GENERAL INFORMATION
The abductor hallucis is a muscle located in the foot that plays a crucial role in maintaining the structural integrity of the foot arches as well as controlling the movement of the big toe. It is part of the first layer of muscles in the foot.
ORIGIN
It originates from specific points within the foot. The origins of the abductor hallucis are as follows:
- Medial tubercle of the calcaneus (heel bone)
- Flexor retinaculum
- Plantar aponeurosis
INSERTION POINT
The abductor hallucis muscle inserts at the following point:
- The medial side of the proximal phalanx of the great toe (first toe)
MAJOR ARTERIES
The abductor hallucis muscle receives its blood supply from various arteries, including:
- Plantar arteries: These arteries branch from the posterior tibial artery as well as provide blood supply to the plantar aspect of the foot, including the abductor hallucis muscle.
NEURAL INNERVATION
The muscle is innervated by the medial plantar nerve, which is a branch of the tibial nerve.
TRIGGER POINT
Trigger points or localised areas of muscle tension, as well as sensitivity, can develop in the muscle due to various factors such as overuse, muscle imbalances or trauma. These trigger points can cause pain and discomfort in the foot, often referred to as abductor hallucis trigger point pain.
CONCENTRIC FUNCTION
The abductor hallucis muscle functions concentrically when it contracts to actively move the big toe away from the midline of the foot, a movement known as toe abduction.
ECCENTRIC FUNCTION
The abductor hallucis muscle also functions eccentrically to control the movement as well as decelerate forces acting on the foot during toe adduction, which is the movement of bringing the big toe back toward the midline of the foot.
ISOMETRIC FUNCTION
Isometric muscle contractions occur when the muscle generates force without changing its length. These contractions help provide stability to the foot during weight-bearing activities.
RELATED MUSCLE SCIENTIFIC NAMES
Other muscles related to the abductor hallucis include:
- Musculus abductor hallucis
ANTAGONIST
The antagonist muscle to the foot abductor hallucis is:
- Adductor hallucis: The adductor hallucis muscle acts as an antagonist to the muscle. It brings the big toe back toward the foot’s midline during toe adduction.
COMMON INJURIES
Joint injuries or conditions associated with the foot abductor hallucis muscle include:
- Strains or sprains: Overstretching or tearing the muscle due to excessive force or trauma.
- Tendinitis: Inflammation of the muscle’s tendon, often caused by overuse or repetitive strain.
EXERCISES
Exercises that target the foot abductor hallucis muscle include:
- Toe abduction exercises: Sit on a chair and place a resistance band around your big toe. Slowly move your big toe away from the foot’s midline against the band’s resistance, also focusing on activating the muscle.
- Single-leg balance: Stand on one leg and maintain balance while engaging the muscle to stabilise the foot and control toe abduction.
- Toe towel scrunches: Place a towel on the floor, use your toes to scrunch and pull the towel toward you, emphasising the activation of the muscle.
STRETCHES
Stretches that can help stretch the foot abductor hallucis muscle include:
- Toe abduction stretch: Sit on a chair and cross one leg over the opposite thigh. Pull your big toe away from the foot’s midline, stretching the muscle.
- Plantar fascia stretch: Sit on a chair and place the affected foot over the opposite thigh. Pull your toes back using your hand, stretching the plantar fascia and indirectly stretching the muscle.