Do the knee flexors or knee extensors produce a greater torque?

Do the knee flexors or knee extensors produce a greater torque?

• A. Knee Extensors
• B. Knee Flexors
• C. Both produce equal torque
• D. None produce torque

Answer: (A)

Torque at the knee is determined by how much force a muscle can produce and how effectively that force rotates the joint (the moment arm). The knee extensors, mainly the quadriceps, are a large muscle group with a larger cross-sectional area, so they can generate more force. In addition, the patellar tendon acts like a pulley that lengthens the quadriceps’ moment arm, making each unit of muscle force produce more rotational effect about the knee. The knee flexors (hamstrings) are smaller and have a shorter moment arm, so even at their best they produce less torque. Because of these factors, the extensor mechanism typically generates greater knee torque across the range of motion, even though both muscle groups contribute to knee movement.

Torque at the knee is determined by how much force a muscle can produce and how effectively that force rotates the joint (the moment arm). The knee extensors, mainly the quadriceps, are a large muscle group with a larger cross-sectional area, so they can generate more force. In addition, the patellar tendon acts like a pulley that lengthens the quadriceps’ moment arm, making each unit of muscle force produce more rotational effect about the knee. The knee flexors (hamstrings) are smaller and have a shorter moment arm, so even at their best they produce less torque. Because of these factors, the extensor mechanism typically generates greater knee torque across the range of motion, even though both muscle groups contribute to knee movement.