Foot drop is defined as ankle foot weakness specifically with ankle dorsiflexion.  Historically, unilateral foot drop has been well documented with most common causes being compression of the sciatic, common and deep peroneal nerves.  Bilateral foot drop is less common, however, we are seeing more and more of these cases with people who have been hospitalized with Covid-19.  There’s a lot out there suggesting that polyneuropathies, Guillian Barre Syndrome, and pressure induced nerve injuries are the causes for these bilateral foot drop presentations.  Inflammation from viruses can also compromise peripheral nerves.  

One theory that is gaining traction has to do with positioning when people are on ventilators.  “Proning” is when a patient is positioned face down to ease breathing.  The goal at this point is survival.  With Covid -19 cases overflowing in hospitals and staff shortages, emphasis is likely not placed on optimal positioning of the limbs.  Unfortunately we are seeing more peripheral nerve injuries as a result of this life saving positioning. They are being observed in one or more of the major joints including:  shoulders, wrists, ankles, and hands.  The extent of nerve damage will likely vary from patient to patient.  It is possible that some may have permanent nerve damage while others may make full recoveries.  Loss of function may lead to reliance on assistive devices including braces, wheelchairs, walkers and canes.  The first 12 months are vital in ones recovery with axon regeneration occurring at a rate of about 1mm/day

I recently have had the pleasure of working with a 47 year old male who, upon our meeting, was in the hospital with Covid-19 for 3 months. He was on a ventilator during part of his stay.  He originally had complete loss of function of both his arms and legs.  While in the hospital he began physical therapy and started to gain mobility and use of his arms, but his lower extremities were not quite as responsive.  He had just begun to gain some movement in the right ankle before his discharge.  It took him about a week to get settled into his new life at home.  During our first visit he had little to no movement in the right foot and no ankle foot movement on the left. I knew that we had to act fast and start working on this immediately. My first thoughts were to load the legs and make him weight bare.  This proved immediately to be problematic as we were running into oxygen saturation issues. He stood supported for 6 seconds and his oxygen dropped to the low 80s.  Okay, so  prolonged loading in standing was out of the question.  My next thoughts were electrical stimulation.  This also proved problematic as he also was having sensory loss and could not feel anything.  This can lead to skin burns.  In the past I have treated foot drop with dry needling with electrical stimulation with great success. I figured it’s worth a shot, it can’t make things any worse.  During our first few weeks of treatment, his right foot was very responsive, improving with each passing week.  The left side however, still did not have much movement at all.  I was worried he might need to use an ankle foot orthosis and even considered purchasing him one to begin gait training with it.  To be honest I didn't find any that I loved. These are typically custom made.  I started to wonder if this was related to the virus? Did he have a stroke in the hospital that they were unaware of?  These are the questions that constantly ran through my head.  Then he had massive onset swelling in his left leg that was extremely concerning. His doctor cleared him of anything serious including blood clots.  When the swelling finally dissipated we started to see small signs of movement.  During this time we were continuing with the dry needling despite not seeing any progress in the left leg as we were seeing huge progressions in the right foot.  We saw our first sign of improvement approximately 6-7 weeks after I initiated treatment with him.  During this time, his endurance was improving, he was getting stronger, he was slowly titrating his oxygen and we were able to do more in standing.  He was ambulating but had to excessively pick up his legs to clear his feet from hitting the ground.  This was concerning because he was a fall risk and was not strong enough to pick himself up from the floor.  Flash forward 3 and half months.  He has gained about 90% ankle foot control back in his right foot, and 75-80% back in his left foot.  He no longer has to excessively lift his legs to clear his feet and walks with a gait that is better than some healthy people. 

So while we are all learning of the residual effects of Covid-19 in real time, if you, a loved one, or anyone you know is suffering from this particular issue, it is imperative that you start treating it as soon as possible.  The earlier you begin to address it, the higher likelihood that you can make improvements.  I mentioned above that the first 12 months are vital for nerve healing, but I think any health care provider would agree that the first 90 days to 6 months are crucial.  In this particular case, he was able to ditch his walker/cane and walk unsupervised. This may not have happened if we didn’t start addressing this immediately which could have been the difference between walking and being in a wheelchair the rest of his life.  

I believe it’s important to mention that a lot of factors play into every individual's recovery including: med history, comorbidities, hospital stay, period of immobility, and severity of the nerve injury.  While this treatment modality definitely played a role in his recovery, it may not be the best treatment for someone else.  If you take home anything from this blog it should be this: Find a professional that can begin to treat your issue immediately. The first 90 days-6 months are imperative and it could be the difference in you walking again.  

Savannah Torrez, PT, DPT, COMT

GRIT

/grit/ noun

Strength of character; perseverance and passion for long-term goals.