Standing Leg Curl

The leg curl is the only exercise in which you can isolate the hamstrings (and the weaker sartorius) from other muscle groups. The hamstrings perform the function of bending the knee, assisted by the weaker sartorius muscle.

This variation uses a machine that allows you to perform the exercise standing. You therefore perform it with one leg.

Standing leg curl execution

Bring your heel toward your buttocks until you cannot go any further. Avoid allowing your thigh to move with the movement; keep it pressed against the machine.

Hold the tension briefly.

Return your foot downward and forward in a controlled manner, stopping when your leg is almost straight.

Repeat with the same leg.

Standing leg curl setup

(also see the instructions on the machine):

Stand up and check the height of the platform where your feet are placed and the foot pad. Your knees should be level with the machine's pivot point. The foot pad should be at ankle height or slightly higher.

Standing leg curl technique

Try to perform the exercise through the entire range of motion. Therefore, do not use too much resistance/weight, causing only the final part of the exercise to be completed.

The position of your foot can affect the relative involvement of the calves and which part of the hamstrings is loaded most.

Foot position and hamstrings

Pointing your toes outward can place more emphasis on the outer part of the hamstrings (biceps femoris). Pointing your toes inward places more emphasis on the two inner hamstring muscles (semimembranosus and semitendinosus).

This is due to the different attachment points (tibia and fibula).

Foot position and calves

The calf muscles consist of two different muscles, the gastrocnemius and soleus. The two heads of the gastrocnemius cross the knee joint and can therefore assist in bending the knee.

However, the position of the feet can affect the extent to which the gastrocnemius can assist. Like an already lengthened muscle, an already shortened muscle cannot produce maximum effort. If, during the leg curl , you point your toes toward your knees or push them downward, the gastrocnemius cannot therefore exert fully. Keep your feet in a neutral position (as when standing upright) to engage it maximally.

Seated vs. Lying and Standing

Whether you perform leg curls lying, standing, or seated makes a difference to the involvement of the different muscles that make up the hamstrings. The hamstrings are three muscles, one of which has two heads. That makes three muscles with four heads. At the bottom (distally), all three muscles cross the knee joint. At the top (proximally), however, only three of the four heads cross the hip joint. The fourth head is connected to the femur, while the other three attach to the ischium. This means, among other things, that only this fourth head is not stretched when, for example, you lift your knee or try to touch your toes.

This fourth head is one of the two heads of the biceps femoris, the most laterally located muscle of the hamstrings (and its outer head).

What does this mean?

In the seated variation, the two inner hamstring muscles and the inner head of the biceps femoris are already slightly stretched. As a result, they cannot exert fully ('passive insufficiency'). The outer head of the biceps femoris is the only one that can, because it is not affected by flexion at the hip.

This is not the case in the lying and standing positions, and the workload is more evenly distributed across all heads.