Tibialis Anterior

Original Editor - Daniele Barilla

Top Contributors - Daniele Barilla, Joao Costa, Kim Jackson, Ahmed Nasr, Nikhil Benhur Abburi, George Prudden, Evan Thomas, Oyemi Sillo, WikiSysop and Simisola Ajeyalemi;

Description

The Tibialis anterior (Tibialis anticus) is situated on the lateral side of the tibia; it is thick and fleshy above, tendinous below. The fibers run vertically downward, and end in a tendon, which is apparent on the anterior surface of the muscle at the lower third of the leg. This muscle overlaps the anterior tibial vessels and deep peroneal nerve in the upper part of the leg.

Variations.—A deep portion of the muscle is rarely inserted into the talus, or a tendinous slip may pass to the head of the first metatarsal bone or the base of the first phalanx of the great toe. The Tibiofasdalis anterior, a small muscle from the lower part of the tibia to the transverse or cruciate crural ligaments or deep fascia.

Origin

It arises from:

• Lateral condyle and upper half or two-thirds of the lateral surface of the body of the tibia;
• Adjoining part of the interosseous membrane;
• Deep surface of the fascia;
• Intermuscular septum between it and the Extensor digitorum longus.

Insertion

Medial and under surface of the first cuneiform bone, and the base of the first metatarsal bone.

Nerve

Deep Pereonal Nerve (L4, L5, S1)

Artery

Anterior Tibial Artery

Function

• Dorsal Flexion of the ankle,
• Inversion of the foot
• Adduction of the foot
• Contributor of maintaining the medial arch of the foot

Clinical relevance

Pain along the path of this muscle is often referred to as "Shin splints". Also called medial tibial stress syndrome (MTSS)

Assessment

Palpation

The client is supine. Place your resistence hand on the medial side of the distal foot.

Resist the client from dorsiflexing and inverting the foot. Look the distal tendon of the tibialis anterior on the medial side of the ankle joint and foot; it is usually visible.

Palpate the distal tendon by strumming perpendicula across it. Continue palpating the tibialis anterior proximally to lateral tibial condyle by strumming perpendicular to the fibers.

Once the tibialis anterior has been located, have the client relax it and palpate to asses its baseline tone.

Power

The action of the tibialis anterior muscle is considerably superior that others three dorsal flextor muscles of the foot, both for the size and for its function that affects the entire foot.

References

Drake R, Vogl W, Mitchell AWM 2004 Gray’s Anatomy for Students. Edinburgh: Churchill Livingstone.

Pasqualino A., Panattoni G.L. 2002 Anatomia Umana. Utet

Joseph E. Muscolino, 2011 Know the Body: Muscle, Bone, and Palpation Essentials. Mosby 1st Edition