In the weight-bearing leg, it brings the leg toward the back of the foot, like in rapid walking. The extensor digitorum longus arises on the lateral tibial condyle and along the fibula, and is inserted on the second to fifth digits and proximally on the fifth metatarsal. The extensor digitorum longus acts similar to the tibialis anterior except that it also dorsiflexes the digits. The extensor hallucis longus originates medially on the fibula and is inserted on the first digit. It dorsiflexes the big toe and also acts on the ankle in the unstressed leg. In the weight-bearing leg, it acts similarly to the tibialis anterior.Peroneal group: the peroneus longus arises on the proximal aspect of the fibula and peroneus brevis below it. Together, their tendons pass behind the lateral malleolus. Distally, the peroneus longus crosses the plantar side of the foot to reach its insertion on the first tarsometatarsal joint, while the peroneus brevis reaches the proximal part of the fifth metatarsal. These two muscles are the strongest pronators and aid in plantar flexion. The peroneus longus also acts like a bowstring that braces the transverse arch of the foot. Posterior group
The superficial layer of posterior leg muscles is formed by the triceps surae and the plantaris. The triceps surae consists of the soleus and the two heads of the gastrocnemius. The heads of gastrocnemius arise on the femur, proximal to the condyles, and the soleus arises on the proximal dorsal parts of the tibia and fibula.
Adverse effects
Adverse effects are relatively rare when used to treat the joints.When used in ophthalmological procedures, sodium hyaluronate may cause postoperative inflammation, corneal edema or decompensation, and short-term increases in intraocular pressure. Medical uses
Intra-articular injection
It is used to treat knee pain in patients with osteoarthritis who have not received relief from other treatments. It is injected into the joint capsule, to act as both a shock absorber and a lubricant for the joint. Thus sodium hyaluronate is used as a viscosupplement, administered through a series of injections into the knee, increasing the viscosity of the synovial fluid, which helps lubricate, cushion and reduce pain in the joint. It is generally used as a last resort before surgery and provides symptomatic relief, by recovering the viscoelasticity of the articular fluid, and by stimulating new production from synovial fluid. Use of sodium hyaluronate may reduce the need for joint replacement. Injections appear to increase in effectiveness over the course of four weeks, reaching a peak at eight weeks and retaining some effectiveness at six months, with greater benefit for osteoarthritis than oral analgesics. It may also be effective when used with the ankle joint. Intraocular viscoelastic injection
It is used as an aid in  ophthalmic surgery acting as aqueous and vitreous humor, e.g. in cataract extraction (intra- and extracapsular), intraocular lens implantation, corneal transplant, glaucoma filtration, and retina attachment surgery and in the treatment of dry eyes.