Tag Archives: injury prevention

Ditching the shoes: Minimalist trend or natural advantage?

The discussion of returning to minimalist ways, namely walking or running barefoot, is a question that rises in many circles, from new parents to elite runners. For example, parents are told to let children learn to walk barefoot, as studies have shown early use of footwear can lead to feet deformities and can alter natural gait, which is especially important when learning to walk. Likewise, many avid and elite runners have shown interest in barefoot running (or minimalist running shoes), as some are convinced that the forefront strike (FFS or also known as NRFS – non rear foot strike), more commonly used during barefoot running, lowers the loading rate on the foot and minimizes injuries from the repeated stress that occurs in the feet during running. 

Diagram illustrating four phases of foot contact with the ground for forefront strike and rear foot strike patterns
Forefront strike (top) and rear foot strike (bottom). Modified from Daniel E. Lieberman et al., Springer Nature 2010

In general, walking or running barefoot yields more frequent steps, a smaller stride length and a slower velocity (most noticeable while running). Barefoot running is thought to reduce some of the injuries many runners are prone to, such as shin splints, stress fractures or plantar fasciitis. Additionally, the stiff fit of modern shoes limits the width and spreading of feet in the natural walking or running motion. However, barefoot running also comes with a cost, with injuries in the achilles region more prevalent. 

A study in the Gait & Posture journal examined foot motion in children and found modern commercial footwear does have a large impact on gait, especially in regards to range of motions of different muscles and joints in the foot, likely due to the stiffness of shoes. More flexible shoes, similar to minimalist running shoes, were found to have a smaller impact on foot motion in reference to bare feet, but still had a significant difference in regards to the added support in the arch area. 

The common belief that barefoot motion lowers the impact on the body has been questioned by a recent research study from Southern Methodist University. The findings indicated that while running barefoot with a forefront strike, the feet strike the ground at a more pronounced angle which generates a longer contact time, thus decreasing the loading rate and allowing the muscles in the back of the feet and legs (especially the Achilles) to absorb some of the loading stress. When humans adapted to running in shoes, especially shoes with thick cushioning, the landing switched to a rear foot strike that allows the heel cushioning to absorb some of the loading stress, resulting in a fairly equal loading rate for both cases. The heel cushioning, with a flatter angle of contact, also allows for decreased impact time with the ground surface, which is why higher running speeds are achieved with footwear. 

barefoot person walking outdoors during the day
Photo by ‏🌸🙌 في عین الله on Unsplash

While the advice to encourage barefoot walking in young children certainly makes sense as they continue to grow and learn to control their bodies, the choice to use shoes or go barefoot for older children and adults remains an individual preference. There is no significant difference in the stresses the body experiences, but the footwear choice does influence the likelihood of certain, which is important for runners with past injuries to consider.

For more information, check out this extensive technical review of studies on barefoot vs. footwear mechanics or this video from Exercising Health comparing running shoes with minimalistic barefoot shoes.

Ankle Sprains: An Epidemic in the World of Athletics

Have you ever been out running on a gorgeous fall day, only to have the run cut short by a painful misstep on a tree root covered by leaves? I have, and let me tell you – it’s awful! And even if you aren’t a runner, according to the Sports Medicine Research Manual, ankle sprains are a common, if not the most common, injury for sports involving lower body movements. Now, the solution to preventing this painful and annoying injury could be as simple as avoiding tree roots and uneven ground, but the real problem behind ankle sprains deals with the anatomy of the ankle.

The ankle is made up of many ligaments, bones, and muscles. However, when sprained, it is the ligaments that are mainly affected. Connecting bone to bone, ligaments are used to support and stabilize joints to prevent overextensions and other injuries. The weaker a ligament is, the easier it is to injure. There are three main lateral (outer) ligaments supporting the ankle joint that can become problematic: the anterior talofibular ligament, the calcaneofibular ligament and the posterior talofibular ligament. According to a study from Physiopedia, these lateral ligaments are weaker than those on the interior (medial) of the ankle, with the anterior talofibular ligament being the weakest.

An image depicting the various ligaments of the ankle, both lateral and medial.
Anatomy of the ankle, highlighting the lateral and medial ligaments

The next question that has to be asked is why are these ligaments so much weaker than other ones? The answer to this question is based on their physical make up. Ligaments are made of soft tissue that has various collagen fibers running parallel to each other throughout it. The more fibers there are, the more structure and rigidity there is. Think of the fibers as a rope: The rope can stretch to a certain point, but once it hits that point it will snap and break. But if you have a thicker rope (such as the medial ligaments), it becomes much harder to break.

The ligaments on the outer part of the ankle have fewer collagen fibers than those on the inside of the ankle. Thus, when the ankle is moved in an awkward position, it is more likely that the lateral ligaments will break.

Once you sprain your ankle, the focus turns to treatment. Treatment will differ slightly for every individual depending on the severity of the ankle sprain. The simplest way to treat a sprained ankle is to follow the RICE (Rest, Ice, Compression, Elevation) method. Other forms of treatment include taping the ankle or using a brace to restrict movement and to add support and extra stability. Wearing proper footwear is another way that one can prevent and help treat a sprained ankle, as certain shoes are specifically designed to help avoid such injuries. To prevent future ankle sprains, exercises are recommended to help strengthen and stabilize the joint and surrounding ligaments and muscles.

For more information on ankle anatomy and sprains, check out these articles on BOFAS and SPORTS-Health.

The Benchmark of Upper Body Strength: Injury Prevention During the Bench Press

Who wouldn’t want to look like Captain America? This common desire to attain a strong Herculean physique, either for athletics or aesthetics, has led many ambitious men and women to weightlifting. An egotistical motivation puts these people at risk of injury, however, as they sacrifice proper form to achieve their next personal best. The bench press is one example of an effective but potentially dangerous lift.

This upper body exercise requires an individual to lie flat on a bench while repeatedly lowering and pressing a straight bar loaded with weights on each end. The hands evenly grip the bar slightly wider than shoulder width apart with the feet remaining flat on the ground and the arms fully extended. During the eccentric (or lowering) phase, the bar is brought in contact with the lower chest. The bar is then pressed up until the arms are once again fully extended (concentric phase).

Recreational weightlifters commonly use a wider grip on the bar, believing that this will increase activation of the chest muscles and allow them to mimic Terry Crew’s version of the Old Spice Man. One study performed on 12 powerlifters, however, found that the prominent muscles used during the lift, such as the pectoralis major, triceps brachii, and anterior deltoids (i.e. chest, triceps, and shoulders), experienced similar electromyographic activity despite varying hand spacing.

Diagram of a human upper body muscular system.
Image by OpenStax from Wikimedia Commons.

Although hand spacing does not significantly affect muscular activity, it can lead to injury. A review of several studies on the effects of hand grip found that a grip width greater than 1.5 times biacromial width, or shoulder width, naturally resulted in shoulder abduction, or rotation away from the body’s centerline, greater than 45°. As this angle increases, shoulder torque increases, causing potential injuries. For instance, the inferior glenohumeral ligament, a ligament restricting translational motion in the anterior direction at the shoulder’s ball and socket joint, may tear as abduction increases, causing instability at that joint. Repetitive cycles with this wider grip may also cause acromioclavicular joint (AC Joint) osteolysis – chronic destruction of the bone tissue at the joint between the clavicle and acromion.

Diagram of shoulder joint.
Image by OpenStax College – Anatomy & Physiology from Wikimedia Commons.

Aside from a wide grip, injuries also commonly stem from over-training and using excessive weight. Research on 18 male college students demonstrated that repeating the bench press motion with high frequency until failure resulted in a significant increase in the medial and lateral force exerted on the elbow joint, which could result in injury over time. Furthermore, performing the bench press with heavier loads could result in a sudden rupture of the pectoralis major. At the bottom of the eccentric phase as the bar touches the chest, the muscle fibers are simultaneously lengthening while also contracting, which increases the risk of muscle tear in this region.

Unlike Captain America, people cannot instantly acquire strength or build muscle. Muscular development and improving one’s bench press require time, patience, and proper form. To learn more about injury prevention or variations of the bench press, check out the video below or read these papers by Bruce Algra and JM Muyor.

Sources can be found below:

The Affect of Grip Width on Bench Press Performance and Risk of Injury

The Effects of Bench Press Variations in Competitive Athletes on Muscle Activity and Performance

Elbow Joint Fatigue and Bench-Press Training

An In-Depth Analysis of the Bench Press

 

What Makes Someone More Likely to Tear Their UCL?

It takes a lot to make a professional athlete collapse to the ground during a game. After throwing a pitch on September 14, 2019, Toronto Blue Jays pitcher Tim Mayza knelt on the side of the mound while clutching his arm, expecting the worst. The next day, MRI revealed that what he had feared: Mayza had torn his Ulnar Collateral Ligament (UCL).

player following through after throwing baseball
Photo by Keith Johnston on Unsplash

Because of UCL reconstruction, or Tommy John, surgery, this injury is no longer the career death-sentence that it once was, but there is still a long road ahead for Mayza. He probably will not pitch in a game again until 2021. Sadly, this injury is only becoming more and more common among MLB pitchers. In the 1990s, there were 33 reported cases of UCL tears by MLB pitchers. In the 2000s, this number more than tripled to 101. From 2010 to the beginning of the 2015 MLB season, 113 UCL reconstruction surgeries had already been conducted. It has become so common that surgeons have called it an epidemic, and researchers in the US and abroad are attempting to find a way to combat this increase.

Digital image of elbow joint, with a small, red tear in the UCL
Orthopaedic and Neurosurgery Specialists, 2019

The UCL connects the ulna and humerus at the elbow joint, and its purpose is to stabilize the arm. During the overhead pitching motion, the body rotates in order to accelerate the arm and ball quickly, putting a large amount of stress on the UCL. In fact, according to a study by the American Sports Medicine Institute, the torque, or twisting force, experienced by the UCL during pitching is very close to the maximum load that the UCL can sustain.

Recently, many studies have investigated factors that could make pitchers more susceptible to UCL injuries, with a hope of identifying ways to prevent them. One of the biggest findings has been the correlation between UCL tears and pitch velocity. According to a study from the Rush University Medical Center, there is a steady increase in the frequency of UCL tears as max velocity increases. This makes intuitive sense, as more torque would be required to accelerate a baseball to the higher velocities. While this finding does have a very strong correlation, it does not help the players avoid injuries. Pitchers are unlikely reduce their velocity because it would also decrease their effectiveness, so another answer must be found.

The University of Michigan conducted another study, and found that, in addition to velocity, the number of rest days between appearances decreased by just under a full day for pitchers who later needed Tommy John surgery. While this does not seem like a large number, starting pitchers typically only receive 4 days of rest between starts, so the extra .8 days is equivalent to a 20% increase in rest time.

Because of these findings, the MLB has increased the max roster size from 25 to 26 for the 2020 season, with the hope that teams will use the extra player to reduce the frequency that each pitcher is used. In addition, pitch counts in Little League Baseball have had a positive effect on youth injuries. This can be explored further here. This discovery has already made a tangible impact on Major League Baseball, and hopefully more findings will reduce the rate of UCL tears in the future.

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

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.

 

 

 

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.

Do Wrist Guards Prevent Snowboarding Injuries?

Snowboarder grabbing board while in the air after going off a jump.
Photo from Markos Mant on Unsplash

Snowboarding is a breathtaking sport yet carries with it an inherent risk of injury. Wrist protectors provide potential protection against snowboarding wrist injuries. However, some studies have argued that wrist protection transfers the injury to other parts of the forearm.

A 2001 joint study by the Lillehammer Central Hospital (Now part of Innlandet Hospital Trust) and University of Oslo Department of Orthopedic Surgery explored the efficacy of wrist protectors in preventing snowboarding injuries.

Studies like this are very important in growing winter sports, as more athletes will pick up snowboarding or alpine skiing if the risk of serious injury can be further decreased.

A total of 5029 snowboarders were included in the study, with 2515 snowboarders wearing a brace and 2514 snowboarders not wearing a brace. The brace used was a D-ring wrist brace. A physician examined the participants at the end of each day snowboarding and was not aware if the subject had worn a wrist protector or not. The physician defined a wrist injury as an evident fracture, sprain, or pain in the wrist that lasted for at least 3 days.

Front and Side view of a participant wearing a D-ring wrist brace.
Front (A) and side (B) views of D-ring Wrist Protector. Modified from Rønning, Rønning, Gerner, and Engebretsen, The American Journal of Sports Medicine 2001

A limitation of this study comes with setting an endpoint for what qualifies as a wrist injury. Both fractures and sprains qualify as wrist injuries. Wrist pain must be accompanied by decreased range of motion for 3 days to qualify as a meaningful wrist injury.

The study results showed that the braced group experienced 8 wrist injuries, while the control group recorded 29 wrist injuries. This is a statistically significant difference in the number of wrist injuries experienced by each group.

Of the subgroups explored in this study, beginner snowboarders with less than 5 days of snowboarding experience were found to have significantly more wrist injuries than the snowboarders with more than 5 or more days of experience.

A snowboard constrains both legs and feet in strapped bindings. When a snowboarder begins to lose their balance, a snowboarder will commonly extend their arms to brace the fall. When the wrist is flexed upwards during a fall, the wrist absorbs the energy of the fall and causes a fracture or sprain.

An effective wrist protector absorbs as much energy as possible without providing additional stress areas to the forearm. A wrist protector that is designed with too much rigidity will generate a high stress force above or below the wrist. The study confirms the benefits of wearing a protective wrist guard while snowboarding, and the physician found no injuries in the arm due to the use of a brace.

However, most wrist guards still available are uncomfortable to wear with winter gloves, so the study recommended future gloves be designed with built-in wrist guards. By improving the safety of alpine sports, snowboarders will feel comfortable pushing the boundaries of the sport and attempting more unforgettable tricks!

For more on injury prevention in snowboarding, check out this article by the Daily Herald or click here.