Originally published in Massage Bodywork magazine, May/June 2011. Copyright 2011. Associated Bodywork and Massage Professionals. All rights reserved.
The tibialis anterior is a large, superficial muscle on the front of the leg. The muscle belly begins near the lateral tibial condyle, following the lateral edge of the tibial shaft prior to inserting on the foot.
The peroneus longus, a lateral leg muscle, inserts on the bottom of the foot at the same location as the tibialis anterior. Together, these two muscles form the anatomical stirrup, which loops around the midfoot and helps control its movements.
The function of the tibialis anterior varies according to foot position. If it is free (not planted), the muscle insertion moves toward the origin, raising the foot up (dorsiflexion). This prevents the toes from catching on the ground during the swing phase of gait. Maintaining a dorsiflexed foot also situates the heel to strike the ground first and positions the foot optimally for transition from heel strike to stance phase.
When the foot is fixed or planted, the origin of the tibialis anterior moves toward the insertion, pulling the leg over the foot (also called dorsiflexion). This occurs as weight is accepted during the stance phase of gait. Once heel strike occurs, the tibialis anterior continues to contract, pulling the proximal tibia and center of gravity over the foot. The body is then positioned so the strong posterior leg muscles can begin the push-off phase of gait (plantarflexion).
Additionally, the tibialis anterior helps support the medial or longitudinal arch of the foot. Its tendon traverses the dorsal ankle from lateral to medial and deep under the extensor retinaculum. Here it bends medially around the malleolus prior to attaching on the plantar surfaces of the medial cuneiform and base of the first metatarsal. This tendon angle gives the tibialis anterior leverage to raise the center of the medial arch and prevent the foot from flattening or rolling inward (pronation). The tibialis anterior works synergistically with the tibialis posterior to dynamically maintain the medial arch and limit or control foot pronation.
Overuse, weakness, or imbalance may create irritation or tendonitis in the tibialis anterior. This is common when initiating or progressing physical activities such as walking or running too rapidly. Excessive foot pronation or lack of support in the medial arch may also irritate the tibialis anterior, the tibialis posterior, the plantar fascia, or any combination of these. Repetitive stress and inflammation in the tibialis anterior is one of several conditions commonly called "shin splints."Palpating The Tibialis AnteriorPositioning: client supine1.
Standing at the client's feet, locate the lateral edge of the client's tibial shaft with your thumb.2.
Slide laterally onto the muscle belly of the tibialis anterior.3.
Continue to palpate distally toward the front of the ankle and medial arch.4.
Resist as the client performs ankle dorsiflexion and inversion to assure proper location. Christy Cael is a licensed massage therapist, and certified strength and conditioning specialist. Her private practice focuses on injury treatment, biomechanical analysis, craniosacral therapy, and massage for clients with neurological issues. She is the author of
Functional Anatomy: Kinesiology and Palpation for Manual Therapists (Lippincott Williams Wilkins, 2009). Contact her at email@example.com.