Dorsiflexion is the action of raising the foot upwards towards the shin. It means the flexion of the foot in the dorsal, or upward, direction.
People use dorsiflexion when they walk. During the middle stages of weight bearing and just before pushing off the ground, the foot will reach its end range of dorsiflexion.
If there are problems with dorsiflexion, then the body will compensate naturally, which in turn can cause issues elsewhere.
For a movement to be considered dorsiflexion, the foot should be raised upward between 10 and 30 degrees.
Dorsiflexion uses the muscles in the front part (anterior) of the foot.
The tendons of the muscles that pass through the front of the foot and into the ankle joint include:
- tibialis anterior
- extensor hallucis longus
- extensor digitorum longus
These tendons are located on the front of the leg and are supplied by the deep peroneal nerve. Damage to this nerve can stop a person from being able to raise their foot.
Plantar flexion is the opposite of dorsiflexion and involves moving the foot in a downward direction, toward the ground.
Plantar flexion occurs when the foot is moved downward between 20 and 50 degrees.
The muscles whose tendons cause plantar flexion are located on the back (posterior) and inside of the leg, and pass into the back of the foot via the ankle joint. These include:
- tibialis posterior
- flexor digitorum longus
Whenever a person is standing upright, their foot is the only part of their body in contact with the ground.
This means that any interaction between the foot and the ground goes through the ankle and then the rest of the body in a kinetic chain.
As a result, problems in the foot and ankle can affect every other part of the body. Often, it is the knees that are affected first, then the hips and back, and eventually the shoulders and neck.
If someone cannot raise their foot upward or the movement is limited, then they may have poor dorsiflexion.
The possible causes of poor dorsiflexion include:
- Ankle joint restriction: This is when the ankle joint itself is restricted. This can result from scar tissue in the joint or a tight joint capsule. A joint capsule is connective tissue filled with fluid that serves as a type of natural 'hinge' in the body.
- Flexibility deficit: Dorsiflexion problems can occur when the muscles in the calf, known as the Gastroc/Soleus complex, are tight and cause restriction.
- Genetics: Poor dorsiflexion can be linked to a person's genetics.
- Ankle injury: If a sprain has not healed properly, a person may limit their movement to avoid pain. Doing this consistently will tighten the joint capsule and cause scar tissue, which limits dorsiflexion.
- Other injuries: Damage to the lower body, and even the hip and back, can make a person modify the way they walk and affect their dorsiflexion.
Any dorsiflexion problems that occur can carry on up the body and cause injuries from the knee all the way to the shoulder. This domino effect can work in both directions.
If someone is worried about their ankle dorsiflexion, there is a simple technique to determine if they have normal movement. It is commonly known as the "knee to wall test."
This is when a person performs a lunge with their feet flat on the ground with one knee just touching a wall.
Using a tape measure to measure from the end of the big toe to the wall will give the degree of ankle dorsiflexion the person has managed, with each centimeter (cm) equating to approximately 3.6 degrees.
Anything over 12.5 cm is considered normal functioning dorsiflexion. Some people believe that the best way to test the range of motion of ankle dorsiflexion is when the foot and ankle are weight bearing.
Depending on the cause of limited ankle dorsiflexion, there are different exercises to help improve it.
A limited dorsiflexion caused by tight calves can be improved by stretching the calves. Helpful stretches include:
- Gastrocnemius stretch: Keep the back leg straight with front knee forward until feeling a stretch. Hold for 20 seconds.
- Soleus muscle stretch: Lean against a wall with the leg that needs stretching at the back. Bend the knee with heel on the ground until feeling a stretch. Hold for 20 seconds.
- Stretching on a step: Place foot on a step and then lower heel down to the ground until a stretch is felt and hold for 20 seconds.
Dorsiflexion problems caused by joint restriction can be reduced using exercises, including:
- Squats and lunges: One of the easiest ways to improve dorsiflexion.
- Training barefoot: Shoes can be restrictive, so if a person trains barefoot the ankle will dorsiflex naturally.
It is important to stretch properly as the wrong technique can make the exercise useless or could cause more problems.
Unless there is permanent damage to the ankle due to trauma, restriction and muscle tightness causing dorsiflexion problems can be improved over time through specific exercises.
With any injury, it is important to ensure adequate recovery and rehabilitation time. Rushing back to activities too early can cause further problems.
Ankles are load bearing, so it is important to give them rest by minimizing walking and prolonged standing after an injury.
As most people cannot avoid walking or standing all the time, over-the-counter sole supports for shoes are one way to limit pain and prevent further problems.