Measuring In Vivo Skeletal Muscle Force

Skeletal muscle force in vivo was determined as described previously^{48 (link)}. Briefly, mice were anesthetized by intraperitoneal injection of xylazine (Xilor; 20 mg/kg) and Zoletil (10 mg/kg). Z small incision was made from the knee to the hip, to expose the sciatic nerve. Before the branch of the sciatic nerve, Teflon-coated 7 multi-stranded steel wires (AS 632; Cooner Sales, Chatsworth, CA, USA) were implanted with sutures on either side of the sciatic nerve. To avoid recruitment of the ankle dorsal flexors, the common peroneal nerve was cut. Torque production of the plantar flexors after nerve stimulation was measured using a muscle lever system (Model 305 C; Aurora Scientific, Aurora, ON, Canada). Normalized muscle force was determined by dividing absolute force by muscle mass.