The Claim

For the outer thigh muscle (vastus lateralis), bending your hip to 40 or 90 degrees during leg extensions doesn’t seem to make a difference in how much the muscle grows in guys who haven’t lifted before.

Source: The effects of hip flexion angle on quadriceps femoris muscle hypertrophy in the leg extension exercise

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
54score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

For the outer thigh muscle (vastus lateralis), bending your hip to 40 or 90 degrees during leg extensions doesn’t seem to make a difference in how much the muscle grows in guys who haven’t lifted before.

See the scientific wording

There is no meaningful difference in hypertrophy of the vastus lateralis muscle between 40° and 90° hip flexion during leg extension exercises in untrained men over 10 weeks.

What the research says

1 study

  1. Study: The effects of hip flexion angle on quadriceps femoris muscle hypertrophy in the leg extension exercise

    The study found that bending your hip to 40° or 90° during leg extensions doesn’t make a meaningful difference in how much the big outer thigh muscle (vastus lateralis) grows — so both positions work just as well for that muscle.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.