: Preacher versus Bayesian Cable Curls

Randomized Controlled Trial

Human

2025 Apr

The study had people do arm curls with their shoulders in two different positions and found that their brachialis muscle got about 8–10% thicker in both cases — so shoulder position doesn’t matter, just doing the curls does.

Contradicting (0)

0

Community contributions welcome

No contradicting evidence found

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

Comparison Between Shoulder Flexed and Extended Positions in Elbow Flexion Resistance Training on Regional Hypertrophy and Maximum Strength: Preacher versus Bayesian Cable Curls

Score: 54

DOI: 10.1002/ejsc.12279

Similar Assertions

Doing bicep curls with your arm in front of your body or behind your body gives you the same muscle growth and strength gains if you're using the same amount of weight and doing the same number of reps.

54

0

83%

After a tough bicep workout, your arm gets a little swollen, but it goes back to normal by the next day — and it doesn’t matter if you changed your shoulder angle during the workout.

0

51

70%