The Claim

In male bodybuilders performing maximal isometric knee extensions, variations in rectus femoris muscle stiffness caused by changes in hip and knee joint angles are not detected by surface electromyography (EMG), which shows no regional or angular differences, indicating that surface EMG may fail to capture regional mechanical changes in muscle activation patterns.

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 bodybuilders push hard with their legs, the stiffness in a key thigh muscle changes depending on leg position—but the usual muscle activity sensors (EMG) don’t pick up these differences, suggesting they might miss some real muscle behavior.

See the scientific wording

In male bodybuilders performing maximal isometric knee extensions, changes in rectus femoris muscle stiffness due to hip and knee joint angles are not reflected in surface electromyography (EMG) readings, which show no regional or angular differences, suggesting that EMG may not capture regional mechanical variations in muscle activation.

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 found that the muscle stiffens differently depending on leg position, but the electrical activity measured by EMG doesn’t show these differences, meaning EMG might miss some mechanical details.

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

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