Relative strengths of the calf muscles based on MRI volume measurements.
BACKGROUND
In 1985, Silver et al. published a cadaver study which determined the relative order of strength of the muscles in the calf. Muscle strength, which is proportional to volume, was obtained by dissecting out the individual muscles, weighing them, and then multiplying by the specific gravity. No similar studies have been performed using {\it in vivo} measurements of muscle volume.


METHODS
Ten normal subjects underwent 3-Tesla MRI's of both lower extremities using non-fat-saturated T2 SPACE sequences. The volume for each muscle was determined by tracing the muscle contour on sequential axial images and then interpolating the volume using imaging software.


RESULTS
The results from this study differ from Silver's original article. The lateral head of the gastrocnemius was found to be stronger than the tibialis anterior muscle. The FHL and EDL muscles were both stronger than the peroneus longus. There was no significant difference in strength between the peroneus longus and brevis muscles.


CONCLUSIONS
This revised order of muscle strengths in the calf based on in vivo MRI findings may assist surgeons in determining the optimal tendons to transfer in order to address muscle weakness and deformity.
Mercy Medical Center, Institute for Foot and Ankle Reconstruction, Baltimore, MD 21202, USA. cjengmd@yahoo.com
Clifford L
CL
Jeng
Gaurav K
GK
Thawait
John Y
JY
Kwon
Antonio
A
Machado
James W
JW
Boyle
John
J
Campbell
John A
JA
Carrino
D000328:Adult; D006801:Humans; D021621:Imaging, Three-Dimensional; D007866:Leg / Q000033:anatomy & histology / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology*