Oh, My Aching Body - 9 - Plantar Fasciitis

Have you ever stepped out of bed in the morning and felt like you stepped onto a Lego, but there's no Lego? If so, you have the primary symptom of plantar fasciitis.

I'll start with the pronunciation. The tissue that holds up the arch of your foot is the plantar fascia. Some people say "FOSH-uh," some say "FAYSH-uh," and I say "FASH-uh," like all of the other people who say it correctly. When we add the suffix "-itis" to anything, it means inflammation of whatever the prefix was. So this is inflammation of the fascia. But if you drop the "a" off of fascia, then add "-itis" you have two "i's" in the middle of the word. Some people pronounce both, and it comes out plantar "FA-shee-I-tis." It's fine. Go ahead. Say it like that. 

Many of us pronounce it plantar "fash-I-tis." This, to me, is correct, and it keeps my blood pressure reasonable.

Regardless of how they pronounce it, if someone is talking about it, it's because at some point they have gotten out of bed and felt like someone was stabbing them in the heel of their foot. 

The plantar fascia is a really thick, inelastic tissue that starts at the bottom of your heel bone, and stretches to the ends of the bones that make up the ball of your foot. It whole job is to support the arch of the foot. Without it you wouldn't have any spring in your step. Those foot bones would just slap on the floor as if you were wearing swim fins.

We all have the same bones and tissues, but you'd be surprised at how many different alignments there are in those tissues.

Here's what we call pes planus (flat feet):

See how the achilles makes a turn between the calf and the heel?

Here's what we call pes cavus (high arch):

The achilles is curving in the opposite direction. 

When your plantar fascia gets inflamed, it lets you know, The intense pain first thing in the morning is the hallmark symptom, but there are other things to know about plantar fasciitis. 

Like other tendinitises, plantar fasciitis has three phases of intensity as the condition worsens.

• Stage 1 - Your heel will hurt when you step out of bed in the morning. As the day progresses, your tissues warm up and the pain lessens.
• Stage 2 - Your foot hurts first thing in the morning, and that pain is getting worse. Your heel will hurt after physical activity, but not during physical activity.
• Stage 3 - Now your heel hurts all the time -- even when you're playing pickleball. After pickleball it's throbbing, and when you get up in the morning you're walking on the outside of your foot, which you are trying to close like a fist, in order to avoid putting the sole of your foot on the floor.

That fascia on the bottom of your foot is experiencing minor tearing at its origin point at your heel. The more you stress it, the more inflamed it gets. The more inflamed it gets, the more it will tell you to stop whatever it is you're doing.

When an athlete comes into the training room with plantar fasciitis, we do cold soaks, ultrasound, friction massage, and strengthening activities. All of these have limited success. We also have a specific tape method to support the plantar fascia, and this is more effective than the exercises and modalities. With the athlete seated, leg straight and ankle flexed, we put the foot into a neutral position, then apply tape to the ball of the foot and around the heel of the foot. When the athlete stands up, the tape prevents the foot from splaying. This relieves a lot of the stress experienced by the plantar fascia when someone is standing, running, and jumping on an overstressed plantar fascia.

But the MUCH MUCH MUCH better option is a rigid arch support.

Over-the-counter arch shoe inserts are available at every drug store. Simple insoles are similar to the inserts that come in your sneakers. They cost about $10, but they aren't supportive enough to relieve the stresses on your plantar fascia.

See how there's nothing under that arch? If you have low arches, this insole will just collapse under your foot. If you have high arches, this insole isn't providing any support. You'll need something more supportive. 

The next level goes beyond a simple insert. These are marginally better. These cost about $20, and they put some cushion and padding under your arch. But that cushion is small and spongy, so it compresses under your foot.

There are over a dozen arch support options at any drug store. None of those are very effective for plantar fasciitis that has progressed to stage 2. There are other supports available that offer more support, like the ones below. These are about $70, and they are rigid.

If you aren't getting relief from these, I'd recommend custom orthotic insoles. They cost between $350 and $500, but in my own experience they're totally worth it. When you see an orthotist, she'll put your foot into a neutral position in a mold, then she'll create an orthotic to correct for your specific misalignment. 

In my own experience, I started getting plantar fasciitis when I was playing soccer and diving in college. During soccer season I got orthotics, I initially got to help my severe shin splints that were on the verge of stress fracture. (The same forces that cause shin splints will contribute to plantar fasciitis.) A podiatrist took a cast of my foot and sent it to a lab, and a few weeks later I had my insoles. A few weeks after receiving my orthotics I moved from soccer into springboard diving, so I was jumping on bare feet for 2-3 hours every day, and my shins and feet got much worse. I've had custom orthotics continuously since 1987, and when my feet start to hurt I know it's time to get new ones. I can wear the same pair for 8-10 years without needing new ones. If I spend too much time in my Tevas during the summer, the soles of my feet get grumpy and I move back to my shoes with supports.

If you have foot pain (or sometimes shin pain, leg pain, knee pain...), you should see a doctor before it gets to stage 3. Amy had to have a PRP (platelet rich plasma) injection into her foot, and she does not recommend that experience to anyone. If you need orthotics, I'd strongly recommend Heather at Boulder Orthotics (boulderorthotics.com). Instead of getting a mold of your foot that's sent out to a lab, Heather will make the orthotics while you're in her office. Instead of waiting for your orthotics for a few weeks, Heather hands them to you while you're there, and then she'll watch your gait to make sure your foot position is properly aligned. Then she'll make more adjustments so that your orthotics are perfect. Amy and I have both gotten our orthotics from Heather, and both of us really notice a difference in our feet and legs when we have the right support.

If you have a topic you'd like to know more about, please send your recommendations to Karina. If you'd like to be a guest author for Oh, My Aching Body, please submit an article!

Oh My Aching Body - 8 - Heat Illness

Oh My Aching Body 

Heat Illness

There's a heat advisory today. It's the middle of summer. I just came inside after about two hours working with Amy to repair our backyard umbrella, which provides the only shade on our back patio. After Amy and I both sweated buckets during that mid-day task, she decided to continue the outdoor tasks in the sweltering heat by mowing the lawn. It's 101° right now. That's the official temperature, which is taken in the shade. The lawn Amy is mowing isn't in the shade. 

Why she's mowing the lawn right now is beyond me. Our smarter dog won't even go outside. When the patio door is closed she looks outside longingly, but as soon as we open the door and invite her out, a wall of heat hits her and reminds her why she didn't go out when we invited her to join us an hour ago. 

The dopey dog goes right outside to be near us and he's miserably hot. We just got his hair cut yesterday.

With all these record high temperatures, it's a good time to review heat illness and what's going on in your body when it's way too hot outside. 

If you've read any of my previous "Oh My Aching Body" entries, you've already read that our bodies are absolutely miraculous. Homeostasis is another of those miraculous things. Homeostasis, simply stated, is the body's ability to keep itself in balance. This is probably the MOST underappreciated of all the underappreciated functions of the body. It includes our heart rate, our breathing rate, our blood oxygen levels, our stress hormone levels, cholesterol levels, neurotransmitter levels, and our body temperature, among many, many other things. You know how every time you get a blood test they list dozens of different factors, and all of them have a normal range? All of those dozens of things are kept in homeostasis, or "normal range" by the body's incomprehensible, miraculous balancing mechanisms. 

Body temperature must remain within one degree of normal, and our body's ability to regulate temperature plays a critical role in overall health. When the body is sick it gets hotter, and when the body gets hotter it gets sick. Let me tell you a story...

From 1991-1994 I was the Athletic Trainer at a high school in Tempe, Arizona. One August the sports teams were in the midst of their pre-season two-a-day practices. In Arizona football teams hold their two-a-day pre-season practices from 6:00-8:00am, and 7:00-9:00pm. There were mandatory water breaks. Students were encouraged to rest up and drink plenty of water and electrolyte beverages between practices, and salt their food a little at each meal. At the very end of one nighttime practice the players were in full pads running sprints from one sideline to the other and back. It was brutal, and I remembered my own pre-season two-a-day workouts. Anyway, one kid puked, almost all the boys were gasping with their hands on their knees at the end of each sprint, and a few took a knee to recover. One player was taking longer to get back to the line than his teammates. His name was Bubba. He was six feet tall and super muscular. He also had very dark skin, which is relevant to this story. The coach asked me to check on Bubba, but Bubba didn't want me to. The coach insisted. I pulled Bubba aside and asked how he was feeling. He assured me he was fine. I checked his pulse, and even checked his blood pressure. All were within normal limits. He said he was fine to keep going. He was a senior, and one of the stars of the team. It seemed reasonable that he'd be exhausted after so many suicide runs at the end of another two-a-day practice in August. In fact, it was surprising to me that ALL of the players weren't collapsing. So I signaled to the coach that Bubba was okay to join the rest of the team for what would be just a few more minutes until practice was over for everyone. Bubba rejoined his teammates for the final two sprints of the day. With practice over, I drove Bubba back to the training room in my golf cart, where I started to fill the whirlpool with tepid water. I got him onto my treatment table and applied some ice packs for the backs of his knees, his arm pits, and the back of his neck to help cool him.

While I was checking the temperature of the cold whirlpool Bubba started convulsing. I got to him before he fell off the treatment table, then I protected his head while his body convulsed for what seemed like a long time, but was probably less than a minute. He wasn't unconscious during all of that chaos, but he wasn't aware of his surroundings, either. I called 9-1-1 and kept applying ice packs to his neck and legs until the ambulance came and took him to the emergency room. After hours of evaluations and blood tests, the ER doctor said he couldn't be sure what caused the seizure. 

Despite the doctor's limitless ability to examine Bubba and run lab tests, without getting a definitive diagnosis, I decided I should have done a lot better by Bubba. The next week I was in a classroom to become an EMT (Emergency Medical Technician), because I felt that my understanding of heat illness needed to be a lot better. I had received training in heat illness while earning my degree in Athletic Training, but surely someone trained in emergency medicine would be better prepared than an Athletic Trainer when it came to heat illness, right? When we got to the section on heat illness that semester I was dismayed that it was even more sparse than what I had already learned. It was really frustrating and disheartening to see how much our text books were racially biased. The text books all talked about how a person suffering from heat illness will look either pale, in the case of heat exhaustion, or bright red in the case of heat stroke. Bubba was never going to be pale or bright red. There was no mention at all about the appearance of a person with dark skin who is suffering from heat illness.

So I researched further. And because this week there's a heat advisory, it seems like a good time to share what I've learned with you. This entry covers three types of heat illness: Dehydration, Heat Exhaustion, and Heat Stroke.

DEHYDRATION

When you get hot your body brings your temperature down through sweating. Air circulating over water has a cooling effect on skin. But prolonged sweating results in dehydration. Mild Dehydration starts when your body loses 1% of your body weight in sweat. For a 150 pound person that's 1.5 pounds. That's the equivalent of only three cups of water. The signs and symptoms include darker-than-normal urine, thirst, a dry mouth, and mild irritability. The salts you're losing in your sweat are called electrolytes. As their name implies, they are responsible for the electrical functions in your body, including muscle contractions and neurons firing in your nervous system. In other words, they're REALLY important.

If you continue sweating, your symptoms will get worse. When you lose about 2% of your weight in sweat you might start to experience muscle cramping. Many athletes experience calf or hamstring cramps during activities like soccer or football, for example. When you increase the amount of sweat you lose from 2% to 3% of your body weight, the likelihood of muscle cramping doubles. 

With Moderate Dehydration you have lost 3% to 5% of your body's weight in sweat. You'll experience fatigue, very dark urine, increased irritability, and your heart rate might increase. Your heart beats faster because it's sole function is to get oxygen to all parts of your body, but with less water in the system you have less blood volume, so your heart has to work harder to circulate what's left. 

When you reach 6% of your body's weight lost in sweat, you've reached a level called Severe Dehydration. This is when the body's systems are wildly out of balance, to the point of being a medical emergency. Without enough blood and/or oxygen to the brain, and without enough electrolytes to make the nervous system function properly, a person is severely in need of fluids, but may be unable to drink because of vomiting reactions, confusion, or weakness. There are stories of wrestlers who try to make their preferred weight class by sweating off pounds, and die as a result.

Here's where things get complicated. Imagine you have one gallon of water and four cups of salt. You mix the salt into the water and it creates a solution with a specific water:salt ratio. If you pour out half of the solution, then fill up the gallon container with water, the concentration of the salt in that solution has been halved. Similarly, if you lose two quarts of sweat during activity, you're experiencing mild to moderate dehydration. If you drink two quarts of water to replace those fluids, the concentration of electrolytes in your system is even lower than before you started to rehydrate. Drinking water without electrolytes dilutes the system and causes more imbalance, and can result in headaches, nausea, vomiting, even more confusion, and swelling.

HEAT EXHAUSTION

The second of three heat-related illnesses we'll cover is Heat Exhaustion. This condition is strongly related to dehydration, because it results from the body becoming so overheated that it dumps 1 to 2 quarts of sweat per hour. This results in all of the dehydration symptoms listed in the previous section, and then some. While dehydration involves the loss of fluids, heat exhaustion adds the complication of an internal body temperature between 100° to 104°.

To keep your body temperature within one degree of normal, not only does the body cool itself through sweating, but it also shifts the body's blood from the core to the extremities. Blood near the skin in your arms and legs will shed heat more quickly than blood that is deep in your torso. So the body, again quite miraculously, shifts where the blood flows. But if your body needs to be at 98°, but you're mowing the lawn where it's 108°, your body can't shed heat, so your internal temperature increases.

With Heat Exhaustion you'll experience heavy sweating with cool, moist skin, and you'll have goose bumps even when it's hot out. You'll experience light-headedness, dizziness, a rapid pulse, and because you've lost so much fluid, your blood pressure will be low. You might also have a headache and nausea. 

If you don't address your Heat Exhaustion, you could end up with Heat Stroke, which is the most serious and deadly of all the heat illnesses.

HEAT STROKE

Heat Stroke is a life-threatening emergency in which the body's ability to regulate its own temperature has failed completely. Internal body temperature is higher than 104°. It's so bad that the body stops sweating. The person might lose consciousness, or become agitated and combative. Text books will tell you that the person's face will be bright red. What they don't tell you is that a black person's skin will be darker or purplish. Some sources tell you that you can determine changes in a black person's skin color by inspecting the nail beds and the insides of the lips by pulling the bottom lip down. This makes no sense whatsoever. I wouldn't recommend approaching someone who is agitated and combative and pulling their bottom lip down to see if the inside of their lip shows increased redness. If they're unconscious you could check their lips, but that doesn't make sense, either. If someone is unconscious, regardless of their temperature or skin color changes, call 9-1-1! They're unconscious! That's bad! Just call!

PREVENTION

Considering all the risks involved in heat illness, the best thing you can do is prevent heat illness altogether. When you see a heat advisory like the one that the National Weather Service posted today, stay indoors. Not to beat a dead horse about our particular demographic, but older people have less efficient circulatory systems, and less efficient sweat mechanisms. This makes people over 60 more vulnerable to high temperatures. If you REALLY have to play pickleball, go to an indoor venue, or play early in the morning or after sunset. Bring your cooling towels and portable fans. Put ice in your insulated water bottle. If you start feeling weak or light-headed, get out of the sun.

Your clothing fabric and colors make a big difference, too. Dark colors absorb heat, and light colors reflect heat. Also, going back to Bubba's situation, black skin absorbs heat more readily than white skin. Whoever you are, and however light or dark your skin, when you're going to be in the sun, wear light, loose-fitting fabrics and light colors. The photos below show surface temperatures from a few feet apart. The white section of wall on our garage is 128°. The black garbage can just a few feet below it is 166°! For context, if you cook beef to 166° internal temperature it's beyond well-done and will be very tough and dry. An egg will fry on a skillet that's 135°.

 

TREATMENT

When you're suffering from Dehydration, drink fluids and replenish your electrolytes. There are a lot of sports drink options to choose from. Some are ready-mixed beverages like Gatorade and Powerade. Others are single-serving pouches of mixes, like Liquid IV, LMNT, Nuun, and others. Costco has a lot of different options in enormous quantities. They're easy to pack, so toss a few pouches in your pickleball bag or hiking pack. Whichever electrolyte replacement method you choose -- sports drinks, extra salt on your food, supplement tablets -- be sure to replace your electrolytes when you've lost a lot of sweat.

For heat exhaustion, get out of the heat and do what you can to lower your internal temperature. Shade is one good option, because temperatures are drastically different in the shade. This spot on our front porch is a great example. I took surface temperatures of our front porch -- one spot exposed to the sun, and the other a few inches away in the shade. These two spots about four inches apart show a temperature difference of over 10 degrees. (The readouts below are a little hard to see. The one in the shade says 88.8. The one in the sun says 98.9.)

If you can get indoors to air conditioning, that's even better. To lower your temperature even more quickly, immerse yourself in a tub or pool of cool water (45° to 55°). If a cool tub isn't available, you can apply ice packs to areas where your blood vessels are closest to the skin, like your arm pits, groin, the backs of your knees, and your neck.

When you suspect that someone has Heat Stroke, call 9-1-1 and get them emergency medical attention. Don't mess around with that because it's life-threatening. 

Those are the basics on heat illness. Please be careful out there, folks! 

Oh, and one more thing! Wear sunscreen!

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Do you have a topic you'd like for me to address? Let me know!

Are you someone with more expertise in aching bodies than I, or do you have a particular area of medical expertise that you'd like to share? I'd love to step aside and let you write an article! Let me know!

 

Oh My Aching Body - 7 - The Knee

Few people make it to middle age (let alone beyond) without some kind of knee problem, so this entry should be relevant to just about everyone. I’ll start with the basics. 

ANATOMY

The knee is a hinge joint, in that it bends and straightens. But like everything in human physiology, it’s more complicated than that. The tibia (shin bone) also does a slight amount of twisting. Additionally, there’s a knee cap, which increases the leverage of our quadriceps, making the thigh muscles more powerful than if they were connected to the shin bone without the knee cap.

Three bones make up the knee: the thigh bone (femur) is the top of the hinge, the shin bone (tibia) is the bottom of the hinge, and the knee cap (patella) is the insertion point for all the tendons of the quadricep muscles on the front of the thigh.

The femur doesn’t come into contact with the tibia, because of two cartilage disks that sit between the femur and tibia. These are the medial and lateral meniscus. 

They’re fibrous, spongy discs that keep the bones from wearing on one another. At the ends of the bones is a second kind of cartilage called articular cartilage. (By the way there’s a third type of cartilage that has nothing to do with joints. It’s the stiff tissue that gives shape to your ears and your nose. I don’t know why the experts didn’t come up with different Latin-sounding words for these three different kinds of tissue. After all, there’s about a dozen ways to refer to skin tissue. But I digress.) Back to articular cartilage. Bones are very strong because of how they’re constructed, and they’re lightweight, porous, and brittle. But the ends of the bones are smooth, like the surface of an ivory piano key. 

The knee joint is surrounded by a capsule, and inside the capsule is fluid, which acts like the oil or grease in a pinion joint.

The smooth piano key surfaces, lubricated by joint fluid, and protected from wear by fibrous discs, can handle a lot of force and torque.

But with an active lifestyle, or with misalignment, so many things can go wrong with the knee. 

CHONDROMALACIA

One of the most common knee problems is chondromalacia patella, or patello-femoral pain syndrome. To find out if you have this condition, sit down on a bed or table with your knee fully extended and your heel supported. Now trap your kneecap with the web of your hand between your thumb and forefinger, gliding your knee cap away from you. Now tighten your quadricep muscles and see what happens. In the photo below the examiner is pressing down much too hard on the distal quadriceps. The test doesn’t require that much force. 

Did your kneecap slide smoothly under your hand?

If yes, then you don’t have chondromalacia. 

Did you screamed in pain while your kneecap crunched like Rice Krispies as it passed under your hand? Or did your quadriceps muscles just quiver because they wouldn’t allow you to force your patella under your hand. Then the test was positive for patello-femoral pain syndrome.  

Several of my teen-age college soccer teammates had chondromalacia, so it’s a condition not necessarily connected to old age. But it is connected to chronic wear and tear of the underside of the knee cap, so it’s more common in young athletes who have poor alignment of their knee cap, with athletes who land on their knees or squat a lot (like goalkeepers and catchers), or with people who have been suffering misalignment of their bones for several decades. So age does factor in for many.

If you’ve ever seen an old piano, you’ve seen piano keys with the ivory surfaces chipped off. If two of those damaged keys were rubbed against each other, they will scrape and erode each another.

With chondromalacia, that’s what the bones of your knee are doing when they’ve lost that smooth articular cartilage. The bones wearing on one another cause a lot of joint inflammation and pain. Even though chondromalacia can happen in one’s youth, it is a progressive condition, so by middle age those knees are pretty irritated. If you have chondromalacia, you’re probably in for a lifetime of arthritic knee pain that will eventually be remedied with knee replacement surgery. 

KNEE SPRAINS

Ligaments are tough, inelastic bands of tissue that keep bones connected to one another. These are the tissues we shred when we sprain an ankle or dislocate a finger. The knee has four ligaments. One is on the inner side of the knee (medial collateral ligament, or MCL) to keep the knee from buckling inward. A second ligament is on the outside of the knee (lateral collateral ligament, or LCL) that keeps the knee from buckling outward. There are two ligaments inside the knee joint. The posterior cruciate ligament  (PCL) keeps the shin bone from sliding backwards, and the anterior cruciate ligament (ACL) keeps the shin bone from sliding forwards. The image below shows the bones and ligaments of the right knee when viewed from the front. In this image the patella (knee cap) has been removed, because it would be blocking the cruciate ligaments.

If we put extraordinary stresses on our ligaments, the tissues will shred or snap, resulting in a sprain. If we sprain the MCL or LCL, we can put the knee into an immobilizer and let those tissues heal over a period of several weeks. While the ligaments are damaged, the knee will be unstable and will buckle, so keeping the knee immobilized is really important for healing.

Unlike the MCL or LCL, the ACL and PCL won’t heal no matter how long we immobilize them. These tissues exist within the knee joint, which doesn’t get much blood flow. Without blood there is little healing, so these ligaments have to be surgically reconstructed. 

You won’t hear about PCL tears very often, because damaging the PCL requires significant force to the front of the shin. This happens most often in sports when a football player tackles another player by diving into his knee and catches the tibia just below the knee. Another way to damage the PCL is when someone is in a car accident and their knees strike the dashboard but the rest of the body keeps going. It’s rare.

The ACL tear, on the other hand, is incredibly common. The ACL can be torn by simply planting the foot and changing directions. You may recall that Lindsey Vonn tore her ACL right before the Olympics when she crashed on a practice run. Adding skis to the feet increases torque on the knee joint, and often results in ACL injuries when the lower leg is twisted. 

A fast recovery from an ACL reconstruction surgery is 6 months, but return to play is more common at 9 months after reconstruction. The surgeon harvests a tendon from somewhere else in the knee – usually a hamstring tendon or part of the patellar tendon – and sews it to a grafting material to ensure that the graft won’t be rejected. Then a channel is drilled through the femur, and the new ligament is screwed into place. Tissues have to undergo a change in function from tendon to ligament, and if this process is hurried the new ligament will rupture again.

If someone decides to NOT have their ACL reconstructed, they’ll experience years of knee buckling. Guys my dad’s age used to talk about “my trick knee from the ol’ football days”. Those are guys who grew up before ACL reconstruction was an option, so every time they stepped left and turned right their knee would give out. Years of this excessive mobility between the bones usually results in bone deterioration and arthritis.

MENISCUS TEARS

The final conditions I’ll cover with this entry are meniscus tears. The fibrous discs of tissue that prevent the knee bones from wearing on one another have to endure a lot of stress every day. Occasionally, these discs will tear. When torn, the meniscus flap can cause the knee to lock, unable to bend or to straighten, as if a door stop was jammed into the joint. 

I’m going to whine about the repetitive use of the term “cartilage” again, because with the meniscus we have many different terms to describe how the meniscus tears. There’s the bucket handle tear, the parrot beak tear, the horizontal tear, and more. If you ask someone with a meniscus tear what happened, they’ll answer “I tore my cartilage.” 

One person who won’t say they have torn cartilage is Evander Holyfield, even though he had some of his cartilage torn off when Mike Tyson bit his ear. But that was a different type of cartilage. 

Remember that event? When Mike Tyson bit off a piece of Evander Holyfield’s ear, and then spit it onto the mat?! I swear this is true – the two of them teamed up and created a cannabis edibles product called “Mike Bites,” with gummies shaped like an ear with a bite out of it. Seriously. I swear. It’s crazy. If any of you tries one of these, please tell me if you experience an increase in bloodlust.

That feels like a good place to stop this entry. We’ve covered many of the nasty things that can happen to the knee, but certainly not all of them. If you want to know more about the knee, let me know. There are 14 bursae that can rupture, for example. There's arthritis. There's the ever-popular knee replacement surgery, which many of you already know about. Some knee problems require immobilization and rest, but several require surgery. The knee is so critical to everyday function and mobility that injury or arthritis results in significant change in one’s lifestyle. So keep those knees healthy, people. Keep moving!

 Oh My Aching Body - 6 - Spinal Discs

This month's article focuses on spinal discs: the fantastic function they provide every day without our acknowledgement, and the awful things that happen when something goes wrong with them. 

Article #4 of Oh My Aching Body is called "Back Pain." It talks about how difficult it is to discern the exact cause of back pain, because there are so many bones, ligaments, and muscles so close together. 

What that article didn't discuss at all was the vertebrae, the intervertebral discs, and the nerves. This article is a brief effort of explaining that. 

We separate the spine into five distinct parts. 

• There are 7 bones in the neck, which flex and rotate to allow impressive range of motion. We call this the cervical spine or c-spine. (Fun fact. Giraffes also have 7 vertebrae in their necks. But each giraffe neck vertebra is almost a foot tall, while the entire human neck averages is between 4.5" and 5" long.)
• There are 12 bones in the mid-back, which connect to the ribs. They don't do a lot of flexing or twisting, but they support the cage that protects our vital organs. We call this the thoracic spine.
• There are 5 bones in the low back. These bones are also capable of twisting and bending. We call this the lumbar spine.
• There are 5 bones fused into a single mass that connects the two sides of the pelvis to the spine. We call this the sacrum.
• Finally, there are the tiny bones referred to as "the tailbone." This "bone" is actually another 3-5 small bones that are fused together at the base of the spine. We call this the coccyx. (It's pronounced cock-six. Really.) The tailbone doesn't wag, so as tails go it's unimpressive. But the lack of wagging makes it possible to play poker without revealing your hand. 

I'm pausing here to draw your attention to the unique shapes of the vertebrae that allow for the incredible mobility of the neck and back, while simultaneously protecting the critical and vulnerable spinal cord. Every vertebra protects the spinal cord that runs through a channel behind the vertebral bodies. 

So despite the fact that it's incredibly flexible, allowing twisting and bending in multiple directions, our spine also protects the spinal cord when we do really stupid things.

The vertebrae are stacked on top of one another from the base of the skull to the tailbone. Between the vertebrae are discs that keep the bones from eroding each other. If the bones are compared to bricks in a wall, the discs are the mortar. When it comes to shape and structure, our discs can be compared to a jelly donut. The outer (donut) part is tough and rubbery, surrounding a soft, gelatin-like filling.

In the picture above you see the "jelly donut" disc, and right above it is the spinal cord, with spinal nerves emerging from it. Simply put, spinal nerves conduct sensations from the body up to the brain, and motor commands from the brain down to the body. 

But sometimes our discs aren't perfect, and those nerves become compromised.

Disc Herniation

If a disc is compressed repeatedly or forcefully, the jelly might squish out of the donut. Below is an image of a herniated disc. This is sometimes referred to as a "slipped disc" or "ruptured disc" or "protruding disc". It's all the same thing. The top view in the image below is looking down on the disc from above. The lower image is looking at the right side of the spine.

With a disc herniation, the jelly squishes out of the donut and pushes against a nerve root, so everything that nerve root innervates is getting mixed signals. With a compressed spinal nerve in your neck, you might feel zinging, tingling, or heat in your entire arm. The muscles might get weaker, because you don't have the ability to maximally contract the muscles that are powered by that nerve. When there's pain or numbness in a muscle, we tend to favor it and avoid using it. We might bend to one side or the other in an attempt to relieve the pressure, thus altering our postural alignment. Every time you bend your spine, it sends jelly out onto the nerve root, which sends a zing to whichever parts that nerve innervates. This results in stiffness, muscle guarding, and limited range of motion.

To relieve pressure on the nerve, we need to get the jelly off of it. 

In the donuts above, the jelly is being contained nicely within the donuts. Imagine slowly compressing one of those donuts between your thumb and fingers. The jelly starts to ooze slowly out of the jelly hole. There's a point at which you can release your compression, pressing on the sides instead of top and bottom. With this counter-pressure, the jelly gets sucked back into the donut. You can do this at home with a toothpaste tube. Slight pressure sends the toothpaste slightly out of the tube, but pressure on the other sides of the tube sucks it back in.

This is why we use traction in the physical therapy clinic. Creating space between the vertebrae might allow the nucleus of the disc to return to where it belongs. For the neck we place a special strap around the chin and base of the skull, then attach the other end to a traction unit that pulls on the skull for about 20 minutes. As the muscles of the neck relax, the traction unit separates the vertebrae, and the patient experiences relief from the disc's pressure on the nerve root. The amount of weight on the traction unit is in the 20-50 pound range.

We do the same thing for the low back, but the muscles are so much thicker and stronger in the low back that we use 20% to 50% of the patient's body weight in pulling strength. For a 200 pound patient we'd use up to 100 pounds of traction, so to keep the patient from being pulled off the table we have to anchor the rib cage to the top of the treatment table. 

Traction works for a lot of patients. Many will feel gradual relief over a period of several visits. A handful will feel immediate relief. 

But for those who have squished out too much jelly, they won't experience any relief at all. 

When your disc looks like the donut above, no amount of counter-pressure will suck the jelly back in. At this point you'll need a surgeon to remove the jelly that's pressing on the nerve. This is called a discectomy. Sometimes this procedure is done with an incision and tissue spreaders, and other times with a much smaller incision and a scope.

When the spongy center of the jelly donut is removed, that gel-like nucleus doesn't grow back. Instead, it is replaced with scar tissue that is less voluminous and less yielding, which results in less mobility of the spine at that spinal level, and less height between the vertebrae. This leads to a higher risk of compression of the nerves emerging between these vertebrae, and quicker degeneration of the disc. Over time, more problems emerge. You already know this: as we age we get more problems with our aching bodies.

Degenerative Disc Disease

Almost everyone over the age of 40 has some degeneration in their discs. This is the main cause of people becoming shorter as they age. There are 23 discs in the spine, so if each one only compresses 1/8" over a lifetime, it will translate to a total of 3" reduction in height. In fact, if you measure yourself in the morning, you'll likely be taller than you are at night. This is due to the compression of the discs throughout the day.

When a disc becomes too damaged to simply clean up the squished out jelly part, it has to be removed entirely. But the bones can't be left to just rub against each other. Options include fusing the spinal vertebrae together with bone or with metal (or both), or replacing the damaged disc.

The most common procedure is the most limiting. To fuse the vertebrae together, the surgeon first places a spacer between the vertebrae. This helps to maintain the space needed to keep from compressing the nerves emerging from between the vertebrae. With that spacer in place, the surgeon removes some bone from the hip (the part where moms rest their hands while scolding) and fuses it to the space between the vertebrae. 

An alternative to spinal fusion with a bone graft is spinal fusion with metal hardware. 

The vertebrae now have no motion at those levels. They are essentially a single, tall vertebra. If you've ever seen a giraffe try to drink water, you know why it's not ideal to have tall vertebrae. Giraffes don't have very much range of motion in those long necks.

 

Additionally, if you don't have any motion at one level of the spine, that need for motion gets transferred to the other levels of the spine, putting more of a demand on the other vertebrae, which speeds the deterioration at those levels. 

An option that doesn't involve fusing the vertebrae is replacement of the deteriorated disc. The disc might come from a cadaver, or it might be a synthetic disc. Replacement with a synthetic is more common than the use of a donor disc, and it carries fewer problems.

With this procedure they carefully measure the angle, circumference, and height of the space between the two vertebrae, then implant a metal plate into the bones above and below that space, then insert a rubbery prosthetic disc into the space between the metal plates.

Following any type of surgery on the spine, there are significant recovery steps involved, with some period of rest followed by physical therapy. But once recovered, people who have experienced disc replacement or spinal fusion are usually much better off in function and quality of life than before the surgery. Having your nerve roots pressed is a terribly uncomfortable thing, so measures as drastic as fusing the spine or inserting synthetic discs are really complicated, and yet preferable to the alternative.

To summarize, spines are super complicated. If you're having chronic back pain, it might be addressed in one of the two posts I've dedicated to back pain so far, or it might be caused by one of the myriad other conditions I haven't even mentioned. (Spondylolisthesis, spondylolisis, arthritis, ankylosing spondylitis, foraminal stenosis, and other difficult to pronounce conditions are plentiful.) If you're having pain in your back, and especially if it's causing pain or function loss in your extremities, please go see an orthopedic specialist and find out what's wrong. There's a good chance they can figure things out and get you on the road to recovery. Don't expect a quick fix, but also don't resign yourself to a life of limitation or pain.

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