Category Archives: Mechanics

15 Myths and Facts for Runners

runningRunners are a very particular type of athlete and will try almost anything to run longer, faster, and remain injury free. Unfortunately, there is a lot anecdotal and pseudoscience being pulled from the internet that leads runners astray. In this article I talk about the biggest myths and facts in running.

  1. Static stretching decreases performance.

MYTH: A study done a few years ago demonstrated static stretching reduced power output and performance. Suddenly, performance experts started saying “Static stretching is the worst thing you can do.” This is not true! These people just misinterpreted the facts.  The data stated that performance decreased when the muscle was stretched for 45 seconds or longer… When a stretch was held for 30 seconds or less – as recommended – there was no performance loss.  A recent study published in the Journal of Strength and Conditioning confirmed this (1). This study found that the threshold of continuous static stretching in which muscular power output decreased was 60 seconds. Static stretching for a short-duration (30 seconds) had a negligible influence on performance.

  1. Static stretching can increase tightness.

stretchFACT:  Muscle is made up of two types of fibers, intrafusal and extrafusal.  Inside the intrafusal fibers is a receptor called the muscle spindle. It’s like a spring-loaded sensory detector. It is a protective mechanism that when over stretched sends a signal to the brain and spinal cord telling the muscle to contract and protect itself, thus making the muscle tighter. Some muscle spindles are overly active causing chronic tightness. So, when you stretch a muscle that already has over active muscle spindle, the tightness can increase. I wrote an article about this phenomena, if you want to read more about that.  I understand this can be confusing, but when you read #3 you will see how all of this comes together.

  1. You should foam roll after running.

Foam Roll TFL

MYTH: Foam rolling or self myofascial release is one of the most effective tools to improve motion and prevent muscle injury. Unfortunately, many runners foam roll after a run. It is just as important, or even more important, to foam roll before a run. As I mentioned in #2, muscle spindles create tightness when stretched. Due to the repetitive nature of running, runners are very susceptible to developing hyper-active muscle spindles. Foam rolling or self myofascial release targets the muscle spindle and inhibits it (hence the term release in myofascial release). Foam rolling overloads the muscle spindle and the nervous system and gets it to relax and turn off. This allows the muscle to be stretched without the muscle spindle becoming overprotective. Every client I see is directed to foam roll first, stretch, then exercise.

  1. Icing or an ice bath after a run helps injury and speeds recovery

MYTH: Inflammation is REQUIRED for the body to bring supplies to worked areas, clean up any debris and help rebuild tissue. When we ice that sore knee, aching Achilles, or painful plantar fascia after a run or workout we are delaying our body’s innate ability to repair that tissue. Yes, icing is not all it is cracked up to be. Even the physician who coined the term RICE (Rest, Ice, Compression and Elevation) has said that icing is wrong. I’ve written many articles about this, but the most recent, explains why RICE is no longer accepted as the cure-all.  If you want to recover, cool down with foam rolling and stretching, and have a few days of light exercise or rest.

  1. Drinking extra liquid will prevent heat illness.

MYTH: In general we overhydrate. Tim Noakes, MD, a long-time researcher of water balance and author of “Waterlogged:  The Serious Problem of Overhydration in Endurance Sports,” says we have been misled to believe that we need to drink to stay ’ahead of thirst’.  Hydration prevents dehydration, but it does NOT prevent heat illness. Dehydration and heat illness have very similar symptoms and often we use the two interchangeably, but they are not the same. If someone is suffering from heat illness, giving them water is not the answer, cooling their body temperature is. Giving excessive water to a person suffering from heat illness can cause a serious or fatal event called exercise-associated hyponatremia encephalopathy (EAHE).   Marathoners and distance runners who drink at every aid station or drink excessively before a run put themselves at risk for this condition. Dr. Noakes states we should aim for ingestion rates that never exceed 27 ounces/hr (2). 20140501More about our hyper-hydration nation can be found in this article.

 

  1. Dehydration kills performance.

MYTH: It’s long been held as fact that losing more than 2 percent of bodyweight to dehydration will hurt performance. But several recent studies, as well as anecdotal evidence from the world’s top runners, suggest it’s possible to lose more than 2 percent with little to no detriment to performance. A study in the British Journal of Sports Medicine found that current hydration guidelines are erroneous and that dehydration does not impair performance (3). In this article the authors found weight loss of up to 3 percent did not slow down athletes (cyclists, in this case) or lower their power output.  Finally, in 2012 a study found that Haile Gebreselassie lost a whopping 9.8 percent of his bodyweight during the 2009 Dubai Marathon—and still won, in 2:05:29 (4).

  1. Energy chews prevent bonk or fatigue.

FACT: But don’t be fooled: Energy chews do work to prevent fatigue during long distance running events, but so do raisins!  A study published a few years ago compared raisins vs. energy gummies. There was no difference in performance between the raisin group and the gummy group. In addition, the raisin group showed a lower insulin spike when compared to the gummy group, a win for the raisin. Plus, the raisin group demonstrated higher free fatty acid content in the blood post activity, demonstrating more fat metabolism. So, for the same performance gains, you can gain additional benefits from raisins over energy gummies.

  1. Bananas prevent cramps

MYTH: While bananas are a great source of nutrition and do contain many electrolyte replacing nutrients, they alone do not prevent cramping. Cramping can be caused by a large number of reasons, including over hydration (see above) or poor conditioning. Tim Noakes, MD, in Lore of Running, 4th Edition, suggests muscle cramps are caused by muscle fatigue and that cramping has more to do with not training properly than nutritional or hydration deficits.

  1. Runners need to strength train.

FACT: Running strengthens your muscles, but it only strengthens certain muscle fibers to a certain degree. A total body strength training is imperative for running performance. Strength and stability of the core and shoulder help translate to lower body power and efficiency. If you need a kick to climb a hill faster or sprint to beat an opponent to the line, strength training is imperative. Proper strength training and targeting specific muscles will also prevent injury. John Martinez, the assistant head doctor for the Ironman World Championships says “You can run five days a week and you’ll finish a marathon, but if you want to PR or qualify for Boston you need to have some kind of strength training in there. It’s about improving our performance.” Always add a strength training component to your training program. Running alone is not enough.

  1. Running is the best way to lose weight.

Graphics like this misguide those seeking weight loss.

MYTH: You’re being duped folks! Long duration cardio training does not make you lose more fat or weight. Running in the “fat burning zone” as depicted on a cardio machine does NOT burn more fat. If you want to lose weight, you need to burn calories. What burns calories? Intensity! Higher intensity requires more oxygen demand and thus a greater oxygen debt.  High intensity training has a caloric after burn that lasts for 12-24 hours. Standard steady state running only has a caloric after burn of 1-4 hours. You can burn more calories in a 20 minute high intensity interval training program than you can running for 60 minutes at a steady pace. If you want to lose weight, get off the treadmill!

  1. Minimalist shoes improve running mechanics and prevent injury.

vibram-shoes1MYTH: Will the minimalist running trend ever end? Minimalist shoes do not prevent injury. In fact, those who jump from a normal shoe to a minimalist shoe without proper training or adaptation are at an increased risk for injury. Five separate studies presented at the annual meeting of the American College of Sports Medicine “found no significant benefits, in terms of economy, from switching to minimalist, barefoot-style footwear.” Minimalist shoes also do not magically improve your running mechanics. There are no quality studies that show running in a minimalist shoe improves mechanics. In order to improve mechanics, you need a quality strengthening and flexibility program that encourages appropriate muscles firing. If you want to go the minimalist route, walk first. Adapt to the new style and supplement with a structured training program.

  1. Getting a shoe that matches your arch height will prevent shin splints.

MYTH: Shin splints are not caused by a high or low arch. Many runners with a high or low arch can avoid shin splints. Similarly, runners with a “perfect” arch can develop shin splints. The cause of shin splints is multifactorial and correcting musculoskeletal dysfunction through a structured program prevents shin splints. The article Shin splints 101 demonstrates how to prevent shin splints. A systematic literature, published in the Journal of Sports Physical Therapy found that selecting running shoes based on arch height had little influence on injury risk. (5)

  1. A midfoot strike is best for performance.

MYTH: If you run slower than a 5-minute mile, it may be most efficient to heel strike. A study published in Medicine and Science in Sports and Exercise found that rear-foot strikers are up to 9.3 percent more economical than midfoot strikers (6). Lead author Ana Ogueta-Alday believes the reason for the improved efficiency stems from the increased ground contact time the study observed in rearfoot strikers. More contact time with the ground allows for more force to be applied, while also decreasing the metabolic cost of running. If you’re a heel striker and haven’t been chronically injured, there’s no need to change your ways.

  1. The more mileage you run per week the better your performance.

MYTH: If you want to improve, you need rest, recovery, and varied training. I challenge you to find an elite marathoner who trains only by running. The elite runners have rest and cross-training built into their weekly programs. See the importance of strength training in item #9 above.  Two of the best known experts on running, Jack Daniels and Hal Higdon, provide run training programs. There programs stress the importance of recovery days and strength training days. In fact, Jack Daniels says that when training for long running events, train for time, not mileage. Getting 20+ miles is not the best for all runners and could cause injury.

  1. Preventing injury is a matter of not doing too much too fast.

FACT: There are many things that can cause injury, but one of the biggest determinants of injury is doing too much too fast. A study in the Journal of Sports Physical Therapy evaluated progression of running distance and its relation to injury. The authors found novice runners who progressed their running distance by more than 30% over a 2-week period seem to be more vulnerable to distance-related injuries than runners who increase their running distance by less than 10% (7). Owing to the exploratory nature of the present study, randomized controlled trials are needed to verify these results, and more experimental studies are needed to validate the assumptions. Still, novice runners may be well advised to progress their weekly distances by less than 30% per week over a 2-week period. So stick with the 10% rule.

If you are a runner and look to increase performance or prevent injury, please feel free to contact me for a free consultation.

References:

  1. Pinto, MD, et al. Differential Effects of 30- Vs. 60-Second Static Muscle Stretching on Vertical Jump Performance. December 2014. 28:12. p 3440–3446.
  2. Noakes, T. Waterlogged: The Serious Problem of Overhydration in Endurance Athletes. Human Kinetics. Champaign, IL. 2012.
  3. Wall, BA, et. al. Current hydration guidelines are erroneous: dehydration does not impair exercise performance in the heat. Br J Sports Med. 2013 Sep 20.
  4. Beis, LY, et. al. Drinking behaviors of elite male runners during marathon competition. Clin J Sport Med. 2012 May;22(3):254-61
  5. Knapik JJ, et, al. Injury-reduction effectiveness of prescribing running shoes on the basis of foot arch height: summary of military investigations. J Orthop Sports Phys Ther. 2014 Oct;44(10):805-12.
  6. Ogueta-Alday, A, et. al. Rearfoot striking runners are more economical that midfoot strikers. Med Sci Sports Exerc. 2014; 46(3):580-5.
  7. Nielsen RØ, et. al. Excessive progression in weekly running distance and risk of running-related injuries: an association which varies according to type of injury. J Orthop Sports Phys Ther.2014 Oct;44(10):739-47.

 

 

POS: Reduce Pain and Increase Performance

SwingDysfunction of one movement system can lead to a multitude of injuries. Treatment and care for one movement system can prevent our most common ailments. Most potential clients I interview complain of one or more of the following: sacroiliac joint (SIJ) pain and instability, non-specific low back pain (LBP), chronic hamstring strains or tightness, and peri-scapular and thoracic tightness or pain. Whether these complaints are isolated to one body part or involve many, the pain can typically be resolved by treating dysfunction of the Posterior Oblique Subsystem.

 

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Butt Battle

A nice booty is not always a good booty.

A nice booty is not always a good booty.

Everyone loves a nice butt. Walking down the street, at the mall, or at the bar, there is bound to be a butt that catches your eye. Like a kitten following a piece of yarn, there is the occasional butt that walks by and causes heads to turn, leaving onlookers with a severe neck strain and mouths agape. Don’t act all innocent and holier than thou, we’ve all done it! Therapists and rehabilitation specialists are no different. In fact they can spend an entire day staring at booty. However, we are not looking to see if “Baby Got Back” or how that plump bump fills a pair of Wranglers, Levis, Seven, or True Religion jeans. We have a reason to look and it is strictly professional; is the little butt working?

For several years now rehabilitation journals have published articles linking a myriad of lower extremity injuries to poor gluteal control. While the glute max – that which makes our heads turn – and the glute minimus are both important, the glute medius is the real problem. We have learned the important role the glute medius has on controlling lower extremity mechanics. Glute medius inhibition precipitates many lower extremity injuries such as ACL tears, Patellofemoral pain, Iliotibial band syndrome, Achilles tendinopathy, plantar fasciitis, MTSS (shin splints), the list goes on. Rehabilitation specialists must pay special attention in strengthening the glute med., but how? What is the best exercise?

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The Glute vs TFL Muscle Battle: Proper Exercise Selection to Correct Muscle Imbalance

Reference:
Selkowitz, DM, Beneck, GJ, and Powers CM. Which Exercises Target the Gluteal Muscles While Minimizing Activation of the Tensor Fascia Lata? Electromyographic Assessment Using Fine-Wire Electrodes. J Orthop Sports Phys Ther. 2013; 43(2):54-64.

Overview and Introduction:
JandaSyndromesVladamir Janda revolutionized human movement dysfunction and rehabilitation when he described three compensatory movement patterns as a result of pattern overload and static posturing. Most musculoskeletal injuries are multifactorial, but more often than Janda’s described three compensation patterns – upper crossed syndrome, lower crossed syndrome and pronation distortion syndrome – are the key contributor to our pain complaints.

Since Janda introduced this topic research has continued to answer what and why questions surrounding these compensatory patterns. We have learned hypertonic / hypotonic muscles and the delicate interplay they have on integrated functional movement. Studies continue to show how these dysfunctional patterns lead to our most common injuries – PFPS, ITBS, Achilles tendinopathy, plantar fasciitis, epicondylopathy, biceps tendinosis, impingement syndromes, MTSS, etc.

As research evolves we continue to fine-tune our clinical decision making. For several years now rehabilitation journals have published articles linking a myriad of injuries to lower-crossed syndrome, gluteal inhibition, and over-activation of the tensor fasciae latae (TFL). We have learned that these should be a focal point in our rehabilitation techniques to resolve lower extremity overuse injuries. The article by Selkowitz, et al., in the Feb 2103 edition of JOSPT is unique and what I believe to be one of the most clinically relevant studies to be published in the last few months. I liked it so much I had to blog it.

Statement of the Problem:
A common descriptor associated with lower-crossed syndrome is femoral internal rotation and hip adduction. From a rehabilitation perspective we must enhance neuromuscular firing of hip abduction and external rotation. In addition we must inhibit over activity of hip adductors and hip internal rotators.

As a health care practitioner we understand the delicate interplay of functional anatomy. The problem is how do we inhibit a chronically hypertonic TFL while activating the hypotonic gluteal group if they both produce similar movements? It is a fine balance we must be cognizant of when designing rehabilitation programs.

This study examined which exercises elicit the greatest gluteal (medius / maximus) activation while minimizing activation of the TFL. This is exactly what we need to know when designing a rehabilitation program to target lower crossed compensatory patterns.

Study Methodology:
Electromyographic data of the gluteus medius and superior gluteus maximus was collected utilizing fine-wire electrodes on 20 healthy participants during the execution of 11 exercises.

Results:
Seven of the 11 exercises -bilateral bridge, unilateral bridge, side step, clam, squat and two quadruped variations – demonstrated statistically significant greater muscle activation in the gluteus medius and gluteus maximus when compared to the TFL. Side-lying hip abduction, hip hike, the lunge, and the step-up were either not significant or demonstrated higher TFL values compared to the gluteal group.

The authors ranked the exercises in order of highest gluteal to TFL ratios. Clam, side step, and unilateral bridge had the highest ratios, while lunge, hip hike, and squat had the lowest ratios.

Clinical Application of Data:
Altered arthrokinematics and muscle imbalances are a common cause of overuse injuries. Lower-crossed syndrome is a common compensatory pattern that is associated with hypertonicity of the hip flexors complex, which elicits altered reciprocal inhibition of the gluteal group. Targeting this dysfunctional pattern using proper exercise selection indicated here can prevent injuries, improve patient outcomes, and restore optimal function. When designing your program be sure to reference the material here to determine a proper rehabilitation program.

Limitations:
Studies are equivocal on reliability of surface EMG vs intramuscular. However, the authors cite using the method by Delagi and Perotto, which appears reliable. Still one has to question specificity and sensitivity to a minimal degree.

The participants were instructed on proper exercise technique. However, substitutions patterns are common in patients exhibiting muscle imbalance. Any slight deviation from proper technique can skew the data. I am curious how closely exercise technique was monitored and what occurred when deviation did occur.

Summary:
Like I said from the top, rarely do we have a published data with such clinical relevance. Studies that show how deep ultrasound penetrates a rats muscle are great, but clinically have little clinical utility. Data revealed here will guide decision making on proper exercise selection and ensure they are applying the proper strengthening exercise to specifically target the underactive glutes while avoiding the over active TFL. Kudos to the authors.

The Geek’s Squat: Proper Squat Techniques for Strength and Injury Prevention

There has been much debate on proper squat techniques. Is it proper to maintain a vertical shin and prevent the knees from going beyond the toes? Is it better to squat and allow the knee to go beyond the toes? Proponents of the vertical shin technique argue it is best to save the knees and this helps increase posterior chain strength. Whereas proponents of parallel lines say, distribute the weight evenly and save the back. The purpose of this blog is to shed some light on the debate and provide the rationale for proper squat technique.

Early studies state that squatting with external loads causes undue stress and damage to soft tissue at the knee joint. This precipitated many experts to change squat mechanics. A vertical shin angle prevents excessive knee flexion, thus limiting the stress placed at the knee joint and potential damage to integral knee structures such as the meniscii, articular cartilage and ligaments. In addition, many state that maintaining a vertical shin angle allows for enhanced strengthening of the posterior chain (hamstrings, glutes, low back).

I agree it is important to protect the knees. However, the lower back is much more important, in my opinion. Low-back pain is one of the major forms of musculoskeletal degeneration seen in the adult population, affecting nearly 80% of all adults (1). It has been estimated that the annual costs attributable to low-back pain in the United States are greater than $26 billion (2). In addition, 6 to 15% of athletes experience low-back pain in a given year (3, 4). The body is an interconnected chain, and compensation or dysfunction in the LPHC region can lead to dysfunctions in other areas of the body (5). So why do we squat to protect the knees? How should we squat?

Proper squat mechanics requires optimal flexibility at the ankle, knees, and hips during the descent of the squat. When these joints are moving together, forces will be disturbed optimally and equally throughout the kinetic chain. If one of the joints has limited ability to move, another joint must compensate to make up for the lost movement. For example, if you are trying to pick something off of the floor and do not bend your knees you must bend at the back. Using this example, if we squat like this (limiting knee flexion or ankle dorsiflexion) we are asking the lower back to lift weight in a biomechanically disadvantaged position. You know the phrase “lift with your legs not your back.”

Do a quick check and test your squat mechanics. Evaluate your technique by watching in a mirror.  At the bottom of the squat the torso and tibia should be parallel to each other (See image below).  Have you ever noticed how a baby squats? Do a quick google search for baby squat. You will be amazed at their technique. They lift properly, because they have the flexibility to get in to a deep squat without excessive leaning at the low back. It does not matter if the knees go past the toes. The most important thing to ask: is the back parallel with the shin?

Fry et al. (2003) examined the hip and knee torque forces of variations of parallel squats and concluded appropriate joint loading during this exercise may require the knees to move slightly past the toes. Restricting squats created significant increases of excessive forward lean and subsequent increased torque loads at the low back and hip (6). Maintaining a vertical shank did not yield change knee torque significantly (6).

Torque is a measure of rotational force about an axis of rotation.  Simply put torque is a product of force and lever length from the axis of rotation to point of force of application (Τ = r x F) where Τ is linear torque, r is the displacement vector and F is force. Look at the two images below and notice the Torque values at the knee and low back:

Squatting with a Vertical Shin

Squatting with vertical shin:

Measurements:
αlb= 78° αk= 102° F = 135lbs (600.5 Newtons)
B to C= 19 inches (.48 meters). A to B = 2.75 inches (0.07 meters).  A to C = 16.25 inches (0.41meters)

Linear Torque Low Back:
Τlb = r x F
Τlb = 0.41m x (600.5N)
Τlb = 246.2 N·m

Linear Torque at the Knee:
Τk = r x F
Τk = 0.07m x (600.5N)
Τk = 42.04 N·m

Squatting to allow toes go beyond the knees

Squatting with parallel lines 
Measurements:
αlb= 90° αk= 90° F = 135lbs (600.5 Newtons)
B to C= 19 inches (0.48 meters) A to B = 9.5 inches (0.24 meters) A to C = 9.5 inches (0.24 meters)

Linear Torque Low back:
Τlb = r x F
Τlb = 0.24m x (600.5N)
Τlb = 144.12 N·mLinear Torque Knee:
Τk = r x F
Τk = 0.24m x (600.5N)
Τk = 144.12 N·m
You can clearly see that squatting with a vertical shin reduces stress placed on the knee, but significantly increases torque on the low back. Do we really want to place an increased load at the lower back, when it is so prone to injury? The most important thing to consider is overall exercise technique. Lifting with ideal posture is paramount for injury prevention. When this occurs forces will be distributed equally throughout the kinetic chain.

References:

1. Walker BF, Muller R, Grant WD. Low back pain in Australian adults: prevalence and associated disability. J Manipulative Physiol Ther 2004;27:238–44

2. Luo X, Pietrobon R, Sun SX, Liu GG, Hey L. Estimates and patterns of direct health care expenditures among individuals with back pain in the United States. Spine 2004;29:79–86.

3. Nadler SF, Malanga GA, DePrince M, Stitik TP, Feinberg JH. The relationship between lower extremity injury, low back pain, and hip muscle strength in male and female collegiate athletes. Clin J Sport Med 2000;10:89–97.

4. Nadler SF, Malanga GA, Feinberg JH, Rubanni M, Moley P, Foye P. Functional performance deficits in athletes with previous lower extremity injury. Clin J Sport Med 2002;12:73–8.

5. Powers CM. The influence of altered lower-extremity kinematics on patellofemoral joint dysfunction: a theoretical perspective. J Orthop Sports Phys Ther 2003;33(11):639–46.

6. Fry, A.C., J.C. Smith, and B.K. Schilling. Effect of knee position on hip and knee torques during the barbell squat. J. Strength Cond. Res. 17(4):629–633. 2003