FOOT 3RD LAYER

GENERAL INFORMATION

The foot’s 3rd layer muscles provide additional support, stability and fine control over foot movements. These muscles work together to maintain the arches of the foot, assist in weight-bearing activities and contribute to the overall function of the foot.

ORIGIN

The muscles in the foot’s 3rd layer have specific points of origin within the foot. The origins of the major muscles in the third layer are as follows:

• Flexor hallucis brevis: Cuboid bone, cuneiform bones and tibialis posterior muscle tendon.

• Adductor hallucis:

• • Oblique head: Bases of the second to fourth metatarsal bones.

• • Transverse head: Transverse metatarsal ligament.

• Flexor digiti minimi brevis: Base of the fifth metatarsal bone.

• Quadratus plantae: Calcaneus (heel bone).

INSERTION POINT

The muscles in the foot’s 3rd layer have various insertion points based on their specific functions. The significant insertions of the muscles in the third layer are as follows:

• Flexor hallucis brevis: Medial sesamoid bones and base of the proximal phalanx of the great toe.

• Adductor hallucis: Base of the proximal phalanx of the great toe.

• Flexor digiti minimi brevis: Base of the proximal phalanx of the fifth toe.

• Quadratus plantae: Flexor digitorum longus tendon and tendon of flexor digitorum brevis.

MAJOR ARTERIES

The muscles in the third layer of the foot receive their blood supply from various arteries, including:

• Plantar arteries: These arteries branch from the posterior tibial artery and provide blood supply to the plantar aspect of the foot, including the muscles in the third layer.

NEURAL INNERVATION

Branches of the tibial nerve innervate the muscles in the foot’s 3rd layer.

TRIGGER POINT

Trigger points, or localised areas of muscle tension and sensitivity, can develop in the muscles of the third layer of the foot due to various factors such as overuse, muscle imbalances or trauma. These trigger points can cause pain and discomfort in the foot.

CONCENTRIC FUNCTION

The muscles in the third layer of the foot primarily function concentrically when they contract to generate force and actively flex or adduct the toes, providing fine control over toe movements.

ECCENTRIC FUNCTION

The muscles in the foot’s 3rd layer also function eccentrically to control the movement and decelerate forces acting on the foot during toe extension, abduction and foot pronation.

ISOMETRIC FUNCTION

Isometric contractions of the muscles in the third layer of the foot occur when the muscles generate force without changing their length. These contractions provide stability and support to the foot during weight-bearing activities.

RELATED MUSCLE SCIENTIFIC NAMES

• Flexor hallucis brevis: Musculus flexor hallucis brevis

 

• Adductor hallucis: Musculus adductor hallucis

• Flexor digiti minimi brevis: Musculus flexor digiti minimi brevis

• Quadratus plantae: Musculus quadratus plantae

ANTAGONIST

• Extensor hallucis longus: The extensor hallucis longus muscle is an antagonist to the muscles in the foot 3rd layer.

COMMON INJURIES

• Tendinitis: Inflammation of the tendons associated with the muscles in the foot’s 3rd layer, often caused by overuse or repetitive strain.

• Muscle strains: Overstretching or tearing of the muscles in the third layer of the foot due to excessive force or trauma.

EXERCISES

• Toe flexion exercises: Sit on a chair and place a resistance band around your toes. Flex your toes against the resistance, activating the muscles in the third layer of the foot.

• Toe adduction exercises: Sit on a chair and place a small ball or towel between your toes. Squeeze your toes together, targeting the muscles in the third layer of the foot.

• Toe curls with resistance band: Sit on a chair and place a resistance band around your toes. Curl your toes against the resistance, activating the muscles in the third layer of the foot.

STRETCHES

• Toe extension stretch: Sit on a chair and cross one leg over the opposite thigh. Gently pull your toes back toward your shin, stretching the muscles in the third layer of the foot.

• 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 muscles in the third layer of the foot.