Author: Kevin B. Rosenbloom, C.Ped, Sports Biomechanist

The ankle joint is one of the most valuable structures in the human body because of its intricate articulating surfaces and function in ambulation. Dorsiflexion is another essential movement of the ankle joint worth discussing. The following is a summary that explores the range of motion, concise descriptions of the muscles contribution to the movement and briefly explores the interesting research into the muscles involved with dorsiflexion.

Introduction to Dorsiflexion

Dorsiflexion is the superior raising of the mid- and forefoot while the tibia and fibula remain static, causing an upward bend at the ankle joint. It is important to note that some studies have chosen to represent dorsiflexion as extension of the ankle joint (Roaas & Andersson 1982). The main muscles contributing to dorsiflexion are the fibularis tertius, extensor digitorum longus, extensor hallucis longus and tibialis anterior (Visible Body 2019).

Range of Motion

Naturally, there is a difference in opinion regarding the specific range of motion for dorsiflexion. This is likely due to the varying flexibility differing between individuals. Generally, 15-20°  has been considered the mean and maximum angulation an individual can reach (Roaas & Anderson 1982, Washington State DSHS 2014, Quinn 2019). However according to Roaas & Anderson, it has been stated that 40° of dorsiflexion was observed in very flexible individuals, with less flexible individuals reaching up to 5°.

Anterior Compartment of the Leg

The dorsiflexors muscles of the ankle all lie in the anterior compartment of the leg. The tibialis anterior is the most superficial and anterior facing muscle amongst them. Alongside the lateral border of the tibialis is the extensor digitorum longus. Just below the superficial surfaces and sitting between the of the t. anterior and the e. digitorum longus is the slender main body of the extensor hallucis longus. In a layer below the other muscles and at distal half of the fibula, the fibularis (peroneus) tertius muscle’s slim body extends distally into the open space between the fibularis brevis and extensor digitorum longus.

Interesting research has been explored regarding dorsiflexors in the leg and foot. Firstly, the tibialis anterior has been considered to be part of an exclusive group of muscles in the body that invoke more excitability in the central nervous system and therefore produce higher results in resistance training when compared to other muscles (Griffin & Cafarelli 2007).

Manipulation of muscles have led to interesting results regarding protein absorption. When an intact nerve supply to the extensor digitorum longus has been disconnected, the muscle can still grow with a passive stretch (Goldspink 1978), thus potentially still preventing complete atrophy in some patients with nerve damage.

Successful repair of muscles is becoming more common with the increasing efficiency of doctors’ diagnosis and surgeons accuracy. A good example of this is the primary repair or reconstruction of the extensor hallucis longus. It is a very reliable procedure with 95% of subjects displaying active hallux dorsiflexion (Wong et al. 2013).

Lastly, variation of muscles in humans are quite common. However, an interesting thought lies with one of the peroneus muscles’ inclusion in anatomical examination. To briefly explain, in two separate studies the fibularis tertius muscle was present in less than 50% of a Chilean sample population (Ramirez et al. 2010) and 63% of a south-western Nigerian sample population (Ashaolu et al. 2013).

Muscle Overview - Ankle Dorsiflexors

Figure 1. Sketch of ankle dorsiflexors (right), anterior view.

Figure 2. Sketch of ankle dorsiflexor insertions (right), superior view.

Tibialis anterior [1]

Extensor digitorum longus [2]

Extensor hallucis longus [3]

Fibularis tertius [4]

References & Works Cited

Ashaolu, J. O., Olorunyomi, O. I., Opabunmi, O. A., Ukwenya, V. O., Thomas, M. A. 2013. “Surface anatomy and prevalence of fibularis tertius muscle in a south-western Nigerian population,” Forensic Medicine and Anatomy Research 1; 2: 25-29. http://dx.doi.org/10.4236/fmar.2013.12005.

Barclay, T. 2018. “Anatomy Explorer,” innerbody.com. Accessed 19 Mar 2019. https://www.innerbody.com/anatomy/muscular/leg-foot.

Goldspink, D. F. 1978. “The Influence of Passive Stretch on the Growth and Protein Turnover of the Denervated Extensor Digitorum Longus Muscle,” Biochemical Journal 174: 595-602. https://dx.doi.org/10.1042%2Fbj1740595

Gray, H. 1918. “The Muscles and Fasciæ of the Lower Extremity,” Anatomy of the Human Body, 20th Ed. Lead & Febiger. Philadelphia & New York, USA. 480-483, 488-489.

Griffin, L., Cafarelli, E. 2007. “Transcranial magnetic stimulation during resistance training of the tibialis anterior muscle,” Journal of Electromyography and Kinesiology 17: 446-452. https://doi.org/10.1016/j.jelekin.2006.05.001

Quinn, E. 2019. “Generally Accepted Values for Normal Range of Motion (ROM) in Joints,” verywellhealth.com. Accessed 19 Mar 2019. https://www.verywellhealth.com/what-is-normal-range-of-motion-in-a-joint-3120361.

Ramirez, D., Gajardo, C., Caballero, P., Zavando, D., Cantín, M., Suazo, G. I. 2010. “Clinical Evaluation of Fibularis Tertrius Muscle Prevalance,” International Journal of Morphology 28; 3: 759-764. Clinical Evaluation Fibularis Tertius Muscle Prevalence.pdf.

Roaas, A., Andersson, G. B. J., 1982. “Normal Range of Motion of the Hip, Knee and Ankle Joints in Male Subjects, 30-40 Years of Age,” Acta Orthopaedica Scandinavica, 53:2, 205-208. https://www.tandfonline.com/doi/abs/10.3109/17453678208992202.

Visible Body. 2019. “Muscle Premium,” VisibleBody.com. Purchasable Application. Accessed 21 Feb 2019.

Washington State DSHS. 2014. “Range of Joint Motion Evaluation Chart,” Washington State Department of Social & Health Services. Accessed 20 Mar 2019. https://www.dshs.wa.gov/sites/default/files/FSA/forms/pdf/13-585a.pdf.

Wong, J. C., Daniel, J. N., Raikin, S. M. 2013. “Repair of Acute Extensor Hallucis Longus Tendon Injuries: A Retrospective Review,” Foot & Ankle Specialists 7; 1: 45-51. https://doi.org/10.1177%2F1938640013514271.

Kevin B. Rosenbloom, C.Ped, Sports Biomechanist

Kevin B. Rosenbloom, founder and president of KevinRoot Medical, is a renowned certified pedorthist and sports biomechanist practicing in Santa Monica, CA. With his continuing research on the historical development of foot and ankle pathologies, comparative evolution of lower extremities and the modern environmental impacts on ambulation, he provides advanced biomechanical solutions for his patients and clients.