What Muscles Are Responsible for Walking Upstairs?

Stair climbing is effective for cardiovascular fitness and leg muscle strengthening. You must use the muscles of the hip, thigh and leg to bend your hip and knee as your foot rises up to the step, then to straighten the leg and plantar flex the foot to get ready for the next step.

Bending Your Hip

Your hip flexors bend your hip and raise your thigh upward as you lift your foot up. Most of the work is done by the iliospoas and rectus femoris muscles, but the pectineus, sartorius and tensor fascia latae help as well. The iliospoas is made up of two muscles: the psoas major and the illiacus. They run from the the hip bone and low back bones to the front of your thigh bone. The rectus femoris is part of the quadriceps femoris. It’s attached to the hip bone and runs in front of the thigh to the knee where it attaches to the quadriceps tendon with the other quadriceps muscles.

Bending Your Knee

Your knee flexors bend your knee as you raise your foot up to the step. The hamstring muscles do most of the flexing, but a leg muscle called the popliteus helps. The hamstrings include four muscles: semitendinosus, semimembranosus and the long and short heads of the biceps femoris. The short head of the biceps femoris starts on the thigh bone, but the other three attach to the bottom and back part of the hip bone. All four run down the back of your thigh to attach to the tibia and fibula, which are the bones of the lower leg.

Straightening Your Leg

You extend your hip and knee as you straighten your leg. The hip extensors include the gluteus maximus and three of the hamstring muscles: semitendinosus, semimembranosus and the long head of the biceps femoris. Your gluteus maximus forms the rounded part of your buttock as it runs from the hip bone to the thigh bone. The quadriceps femoris muscles extend your knee.

Plantar Flexion

Plantar flexion is the the movement you make as you push the ball of your foot into the step and raise your heel up. Two calf muscles plantar flex your ankle: the gastrocnemius and the soleus. The gastrocnemius attaches to the bottom of the thigh bone, and the soleus muscle attaches to the tops of the tibia and fibula. The muscles merge to form the Achilles tendon that attaches to the back of your heel. Three muscles that run from the leg bones to the toes also help plantar flex the ankle. They are the flexor hallucis longus, the flexor digitorum longus and the tibialis posterior.