GENERAL INFORMATION
The flexor digitorum longus is a muscle located in the lower leg’s deep posterior (back) compartment. It plays a crucial role in flexing the toes, aiding in gripping actions as well as providing stability during walking and running.
ORIGIN
The flexor digitorum longus muscle originates from the posterior surface of the tibia, which is the more prominent bone of the lower leg.
INSERTION POINT
The flexor digitorum longus muscle inserts into the plantar surface (underside) of the distal phalanges (end bones) of the four lesser toes (second to fifth toes).
MAJOR ARTERIES
It receives its blood supply from the following arteries:
- Posterior tibial artery
- Peroneal artery
These arteries ensure that the muscle gets adequate oxygen as well as nutrients to function correctly.
NEURAL INNERVATION
The flexor digitorum longus muscle is innervated by the tibial nerve, which arises from the sciatic nerve. The tibial nerve provides motor innervation to the flexor digitorum longus, allowing it to contract as well as produce movement.
TRIGGER POINT
Trigger points in the flexor digitorum longus muscle can develop, typically causing pain and tension in the foot and lower leg. These trigger points may be associated with excessive muscle tension or overuse.
CONCENTRIC FUNCTION
The concentric function of the muscle involves the shortening or contraction of the muscle. This function is primarily responsible for flexing the four lesser toes, allowing them to curl downward.
ECCENTRIC FUNCTION
The eccentric function of the muscle refers to the controlled lengthening of the muscle while resisting an external force. It assists in movements such as controlling the extension of the lesser toes as well as decelerating the foot during walking or running.
ISOMETRIC FUNCTION
The isometric function of the muscle involves contracting the muscle without any change in length. Isometric contractions of the muscle occur during activities that require maintaining the position of the toes, such as gripping or pushing off the ground.
RELATED MUSCLE SCIENTIFIC NAMES
- Musculus flexor digitorum longus
ANTAGONIST
The antagonist muscle to the flexor digitorum longus is the extensor digitorum longus muscle. The extensor digitorum longus muscle extends (lifting) the lesser toes.
COMMON INJURIES
- Tendinitis: Inflammation of the tendon due to overuse or repetitive stress.
- Tendinopathy: Degenerative changes in the tendon, often caused by chronic overuse or ageing.
- Sprains: Injury to the ligaments surrounding the muscle and tendon, often caused by sudden movements or trauma.
EXERCISES
Exercises to strengthen the flexor digitorum longus muscle include:
- Toe curls: Place a small towel or cloth on the ground as well as use the toes to curl and grip the fabric.
- Resistance band exercises: Using a resistance band looped around the toes, performing resisted flexion and extension exercises to strengthen the muscle.
- Standing calf raises with toe flexion: Performing calf raises while actively flexing the toes to engage and strengthen the muscle.
STRETCHES
Effective stretches for the flexor digitorum longus muscle include:
- Toe extension stretch: Gently pull the toes upward, stretching the muscle.
- Plantar fascia stretch: Stretching the plantar fascia indirectly stretches the muscle.
- Calf stretches: Stretching the calf muscles can help alleviate tension in the muscle.