Quadriceps are a group of anterior muscles that function as extensors of the knee. The anatomy of the quadriceps provides aid in daily leg activities such as walking, running and squatting. It facilitates the forward movement of the knees.
As the name suggests, there are four main leg muscles that this group contains. These are:
Vastus lateralis – Also known as the vastus externus. It is the largest and most powerful leg muscle in the quadriceps group and is found on the side of the thigh. Its job is to extend the lower leg and assist the body in standing up especially from squatting.
Vastus medialis – This is a teardrop-shaped muscle in the thigh that extends to the knee. It is the most medial among all those in the quads group which functions to extend the leg and stabilize the knee.
Vastus intermedius – This is the deepest among all the muscles in this group. It is located on the lateral upper surface of the femur. It functions to cover the front and side part of the femur.
Rectus femoris – This muscle attaches at the hip and reaches the kneecap. It is responsible for helping the extension and raising of the knee.
The hamstrings are posterior thigh muscles located in the middle of the hip and the knee and at the back of the upper leg. They help with the flexibility of the knee and extends the thigh to the rear side of the body. These muscles are essential in walking, running, and other leg activities.
Hamstrings are a group of muscles composed of three “strings”. These three muscles work together to allow the leg movements mentioned above. These hamstring muscles are:
Semimembranosus – This muscle is characterized by its flat tendon of origin. It is located deep into the semitendinosus and originates from the ischial tuberosity on the inferior pelvis.
Semitendinosus – This muscle is located in between the biceps femoris and semimembranosus. It is a long tendon of insertion which helps the two other latter muscles to produce dynamic movements.
This muscle group is also known as the “inner thigh muscles” and contains five muscles. They hold the thighs and the rest of the muscles together and function to stabilize and balance the movement of the body from left to right.
The five muscles included in the adductors muscle group are:
Adductor magnus – This is a large triangular muscle inside the thighs. Its two main parts are the pubofemoral portion (arising from the ischiopubic ramus) and the ischiocondylar portion (arising from the tuberosity of the ischium).
Adductor longus– This is a skeletal muscle that forms the medial wall of the femoral triangle. It is a hip abductor that helps manage the movement of the thigh bone inwards and sideways.
Adductor brevis– This muscle is deep within the adductor longus. It is the smallest and shortest among all the muscles in the adductor group and functions mainly to pull the thigh medially.
Obturator muscles – This is a flat triangular muscle covering the outer surface of the wall of the pelvis. It further consists of two muscles namely the obturator internus and obturator externus. The obturator externus functions to stabilize the head of the femur which helps in producing a balanced movement of the trunk.
Gracilis – This thin and flat muscle is found in the groin. It is the outermost external muscle of the inside of the thigh which functions to manage hip adduction and knee flexing.
4. Calf Leg Muscles
The calf muscles are the muscles that help pivot the ankles, toes, and feet. Here are some of the major muscles in the calves:
Gastrocnemius – This is also known as the calf muscle. This is one of the largest muscles of the leg and helps the foot, ankle, and toes to extend and flex. It is a very powerful muscle that contributes a large portion of the muscle group at the back portion of the lower leg.
Soleus– This is the muscle in the calf just below the gastrocnemius. It is located from below the knee to the heel and helps in stabilizing the legs while standing or walking. It provides powerful forces to the ankles and joints and connects the bones around the area.
5. Tibialis Anterior
The tibialis anterior is the muscle that is found in the shin and is responsible for the flexing of the ankle. It is located on the lateral side of the tibia and is the largest muscle in the anterior portion of the leg. Some of its functions include the dorsiflexion and inversion of the foot.
Do you want to learn more about leg muscles? Watch this video from AnatomyZone:
The leg muscles enable the different movements and activities of the lower part of the body. These muscles manage our daily leg activities such as standing, sitting, walking, running, etc. Knowing more about these muscles will help us understand how our body functions and how the different muscles work together to produce movement.
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