Your bicep works best at different elbow angles depending on whether your palm is up, down, or straight — it’s strongest at 45° if your palm is down, and 60° if it’s up.

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Pro

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Against

Evidence from Studies

Supporting (1)

34

Community contributions welcome

34

Forearm rotation and elbow angle differentially modulate biceps brachii and brachioradialis muscle stiffness and EMG activity during low-load isometric contractions: a cross-sectional study in healthy individuals

Cross-Sectional Study

Human

2025 Jul 2

When you bend your elbow with your palm facing down, your bicep works best at 45 degrees, but when your palm faces up or forward, it works best at 60 degrees — and this study proved it.

Contradicting (0)

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No contradicting evidence found

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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

Forearm rotation and elbow angle differentially modulate biceps brachii and brachioradialis muscle stiffness and EMG activity during low-load isometric contractions: a cross-sectional study in healthy individuals

Score: 34

DOI: 10.1186/s13102-025-01226-y

Similar Assertions

When you bend your elbow with a light weight, your bicep works harder if your palm is facing up than if it’s facing down or straight ahead.

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