The Calf Muscles

The upper calf muscles are located on the posterior (rear) of the lower leg just underneath the knee joint. They originate at the bottom of the femur, just above the knee joint, and extend down into the Achilles tendon.

The primary actions of the upper calf muscles are to plantar flex the ankle joint and flex the knee. The superficial gastrocnemius has two heads and crosses two joints; the knee and the ankle. It is part of the composite muscle known as triceps surae, which forms the prominent contour of the calf.

The triceps surae comprises: gastrocnemius, soleus, and plantaris. Gastrocnemius is quite a thin muscle when compared to the thick soleus. As well as plantar flexing the ankle, gastrocnemius assists in flexion of the knee joint, and is a main propelling force in walking and running. Explosive sprinting, for example, may rupture the Achilles tendon at its junction with the muscle belly of gastrocnemius, hence the need to keep it well stretched. Plantaris is a small muscle, which is a weak plantar flexor of the ankle, but plays an important neurological role in assessing and adjusting the tension in the Achilles tendon. The long slender tendon of plantaris is equivalent to the tendon of palmaris longus in the arm. Interestingly, plantaris is thought to be what remains of a larger plantar flexor of the foot.

Sports that benefit from upper calf stretches include: basketball and netball; boxing; cycling; hiking, backpacking, mountaineering and orienteering; ice hockey and field hockey; ice-skating, roller-skating and inline skating; martial arts; racquet sports like tennis, badminton and squash; running, track and cross-country; running sports like football, soccer, American football (gridiron) and rugby; snow skiing and water skiing; surfing; swimming; walking and race walking.

The lower calf muscles are located on the posterior (rear) of the lower leg below the knee joint. They originate at the top of the tibia, just below the knee joint, and extend down into the Achilles tendon. The primary action of the lower calf muscles is to plantar flex the ankle joint. Peroneus (fibularis) longus and peroneus (fibularis) brevis form the lateral compartment of the lower calf. Both these muscles act as plantar flexors and everters at the ankle joint, but also as preventers of inversion and protectors against ankle sprain. The course of the tendon of insertion of peroneus (fibularis) longus helps maintain the transverse and lateral longitudinal arches of the foot. Flexor digitorum longus, flexor hallucis longus, and tibialis posterior form the deep posterior compartment of the lower leg.

Tibialis posterior is the deepest muscle and helps maintain the arches of the foot. Flexor hallucis longus helps maintain the medial longitudinal arch of the foot. Part of the triceps surae, soleus is so-called because its shape resembles a fish. It is deep to gastrocnemius, but its medial and lateral fibres bulge from the sides of the leg and extend further distal than gastrocnemius. As well as help to plantar flex the ankle, soleus assists in flexing the knee. Constant wearing of high-heeled shoes tends to cause this muscle to shorten, which can affect postural integrity.

Sports that benefit from lower calf stretches include: basketball and netball; boxing; cycling; hiking, backpacking, mountaineering and orienteering; ice hockey and field hockey; ice-skating, roller-skating and inline skating; martial arts; racquet sports like tennis, badminton and squash; running, track and cross-country; running sports like football, soccer, American football (gridiron) and rugby; snow skiing and water skiing; surfing; swimming; walking and race walking.