Tag: pain

Why Do Your Fingers Make A “Pop” Noise When You Crack Your Knuckles?

When cracking your knuckles, one tends to hear a “pop” noise that is loud, sharp, and irritating to most. This noise can be addicting in the sense that it makes others want to crack their knuckles. The main questions that I focused my research on were “Does cracking your knuckles or joints cause potential health issues for your future?” and “ Why does cracking a joint such as your knuckles make a “pop” noise?” 

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Is my cell phone causing me neck pain?

Female in her early twenties viewing her phone with a smile.
By: Ashley Newbold

77% percent of people in the world have a smartphone according to researchers. The most popular form of communication is text messaging. On average, people are spending 3-6 hours per day on their phone. Children are getting their first smartphones earlier and earlier. The unique capabilities provided by this technology are unmatched, but at what cost?

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Pressurized Vessels Supporting the Spine: Structure and Function of Intervertebral Discs

Back in 1989, it was estimated that about 2.5 million U.S. workers suffered from low back pain, and low back pain has even been talked about as one of the largest causes of disability in the world. Intervertebral disc degeneration is one of the most common reasons for low back pain in adults. In order to understand how disc degeneration occurs and causes pain, it is important to examine the structure and function of discs in the back.

Computer generated image of a healthy lumbar spine
Vertebral Column: Obtained from Smart Servier Medical Art

Discs are structures that sit in between vertebrae in the spine (blue in the image). Their consistency has been compared to Jell-O and the seemingly mythical product called the waterbed. This consistency comes about because of the microstructure of the discs. The main structural component is collagen which not only surrounds the discs but also traverses across the fluid-filled center to give support. Collagen is found all over the body in places ranging from bones to eyes. There are many different types of collagen that are able to account for the softness of the cornea and the strength and stiffness of bones. In discs in the back, the collagen that traverses the middle is the same as that found in cartilage, while the collagen that makes up the outer layer is the same collagen found in skin and bones. This gives the discs a strong, thin outer layer surrounding the gel-like center, warranting the comparison to the waterbed.

Because of this structure, intervertebral discs provide support for the spine in compression. The spine can be compressed by activities as simple as carrying a backpack, sitting, or bending over. When these and other activities occur, the vertebrae press in on the discs, causing pressures from about 15 to 300 psi, or pounds per square inch, depending on the activity. For reference, the recommended tire pressure for a car is 30-35 psi and the pressure inside a champagne bottle is 60-90 psi.

As discs degenerate, either with age or trauma, they respond differently to the large compressive stress applied from the spine. With age, this change in response is most commonly attributed to the inside portion of the disc drying up and changing from a gel to a solid. Discs rely heavily on fluid flowing through their pores, and once they dry up, this no longer occurs. As loads are applied, instead of increasing pressure, degenerate discs can expand outward creating a phenomenon known as a bulging disc. While this is just one of the many medical problems a degenerate disc can cause, it is

Computer generated image of a lumbar spine with disc herniation.
Disc Herniation: Obtained from Smart Servier Medical Art

common and typically leads to an increase in pain. When the discs expand outwards, it reduces the space between the vertebrae causing irritation. If the discs expand far enough outward, they can leave the space between the vertebrae, entering the region where many nerves lie, potentially causing pain throughout the body.

Despite their odd consistency, intervertebral discs play an important role in the spine, sometimes pressurizing to more than 3 times that of a champagne bottle. Both injuries and natural degeneration leads to negative changes in the biomechanical properties of discs, causing an increase in back pain. If you are interested in learning how to take care of your discs, worried you have an injured disc, or simply want to learn more, I recommend going here.

Hell for your Heels: Plantar Fasciitis and Heel Spurs

Heel and foot pain are somewhat universal issues, impacting people of all different sizes and activity levels. This type of pain can be seen in obese people, who have increased strain on their feet and heels. This pain can limit their mobility, and even discourage healthy amounts of exercise.  It is also common to extremely active people, such as runners or sports players. This type of pain can prevent a person from participating in the athletics that they work so hard to compete in. I experienced a great deal of heel pain during high school, which made it difficult for me to play sports such as soccer, basketball, and track and field. This was an issue I had to deal with throughout high school, however I never understood what caused this pain that kept me on the sidelines at times.

Image showing the plantar fascia ligament and where inflammation is common
Image from Energize Health

By far the most common cause of heel pain is damage to the plantar fascia. The plantar fascia is a ligament connecting the ball of the foot to the heel bone, critical for stability and power in human locomotion. Damage to this ligament is caused by 2 main factors: weight and use. Increased weight, especially over a short period of time, significantly increases the load experienced by the plantar fascia. This increased load pushes the ligament past its yield load and causes tears in the ligament, weakening its mechanical abilities and causing pain. Another important contributor to this ligament’s damage is its workload. Active athletes and runners push this ligament to its limit by regularly undergoing periods of high-intensity loading, causing fatigue failure. In my case, a combination of these two factors caused damage to my plantar fascia: a large growth spurt combined with regular athletics overloaded this ligament, causing damage.

Artist's rendition of the medical conditions plantar fasciitis, where the ligament is damaged and swollen, and heel spurs, where abnormal bone growth is seen to to ligament damage.
Image from 2019 Harvard Health Publishing

This damage to the plantar fascia relates to two resulting conditions: plantar fasciitis and heel spurs. Plantar fasciitis is the swelling of the plantar fascia ligament. This inflammation is caused by the tears and damage as previously discussed, causing sharp pains to the bottom of the foot and heel. Tears in the ligament typically occur at the connection of the bone and ligament. Certain factors can make a person more susceptible to this condition, such as having flat feet or wearing footwear with poor support. In both cases, the plantar fascia is loaded poorly, causing the painful inflammation. There are conflicting studies as to how this condition relates to heel spurs and heel pain.

Heel spurs are calcium deposits located around the connection of the plantar fascia to the heel bone, which cause abnormal bone growth in the area. Heel spurs are caused by prolonged loading and damage to the foot muscle and plantar ligament. Heel spurs are often seen as a result of plantar fasciitis, however the two aren’t mutually exclusive. Heel spurs are found in patients without any evidence of heel pain, raising doubts about how they are directly related. Some studies argue that the heel spurs themselves cause pain, while others contest that they develop in response to plantar fasciitis, the true source of the pain.

These conditions are typically first treated through non-invasive methods. These strategies include specific stretches, targeted exercising, a reduction in workload, and weight loss (if safe). These treatment methods help to improve the mechanical properties of the ligament, making it stronger, less stiff, and less fatigued. Dr. Jarocki from Michigan Medicine gives a thorough and concise summary of the causes of heel pain, as well as some exercises that can help to alleviate this pain.

If these fail, invasive surgery can be required. Surgery can be used to repair the ligament itself or to remove the heel spur. The controversy over the relationship between heel spurs and pain has important implications for the effectiveness of this type of surgery.

Sources and Additional Information:

https://www.health.harvard.edu/a_to_z/heel-pain-a-to-z

https://www.sciencedirect.com/science/article/pii/S1067251601800715

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3309235/

https://www.sciencedirect.com/science/article/pii/S1067251609800653

Ways to Prevent and Treat a Common Annoyance: Headaches

Headaches can range from a mild annoyance to a debilitating condition that results in the inability to complete simple daily tasks. Odds are you have experienced a headache since about 50% of the population has suffered some type of headache. While there are many different variables that may have triggered it (injury, stress, chemical imbalances, etc.), the resulting symptoms are always negative. Scientists have been investigating what causes different types of headaches in hopes that they can help people prevent their occurrence and mitigate their symptoms.

One of the most common types of headaches is a cervicogenic headache – a secondary headache caused by referred pain from the neck to the head and facial regions. The high prevalence of cervicogenic headaches – 70% of people who suffer from headaches – prompted one study using a MyotonPRO device to measure and compare the tone, stiffness, and elasticity of the suboccipital and upper trapezius neck muscles in people who have and have not suffered from cervicogenic headaches.

Human suboccipital muscles located underneath the back edge of the skull.
Modified from BodyParts3D, Copyrightc 2008 Life Sciences Integrated Database Center licensed by CC Display-Inheritance 2.1 Japan.

Human trapezius muscle shown spanning the upper back through the neck.
Modified from BodyParts3D, Copyrightc 2008 Life Sciences Integrated Database Center licensed by CC Display-Inheritance 2.1 Japan.

The results showed that the tone – the degree of tension in a relaxed muscle – and stiffness – movement ability of the muscle – values were significantly higher in people who have suffered from cervicogenic headaches in the past. This can likely be attributed to overuse or high levels of past activity of these muscles. This can cause inflammation or other physiological changes that aggravate the nerve fibers in the neck resulting in a cervicogenic headache. The tone and stiffness data can be used to help educate patients on the importance of properly stretching their neck muscles before and after physical activity in order to keep them from tightening and shortening due to overuse. Muscle relaxing medications could also be used as a type of treatment when someone is suffering from a headache.

Tone and stiffness data for people with and without cervicogenic headaches.
Modified from Park, et al., The Journal of Physical Therapy Science 2017.

Another common type of headache is a migraine – a primary headache that has occurred multiple times throughout someone’s life. While a migraine can also have many different triggers, one study investigated the impact of a chemical imbalance of dopamine. This study found patients who suffer from migraines experience a decrease in dopamine levels before they feel the symptoms. There are a couple theories as to why decreased dopamine levels result in migraine symptoms: 1) decreased dopamine increases sensory sensitivity which may result in normally painless signals becoming painful, 2) decreased dopamine impacts motivation and reward/aversion to a point where patients withdraw and seclude themselves. In general, these findings can be useful for the advancement of dopamine regulating drugs in order to combat migraines. Further reading on different chemical causes of headaches in mice can be found here.

Figure showing dopamine levels decreasing during the onset of a migraine.
Modified from DaSilva, et al., Neurology 2017.

Overall, there are many different headache triggers and a lot more research needs to be done before science fully understands how they work. However, there are some things people can do now in an effort to lessen the probability they will suffer from headaches. Additionally, there are  medications and other techniques that work through different paths to mitigate the symptoms of a headache.

Runner’s Knee: Knee Pain Isn’t Just for Old People

Don’t knee problems only plague old people or people who have run for a lifetime? I questioned this when, for the seventh time in a row, my knee was hurting only a mile and a half into my run. I’m too young for this! However, a plethora of information suggests that knee pain is perhaps not so uncommon in younger runners and athletes as I thought.

The American Family Physican published an article detailing one form of knee injury informally called “Runner’s Knee”. A shockingly high number, between 16 and 25 percent, of running related injuries fall into this categorization. Medically termed patellofemoral pain syndrome (PFPS), the ailment manifests in pain or stiffness in the knee, particularly when bent in load-bearing scenarios such as walking, running, jumping, or squatting. The patellar region experiences shocking loads even in the day to day: in walking alone the region experiences up to a half the person’s body weight while in an activity like squatting it can experience up to seven times one’s body weight. Often the pain is hard to pinpoint but occurs in or around the front of the knee within a circular range. It can inhibit or put a stop to training, however, if addressed early on, can often be healed or corrected much more quickly.

an animated image of a runner mid-stride with the pain region for patellofemoral pain syndrome highlighted
Photo by www.scientificanimations.com from Wikimedia Commons

In PFPS, the patella (the kneecap) moves abnormally within the groove on the end of the femur (called the femoral trochlear groove) due to imbalanced or unusual loads on the joint. This results in over-stressing the joint and causing pain. Several possible causes exist for PFPS; here, I will focus on three of most commonly cited: increased intensity of activity, weak hip muscles, and overpronation.

an image of the muscular and skeletal structure of the knee, including the patella
Photo by BruceBlaus on Wikimedia Commons

Increased Activity

One review explored that women are more likely to suffer from PFPS. In this study they saw that women of higher activity levels were not necessarily more likely to experience pain due to PFPS than women who had a lower activity level. Rather, a substantial increase in activity level seemed to be the cause of pain. Therefore, more than overuse of muscles or joints, PFPS often develops with increased amounts of activity, or temporary overuse, such that the body is not prepared to handle the increased and repetitive forces on the knee.

Weakness in Hip Muscle Strength 

This study shows that lower extremity mechanics and motion can be affected by hip strength. For example, inward rotation of the hip can be lessened through strengthening of hip muscles that counteract that rotation. With less internal hip rotation, the knee abduction moment (the tendency of the knee, due to reaction forces from the ground, to rotate  inward and away from the balanced midline of the knee joint) decreased which often resulted in less stress in the knee. Therefore, the review suggests that strengthening hip muscles can lower the patellofemoral joint stress and help treat PFPS. 

Overpronation

Pronation refers to the natural movement of one’s foot and ankle slightly inward while stepping. When the ankle rotates too far inwards, it is called overpronation. Overpronation can lead to further improper structural alignment in the lower body as the tibia rotates improperly in response to the ankle rotation. The tibia’s rotation then disrupts the natural movement of the patellar joint and can contribute to PFPS. In many cases, overpronation can be corrected through use of orthotic shoe inserts that prevent the over-rotation of the foot and ankle.

In conclusion, while we may often associate knee problems with older people or arthritis, PFPS affects many athletes, particularly runners, at any age. Often, proper training programs that do not accelerate activity too quickly, strengthening exercises that focus on the hip muscles, and proper, overpronation-correcting footwear can treat or prevent an individual from being affected by PFPS. Check out some strengthening exercises here.

Why your Muscles Hurt after a Workout

How often do we cut our overly ambitious workouts short because of exhaustion or muscle soreness? Probably more than we care to admit. But have you ever stopped to ask yourself why your muscles hurt, especially a day or two after your workout? The simple answer is, you’ve put so much strain on your muscles that you aren’t used to, so they tore, and now your body has to repair the tears and build up more muscle, so the same thing doesn’t happen in the future.

Normal muscle tissue in the arm versus strained muscle tissue
Fitness Science, 2015

When your muscles become sore after a strenuous workout, that is called Delayed Onset Muscle Soreness, or DOMS. Matthew Ely, a graduate employee in the Department of Human Physiology at University of Oregon states that DOMS occurs often when you are doing a new workout or using muscles that you typically don’t utilize. What happens then, is that since these muscles are not accustomed to enduring so much stress, they tear. On a microscopic level, what is happening is that after these muscles have torn, local cells begin to work together to repair the muscle fibers. Correspondingly, tissue cells, immune cells, and proteins migrate to the torn ligaments to remove the damaged proteins and repair and replace them with new ones. This process is ultimately the soreness we feel. As the proteins and muscles build up, that exercise that made us sore no longer does as we’ve gotten stronger with visible muscle growth. While this pain ultimately supports the saying “no pain no gain”, this pain shouldn’t last longer than a few days. If it does, the damage could be more serious and require medical attention.

Damaged muscle torn across the fibers
Total Cheer Performance, 2018

Since 2010, a group of Japanese neurologists have been studying DOMS and nerve damage. Ultimately, their findings don’t show us too much more than what is already known.

Inflammation of muscle fibers due to over exertion
Physio4fight, 2014

Their research essentially suggests that the pain we feel is nerve growing pains. However, after examining the effect of DOMS in rats, the Japanese were able to begin working on a “cure” for DOMS, meaning they thought they were able to completely suppress this soreness. So far, though, cryotherapy, stretching, homeopathy, ultrasound, and electrical current modalities have not proven to be entirely fruitful.

There are several reasons that the Japanese and other researchers have proven fruitless in their efforts of understanding this topic, primarily, the early stage in history that DOMS are even being studied. While many remedies have been created to combat diseases, athletic injuries and musculoskeletal research are in their earlier stages of study. The second reason is that DOMS have proven to be more complicated than originally thought. The basic theories tend to prove to be false. But the most accepted theory for DOMS is that when the muscles tear, they swell up and push on nerves which sends a message to our brain that we are in pain, similar to more basic injuries from cuts or broken bones.

In the end, muscle soreness is not a bad sign that you’ve damaged your body like simple injuries. As far as research has shown, muscle soreness is the response your brain receives when too much stress has been placed on an unused muscle so that it tears and swells. When the swelling pushes on nerves, we feel pain. As our bodies repair the damage by replacing proteins, the swelling goes down and the muscle gets larger so it can compensate for the stress it now knows it must overcome when we do that specific exercise. This process would then repeat as we push ourselves further every time we work out.

https://powerplantbody.com/doms-delayed-onset-muscle-soreness/