Did you know that most of the muscles that control the movement of your foot are actually located in your lower leg? Learn about the muscles below the knee that control the feet and toes in this lesson.
Movement, we all depend on it to survive.
We depend on our skeletal or voluntary muscles to get us from one spot to another, and we depend on our involuntary or smooth muscles to breath and digest – and even our heart is a muscle, without which, we wouldn’t be alive! And, while we have tons of muscles in our bodies, the ones most responsible for getting us from one place or position to another are those found in our legs.If you’ve been following some of our other lessons on anatomy, you have probably already learned about the leg muscles located above the knee. So, for this lesson, we are going to go through some of the main muscles located below the knee.
These muscles are used in the movement of the ankle, feet and toes.
The Knee Muscle
So, let’s get started at the patella (that’s your knee cap).
The popliteus muscle kind of has its own category; it’s neither below nor above, but is located at the knee. This muscle allows you to unlock your knee during flexion of the leg.Flexion of a body part – in this case your lower leg – is a bending motion at a joint that decreases the angle between the two bones on either side of the joint.
The opposite of flexion is extension, which usually involves the straightening of a bent joint, increasing the distance between the bones on either side of the joint. So, flexion of the knee brings the lower leg closer to the upper leg. This movement is aided by the popliteal muscle of the knee. It wraps around the back of the knee, helping to stabilize your knee joint.
When your legs are moving, like running or walking, the popliteus rotates the tibia bone inward, helping to initiate flexion at the knee.
Other than the popliteus, all other muscles below the knee are connected to the foot. They can be divided into three general groups:
- Muscles that flex or extend the foot
- Muscles that flex and extend the toes
- Muscles that support the structure of the foot
Movements of the Foot
Let’s start with those that flex and extend the foot.
These muscles are located above, along the tibia and fibula of the lower leg. The movement and structure of your foot is probably more complex than you may have thought. While they don’t have all the dexterity that your hands do, they can still move and rotate in multiple directions requiring the use of many muscles. The coordination of all the muscles in your feet and toes is essential to keep you walking upright, to allow you to dance or to dribble a soccer ball.We won’t get into all those muscles here, but we will cover the general function of the muscles that move the foot. So, let’s start with an exercise.
Put your right leg out in front of you so your foot isn’t touching the floor. Now, pull the toes of your right foot toward the front of your body. This movement is called dorsal flexion. Now, point your foot and toes back, as far you can towards the floor. This movement is called plantar flexion.
Most of the muscles that move your ankle and foot are extensors and produce plantar flexion. I know, the terms sound confusing, I mean, ‘an extensor produces flexion?’ But, if you think about the movement itself and not the name, you will see you are actually extending your foot and ankle away from your body.These muscles are also involved in other movements of your foot called eversion and inversion. So, let’s go back to our exercise.
Are your feet out in front of you? Now, twist your right foot so that the underside is facing the left foot. This action is called foot inversion. So, inversion turns your foot inward.
Now, rotate your foot in the other direction, like you are trying to face the bottom of your foot outward towards your right side. This movement is called foot eversion and is the opposite movement of foot inversion. These movement help you make adjustments in your posture so that you don’t fall over.
Muscles of the Foot
These movements are performed by the same sets of muscles that allow dorsal and plantar flexion. Most of these muscles originate on the shaft of the tibia or fibula of the lower leg, those bones below. They travel down to your leg and insert into the tendons or bones in your ankle and foot.
The most well-known and strongest of these tendons is commonly called the Achilles tendon – for the Greek hero Achilles – but its actual name is the calcaneal tendon. This tendon is the insertion point for two of the largest muscles of the calf. The first is the gastrocnemius muscle. This muscle is important in plantar flexion, allowing you to lift your heel when walking, running and jumping. Underneath it lies the soleus muscle, which, in addition to plantar flexion, continually adjusts your posture when standing and moving.These two are helped out by other, smaller muscles, called deep extensors, which are located underneath and to the side of the soleus and gastrocnemius muscles.
On the front of your lower leg is another large muscle called the tibialis anterior (anterior because of its location at the front). This is the opposite of the gastrocnemius muscle and, therefore, is the main muscle responsible for dorsal flexion of the foot.
|Simply composed of lengths of collagen fibers