The Claim
The lack of statistically significant differences in biceps hypertrophy between shoulder-extended and shoulder-flexed curl exercises does not rule out the presence of a biologically meaningful difference, especially due to small sample sizes and potential underpowering in the studies.
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.
Just because a study doesn’t find a clear difference in arm muscle growth between two curl types, it doesn’t mean there isn’t a real difference — the study might just be too small to catch it.
See the scientific wording
The absence of statistically significant differences in biceps hypertrophy between shoulder-extended and shoulder-flexed curls does not necessarily indicate the absence of a biologically meaningful difference, particularly given small sample sizes and potential underpowering.
When you move your arm in different positions during a curl, the way your biceps muscle stretches and tightens changes slightly. This changes how much force each part of the muscle feels and how much energy it uses, which can lead to small differences in how much the muscle grows over time — even if those differences are too small to easily measure in short studies with few people.
What the research says
3 studiesStudy: The effects of shoulder extension angle on elbow flexor hypertrophy in the cable curl exercise
Just because this study didn’t find a big difference between two types of bicep curls doesn’t mean one doesn’t work better — it might just not have had enough people to spot a small but real difference.
The study didn’t find a clear winner between two curl types for arm growth, but the results suggest one might still be better — we just can’t tell for sure because the study was too small. This supports the idea that no clear difference doesn’t mean there isn’t one.
The study found that one arm exercise might build muscle slightly more than another, but the difference wasn’t strong enough to be sure. This supports the idea that small studies might miss real differences.
Related videos
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 3 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.