Plantarflexor torque and work is positively correlated with medial gastrocnemius fascicle length in healthy adults

In this study, we determined the relationship between muscle architecture and peak torque and total work produced by the plantarflexors during maximal effort isokinetic contractions. We measured resting fascicle length and pennation angle and calculated muscle thickness in the medial gastrocnemius using ultrasound in healthy adult subjects (n=12). Subjects performed maximal effort isokinetic contractions on an isokinetic dynamometer at 0, 30, 120 and 210 °/s. We calculated peak torque and total work at each velocity and used linear regression to examine the relationship relating fascicle length, pennation angle, and muscle thickness to peak torque and total work. We found that fascicle length was more strongly correlated with both peak torque and total work than pennation angle or muscle thickness. This provides experimental evidence linking resting muscle architecture to dynamic muscle performance in healthy adults which has been hitherto not experimentally demonstrated in existing literature.