Foot Drop; A Comprehensive Guide by FootHouse

Foot Drop, understanding causes and treatment

At FootHouse Podiatry and MSK Biomechanics we specialise in fixing foot and lower limb musculoskeletal  (MSK) disorders. One of these disorders is the difficult problem of Foot Drop.

If you have a foot drop then you will know what problems it cause with walking and balance. If you’d like to know what the best intervention is for you and how we will assess and design a treatment plan for you then read on.

There are several reasons why a person may have a foot that either drops or does not lift, either at all or not at the right time.

The cause of foot drop is because the muscles do not work properly or not at all.

The reason why the muscles fail to function is either due to direct muscle trauma or dysfunction of the nerves supplying the muscle action causing weakness, paralysis or an over contracted known as spasticity.

The nerve damage may be in the foot or leg, known as peripheral nerves, or in the spinal column or brain together known as the central nervous system (CNS)

Typically the peripheral nerves have suffered a direct injury, perhaps a motorbike accident injures the peroneal nerve as it courses around the outside of the knee for instance. CNS foot drop occurs typically from a stroke or a neurological disease.

Do you know the cause of your foot drop and understand why it changes how you walk?

To understand your foot drop let’s have a look at the Biomechanics of walking. The action of walking is also known as the ‘gait cycle’.

When considering the gait cycle we often separate the stride, which is two steps, into two sections

1.       Stance phase

2.       Swing phase

If we consider just the right leg the stance in when the right foot is on the ground and swing is when it is in the air.

The stance phase is further split into three  phases of progression

1.       Heel (foot) strike (it’s not always the heel that strikes first )

2.       Mid-stance - usually the whole foot is on the ground and the body passes over the foot

3.       Heel off to Propulsive phase or push off

So far we are considering the right foot and, in normal walking, as the heel lifts this is when the left foot stance phase begins. It is at this point in the gait cycle that foot drop disrupts the gait cycle as, of course, you will know if you live with foot drop.

Let’s look at what is happens at the foot and ankle joint in normal walking: The ankle joint allows the foot to go up and down - or dorsiflex and plantarflex respectively. The muscles at the front of the shin pull the foot up and the muscles in the calf pull the foot down. Of course, in swing phase, gravity will also pull the foot down.

So, at heel lift the foot begins to plantarflex and if the shin muscles, or anterior tibial muscles, are weak then gravity and the stronger calf muscles, or gastric-soleus muscles, will pull the foot down.

During early swing phase the foot would normally dorsiflex to clear the ground and remain there though swing until heel strike. However, with weak anterior tibial muscle the foot cannot dorsiflex and so the toe tends to catch the ground and cause tripping.

As the leg comes to the end of swing phase, in the person with foot drop, the foot is still dorsiflexed and so the foot strikes at the forefoot and toes.

I said earlier that there is a tendency to trip and indeed it often happens, you may have experienced this. To avoid tripping the person with foot drop must lift the knee or swing the leg outward or a combination of both to clear the ground but there is still the problem of forefoot strike. This changes how the gait cycle progresses and overall is not so propulsive and there is the risk of tripping and falls.

This describes a foot with weak shin muscles, which is most common, sometime though there is paralysis of muscles that results in a flaccid or floppy foot drop or a spastic calf muscle that rigidly fixes the foot in plantarflexion.

If you have these types of foot drop then you will probably have experienced similar problems with gait progression and walking. As clinicians we must consider the different types presented as they each may require a different intervention, orthotic device and rehab plan.

What’s an orthotic? You probably already know but just to be clear for everyone:

An orthotic is a device that assists the function of a limb, whereas a prosthetic replaces a limb. Prosthetics are typically used and fitted by surgeons and orthotists but orthotics are typically used and fitted by podiatrists, biomechanists and MSK specialists.

The orthotic used for foot drop is usually an ankle foot orthotic or AFO and is specially designed to assist the foot lifting or hold the foot in dorsiflexion so it can clear the ground and have a better foot strike action, which improves gait progression.

When someone comes to FootHouse with a foot drop problem we will first evaluate the walking, the gait progression, muscle and nerve function and the mechanics and anatomy of the lower limbs and feet, these are the clinical considerations.

However, with foot drop especially, it is important to listen to how the person copes with the presenting gait changes, what activities they are capable of or have the potential to achieve, can they put it on without help for instance.

What they expect or hope for after treatment is complete, how they will cope or adapt to a certain intervention or rehabilitation plan and even things like what kind of shoes they like to wear and how they feel about how an appliance or intervention will impact on aesthetics or lifestyle. This is known as the bio-psycho-social (BPS) approach but really it is about listening, being considerate and pro actively holistic throughout the whole treatment process.

So, with the clinical and BPS considerations in mind, and as you might have already found if you have foot drop, the choice of treatment, especially the orthotic or AFO (ankle foot orthotic) is crucial for ensuring outcomes of optimal gait progression and balance plus customer compliance and satisfaction. It really doesn’t matter how good a functional design an AFO is if the person with foot drop doesn’t feel they can use it.

So at FootHouse Podiatry and Biomechanics we want to give you great outcomes that allow you to walk with confidence and comfort and set you free to do the activities you want to do.

We will find just the right treatment plan for you which may include an AFO to assist the lifting of your foot or keep it in a dorsiflexed position.

There are many types and makes of AFO, below is an example of one, and they can be supplied ready made and modified to your requirements or they could be a fully bespoke and customised device as from a mould or scan of your leg or foot.

An AFO can make a huge difference to how you walk and feel in everyday life but it not the whole story and there may also be rehabilitation exercise where appropriate and some conditions may require input from a physiotherapist or neuromuscular specialist.

With your help we will choose the right AFO and treatment plan for you. If you would like to know more about how AFO’s work and what different types there are then please go to our blog - Choosing an AFO. (Ankle Foot Orthotic for 1. Lateral ankle instability, 2. Weak foot/ankle/leg muscles 3. Foot drop.)