LEG exercises
The main muscle groups responsible for movement of the lower body are: the quadriceps, the muscles that give the upper front leg its shape; the hamstrings, the equivalent muscle group at the back of the upper leg; the gluteal muscles, resting on the back of the pelvis; and the calves, at the back of the lower leg.
The main role of the quadriceps (or quads) is to extend the knee, with one division (rectus femoris) specifically also enabling hip flexion. Hamstrings, meanwhile, extend the hips and flex the knee. The glutes work to extend the hips, as well as aiding internal and external rotation of the leg at the hip. The calves mainly plantarflex the ankle and flex the knee.
Within lower-body training, multiple muscle groups combine to help coordinate movement around the hip, knee, and ankle joints.
When performing compound exercises (which involve more than one joint), you will be using muscles across the lower body to perform the movement while controlling the forces around each joint. Examples include back squats and deadlifts.
When performing isolation exercises (which involve only one joint), you will be biasing one muscle group over others. You still use other muscles though—to stabilize the forces around the working joint. Examples are leg extensions and calf raises.
n Double-tap image to read the labels
POSTERIOR VIEW
Gluteus medius
Fan-shaped muscle that extends the hip more laterally and rotates the leg
Gluteus maximus
One of the biggest muscles in the body; it extends the hip and rotates the leg
Adductor magnus
Known as an adductor of the hip but also acts as a powerful hip extensor
Vastus lateralis
Division of the quadriceps
Biceps femoris long head
The most lateral of the hamstrings, which extend the hip, flex the knee, and rotate the leg
Semitendinosus
A division of the hamstrings
Semimembranosus
A division of the hamstrings
Biceps femoris short head
A division of the hamstrings
Femur
The thighbone; the longest, strongest, and heaviest bone in the body
Gastrocnemius
Forms the major bulk of the calf; it has two heads and helps plantarflex the ankle and flex the knee
Soleus
Large, flat muscle lying beneath the gastrocnemius; its name comes from the Latin for sole or flatish
Achilles (calcaneal) tendon
This common tendon, shared between the gastrocnemius and soleus muscles, winds 90° on its path toward the heel
Fibula
A thin bone that sits on the outside of the lower leg
ANTERIOR VIEW
Iliopsoas
Formed of two merged muscles (psoas and iliacus), it flexes the hip
Tensor fascia latae
Often abbreviated to TFL, it helps stabilize the femur, alongside the hip and knee joints
Pectineus
Flexes and adducts the hip
Adductor longus
Fan-shaped muscle that is one of the adductor muscles
Gracilis
Long, thin, superficial muscle that aids in flexion and adduction at the hip and knee
Sartorius
Flexes, abducts, and laterally rotates the hip, and flexes the knee
Rectus femoris
Division of the quadriceps; flexes the hip and extends the knee
Vastus medialis
Division of the quadriceps
Patella
Also called the kneecap, attached to the quadriceps tendon
Tibialis anterior
Dorsiflexes the ankle
Peroneus (fibularis) longus
Moves the foot and ankle in various directions; its tendon wraps under the foot
Extensor digitorum longus
Extends lateral four digits and dorsiflexes the ankle
Flexor digitorum longus
Flexes the second to fifth toes and helps plantarflexion of the ankle
Extensor hallucis longus
Flexes the big toe and helps plantarflexion of the ankle
“Building muscle and strength in your legs can improve your performance across workouts.”