Research

Mixed

Ultrasound-measured muscle thickness (MT) is a valid and reliable proxy for MRI-measured anatomical cross-sectional area (ACSA) at a specific site (mid-thigh) following resistance training, but it does not accurately predict changes in total muscle volume (VOL) due to regional hypertrophy.

If you are tracking muscle growth using ultrasound, measure muscle thickness at the mid-thigh (50% of femur length). It is a reliable indicator of local muscle area growth after 12 weeks of resistance training. However, do not assume this thickness increase equals a proportional increase in your total leg volume, as muscles grow unevenly (regionally).

GoodQualifiesHIGH confidence
These data support evidence that MT is a reliable index of muscle ACSAmid and VOL at a single time point. MT changes following RT are associated with parallel changes in muscle ACSAmid but not with the changes in VOL, highlighting the impact of RT on regional hypertrophy.
Martino V. Franchi et al. · Scandinavian Journal of Medicine and Science in Sports · 2017

Why this rating

Small sample size (N=9) but rigorous within-subject design with gold-standard MRI validation.

Source

Muscle thickness correlates to muscle cross‐sectional area in the assessment of strength training‐induced hypertrophy

Martino V. Franchi et al. · Scandinavian Journal of Medicine and Science in Sports · 2017

DOI 10.1111/sms.12961

rct · n=9Cited 302×
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DOI resolved against Crossref · corpus check 2026-06-10

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