Leg Muscles

Quadriceps - Thighs

Quadriceps/Thighs

The thighs or quadriceps are a four-headed muscle located on the front of the upper leg. Your quadriceps femoris are among the largest and strongest muscles in your body. Its primary function is hip flexion/extension and knee extension/flexion. During movements such as butt kicks, the quads are stretched (extension) as the feet and thigh are lifted behind the body. And contracted (flexion) during leg movements in front of the body, where the muscle is shortening and contracting like front kicks or leg raises. The quads and hamstrings work together in each movement, while the quad’s contract the hamstrings will be in flexion and vice versa.

Vastus Lateralis

This muscle connects your thigh bone to your kneecap. It’s the largest of your quadriceps muscles and it runs down the outside/lateral meaning lateralis side of your thigh.

Vastus Medialis

This Muscle also connects your thigh bone to your kneecap, but this muscle runs on the inside of your thigh, medialis meaning middle.

Vastus Intermedius

This is the third quad muscle that is involved with supporting your knee and connecting your thigh bone to your kneecap and is located in between the other two (intermedius meaning middle).

Rectus Femoris

This muscle attaches at your hip bone and runs along the front of your leg and connects to your kneecap.

If your quads are tight this will cause an anterior tilt (your pelvis tilts down towards the floor often causing you to stick your tummy out) which contracts and tightens your hamstring as your body works to balance the forward tilt your tight quads have created. This can also cause knee, shin and ankle pain.

Hamstrings - Back of Thighs

Hamstrings – Back of Thighs

The hamstrings are located behind your thighs, on the back of the upper leg, and are composed of three muscles: semitendinosus, semimembranosus, and biceps femoris. The primary function of the hamstrings is hip extension/flexion and knee extension/flexion. The hamstrings are highly involved in explosive lower body movements such as sprinting, jumping, and even walking.

Semitendinosus

This is the longest muscle of the three and crosses both hip and knee joints, attaching at the bottom of the pelvis to the top of your main lower leg bone tibia. This muscle has a major postural role as it is responsible for internally rotating the thigh and leg bones and stabilizing your pelvis.

Semimembranosus

This works alongside the semitendinosus muscle and is also attached from the bottom of your pelvis to your lower leg shin bone (Tibia). Helping with posture and hip extension and knee flexion.

Bicep Femoris

This muscle attaches from the pelvis to the fibula, a bone attaching the knee and the ankle.

Tight hamstrings are often caused from sitting for long periods of time such as at work or on the computer and also running. This can cause the hips and pelvis to rotate back, flattening the lower back and causing back, knee and foot pain. Tight hamstrings can also cause postural problems, tight hamstrings can pull the pelvis out of normal position.

Calves

Have you ever had pain in your feet or feel restricted in your foot and ankle movements, like getting down low in squats? This could be due to tight calf muscles and hamstrings. Your gastrocnemius and soleus are the muscles that make up your calf, and they are located on the back of the lower leg. These muscles are responsible for plantarflexion in your foot and ankle and are largely used in movements such as jumping, running and even walking.

If you notice your heel is rising and your weight is shifting to the balls of your feet this may indicate that your calf and hamstrings are tight and need extra stretching. Tight calves can also put the smaller muscles behind the shin to overwork, causing shin splints.

Gastrocnemius

This muscle connects your thigh bone to your kneecap. It’s the largest of your quadriceps muscles and it runs down the outside/lateral meaning lateralis side of your thigh.

Soleus

This Muscle also connects your thigh bone to your kneecap, but this muscle runs on the inside of your thigh, medialis meaning middle.

Safety and Precautions

If you have knee pain or are recovering from surgery, you may want to avoid exercises like lunges until you’re healed. Ask your doctor, physical therapist, or trainer for suggestions, modifications, or similar moves you can add to your workout as you rehabilitate and heal.

As always, it’s a good idea to chat with your doctor before you start a new workout or add a new exercise to your routine.