Ankle Passive Range of Motion: Understanding, Benefits, and Exercises

What is a Passive Range of Motion Exercise for the Ankle?

A passive range of motion (PROM) exercise for the ankle involves moving the ankle joint through its available range of motion without any muscular contraction from the individual, typically assisted by an external force such as a therapist, caregiver, or even the individual's other hand.

What is Passive Range of Motion (PROM)?

Passive range of motion refers to the movement of a joint through its full available arc by an external force, without any active muscle engagement from the person whose joint is being moved. This contrasts with active range of motion (AROM), where the individual actively contracts their own muscles to move the joint, and active-assisted range of motion (AAROM), which involves both self-effort and external assistance.

The primary purposes of PROM are to:

• Maintain joint mobility: Prevent stiffness and contractures when active movement is limited or contraindicated.
• Preserve articular cartilage integrity: Promote nutrient diffusion within the joint by moving synovial fluid.
• Minimize formation of adhesions: Prevent scar tissue from binding joint structures.
• Enhance proprioception: Provide sensory input to the joint receptors.
• Reduce pain: Gentle movement can sometimes alleviate discomfort.
• Aid in circulation: Promote blood flow to the area.

Why is Ankle Passive Range of Motion Important?

The ankle is a complex joint crucial for locomotion, balance, and shock absorption. It primarily consists of the talocrural joint (responsible for dorsiflexion and plantarflexion) and the subtalar joint (responsible for inversion and eversion). Maintaining full, pain-free range of motion at these joints is vital for:

• Optimal gait mechanics: Allowing proper push-off and landing phases during walking and running.
• Injury prevention: A mobile ankle can better absorb forces and adapt to uneven terrain, reducing the risk of sprains.
• Rehabilitation: Restoring movement after injury, surgery, or prolonged immobilization.
• Reducing stiffness: Counteracting the effects of inactivity or certain medical conditions that limit joint movement.

Who Benefits from Ankle PROM Exercises?

Ankle PROM exercises are particularly beneficial for individuals who:

• Are unable to actively move their ankle: Due to pain, weakness, paralysis (e.g., stroke, spinal cord injury), or severe neurological conditions.
• Are recovering from injury or surgery: Where active muscle contraction is contraindicated or too painful in the early stages (e.g., ankle fracture, Achilles tendon repair).
• Experience prolonged immobilization: Such as after casting for a fracture, to prevent joint stiffness and muscle shortening.
• Have conditions causing joint stiffness: Like severe arthritis or fibrotic changes, to maintain what range is available.
• Are unconscious or comatose: To prevent contractures and maintain tissue health.

How to Perform Ankle Passive Range of Motion Exercises

When performing ankle PROM, the key is to be gentle, controlled, and never push into pain. The movement should be smooth and within the individual's comfortable range. These exercises can be performed by a caregiver or self-assisted.

General Principles:

• Support the limb: Ensure the lower leg is supported to prevent unwanted movement at the knee or hip.
• Grasp firmly: Hold the foot securely, typically around the heel and forefoot.
• Move slowly and smoothly: Avoid jerky movements.
• Do not force: Stop if pain is experienced.
• Repetitions: Aim for 5-10 repetitions of each movement, 2-3 times per day, or as advised by a healthcare professional.

Here are common ankle PROM exercises:

• Ankle Dorsiflexion/Plantarflexion PROM

  • Action: This movement occurs at the talocrural joint. Dorsiflexion brings the toes towards the shin, while plantarflexion points the toes away from the shin.
  • How to perform:
    • Self-assisted: Sit with your leg extended. Use one hand to gently pull your toes towards your shin (dorsiflexion). Then, use the same hand to push your foot away from your shin, pointing your toes (plantarflexion).
    • Assisted: The helper supports the lower leg with one hand just above the ankle. With the other hand, they gently grasp the sole of the foot and move it up towards the shin (dorsiflexion) and then down, pointing the toes (plantarflexion).

• Ankle Inversion/Eversion PROM

  • Action: This movement occurs primarily at the subtalar joint. Inversion turns the sole of the foot inward, towards the midline of the body. Eversion turns the sole of the foot outward, away from the midline.
  • How to perform:
    • Self-assisted: Sit with your leg extended. Hold your foot with one hand, gently turning the sole inward (inversion) and then outward (eversion).
    • Assisted: The helper supports the lower leg. With the other hand, they grasp the midfoot and gently turn the sole inward (inversion) and then outward (eversion), ensuring the movement is at the ankle and not the knee or hip.

• Ankle Circumduction PROM

  • Action: This is a combination of all ankle movements, creating a circular motion. It mobilizes the joint in multiple planes.
  • How to perform:
    • Self-assisted: Gently rotate your foot in a circular motion, moving through dorsiflexion, inversion, plantarflexion, and eversion in one continuous sweep. Reverse direction.
    • Assisted: The helper supports the lower leg. With their other hand, they gently guide the foot through a smooth circular path, ensuring the movement is fluid and pain-free.

Precautions and Considerations

While PROM is generally safe, it's crucial to observe certain precautions:

• Avoid if unstable: Do not perform PROM if the joint is unstable (e.g., acute fracture, ligament rupture, or suspected dislocation).
• No pain: Never force movement into a painful range. Pain is a signal that the movement may be causing harm.
• Recent surgery: Always follow specific post-operative instructions from a surgeon or physical therapist regarding range of motion limitations.
• Inflammation: In cases of acute inflammation or infection, aggressive PROM may exacerbate the condition.
• Consult a professional: It is highly recommended to consult a physical therapist, athletic trainer, or other qualified healthcare professional before initiating any PROM program, especially after an injury or surgery. They can provide a proper assessment, teach correct techniques, and ensure the exercises are appropriate for your specific condition.

Integrating passive range of motion exercises for the ankle can be a critical component of rehabilitation, injury prevention, and maintaining overall joint health, particularly when active movement is compromised.