Flexor Digitorum Longus

Flexor Digitorum Longus

Pictured above is the flexor digitorum longus muscle. It stabilizes your foot & ankle for balance by pulling all of your toes except the big toe toward the bottom of your foot. If contracted hard enough, it pulls the bottom of your foot toward the back of your lower leg like when you point your toes. It attaches underneath the soleus muscle along most of the back of the bigger of your lower leg bones (the tibia), and its tendon runs down the back inside of your ankle and attaches to the bottom of all the toes except the big toe.

If this muscle locks up it will feel tight and possibly painful along the center portion of the back of your lower leg, and your toes will not move well. This muscle and the flexor hallucis longus are BIG contributors to hammer toes, claw toes, and other general lower leg and foot pains. Rarely will this muscle lock up without the other toe flexor muscle needing attention too (the flexor hallucis longus). The soleus muscle ALWAYS needs attention if your flexor muscles are locked up, and your toe extensors will also likely need some TLC on the front of your lower leg deeper than the anterior tibialis.

The flexor digitorum longus muscle is displayed on the right leg. On the left leg the muscles located in the back of your lower leg are layered, showing how some of the muscles are covered by the others. All of the muscles are see-through so that you can appreciate the location and size of each muscle relative to the others. You can access detail for all the muscles in the body with our Coach membership.

Click here for a list of all the muscles.

Muscles that cross or attach to the hip or thigh bone (femur) and attach below the knee joint and DO NOT attach to the knee cap (patella)

  1. Sartorius
  2. Gracilis
  3. Biceps Femoris
  4. Semitendonosis
  5. Semimembranosis
  6. Gastrocnemius
  7. Popliteus
  8. Plantaris


Lower Leg
The following muscles attach across or below the knee.
Click the appropriate link for your interest.

Muscles that cross the knee

  1. Gastrocnemius
  2. Popliteus
  3. Plantaris


Muscles that pass or attach between the knee & ankle

  1. Gastrocnemius
  2. Popliteus
  3. Plantaris
  4. Soleus
  5. Peroneus Longus
  6. Peroneus Brevis
  7. Flexor Digitorum Longus
  8. Flexor Hallucis Longus
  9. Posterior Tibialis
  10. Anterior Tibialis
  11. Extensor Digitorum Longus
  12. Extensor Hallucis Longus


Good luck working out those tight knots.

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