Ratios of cross-sectional areas of muscles and their tendons in a healthy human forearm.
The muscles and tendons in the forearm and hand of a young man, amputated after an accident, have been weighed and measured. The physiological cross-sectional areas of those muscles that had long tendons were 35 +/- 9 (mean and standard deviation) times the cross-sectional areas of the tendons. The mean is very close to the optimum calculated from the theory of Ker, Alexander & Bennett (1988). It implies that the tendons experience stresses of about 11 MPa and strains of about 1.3%, when the muscles exert their maximum isometric forces. Very much larger forces would be needed to break the tendons.
Cutts
A
A
Rheumatism and Rehabilitation Research Unit, University of Leeds.
Alexander
R M
RM
Ker
R F
RF
D000328:Adult; D005542:Forearm / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D009132:Muscles / Q000033:anatomy & histology*; D009929:Organ Size; D013710:Tendons / Q000033:anatomy & histology*