The Claim

In male bodybuilders performing isometric knee extension at 30° knee flexion with the hip positioned at either 0° or 40°, the middle region of the rectus femoris demonstrates greater stiffness compared to the middle region of the vastus lateralis, suggesting that hip angle influences the mechanical loading distribution among quadriceps muscles.

Source: Effects of knee and hip flexion angle on region-specific and longitudinal compartmental muscle stiffness of the rectus femoris using shear wave elastography in male bodybuilders

What the research says

Supports is higher

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

Supports
40score
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.

How it works
1 study reviewed
In plain English

When male bodybuilders flex their knees and push without moving their legs, the front thigh muscle feels stiffer than a neighboring muscle — and this difference depends on how much the hip is bent.

See the scientific wording

During isometric knee extension at 30° knee flexion and hip angles of 0° or 40°, the middle region of the rectus femoris exhibits higher stiffness than the middle region of the vastus lateralis in male bodybuilders, indicating differential mechanical loading between quadriceps muscles depending on hip position.

What the research says

1 study
  1. Study: Effects of knee and hip flexion angle on region-specific and longitudinal compartmental muscle stiffness of the rectus femoris using shear wave elastography in male bodybuilders

    The study tested leg muscle stiffness in bodybuilders doing knee extensions with hips straight or slightly bent, and found the front thigh muscle (rectus femoris) was stiffer than the outer thigh muscle (vastus lateralis), just like the claim says.

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

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