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Strong Support

You can't fully work just the upper or lower part of your chest muscle when pushing as hard as you can — no matter how you position your arms, both parts end up working together.

41
Pro
0
Against

Evidence from Studies

Supporting (1)

41

Community contributions welcome

41

Force direction and arm position affect contribution of clavicular and sternal parts of pectoralis major muscle during muscle strength testing

Cross-Sectional Study
Human
2019 Jan-Mar

The study tested different arm positions and pushing directions to see if one part of the chest muscle could be worked alone, but found that both upper and lower parts always worked together during maximum effort, which supports the claim.

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

Force direction and arm position affect contribution of clavicular and sternal parts of pectoralis major muscle during muscle strength testing

Score: 41
DOI: 10.1016/j.jht.2017.08.007

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