GENERAL INFORMATION
The foot’s 2nd layer muscles provide additional support, stability and 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 2nd layer have specific points of origin within the foot. The origins of the major muscles in the second layer are as follows:
- Flexor digitorum longus: Posterior surface of the tibia (lower leg bone) and fibula (outer lower leg bone).
- Flexor hallucis longus: Posterior surface of the fibula.
- Tibialis posterior: Interosseous membrane (between the tibia and fibula) and posterior surface of the tibia and fibula.
INSERTION POINT
The muscles in the foot’s 2nd layer have various insertion points based on their specific functions. The significant insertions of the muscles in the second layer are as follows:
- Flexor digitorum longus: Bases of the four lesser toes’ distal phalanges (toe bones).
- Flexor hallucis longus: Base of the distal phalanx of the great toe (first toe).
- Tibialis posterior: Navicular bone, cuneiform bones and metatarsal bone bases.
MAJOR ARTERIES
The muscles in the foot 2nd layer receive their blood supply from various arteries, including:
- Posterior tibial artery: This artery branches off the popliteal artery and provides blood supply to the posterior compartment of the lower leg, including the second layer of foot muscles.
NEURAL INNERVATION
Branches of the tibial nerve innervate the muscles in the foot’s 2nd layer.
TRIGGER POINT
Trigger points, or localised areas of muscle tension and sensitivity, can develop in the muscles of the second 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 second layer of the foot primarily function concentrically when they contract to generate force and actively flex or plantarflex the toes.
ECCENTRIC FUNCTION
The muscles in the second layer of the foot also function eccentrically to control the movement and decelerate forces acting on the foot during toe extension or dorsiflexion.
ISOMETRIC FUNCTION
Isometric contractions of the muscles in the foot’s 2nd layer occur when the muscles generate force without changing their length. These contractions provide stability to the foot during weight-bearing activities.
RELATED MUSCLE SCIENTIFIC NAMES
- Flexor digitorum longus: Musculus flexor digitorum longus
- Flexor hallucis longus: Musculus flexor hallucis longus
- Tibialis posterior: Musculus tibialis posterior
ANTAGONIST
- Extensor digitorum longus: The extensor digitorum longus muscle acts as an antagonist to the muscles in the second layer of the foot.
COMMON INJURIES
- Tendinitis: Inflammation of the tendons of the muscles in the foot 2nd layer, often caused by overuse or repetitive strain.
- Muscle strains: Overstretching or tearing of the muscles in the second layer of the foot due to excessive force or trauma.
EXERCISES
- 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 second layer of the foot.
- Toe extensions with resistance band: Sit on a chair and place a resistance band around your toes. Extend your toes against the resistance, targeting the muscles in the foot’s 2nd layer.
- Plantarflexion exercises: Perform exercises that involve pointing your toes downward, such as standing calf raises or seated ankle plantarflexion exercises.
STRETCHES
- Toe extension stretch: Sit on a chair and cross one leg over the opposite thigh. Pull your toes back toward your shin, stretching the muscles in the foot’s 2nd layer.
- Calf stretch: Stand facing a wall with one foot forward and the other foot back. Lean toward the wall, keeping the back heel on the ground to stretch the calf muscles, including the muscles in the second layer of the foot.
- Plantar fascia stretch: Sit on a chair and place the affected foot over the opposite thigh. Using your hand, pull your toes back, stretching the plantar fascia and indirectly stretching the muscles in the second layer of the foot.