GENERAL INFORMATION
The leg extensor digitorum longus is a muscle located in the anterior compartment of the lower limb. It plays a crucial role in extending the toes and assisting in the dorsiflexion of the ankle. Furthermore, this muscle is involved in activities such as walking, running, and maintaining balance.
ORIGIN
This muscle originates from two sites:
- Firstly, it arises from the lateral condyle of the tibia (shinbone), specifically the anterior surface.
- Secondly, it also originates from the proximal part of the fibula (the smaller bone of the lower leg). Specifically the anterior surface.
INSERTION POINT
The extensor digitorum longus muscle inserts onto the middle and distal phalanges (bones) of the four smaller toes (digits 2 to 5) in the foot. It attaches to the top surface of these bones.
MAJOR ARTERIES
The leg extensor digitorum longus muscle receives its blood supply primarily from the anterior tibial artery. Which is a branch of the popliteal artery. Importantly, this artery provides oxygenated blood to the muscle to support its function.
NEURAL INNERVATION
This muscle is innervated by the deep fibular (peroneal) nerve, which arises from the common fibular (peroneal) nerve. Consequently, this nerve provides both motor innervation for muscle contraction and sensory innervation for transmitting sensations from the skin of the lower leg and dorsum of the foot.
TRIGGER POINT
Trigger points may develop in this muscle, causing localised pain and tenderness. These trigger points can be associated with muscle overuse, strain, or postural imbalances.
CONCENTRIC FUNCTION
The concentric function of the leg extensor digitorum longus is to actively contract while generating force during the extension of the four smaller toes. This action involves straightening and lifting the toes away from the ground.
ECCENTRIC FUNCTION
During specific movements, such as controlled lowering of the toes. The leg extensor digitorum longus muscle functions eccentrically to resist the force of gravity and control the descent of the toes.
ISOMETRIC FUNCTION
This muscle can contract isometrically to stabilise the metatarsophalangeal joints of the toes, maintaining their position and resisting excessive flexion.
RELATED MUSCLE-SCIENTIFIC NAMES
The Extensor Digitorum Longus muscle is scientifically known as the Musculus Extensor Digitorum Longus.
ANTAGONIST MUSCLES
- Flexor Digitorum Longus: Located in the posterior compartment of the lower limb, responsible for flexing the four smaller toes and opposing the extension action of the Extensor Digitorum Longus.
COMMON INJURIES
- Tendinitis or Tendon Rupture: Inflammation or tearing of the tendon, often due to overuse or sudden injury. It may lead to pain and impaired movement.
- Muscle Strains or Tears: Overstretching or excessive force can cause muscle fibres to tear, resulting in pain and reduced function.
- Compartment Syndrome: Increased pressure within the anterior compartment can restrict blood flow and damage muscles and nerves, though it is rare in this area.
RESISTANCE TRAINING EXERCISES
- Toe Extensions with Resistance Bands: Secure a resistance band around the toes and extend the toes upward against the band’s resistance. Strengthens the Extensor Digitorum Longus and improves toe extension strength.
- Ankle Dorsiflexion Activities: Use resistance bands or weights to perform dorsiflexion movements. That targets the Extensor Digitorum Longus and increases ankle strength.
- Toe Curls with Towel Scrunches: Place a towel on the floor and use the toes to scrunch it up. It engages the muscles in the lower leg and foot.
- Balancing on Unstable Surfaces: Stand on a balance board or cushion to engage the stabilising muscles of the lower leg, including the Extensor Digitorum Longus.
- Single-Leg Calf Raises: Stand on one leg and raise the heel off the ground, engaging the muscles of the lower leg to improve balance and strength.
STRETCHES
- Toe Flexion Stretch: Gently pull the toes downwards with the hand, stretching the Extensor Digitorum Longus and improving flexibility.
- Ankle Dorsiflexion Stretch: Sit with legs extended, loop a towel around the ball of the foot, and gently pull the toes towards the shin, stretching the muscle.
- Calf Stretch: Stand facing a wall, place one foot back with the heel on the ground, and lean forward into the wall, stretching the calf muscles and indirectly stretching the Extensor Digitorum Longus.
- Seated Forward Fold: Sit with legs extended, reach towards the toes, and hold to stretch the hamstrings and lower leg muscles, including the Extensor Digitorum Longus.
- Heel Drop Stretch: Stand on a step with the heels hanging off, and slowly lower the heels down below the step level, stretching the calves and lower leg muscles.