By: Gabrielle Dobbs
Motion:
Eversion is the movement of the foot when the sole of the foot is turned laterally or to the outside of the body. This movements occurs at the subtalar and transverse tarsal joints. The line of axis of these joints runs obliquely (diagonally) to the normal anatomical planes of movement. Because of this, eversion cannot happen on its own it is accompanied by abduction and dorsiflexion. The three movements of eversion, abduction and dorsiflexion create pronation of the foot.1The motion of eversion allows for stabilization while walking or running on uneven surfaces. The evertor muscle system helps in preventing injury during activities that involve walking, running, stepping, and other sports, especially on uneven surfaces.2
Muscles:
Primary:Fibularis (peroneus) Longus
Fibularis (peroneus) Brevis
Secondary:
Extensor digitorum longus (EDL)
Fibularis (peroneus) tertius34
Ligaments:
Anterior Talofibular Ligament (ATFL) which resists the foot going into inversion while the foot is in plantar flexion. Most commonly injured in lateral ankle sprains.Calcaneofibular Ligament (CFL) resists the foot going into inversion while the foot is in dorsiflexion. This is the second ligament most commonly injured in lateral ankle sprains.
Posterior Talofibular Ligament (PTFL) resists posterior talar displacement and external rotation while the foot is in dorsi flexion. This is the most difficult ligament in lateral ankle sprain to injure. Injury usually accompanied by a fracture of the talus and or fibula.56
Nerve Supply:
Innervation of eversion comes from the L5, S1 nerve roots which supply the superficial fibular nerve7
Mobilization
Normal range of motion for eversion of the foot is 25o.
Indications:
If the fibularis muscles are tight it can affect joints and muscles higher in the chain of the body including the knees, hips, and associated muscles. Stretching may also be beneficial after the ankle as been immobilized to regain range of motion. Another, benefit of stretching the evertors is to reduce over pronation of the foot.89
Stretches:
These stretches are in order of less aggressive to more aggressive. Stretches are typically performed by holding each stretch for 20-30 seconds and repeated three times. They can be performed through out the day and especially after activity that has stressed the affected muscles.
1. Using a band or towel wrapped around the arch of the foot. Pull the foot into eversion and dorsiflexion.
2. Using a step or slanted surface place foot on surface with toes turned in and lean into the stretch by bending leg.
3. In standing turn the foot inward (inversion) and allow weight through the outside part of the foot.
Strengthening
Weak fibularis muscles can make one more susceptible to lateral ankle sprains. Also, after one has suffered from a lateral ankle sprain they may perform the following exercise along with other ankle motions to rehabilitate the ankle and prevent future sprains.
These exercises are in order from least aggressive to more aggressive. Must start with the least aggressive and progress accordingly with ability and stage of healing of injury.
1. Windshield wipers (active eversion)
a. In sitting foot is flat on floor with toes facing straight. Begin turning toes to the outside so that the inside (medial) part of the foot is touching the ground. Then return to straight
b. Perform three sets of 10-15 repetitions, two to three times a day.
2. Eversion with a resistance band
a. Sit with injured leg straight and have resistance band held or tied medial to injured foot. Loop band around the balls of the foot with toes point straight in the air. Begin turning toes outward away from where is the resistance is being given then return to start position. Make sure to only move the foot and not allow the leg to guide the movement.
b. Perform three sets of 10-15 repetitions, two to three times a day.
3. Wobble board exercises (dynamic and static)
a. Stand on board on injured ankle hold on to a stable surface lightly for support. Move the board side to side so the edges of the board touch the ground.
b. Preform three sets of 10-15 repetitions or preform for time, one to two minutes
c. Again stand on board on injured ankle hold on to a stable surface lightly for support. Try to remain balanced with out letting the edges of the board make contact with the ground
d. Preform three sets until failure. Aim for completing two minutes.
10
Potential Clinical Syndromes or Etiologies
Lateral Ankle Sprains:
Occur when one lands on the ankle while it isn in inversion thereby putting stress on the lateral ankle ligaments and tendons.11
[[http://www.backtothebox.com/wp-content/uploads/inversion-ankle-sprain.jpg]]
Fibularis tendon tendonitis:
Occurs with repetitive stress to the fibularis longus and fibularis brevis. The stress can be from excessive standing or walking. It has also been found that certain foot shapes can predispose someone to developing tendonitis.12
Sinus Tarsi syndrome:
Occurs after time when there is an instability of the subtalar joint. This can occur from multiple ankle sprains.13.jpg)
Fracture:
Occurs with trauma to the fibula. Fractures can occurs anywhere along the fibula. The most common involve an avulsion to the distal fibula (the lateral malleolus), along the syndemosis line of the distal fibula, or along the shaft of the fibula.14
