Gastrocnemius Essay, Research Paper

Gastrocnemius Origin: 1.medial head: posterior surface of the medial femoral condyle 2.lateral head: posterior surface of the lateral femoral condyle Insertion: posterior surface of the calcaneus (Achilles tendon) Action: 1.plantar flexion the ankle 2.knee flexion (when not weight bearing) Nerve: tibial nerve, S1,2Application, strengthening & flexibility: Because the gastroc. Is a biarticular muscle, it is more effective as a knee flexor if the ankle is dorsiflexed and more effective as a plantar flexor of the foot. When the knees are bent, the muscle becomes an ineffective plantar flexor. Running, jumping, hopping, and skipping exercises all depend on the gastroc and soleus to propel the body upward and forward.  Heel raising exercises with the knees in full extension and the toes resting on a block of wood are an excellent way to strengthen the muscle through the full range of motion.  The gastroc may be stretched by performing a wall push-up. Soleus Origin: Posterior surface of the proximal fibula and proximal 2/3 of the posterior tibial surface Insertion: posterior surface of the calcaneus Action: plantar flexion the foot Nerve: tibial nerve, S1,2Application, strengthening & flexibility: The soleus is stretched in the same manner as the gastroc except that the knees must be flexed slightly, which releases the stretch on the gastroc and places it on the soleus. Again it is important to keep the heels on the floor. Tibialis posterior Origin: 1.posterior surface of the upper half of the interosseus membrane and adjacent surfaces of the tibia and fibula. Insertion: 1.Lower inner surfaces of the navicular and cuneiform bone and bases of the second, third, fourth, and fifth metatarsal bones. Action: 1.Plantar flexion of the ankle 2.inversion of foot Nerve: tibial nerve, L5,S1Application, strengthening & flexibility: ?Shin Splints? is a slang term frequently used to describe an often chronic condition in which the tibialis posterior, tibialis anterior, and extensor digitorum longus muscles are inflamed.  Sprints and long-distance running are common causes, particularly if the athlete has not developed appropriate strength, flexibility, and endurance in the lower leg musculature. The tibilias posterior may be stretched by passively taking the foot into extreme eversion and dorsiflexion while the knee is flexed. Flexor digitorum longus Origin: 1.middle 3rd posterior surface of tibia Insertion: bases of the 2-5th distal phalanges Action: 1.primarily flexes 2nd – 5th toes 2. plantar flexion of ankle 3.inversion of foot Nerve: tibial nerve, L5,S1Application, strengthening & flexibility: It may be strengthened by performing towel grabs against resistance in which the heel rests on the floor while the toes extend to grab a flat towel and the flex to pull the towel under the foot. This may be repeated numerous times, with a small weight placed on the opposite side of the towel for added resistance.  The flexor digitorum longus may be stretched by passively taking the four lesser toes into extreme extension while the foot is everted and dorsiflexed. The knee should be flexed. Flexor hallucis longus Origin: 1.middle 2/3 of the posterior surface of fibula Insertion: Base of the distal phalanx of the big toe, under the surface Action: 1.flexes big toe (hallux) 2.plantar flexion of the ankle 3.inversion of foot Nerve: tibial nerve, L5,S1,2Application, strengthening & flexibility: Running, walking, jumping, hopping, and skipping provide exercise for this muscle group. The flexor hallucis longus muscle may be specifically strengthened by performing towel grabs as described for the flexor digitorum longus. The flexor hallucis longus may be stretched by passively taking the great toe into extreme extension while the foot is everted and dorsiflexed. The knee should be flexed. Peroneus longus Origin: 1.head and upper 2/3 of the lateral surface of the fibula Insertion: 1.undersurfaces of the medial cuneiform and first metatarsal bones Action: 1.eversion of the foot 2. plantar flexion of the ankle Nerve: superficial peroneal nerve, L4,5,S1Application, strengthening & flexibility: Eversion exercises to strengthen this muscle mat be performed by turning the sole of the foot outward while resistance is applied in the opposite direction. The Peroneus longus may be stretched by passively taking the foot into extreme inversion and dorsiflexion while the knee is flexed. Peroneus brevis Origin: 1.lower 2/3 of lateral fibula Insertion: tuberosity of 5th metatarsal Action: 1.eversion of the foot 2. plantar flexion of foot Nerve: superficial peroneal nerve, L4,5,S1 Peroneus tertius Origin: 1.distal 1/3 of anterior fibula Insertion: base of 5th metatarsal Action: 1.eversion of the foot 2.dorsal flexor of the ankle Nerve: deep peroneal nerve, L4,5,S1 Tibialis anterior Origin: 1.upper 2/3 of the lateral surface of the tibia Insertion: 1.inner surface of the medial cuneiform and the 1st metatarsal Action: 1. dorsiflexor of the ankle 2.inverts the foot Nerve: deep peroneal nerve, L4,5,S1Application, strengthening & flexibility: Turning the sole of the foot inside against resistance to perform inversion exercises is one way to strengthen this muscle. Dorsal flexion exercises against resistance may also be used for this purpose.  Tibialis anterior may be stretched by passively taking the foot into extreme eversion and plantar flexion Extensor digitorum longus Origin: 1.lateral condyle of the tibia 2.head of the fibula 3.upper 2/3 of the anterior surface of the fibula Insertion: 1. tops of the middle & distal phalanxes of the 2nd-5th toes Action: 1.extends the lateral 4 toes 2.dorsiflexor of the ankle Nerve: deep peroneal nerve, L4,5,S1Application, strengthening & flexibility: Action that involves dorsal flexion of the ankle and extension of the toes against resistance strengthens both the extensor digitorum longus and the extensor hallucis longus muscles. This may be accomplished by manually applying downward force on the toes while attempting to extend them up. The extensor digitorum longus may be stretched by passively taking the four lesser toes into full flexion while the foot is inverted and plantar flexed. Extensor hallucis longus Origin: 1.medial 2/3 of the medial surface of the anterior fibula Insertion: base of distal phalanx of big toe Action: 1.extends distal phalanx of big toe 2.dorsiflexor of the ankle 3.weak inversion of the foot Nerve: deep peroneal nerve, L4,5,S1Application, strengthening & flexibility: The three dorsiflexors of the foot ? tibialis anterior, extensor digitorum longus, and extensor hallucis longus ? may be exercised by attempting to walk on the heels with the ankle dorsiflexed against resistance, will provide strengthening for this muscle. The extensor hallucis longus may be stretched by passively taking the great toe into full extension while the foot is everted and plantar flexed.