- Sim Chin Seng
UNDERSTANDING WHAT IS ‘FOOT DROP” AND ITS SYMPTOMS, CAUSES AND TREATMENT
UNDERSTANDING WHAT IS ‘FOOT DROP” AND ITS SYPTOMS, CAUSES AND TREATMENT
“Foot Drop”, sometimes called “Drop Foot”, is a general term for difficulty Lifting the Front Part of the Foot. If you have “Foot Drop”, the Front of your Foot might ‘Drag’ on the ground when you walk.
“Foot Drop” isn't a disease. Rather, “Foot Drop” is a sign of an underlying Neurological, Muscular or Anatomical problem.
Sometimes “Foot Drop” is temporary, but it can also be permanent too. If you have “Foot Drop”, you might need to wear a Brace on your Ankle and Foot to hold your Foot in a Normal Position.
WHAT ARE THE POSSIBLE CAUSES OF “FOOT DROP”
“Foot Drop” is usually caused by a Weakness or Paralysis of the Muscles involved in ‘Lifting’ the Front Part of the Foot. Causes of “Foot Drop” might include Nerve injury. The most common cause of “Foot Drop” is the Compression of a Nerve in your leg that controls the muscles involved in Lifting the Foot (the Common Peroneal Nerve).
The “Common Peroneal Nerve” which branches from the Sciatic Nerve and provides sensation to the Front and Sides of the Legs and to the Top of the Feet. This Common Peroneal Nerve also controls the Muscles in the Leg that ‘Lift’ the Ankle and Toes Upward.
“Foot Drop” is a deceptively simple name for a potentially complex problem. It can be defined as a Significant Weakness of the Ankle and Toe Dorsiflexion. The Foot and Ankle Dorsiflexors include the Tibialis Anterior, the Extensor Hallucis Longus (EHL), and the Extensor Digitorum Longus (EDL). These muscles help the body clear the Foot during the “Swing Phase” and Control Plantarflexion of the Foot on Heel Strike.
Weakness in this Group of Muscles results in an “Equinovarus Deformity”. This is sometimes referred to as “Steppage Gait”, because the patient tends to walk with an “Exaggerated Flexion” of the Hip and Knee to prevent the toes from catching on the ground during the “Swing Phase”.
UNDERSTANDING THE VARIOUS SYMPTOMS OF “FOOT DROP”
“Foot Drop” makes it difficult for you to Lift the Front Part of your Foot, so it might ‘Drag’ on the floor when you walk. This can cause you to raise your thigh when you walk, as though climbing stairs (the “Steppage Gait”), to help your Foot clear the floor. This “Unusual Gait” might cause you to slap your foot down onto the floor with each step. In some cases, the skin on the top of your foot and toes may feel numb. Depending on the cause, “Foot Drop” can affect either ONE or BOTH feet.
The symptoms of “Foot Drop” may occur gradually or appear suddenly, making it difficult to Stand, Walk, or Lift the Affected Foot. The “Walking Pattern” or “Gait” of the person typically changes to compensate for the weakness experienced in the Foot Muscles.
The symptoms of “Foot Drop” may vary depending on the type and severity of the underlying condition. A few of these symptoms and warning signs of “Foot Drop” are discussed below.
Symptoms and Signs of “Foot Drop”
“Foot Drop” causes an abnormal decrease in the extent to which the Foot can be lifted off the ground during the “Swing Phase” of normal walking. The ‘Gait Cycle” can be broken down into TWO primary phases, the Stance Phase and the Swing Phase, which alternate for each lower limb. The “Stance Phase” - Consists of the entire time that a Foot is on the Ground. The “Swing Phase” - Consists of the entire time that the Foot is in the Air.
A few of these symptoms and signs of “Foot Drop’ includes:
(1) Inability to Hold Footwear
A feeling of the ‘Loosening’ of the Footwear may cause Discomfort and Dragging of the Affected Foot while Walking.
(2) Frequent Tripping
Weakness in the Muscles of the Foot and Toes may result in frequent tripping.
It is common to lose balance, stumble, and fall with a “Foot Drop”. Falls occur due to the inability to properly Lift the Front Part of the Foot and Toes while walking.
(4) High “Steppage Gait”
This type of “Walking Pattern” is characterized by raising the thigh up in an ‘Exaggerated’ fashion, such as like in climbing stairs. A high “Steppage Gait’ is attempted to prevent the Toes from “Abnormally Hitting” or “Scraping” the floor while walking.
(5) Circumduction Gait
Sometimes, in order to avoid falls or tripping, a “Circumduction Walking Pattern”, where the Leg remains straight and swings to the side in a “Semicircle” to move forward may be attempted.
The Medical Definition of the term “Circumduction” is the movement of a Limb that causes the Hand or Foot to describe a “Circle”.
In “Circumduction Gait”, the Leg moves in a “Semicircular Pattern” and we can define “Circumduction Gait” as an “Abnormal Gait” in which a person in order to clear the ground lifts the leg and takes away from the body and moves forward in a “Semicircular Pattern”.
(6) Limp Foot
The Affected Foot may ‘Flop Away’ from the body. It may also be difficult to climb stairs.
Loss of Sensation may occur on the Front and/or Outer Side of the Lower Leg, and/or along the Upper part of the Foot. Numbness in your Foot may be a temporary condition or it can be the result of a Chronic Condition, such as Diabetes. The symptom can also be progressive. You may begin to lose some sensation in your Foot, then slowly lose more and more feeling as time goes on. Seeking medical advice for numbness in your Foot may help slow or delay its progression.
That “Pins-and-Needles” Effect is called “Paresthesia”. It happens when your Nerves are Compressed, usually because you're putting too much pressure on them.
Nerves are what give you sensations, like feeling pain, through signals sent from your body to your brain. If there's too much pressure on your Nerves, they can't do their job of transmitting those messages.
Here's how it works - the pressure cuts down the blood flow in vessels that nourishes your Nerves. Without that vital blood supply, the Nerves can't transmit messages from your body to the Brain. They end up sending signals that the Brain doesn't know quite what to do with, so it starts producing different sensations, like ‘Tingling’ or ‘Numbness’.
When you relieve that pressure on the Nerves, usually by switching your position, your Nerves start to get their function back. For a little while, blood flows more freely to that part of your body, which makes the “Pins- and-Needles” feeling worse for a bit. When the blood flow is restored and the Nerves start working properly again, the feeling subsides.
(8) Often Unilateral (One Foot Affected Only)
“Foot Drop” typically affects ONE foot, especially when caused by a Pinched Nerve in the Lower Back or Leg.
(9) Decrease in Muscle Mass
Weakening of the Muscles may also cause the “Muscle Mass” to reduce, especially when “Foot Drop” is caused by certain Autoimmune conditions, such as “Multiple Sclerosis (MS)”.
(10) Romberg’s Sign
There may be a “Loss of Balance” while standing without support and with the eyes closed.
The “Romberg Sign” is present when a patient is able to stand with feet together and eyes open, but sways or falls with eyes closed. The “Romberg Sign” developed in the 19th century from a patient-reported symptom into a bedside-elicited sign.
In the first half of the 19th century, European Physicians—including Marshall Hall, Moritz Romberg, and Bernardus Brach—described Loss of Postural Control in Darkness of Patients with Severely Compromised Proprioception. Romberg and Brach emphasized the relationship between this Sign and “Tabes Dorsalis”.
“Tabes Dorsalis” is a slow Degeneration of the Nerve Cells and Nerve Fibres that carry Sensory Information to the Brain. The Degenerating Nerves are in the Dorsal Columns of the Spinal Cord (the portion closest to the back of the body) and carry information that help maintain a person's sense of position.
Later, other Neurologists evaluated the phenomenon in a broader range of neurologic disorders using a variety of simple but increasingly precise and sensitive clinical tests. Although now known as “Romberg’s Sign”, among Neurologists in the late 19th century this phenomenon was sometimes credited to Romberg, sometimes to both Brach and Romberg, and sometimes discussed without attribution.
The symptoms of “Foot Drop” may be “Constant” or “Intermittent” with periods of normal foot strength in between.
WHAT ARE SOME OF THESE POSSIBLE CAUSES OF “FOOT DROP”
“Foot Drop” is usually caused by a “Weakness” or “Paralysis” of the Muscles involved in Lifting the Front Part of the Foot. Some of the possible Causes of “Foot Drop” might include:
(1) Possible Nerve Injury
The most common cause of “Foot Drop” is from the Compression of a Nerve in your leg that controls the muscles involved in lifting the foot (“Common Peroneal Nerve”). This Nerve can also be injured during a Hip or Knee Replacement Surgery, which may then cause you to have “Foot Drop”.
(2) A Nerve Root Injury
"Pinched Nerve" — in the spine can also cause “Foot Drop”. People who have Diabetes are usually more susceptible to these types of Nerve Disorders, which are often associated with “Foot Drop”.
(3) Muscle or Nerve Disorders
Various forms of “Muscular Dystrophy”, an inherited disease that causes progressive muscle weakness, can also contribute to “Foot Drop”. So can other disorders, such as “Polio” or “Charcot-Marie-Tooth (CMT)” Disease.
(4) Brain and Spinal Cord Disorders
Disorders that affect the Spinal Cord or Brain — such as “Amyotrophic Lateral Sclerosis (ALS)”, “Multiple Sclerosis (MS)” or “Stroke” — may also cause you to have “Foot Drop”.
WHAT ARE SOME OF THESE RISK FACTORS THAT MAY CAUSE “FOOT DROP”
The Common Peroneal Nerve controls the Muscles that Lifts your Foot. This Common Peroneal Nerveruns near the surface of your skin on the side of your Knee closest to your Hand. Activities that may Compress this Common Peroneal Nerve can increase your risk of “Foot Drop”. Examples of some of these activities may include:
(1) Habitually Crossing Your Legs
Habitual postures such as Regular Crossing of Legs may lead to Common Peroneal Nerve Compression near the Knee and this is a risk factor for “Foot Drop”. While “Foot Drop” may be a temporary symptom of an underlying cause, sometimes it can be permanent. The symptoms usually improve with prompt treatment.
(2) Prolonged Kneeling or Squatting
Occupations that involve prolonged Squatting or Kneeling — such as picking strawberries or laying floor tiles — can also result in “Foot Drop’.
Certain Yoga Positions can also cause Nerve Compression resulting in “Foot Drop”. Recent experience indicates that Common Peroneal Nerve Injury may also result from a well-known Yoga practice (the “Kneeling Pose”), giving rise to what may be called "Yoga Foot Drop".
(3) Wearing a Leg Cast
Plaster Casts that enclosed the Ankle and end just below the Knee can exert pressure on the Common Peroneal Nerve and this may cause “Foot Drop”.
CAN YOU FULLY RECOVER FROM “FOOT DROP”?
If the cause is successfully treated, “Foot Drop” might improve or even disappear. If the cause can't be treated, “Foot Drop” can also be permanent. Treatment for “Foot Drop” might include the wearing of Braces or Splints to keep the Foot and Ankle in a Normal Position.
Prognosis and outcome vary according to the cause of the “Foot Drop”. In a “Peripheral Compressive Neuropathy”, recovery can be expected in up to 3 months, provided that further compression is avoided. A partial Peroneal Nerve Palsy after Total Knee Replacement has a uniformly good Prognosis.
WHAT ARE THE VARIOUS EXERCISES THAT ARE DESIGNED TO HELP IMPROVE YOUR CONDITION OF “FOOT DROP”
Exercises for “Foot Drop” are designed to help Strengthen the Lower Limb Muscles so that you can ‘Lift’ your foot up normally again. Exercise also helps stimulate and rewire the brain, which make it an effective way to overcome “Foot Drop after a Stroke or Brain or Spinal Injury.
Before we introduce the Exercises, we must first understand the functions of each of those Muscles involved in the Movement of the Ankle.
Muscles in the Anterior Compartment
THREE muscles in the Anterior Compartment of the Leg act to “Dorsiflex” and “Invert” the Foot at the Ankle Joint
(1) Tibialis Anterior
The Tibialis Anterior muscle is located alongside the Lateral Surface of the Tibia and is the strongest Dorsiflexor of the Foot.
o Attachments: It Originates from the Lateral surface of the Tibia and attaches to the base of the big toe.
o Actions: “Dorsiflexion” and “Inversion” of the foot.
(2) Extensor Digitorum Longus
The Extensor Digitorum Longus is a deep-lying extrinsic muscle that runs the length of the Tibia.
a. Attachments: It Originates from the Tibia and transitions into a tendon, passes into the foot, splits into four, and attaches to the toes.
b. Actions: “Extension” of the Toes and “Dorsiflexion” of the Foot.
(3) Extensor Hallucis Longus
The Extensor Hallucis Longus is a deep lying extrinsic muscle beneath the Extensor Digitorum Longus.
a. Attachments: It Originates from the Fibula and attaches to the Big Toe.
b. Actions: “Extension” of the Big Toe, and “Dorsiflexion” of the Foot.
Muscles in the Posterior Compartment
Several muscles are located in the Posterior Compartment of the Leg, typically grouped into Superficial and Basal Groups. The majority of these muscles work to Plantarflex the Foot at the Ankle.
Superficial Muscles in Posteriror Compartment
The Superficial Muscles give rise to the characteristic shape of the Lower Leg. These comprises of the following:
(1) Gastrocnemius Muscle
The Gastrocnemius Muscle, a two-headed muscle, is the most Superficial of the muscles in the Posterior Compartment.
o Attachments: Both Heads originate from the Femur. The fibers converge to form the Calcaneal Tendon which attaches to the Heel.
o Actions: “Plantarflexes” the Foot, can also flex the Lower Leg at the Knee but is not key in this movement.
(2) Plantaris Muscle
The Plantaris is a small muscle lying between the Gastrocnemius and Soleus. It is absent in about 10% of people.
o Attachments: Originates from the Femur and attaches to the Heel via the Calcaneal Tendon.
o Actions: “Plantarflexes” the Foot, can also flex the Lower Leg at the Knee but is not key in this movement.
(3) Soleus Muscle
The Soleus is a large flat muscle which is the deepest lying of the Superficial Muscles.
a. Attachments: Originates from the Tibia and Fibula and attaches to the Heel via the Calcaneal Tendon.
b. Actions: “Plantarflexes” the Foot.
Deep Muscles in Posterior Compartment
The Deep Posterior Compartment Muscles include the Flexor Hallucis Longus, Flexor Digitorum Longus, Tibialis Posterior and Popliteus Muscles.
(1) Tibialis Posterior
The Tibialis Posterior is the deepest lying of the muscles in the Posterior Compartment.
o Attachments: Originates from the Tibia and Fibula and attaches to the Plantar Surfaces of the Toes.
o Actions: “Inverts” and “Plantarflexes” the Foot, maintains the Arch of the Foot.
Muscles in the Lateral Compartment
There are TWO muscles in the Lateral Compartment of the Leg; the Fibularis Longus and Brevis(also known as Peroneal Longus and Brevis). The common function of the muscles is “Eversion” – turning the Sole of the Foot Outwards. They are both innervated by the Superficial Fibular Nerve. Physiologically, there is a preference for the Foot to invert, so these muscles also prevent excessive inversion.
(1) Fibularis Longus Muscle
The Fibularis Longus Muscle is the longer and more superficial of the two muscles.
o Attachments: Originates from the Fibula and Tibia. The Fibers converge into a Tendon which passes under the foot and attaches to the Medial Side of the Foot.