Chronic Ankle Sprain

 

Ankle sprain is a common occurrence:

2328 sprains occur in the USA every day!

How do you sprain your ankle?

The foot rolls into inversion with damage to the lateral structures of the foot and ankle

Swelling and pain

Ligament injuries are often associated with inversion sprains

These may lead to prolonged periods of immobilization or surgery to re-establish stability

A high ankle sprain?

Injuries to the syndosmosis can also occur, further complicating treatment and recovery

What causes the development of chronic pain?

There is an interrelationship between motion and pain!

Think of hitting your thumb with a hammer the immediate response is to SHAKE it to relieve the symptoms

The

nociceptors (pain receptors) are the “free” nerve endings and are grouped with the proprioceptive (movement sensing) nerves throughout the body

The proprioceptors are the faster conducting mylenated fibers and the nociceptors are slow non mylenated fibres

Pain sensation can be regulated and influenced:

Pain and movement nerves join together in the smae cells in the spinal cord, which means abnormal movement input can affect the pain signalling

This results in over sensitisation

This causes a neurological confusion between what is moving and what is hurting

So movement is mistaken for pain!!!

What does hypersensitivity do?

Secretion of Neuropeptides from the free nerve endings, which causes the following:

Vasoactivity (constriction and dilatation)

Raynaud’s like phenomena

Increased hypersensitivity to local nociceptors

Ultimately confusing motion with pain

Progressive stimulation of pain with guarded motion can lead to:– Complex regional pain syndrome (CRPS), Reflex sympathetic distrophy (RSDS)

It's not always just the lateral ligaments that are injured!

While some ankle sprains are only inversion in nature, many more involve forward motion as well

When the foot is overly nverted, and then a maximum adductory moment is applied, additional rotational injury occurs too.

Fibula restriction:

Prevent normal dorsiflexion

Inhibit the peroneus longus

Exacerbate nociceptive hypersensitivity

Due to the peroneal muscles being loaded in the action of trying to stop the ankle turning over other structures are involved:

The tendon runs under the cuboid bone of the foot and the force on the tendon causes an eversion/plantarflexion moment to the cuboid, which causes a loss of lateral ankle and foot movement

This lack of movment obviously affects pain as pain and movement are linked

Muscle inhibition: 

The peroneals are inhibited so this creates a muscle imbalance so the tibialis posterior over powers the peroneals and this causes more inversion, which is painful.

So what do most people do when the injure the ankle?

Immobilise it?

but this lack of movement will actually create more pain due to the link  between pain and movement!

If the pain increases then this inhibits the muscles and this causes more pain (Vicious circle)

Treatment possibilities

Fibula head manipulation

Ankle traction

Cuboid manipulation

Peroneal strengthening

Proprioceptive exercises

So tissue damage alone isn't the only reason why the ankle can struggle to recover fully after an ankle sprain. Issues around lack of movement, muscle imbalance and these links to pain signals can be blocks to the resolution of your symptoms.