Canine Hip Dysplasia: What You Should Know

Canine hip dysplasia (CHD) is a degenerative hip disease that tends to develop in large breed dogs, such as the Bernese Mountain Dog, affectionately referred to as Berners. CHD significantly decreases the quality of life of a dog and often leads to complete immobility if left untreated. Experts estimate that about 28% of Berners are affected by dysplastic hips, making them the 8th most susceptible dog breed.

Bernese mountain dog with superimposed image of hip ball and socket joint.
Image from Packerland Veterinary Clinic.

At birth, puppy skeletal structures are largely composed of cartilage that is much softer than bone. This softer cartilage is able to adapt much more easily to the rapid growth that occurs during the early months of a dog’s life. In their first few months, Berners will typically gain 2-4 pounds per week, which adds increasingly large stresses to their developing bones and joints. While genetics play a large role in the susceptibility of a dog to develop CHD, the loading cycles and forces on the cartilage greatly shape the development of the dog’s hip.

Correctly formed hip versus a deformed femur head and shallow hip socket.
Image from Dog Breed Health.

The hip is a ball and socket joint, where the head of the femur, the very top of the dog’s leg, should fit perfectly into a socket in the pelvis. If the ligaments that hold the femur in the hip socket are too weak or damaged at all, the positioning of the

Evenly distributed forces on a correctly developed hip joint versus force concentration acting on a dysplastic hip joint.
Modified from The Institute of Canine Biology.

hip joint will be off and the hip will be subjected to unbalanced forces and stresses over the course of the dog’s life. The distribution of forces experienced by the hip joint in normal hips is evenly spread, while dysplastic hips are subjected to a stress concentration on the tip of the femur. These unnatural forces will cause laxity in the hip joint, leading to instability, pain, and often times the development of osteoarthritis.


There are also a number of environmental factors, many of which are inherent to large dog breeds, that dramatically increase a dog’s susceptibility to CHD. A study by Dr. Wayne Riser concluded that factors such as oversized head and feet, stocky body type with thick, loose skin, early rapid growth, poor gait coordination, and tendency of indulgent appetite all contributed to the development of CHD. All of these features are generally inherent to large breed dogs, such as Berners, so great care must be taken in order to mitigate their effects on the quality of life for these dogs.

Multiple studies have shown that treatment that is implemented early in the dog’s life is much more effective than late-in-life treatments. CHD warning signs can be seen in puppies as young as 4 months old, and most veterinary professionals agree that if scans occur at 2 years of age, the most optimal time for treatment has passed. Since larger stresses will be put on the hip joint as the dog grows, surgical repairs, or changes in diet and exercise, are most effective if implemented before the dog’s skeletal frame is completely developed.


timeline of canine hip dysplasia development
Modified from The Institute of Canine Biology

Additional information regarding this topic can be found at The US National Library of Medicine or The Journal of Veterinary Pathology.

Look Strong, Be Strong, or Be Safe?: The Perils of a New Deadlifter

So, you’ve started deadlifting, but you’re not sure if you’re just weak, or if you’re going to break your spine, and there are plenty of “gym bros” slamming the weights, grunting, and walking around wearing equipment (wrist straps and back belts) that says “I’m literally too strong for my own body.” So, what do you do? Do you need to buy that stuff too?

This blog post will walk you through a biomechanical analysis of the deadlift while wearing supportive equipment, in the hopes of helping you face this daunting task.

First, let’s look at the proper form and muscles recruited in the Deadlift.  As can be seen in the graphic below, the lift begins on the ground in a hinged squat. From A to C, The gluteus maximus (butt), trapezius and lower erector spinae (long muscles that run alongside the spine) are primarily activated, whereas from C to D, the hip extensors and numerous smaller upper back muscles help to “lock out” the form, with the forearms supporting the load throughout.

Graphic of a side view of the proper deadlifting motion
Graphic Depicting Proper Form

The science of using wrist straps as discussed here.  Your forearms are significantly weaker than your gluteus and back, and as such, they will fail first. A comparison of different kinematic variables as a function of wrist straps and unsupported showed a higher activation in the back when using straps.  This means, when using wrist straps, you reduce the load on your forearms, which allows you to go heavier with weight.  In essence, it takes grip strength out of the lift.

Improper form, like arching your back, hips rising too early, leaning too far forward, or many other small inefficiencies can lead to concentrated shear stresses between the vertebrate in the back (not good), excessive reliance on small ligaments in lower back (not good), and high stress concentrations at the moment hinge (especially not good considering your lower back is a nerve junction between your sciatic and spinal nerves).  So how do you prevent this?

Many people instantly reach out to supportive equipment as their saving grace, but does this really prevent injury or does it just add a false sense of security to allow dangerous form? Studies by Thomas and Kingma both look at the effectiveness of weightlifting belts in protecting your spine in various loading conditions.  Although I encourage you to read them and discover their findings for yourself, they both reach generally the same conclusion.  Belts might help, by increasing Internal Abdominal Pressure (IAP) says Thomas, and by decreasing spinal load, tested by Kingma, however, any benefit is nominal.

As far as my suggestion goes, you should begin deadlifting at lower weights, without a belt or straps, until you get a feel for the form.  This will begin to increase your strength in the smaller muscles and form muscle memory required for heavier lifting.  Listen to your body. If a lift went well, and you think you can increase the wight without sacrificing form then go up in weight. Eventually, a weightlifting confidence will step in, and you’ll be able to determine for yourself which strength you want to strive for (grip strength, or bigger deadlift numbers).

If profane language is no issue for you, I STRONGLY encourage watching the YouTube video appended below. Eddie Hall, a now retired professional strongman, owns the record for the ONLY 500 kg Deadlift, and he most certainly knows what he’s talking about.

PS he trains without any supportive equipment, and safe to say he’s lifting heavier than you.

Continue reading Look Strong, Be Strong, or Be Safe?: The Perils of a New Deadlifter

Brace yourself… You might need surgery

A surgery? For my PCL? Could be more likely than you think.

Usually hiding behind it’s annoying and commonly ruptured brother the ACL, the PCL (posterior cruciate ligament) is a durable ligament that usually doesn’t cause problems for athletes… until it does.

Because of the strong nature of the ligament, injuries that tear the PCL are usually sudden and traumatic. Think car accidents, falling hard on a bent knee… you get the picture. When enough force is applied to the top of the tibia, the tibia can be pushed backwards, past the threshold of the PCL. Even though the PCL does its best to hold your femur and tibia together in the right spot, it just doesn’t hold up to the brute force of a dashboard. These injuries can usually be diagnosed by the presence of a “sag.” When your doctor holds your bent knee up, it looks like your shin bone is sagging underneath your knee. This is your torn PCL crying for aid.

A photo showing the location of the PCL and ACL inside of the right knee. The ACL crosses from left to right over the PCL. Both are attached at the top to the femur and at the bottom to the tibia.

When it comes to fixing these injuries, the nonsurgical approach has typically been recommended for low-grade tears that don’t totally rip the PCL apart. These braces are attached to the leg right above the knee, and are supposed to hold the bottom part of your leg under the knee in place. This prevents from your knee from going too far forwards and backwards, and allows scar tissue to build up over your PCL. While your body tries to heal itself with scar tissue, you will work with a physical therapist to build up your quad strength and restore your range of motion. Over 80% of athletes are able to return to play after bracing their knees.

A PCL brace is shown in place on a knee. There are two stabilizing straps above the knee, and two below the knee. They are connected by a metal frame that meets at a hinge joint over the side of the knee.

However, surgery, which was once only reserved for extreme PCL tears, is now seen as a viable, cost-efficient option for even low-grade tears. PCL surgery is intended to restore normal knee biomechanics and stability to about 90% of their post-injury strength. Sometimes, a part of the Achilles tendon is used to create a graft, or a “new” PCL. This is called an allograft, and results in safer and shorter surgeries (8). Within a month, the athlete can walk and bear their own weight. After six months, athletes are able to return to sports.

In theory, surgery sounds like the most “permanently good” option there is for fixing your PCL. However, no scientific studies have yet been done that can accurately compare the return-to-play rates, or even the relative healing of people in braces versus people who immediately got surgery. When people don’t comply with their treatment plans (aka, take off their braces early, skip physical therapy after surgery, etc.) the data for comparisons between bracing and getting surgery aren’t clear. While your PCL may be out of commission, so is the jury on this one. At the end of the day, the best treatment method for you is dependent on the mechanism of injury, severity of your injury, and whether you plan on listening to your doctor or not!

For more info on PCLs:

Posterior Cruciate Ligament Injury

Management of PCL tears

What an Optimized Running Gait Can Do for You

Running is one of the oldest and most common forms of exercise, but there are many ways that running mechanics vary from person to person. Identifying the different running gaits is important so that their efficiencies and effects on the body can be analyzed. Injuries in runners are common and having an understanding of how different gaits apply stresses on the body differently can be used to educate runners on how to run in a way that will reduce the risk of injury.

Running with poor mechanics can lead to overuse injuries, which are more common than acute injuries in serious runners. The majority of these injuries occur in the leg either at or below the knee and include patellofemoral pain syndrome (PFPS) and medial tibial stress syndrome (shin splints). Running gait analysis can be used to identify the poor mechanics and the potential risks associated with the mechanics. Further studies have grouped the variations so that the effects of similar gaits can be identified. Extensive analysis has led to the identification of several potential variations in running gait.

A study at Shanghai Jiao Tong University‘s School of Mechanical Engineering determined the effects of step rate, trunk posture, and footstrike pattern on the impact experienced by the runner. Data was collected by instructing runners to run with specified gait characteristics. Sensors made used to make sure that the gait was correct and the impact forces on the running surface were measured. This study showed the lowest impact was experienced with a high step rate, a forefoot strike pattern, and an increased anterior lean angle. Limiting the impact reduces the effects of the loading. As a result, running with these gait characteristics reduces the risk of knee pain and stress fracture in the tibia.

Runner on treadmill with attached sensors following instructions to modify gait
from: Huang, Xia, Gang, Sulin, Cheunge, & Shulla, 2019

While the most important factor in this analysis is how forces are translated through the body, this is difficult to measure directly. The technology does not exist to measure these forces accurately and noninvasively. Since invasive techniques would not allow the person to run normally, indirect ways of measuring this data have been developed. One of these alternatives involves collecting kinematic data which can be used to calculate the forces and observe different gait patterns. They do this by recording high speed video of runners. Usually, photo reflective stickers or LEDs are fixed to critical points of motion so that the motion of these points relative to each other can be plotted and analyzed. This data can be used to develop algorithms that describe different gaits.

Running gait does not only affect risk of injury, but also efficiency. Kinematic studies have shown that as running speed increases, a runner’s gait changes to accommodate this change in speed. One change in the gait was the foot strike pattern changed from rear foot to forefoot. This motion shortens the gait cycle and increases the step rate. However, when the runners ran at their top speeds for an extended period of time, their mechanics broke down and some of the gait characteristics that increase injury risk became pronounced. Because of this tendency, incremental training with focus on proper mechanics is necessary to reduce injury risk.




How much wood can a woodpecker peck? The Science Behind a Woodpecker’s Anatomy

Woodpecker anatomy: showing the location of the tongue
Diagram showing the tongue of a woodpecker, obtained from “”

Have you ever wondered how a woodpecker is capable of banging its head against a tree so furiously without seriously injuring itself? The impact of a woodpecker’s beak with a tree can exceed speeds of up to 6 meters per second and occur over 12,000 times a day.These kinds of numbers are what allow woodpeckers to smash through trees to get to those tasty bugs that live inside.

How is this possible you may ask? Scientists have studied the anatomy of a woodpecker and have come across an extraordinary discovery: the tongue of a woodpecker wraps completely around its neck before exiting the mouth, constricting the blood flow to and from the brain. This increases the amount of blood volume in the skull, making it, and its precious cargo, filled to the brim with fluid. This creates an effect known as “slosh mitigation”, where an object that is completely enclosed by an incompressible fluid becomes protected from an outside force due to the constant stabilization of pressure within the enclosed system. Thus, the harsh vibrations translated throughout the skull of the woodpecker are mitigated by a cushioning effect induced by the increased volume of blood in the brain. Ever notice how a snow globe always has a little pocket of air sitting on top of the water? Without it, there would be no pressure changes, and the flakes of snow would be restrained from ever creating that magical snowy blizzard we all love.

This incredible discovery is not just a fascinating fact you can pull out to impress your friends. In fact, companies have begun applying the science behind a woodpecker’s anatomy to the sports arena. A company by the name of Q30 Innovations has been on a mission to curb the estimated 3.8 million concussion occurrences every year. Their latest product, the Q Collar, features a tightly fitted neck brace that applies a mild compression to the jugular in the neck, thus creating the “slosh mitigation” effect on the brain. The Q-Collar has already been put to the test, showing positive results on football players and hockey players. Their latest test showed the effects of wearing the Q-Collar for a high school girls soccer team, whose total head impacts were collected via an accelerometer throughout the entire season. Half the team was selected to wear the Q-Collar, and at the end of the season, the accelerometers of both groups reported similar levels of head impact, both in quantity and severity. However, it was shown the group wearing the Q-Collar required less brain activity to complete a concussion protocol than those of the control group. This shows that despite any of the girls having a reported concussion, the high impact loads exhibited on the brain during the season were enough to prohibit the brain from performing at its optimal level.

Want to learn more about breakthrough technologies covering the challenges of concussions? Learn more at Q30 Innovations.



  1. “Do Woodpeckers Get Concussions?”
  2. “Response of Woodpecker’s Head during Pecking Process Simulated by Material Point Method”
  3. “What is a Concussion?”
  4. “Q-Collar tests produce positive results in protecting girl soccer players from concussions”

Put One Foot in Front of the Other? It’s Not that Easy

From Christmas movies to pop songs to motivational posters, we are encouraged to keep putting “one foot in front of the other.” While the sentiment is inspiring, recent studies show that there is a lot more to the seemingly simple task of walking than this phrase would suggest. Understanding this is especially important for balance and mobility after an injury or as people age.

The steps that make up the human walking cycle. Order of steps: heel-strike right, toe-off left, midstance right, heel-strike left, toe-off right, midstance left, hell-strike right. The body spends the time between heel-strike and toe-off with double support and the midstances are single-leg support.

Image from Wikimedia Commons

The human gait has a set structure that switches the weight between each leg, with only 20% of the typical walking motion distributing the weight across both feet. Maintaining balance throughout this process requires coordination in the muscles controlling the hips, knees, ankles, and feet. Mechanically, these adjustments keep the body’s center of mass (also known as center of gravity) over the base formed by feet positioning.

Obstacles and challenges to balance require a body’s quick response to mitigate shifts in the acceleration and momentum at the center of mass. Lack of efficient control over these parameters results in a fall. Many conditions, as well as age, can affect a person’s ability to respond to mobility challenges.

One specific study looked at how people who had had a stroke and subsequent partial paralysis on one side (paresis) faced mobility challenges compared with healthy folks. This condition effects approximately 400,000-500,000 people in the United States annually. It presents a unique opportunity to compare an individual’s non-damaged stride with their deficient stride at the point in the gait at which only one leg is on the ground (SLS, or single-leg-stride). The timing of the gait, the body’s momentum in all three planes of the body, and the location of the center of mass were recorded in this study.

Anatomical planes of the body. The sagittal plane splits the body left and right. The coronal plane splits the body forward and back. The transverse plane splits the body top and bottom.
Image from Wikimedia Commons

Versus healthy people, stroke survivors had significant trouble regulating momentum in the coronal plane, making falls more likely. Although it makes sense that momentum regulation suffers when muscles are paretic, it is yet unclear why the coronal plane was most affected. Additionally, post-stroke individuals’ centers of gravity were higher, which is also linked to instability. For stroke survivors, the partially paralyzed SLS took longer and extended farther from the center of mass than the regular SLS. While this is not as immediately dangerous as increasing falling risk, it slows mobility, unevenly works muscles (which can lead to injury), and is less efficient.

Going forward, these findings can be used to improve mobility success in people with balance issues or after injuries. This could manifest in better technologies, such as walkers that better help settle a person’s center of mass and partial exoskeletons that would help a person mitigate acceleration and momentum changes, or more targeted and individualistic physical therapies to strengthen weakened muscles and practice patient-specific challenges, such as overcoming obstacles that threaten coronal-plane balance. Understanding more about balance adjustment when walking may make some common phrases trite, but its potential benefits have life-changing impacts for many.

Further Reading and Sources:

Stroke/Paresis Information

Stability of Stepping

ACL Reconstruction: Which Option Is Best For You?

200,000 ACL injuries occur each year, and ACL reconstruction is the 6th most performed surgery in the United States, so to come back bigger, faster, and stronger, the right recovery path is critical.

The anterior cruciate ligament (ACL) is a critical part of the knee joint that connects the femur (‘thighbone’) to the tibia (‘shinbone’). Its main functions are to support the knee joint during side-to-side motion, such as cutting, shuffling, or pivoting, and to prevent the tibia from moving too far forward relative to the femur. When an ACL ruptures, it is very common to reconstruct it to bring someone back to performance level.

Location of the ACL inside the knee joint with other labeled bones and ligaments with another diagram showing a ruptured ACL.
Image from Wikimedia Commons “Anterior Cruciate Ligament”

The basis of ACL reconstruction is using living tissue, also known as grafts, to replace, and function as a substitute, for the torn ACL. There are four types of ACL reconstruction surgeries that use different types of grafts. Those four types of surgeries are classified as autograft reconstruction, allograft reconstruction, xenograft reconstruction, and synthetic reconstruction. Autograft surgeries require one’s own grafts to repair the ACL, allografts require a cadaver’s grafts to repair the ACL, xenografts require an animal’s grafts, and synthetics require manufactured materials. Additional articles on xenograft reconstruction and synthetic reconstruction can be accessed here and here.

Each surgery requires the removal of the damaged ACL, and then the incorporation of a new substitute by tunneling the newly selected graft through the femur and tibia. Within the autograft group, the two popular grafts for reconstruction are patellar tendon and hamstring tendon, with quadricep tendon being another, less popular, choice. The patellar tendon surgery takes the middle third of the patellar tendon, a tendon that connects the kneecap to the tibia, and makes sure to include the bony ends.

The hamstring tendon surgery takes two small slivers of each of the two hamstring tendons, connecting the hamstring muscle to the tibia, coils them up, and then finally bundling them to increase strength.

A knee joint with bones, ligaments, and tendons labeled.
Image from Wikipedia “Knee Joint”

For the allograft surgeries, a surgeon may select an Achilles, patellar, hamstring, or quadricep tendon from the donor.

It is very important to choose the right surgery. While the determination of which surgery and technique to perform falls heavily on the surgeon’s and patient’s preference, there are advantages and disadvantages of each technique which tend to persuade the choice of surgery. The main concepts surrounding the decision of which surgery to perform are the activeness of the patient, muscle strength, and previous knee injuries. Depending on the job, sport, or activity of the patient and the desired return time, one technique may be a better fit.

For a patient participating in low demand activities, allograft surgery may be the best fit due to less post-surgery pain and quicker surgery time, however it is very expensive and offers less tensile strength compared to autografts. As for autograft surgeries, patellar tendon reconstruction allows faster recovery time due to the bone-to-bone bonding and offers a strong substitute for a torn ACL, however future knee pain is very common. Hamstring tendon reconstruction requires more recovery time; however, the post-surgery pain is significantly less than the patellar tendon reconstruction and the tensile strength of the hamstring tendon is the strongest possible substitute.

Additional reading and comparisons between the popular autografts and allograft techniques can be accessed here and here.

Patellar Tendinitis: The Kryptonite of Jumping Athletes

Volleyball is a sport of quick movements. For hitters, one of the most common movements in the game is the jump, whether that be to block or to hit. Although a higher vertical leads to improvement in game performance, it can increase the risk of developing a serious injury that affects many volleyball players: patellar tendinitis. This condition is associated with pain and tenderness directly below the knee cap that is especially apparent during explosive, jumping movements. But what exactly causes this condition? And what can be done to remedy it?

A schematic of the knee and patellar tendon.
Image from Wikipedia “Patellar Tendinitis”

Since volleyball is such a quick game, muscle memory is required to react to different situations that can occur. The main way to build muscle memory is repetition. Therefore, young volleyball players are encouraged to play the sport as much as possible. For many athletes, this means playing for their school during that season and then playing for an independent club for the rest of the year. Although this increases the athlete’s skill level, it also increases the chance of patellar tendinitis, according to a study.

Besides overuse, lack of ankle mobility can also lead to a higher risk of the condition. A study found that players that couldn’t flex their ankle upward past 45 degrees could have 2 times the risk of patellar tendinitis as players with a higher ankle mobility. This is most likely due to the ankle and calf’s role in absorbing impact upon landing. Less absorption by the ankle causes more force to be put on the patellar tendon. This is bad news for volleyball players who often have poor ankle mobility due to a past injury.

There are a few ways to treat patellar tendinitis. For an orthotic approach, players use straps or tape around their patellar tendon. Some think this is simply due to the fact that the strap or tape makes the athlete feel more stable, which allows them to load the tendon more properly. However, a study done in 2011 analyzed the strain in the patellar tendon using a computational model. The researchers found that the patellar tendon strap increased the angle between the tendon and the kneecap, which caused the strain to decrease. Decreased strain means that the tendon stretches less, which would decrease the incidence of patellar tendinitis. Another way to treat the condition is surgically. One of the more simple surgeries is a removal of the dead or torn tissue of the patellar tendon. This allows new, healthy tissue to form.

A strap being put around the patellar tendon that can ease pain.
Image from Sports Injury Clinic “Patella Tendon Taping”

Patellar tendinitis is a serious condition affecting many high-level athletes. Although there isn’t a simple cure, researchers have brought to light different causes and treatments of the condition. These can be used to help athletes remedy the pain they are experiencing and perform at their best.


Study on How Vertical Affects Patellar Tendinitis

Study on How Training Volume Affects Patellar Tendinitis

Ankle Flexion Study

Patellar Tendon Strap Proprioception Study

Patellar Tendon Strain After Applying a Strap

Additional Reading:

Clinical Trial on Patellar Tendon Strap

Biomechanics of Pitching: Pushing Limits on the Shoulder and Elbow

Aroldis Chapman of the New York Yankees holds the Guinness World Record for the fastest recorded baseball pitch at 105.1 MPH; a record that has held for almost a decade. Why has no one been able to top his record? — An answer to this question may be found in the biomechanical limits of the human shoulder and elbow during the throwing motion.

As a little background on the subject, the throwing motion can be broken down into six separate phases: windup, stride, arm cocking, arm acceleration, arm deceleration, and follow-through as can be seen below.

Images depicting the six phases of the throwing motion.
Image from the article “Throwing Biomechanics”

Of the six phases only two are the main instances of injury: the arm cocking phase and the arm deceleration phase.

Injury can occur in the labrum and rotator cuff in the shoulder, as well as in the ulnar collateral ligament (UCL) in the elbow during the throwing motion. In pitchers the stresses are at their extremes due to the unique positions the arm reaches, thus leading to a higher chance of failure in the muscles and ligaments of the arm.

Torques and forces on the shoulder and elbow at the end of the arm cocking phase.
Image from The American Journal of Sports Medicine article “Kinematics of Baseball Pitching with Implications About Injury Mechanisms” by Fleisig et al.

At the end of the arm cocking phase, the arm is in a position of 160° to 180° from the horizontal and puts the arm in the position to accelerate the ball forward. According to one study, extreme torques of 64 N-m and 67 N-m are applied at the elbow and shoulder, specifically loading the rotator cuff and the UCL. Furthermore, the anterior (forward) force at the shoulder of 310 N loads the labrum in such a way that may cause it to tear. The feeling of these loads is equivalent to holding 60 lbs in your hand in the position shown on the right!

Force and position of the shoulder and elbow during the arm deceleration phase.

During the arm deceleration phase the arm is in a position of 64° from the horizontal and the shoulder resists the extreme speed and acceleration it just endured. An article showed that during the deceleration phase the arm experiences angular velocities in the shoulder of almost 7,000 degrees/sec making it one of the fastest known human motions. That is about 1,200 RPM which is comparable to the rotational speed of some car engines during cruise control, while traveling at about 50 MPH! Additionally, the rotator cuff and the labrum take the brunt of the 1090 N (245 lbs) compressive force needed to slow down the arm and it is enacted in just an instant!

According to one article, the limiting factor on pitch speed is that the force pitchers apply to their UCL is at the limit of what makes it tear. This means that attempting to throw any faster would result in the UCL tearing! In summary, pushing to gain more MPH on the fastball would mean even higher loads and thus more demand from the shoulder and elbow despite already being at their limits.

All in all,  biomechanical data shows that limits in the rotator cuff, labrum, and especially the UCL explain why  Aroldis Chapman’s record has been preserved for almost a decade and why the chances of throwing any faster are almost impossible. However, in the world of sports, limits and impossibilities are just waiting to be broken.


Sources and Additional Reading:

“Fastest Baseball Pitch (Male)”

“Kinematics of Baseball Pitching With Implications About Injury Mechanisms”

“Biomechanics of baseball pitching: A preliminary report”

“Why It’s Almost Impossible For Fastballs to Get Any Faster”

“Throwing Biomechanics”

“Your car’s engine rpm at highway cruising speeds”

The Spinal Fusion that Reignited a Legendary Career

Can you imagine being the best player in the world at a certain sport and one day, aggravating an injury that not only put your athletic career in doubt, but also did not allow you to do normal daily activities? This is the challenge that faced Tiger Woods.

Tiger Woods is one of the greatest golfers to ever play the sport but has been plagued with back issues over the past few years that have prevented him from winning and also playing in golf tournaments. A golf swing applies a significant amount torque to one’s back. Repeating this motion as many times as Tiger has, through practice and tournaments since he began his career, caused him to have chronic back issues that had to be dealt with. In order to deal with these back issues, he had three back surgeries over the course of three years. After these, he was still unable to not only golf but also do daily activities without pain such as get out of bed, or play ball with his kids. Tiger was at a crossroads, and decided to get a spinal fusion surgery.

An image of the spine with the three regions labeled: cervical (upper region), thoracic (middle region), lumbar (lower region)
Taken from Wikimedia Commons

The spine has three regions: cervical, thoracic and lumbar. The cervical region is in the upper spine near the neck, the thoracic region is in the middle of the spine and the lumbar region is in the lower back. The lumbar region takes the majority of force in a golf swing and is where Tiger had his fusion done. In the spine, discs are in between each vertebra. The disc acts as a shock absorber and allows for slight mobility of the spine. Tiger had a severely narrowed disc in between two of his vertebrae in the lumbar region due to the previous three back surgeries he had. In order to be pain free, that disc had to be removed. This brought about the discussion of him receiving spinal fusion surgery.


Spinal fusion surgery is a process which removes the problematic disc from the spine and inserts a bone graft in place of the disc. A plate with screws is then placed in the vertebrae above and below the bone graft. The plate helps with the healing process and over time, it will heal as one unit. The essential goal of spinal fusion surgery is to take two vertebrae in your spine and make them act as one. When these two vertebrae become one through the surgery, it eliminates motion in between them and hopefully, removes the pain as well.

This is an image of a spinal fusion surgery with screws helping to hold the vertebrae together
Image taken from Wikimedia Commons

This spinal fusion surgery was a huge success for Tiger and allowed him to keep playing golf at a high level. Through his win at the 2019 Masters tournament, it’s safe to say that he has at least a few more years of winning tournaments and playing competitive golf before calling it a career.

Additional information and sources used can be found here and here.