Physiology and Anatomy of Lower Limbs

The lower limbs, hips, thighs, knees, legs, ankles, and feet, are vital for walking, running, standing, and maintaining posture.

The femur (thigh bone), patella (knee cap), tibia (shin bone), fibula, and the bones of the foot.

The hip joint (ball-and-socket), knee joint (hinge), and ankle joint (hinge).

The hip joint is a ball-and-socket joint, allowing for a wide range of motion in all directions. It is responsible for movements like flexion, extension, abduction, adduction, rotation, and circumduction.

The knee joint is a hinge joint, allowing for flexion and extension movements like bending and straightening the knee.

The ankle joint is a hinge joint, allowing for dorsiflexion and plantarflexion movements, like pointing your toes up and down.

Muscle groups in the lower limbs include the quadriceps, hamstrings, gluteal muscles, calf muscles (gastrocnemius and soleus), and smaller muscles in the foot.

Different muscles work together to allow movement. Agonists are the muscles that are primarily responsible for a specific movement. Antagonists oppose the action of the agonist, helping control and stabilize the movement.

Slow-twitch muscle fibers support endurance and sustained contractions, while fast-twitch fibers provide strength and power for short bursts of activity.

Major arteries in the lower limbs include the femoral artery, popliteal artery, and tibial arteries. These arteries deliver oxygen-rich blood to the muscles and tissues of the lower limbs.

Veins in the lower limbs are responsible for returning deoxygenated blood back to the heart.

Venous valves within the veins prevent blood from flowing backwards.

Muscle contraction in the lower limbs acts as a pump, squeezing blood back to the heart, aiding return.

The sciatic nerve, femoral nerve, tibial nerve, and peroneal nerve are important nerves in the lower limbs.

The sciatic nerve, the largest nerve in the body, originates in the lower spine and branches out to control muscles and provide sensation in the legs, thighs, and feet.

The femoral nerve controls the muscles at the front of the thigh and provides sensation to the skin of the thigh and lower leg.

The tibial nerve, a branch of the sciatic nerve, controls muscles at the back of the lower leg and part of the foot.

The peroneal nerve, another branch of the sciatic nerve, controls muscles involved in lifting your foot and toes. It also provides sensation to parts of the foot.

Nerves communicate and control the muscles and sensation through electrical signals traveling to and from the spinal cord.

The nerves of the lower limbs are connected to the spinal cord. This connection is vital for transmitting messages between the brain and the lower limbs.

The gait cycle involves a series of movements that occur during walking or running. It includes the stance phase and swing phase.

The stance phase is when your foot is in contact with the ground. It is further divided into initial contact, loading response, midstance, terminal stance, and pre-swing.

The swing phase is when your foot is not in contact with the ground. It includes initial swing, midswing, and terminal swing.

Balance is the ability to maintain equilibrium or a stable body position. The lower limbs play a crucial role in balance by providing a base of support.

Posture refers to the alignment of the body's segments during standing, sitting, or lying down. The lower limbs play a key role in maintaining good posture.