Origin: At the posterior surface of the medial and lateral epicondyles of the femur (thigh bone). Insertion: Into the Achilles tendon, that inserts into the tuberosity of the calcaneus (on the bottom of the heel). Function: The gastrocnemuis is the third strongest muscle in the body after the gluteus maximus and quadriceps. Its primary function is plantar flexion of the foot (point the toes), but it can assist the hamstrings with approximately 19% of the flexion of the knee. When the knee is fully extended, the gastrocnemius works at it’s best advantage (due to it being passively stretched in this position). During straight-legged toe raises it will do nearly 90% of the work because of it’s greater size and strength over the soleus. When the knee is bent, the gastrocnemius loses it’s strength efficiency, because the muscle tension decreases. In the seated-heel-raise (knees bent at 90 degrees) the soleus does approximately 80% of the work.
Origin: At the upper one-third of the posterior shaft of the fibula (smaller lower leg bone behind the tibia (shin bone), middle one-third of the medial border of the tibia and the popiteal line. Insertion: The soleus joins with the fibers of the gastrocnemius to insert into the Achilles tendon. Function: The soleus’ main function is plantar flexion of the foot. The soleus functions in all positions of the knee during exercise, climbing, jumping and running, but it is considerably weaker and smaller in relationship to the gastrocnemius and does not do much of the work until the knee is bent at 90 degrees. The soleus is a broad flat muscle that lies under the gastrocnemuis.
Indication of Weakness
Weakness in the calf can cause a person to stand with an anterior lean, due to the calf not having enough strength to keep the body upright. After surgery, for a ruptured Achilles tendon, the patient will probably be unable to rise up on their toes. Remember: Both the gastronemius and the soleus insert into the Achilles tendon.
Optimum Training Principals
Arguably the best calf exercise is the “donkey calf raise” though this position can be simulated in the leg press machine and “selectorized calf machines” that put the torso flexed at approximately 90 degrees to the legs. The knees remain straight; the torso is simply bent at the waist. Larry Scott, the first Mr. Olympia and greatest bodybuilder of his generation, made the discovery on why this is such an effective exercise for the gastrocnemius. The hamstrings circle around the outside and under the heads of the gastrocnemius, before the hamstring inserts into the tibia and fibula (lower leg bones). Bending over stretches the hamstrings and therefore stretches the gastrocnemius. The more the gastrocnemius stretches, the more tension is on it, and the stronger it becomes and therefore increases the effectiveness of the exercise. The standing calf raise with the knees straight during both the concentric and eccentric phase would be the second best exercise behind the “donkey calf raise”. The seated calf raise (knees bent at 90 degrees) takes the stress off the gastrocnemius and requires the soleus to do the work. Larry Scott also suggests that athletes perform their calf raises in their bare feet. This is so you can work the Flexor Digitorum, Flexor Hallucis Longus and Peroneus Brevis. Most athletes find this painful. If you are going to attempt this, I recommend you use all toes, except the pinky toe. This is because the Peroneus Brevis inserts at the base of the fifth metatarsal (pinky toe). This muscle is located on the back of the lower leg and bodybuilders and ladies looking to develop their lower legs are generally looking for size in the upper calf and small, lean ankles (that’s why ladies wear high heels, to flex the calf, bunching all the muscle fibers up high and leaving the ankle looking tiny). Since the Peroneus Brevis is on the lowest one third on the leg, it will made your ankles look thicker, giving you “CANKLES” and destroying the lean ankle look bodybuilders and figure models strive for. Note: “CANKLES” are when the lower leg looks like a stove pipe and you can’t tell where the calf begins and the ankle ends! Bodybuilders are not allowed to wear high-heels during competition, which seems a little unfair since the guys spend all that time shaving their legs. Heel raises when pushing up on the big toe will activate the “flexor hallus longus” which is located laterally under the gastrocnemius and inserts under the big toe. When it comes to working the smaller muscles of the calf group, you will need to focus on your toes. Many of the smaller calf muscle have their insertions on the phalanges (toe bones) or the metatarsals. The most effective way to work these muscles is to focus on pushing with the toes. The most effective way to focus on the toes is to do your calf raises in your bare feet, toes only on the platform, feet angled inward (forces some inversion so you can focus on pushing with the little toe) or feet angled outward (forces some eversion so you can focus on pushing with the big toe). Notes: If you’re worried about shape, you might want to leave the pinky toe out of the exercise. The peroneus brevis has it’s insertion on the fifth metatarsal and will “thicken the ankle” when it gains size. It is located laterally and low at the ankle. The peroneus longus is located laterally under the gastrocnemius and inserts under the foot first cuneiform and base of the first metatarsal and flexes the big toe. The flexor digitorum longus is located laterally and under the gastrocnemius and inserts under the base of the third phalange (of the second through the fifth toes). The flexor hallus longus is located laterally under the gastrocnemius and inserts under the base of the terminal phalange of the big toe and flexes the big toe. The tibialis posterior has it’s origin on the middle one-third of the posterior lateral surface of the tibia and middle one-third of the posterior medial surface of the fibula. It’s location, on most people, tends to be slightly lateral of center under the gastronemius. It inserts into the first second and third cuneiformis and the second and third metatarsals. You can work it by toe raises from the first (big toe) second and third toes. Dorsal flexion (lifting the toes and foot upward and extension and hyperextension of the toes (flexing the toes upward – toe nails toward knee) work the tibialis anterior and other extensor muscles in the lower leg. These muscles should not overlooked, particularly in runners, who need the conditioning to prevent lower leg, ankle and foot injuries. The extensor muscles can be worked on foot extensor machines or by using a weight or tubing to resist the foot and/or toes while doing dorsal flexion of the ankle/foot/toes. Sincerely, Dr. Jim Bell, CEO IFPA