Part 1: Introduction & Shoes and Sitting
Part 2: Systemic biomechanical issues
Part 3: Evaluation of lower body dysfunction and corrections
Part 4: Soft tissue optimization and corrections
Part 5: Summing it up
It is a thorough analysis of how many of the common orthopedic problems today arise from shoes and sitting, how to evaluate their development, and finally a look at how to implement prehabilitation or rehabilitative protocol to improve their condition. I sincerely wish that you will read through the whole thing even though it is a monster. I promise you will come out with a new outlook on this topic.
I’ve noticed that the page hits for page 2 and beyond are about 1/5th of this page. Please do note that this is part 1 of a 5 part article. You will have to click on to read the other parts at the bottom of this page.
Many thanks KC Parsons for taking the time to find pictures.
Introduction & Shoes and Sitting
Table of Contents
Note: We have an in-depth article on the feet as well, however, it does refer back to this article so I would suggest reading both if you have foot issues.
Introduction / To the top
Shoes and sitting. Two things that are ubiquitous in modern society.
There has been recent media sensationalization of the detrimental effects of shoes. However, there has not been a lot on sitting other than upper body postural issues. Do these two things really have that much of an impact on our lives? Or is it just athletes?
Unfortunately, most information out right now does not look specifically at the effects that injuries have on the body as a system. Rather, most of the solutions to problems tend to focus on only reducing the pain or alleviating the problem at one joint specifically.
For example, shoulder problems often arise up around the ball head of the humerus and usually manifest in rotator cuff problems, but that pain and injury may be from a cascade of problems from loss of thoracic extension, proper scapular movement, and incorrect muscular activation. This is a topic for another article.
In this article, I am going to build a case against shoes and sitting. My eventual conclusion is there is a detrimental effect on most people and not just athletes. I will walk you through this process noting biomechanical and physiological issues. Then we will talk about how to correctly evaluate these conditions, and how to solve them. In the end, all should see the widespread damaging effects of these two things that we have not even considered dangerous.
Shoes / To the top
There have been numerous articles in the past saying how shoes are bad for you. For example,
You Walk Wrong,
The painful truth about trainers: Are running shoes a waste of money?,
Cure all Running Injuries (and Pain) with One Simple Fix….Barefoot Running
Footwear Alters Normal Form And Function Of The Foot
Barefoot running debate – GREAT image that shows some of the dysfunctions we will look at later.
And more recently since this article has been written:
Barefoot Running: How Humans Ran Comfortably and Safely Before the Invention of Shoes
In general, these are true. For example, this abstract published in the Journal of the Southern Orthopaedic Association in 1994 states:
The shod foot and its implications for American women.
Throughout history, members of human societies have gone barefoot, and those societies seemingly had a low incidence of foot deformities and pain. Only one study has addressed the problem of infection through injury to the bare foot; otherwise, the unshod foot seems to have had minimal problems. Initially shoes were made in the shape of the foot and were sandals. Over time, shoes became decorative items and symbols of status and vanity. As the shape of shoes changed, they became deforming forces on the foot and the source of pain. Recent studies by the Council on Women’s Footwear of the American Orthopaedic Foot and Ankle Society have tried to document the problems caused by shoes on the feet of American women. Attempts should continue to educate women on appropriate shoes and proper fit.
These are not the only cases. Another instance is this abstract from the August 1991 issue of Pediatrics. (I have a full text; if anyone is interested post in the comments.)
Shoes for children: a review.
1. Optimum foot development occurs in the barefoot environment. 2. The primary role of shoes is to protect the foot from injury and infection. 3. Stiff and compressive footwear may cause deformity, weakness, and loss of mobility. 4. The term “corrective shoes” is a misnomer. 5. Shock absorption, load distribution, and elevation are valid indications for shoe modifications. 6. Shoe selection for children should be based on the barefoot model. 7. Physicians should avoid and discourage the commercialization and “media”-ization of footwear. Merchandising of the “corrective shoe” is harmful to the child, expensive for the family, and a discredit to the medical profession.
These are some pretty harsh words. However, beyond that let’s dig a little deeper by looking at shoes and running.
The incidence of running injuries before the 1950s was low. But since the 1970s when shoe manufacturers have started to put more and more padding into shoes, the incidence of runners that have some injury every year is up to nearly 60%. Some of the cause could be to due confounding factors such as the rise in obesity, improperly fitted shoes, etc.; however, there is at least some reason to believe otherwise as we will shortly discuss.
Most of the common running shoes have lots of padding in the heel which incorrectly gives the user an impression that heel-toe running is correct. Significant amounts of heel-toe running can potentially cause long term damage in combination with other factors such as obesity, improperly fitted shoes, and strenuous activity, especially in children and the elderly. In heel-toe running, the joints are taking the impacts rather than your musculature dissipating the force correctly with mid- and fore-foot striking. One study showed that shoes mechanically alter stride compared to barefoot running resulting in lower net efficiency.
Walking, in which the heel does strike the ground first, is a fundamentally different gait from jogging, running, and sprinting which require a mid- and fore-strike to protect the body and operate at a high level.
However, beyond the walking and running mechanics, let us analyze why shoes are a problem.
- Most shoes now have an elevated heel as padding. In walking or running, the knee tracks over the toe as you take a step. With an elevated heel, the foot is already tilted forward which means the ankle does not need to bend as much during movement. Not taking a muscle often to the edge of its range of motion means that the muscles start tightening up. This limits the range of motion (ROM). Thus, with shoes there tends to be a loss of 10-20 degrees range of motion in ankle leading to tight calves.
- The padding in the shoes is problematic as well. Our body and feet have proprioceptors that allow us to feel the ground as we are moving. This gives us the ability to make small corrections to maintain proper posture and movement. The padding in the shoes allows improper corrections to be made (as they will not be punished by awkward landings), and decreases our natural proprioceptive ability and affect ankle coordination abilities. This leads to inactivated muscles on the plantar aspect (bottom) of the foot and decreased ankle stability especially with inversion and eversion corrections. In addition, this may lead to increased frequency of falls in the elderly.
As you can see, shoes are a problem especially compared to barefoot ability. This is even more evident if we are aware of the fact that the plantar aspect of the foot has 3 different muscle layers including the plantar fascia. Let’s now take a look at some more studies supporting the two points above.
Photos from medlineplus and eorthopod
This study showed that “a significant increase in leg stiffness from the barefoot to the “cushioned” shoe condition was noted during hopping. When running shod, runners landed more dorsiflexed (foot tilted upward) but had less ankle motion than when running barefoot. […] The primary kinematic difference was identified as running speed increased: runners landed in more knee flexion. At the ankle, barefoot runners increased ankle motion to a significantly greater extent than did shod runners as speed increased.” When running barefoot, the forefoot receives the ground* with less than 90 degrees of dorsiflexion. Thus, the comment above regarding dorsiflexion with shoes running is deceptive. Obviously, decreased range of motion is the big thing as I talked about above.
* Note that minimalist shoes like sprinters use with proper technique show similar biomechanical patterns as barefoot running. I will talk about this in the next few segments.
Likewise, flatter foot touchdown and increased leg stiffness was found in barefoot running. Increased “leg stiffness” is good because that means the muscles are taking the brunt of the forces rather than your joints.
One study on ankle sprains showed that awareness of foot position is impaired by shoes. The authors also noted that there was increased muscle activity during inversion with shoes. They concluded that this was the body’s adaptive mechanism to oppose the increased tendency to roll the ankles with shoes as opposed to barefoot.
In a similar vein, this investigation showed that as the “shock ability” of the materials in running shoes decreased, foot control (proprioception) increased. Loss of proprioception is implicated in as much as 50% of running shoe injuries!
“This experiment showed that the sandals not only restricted the natural motion of the barefoot but also appeared to impose a specific foot motion pattern on individuals during the push-off phase.”
The best evidence, however, as far as we are concerned it from actual biomechanical evidence. This can be seen clearly in this study of the biomechanics of shod vs. barefoot running.
Increased joint torques at the hip, knee, and ankle were observed with running shoes compared with running barefoot. Disproportionately large increases were observed in the hip internal rotation torque and in the knee flexion and knee varus torques. An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.
In the next section, we will talk extensively about internal rotation, valgus, and varus states. However, the discussion here provides an ample preview:
“The observed 36% increase in the knee flexion torque with running shoes potentially increases the work of the quadriceps muscle, increases strain through the patella tendon, and increases pressure across the patellofemoral joint. Furthermore, a 38% increase in the knee varus torque implies relatively greater compressive loading on the medial tibiofemoral compartment, an anatomical site prone to degenerative joint changes, as compared with the lateral compartment. Finally, the disproportionately large 54% increase in the hip internal rotation torque may have particularly high clinical relevance, given previous findings that indicate that competitive running may increase the risk of OA of the hip joint.”
The internal rotation torque and quad dominance in particular in conjunction with tight calves are some of the main reasons of the dysfunctions we will discuss later.
Finally, we have this study which indicates that “selecting shoes based on plantar shape had little influence on injury risk.” Basically, no matter how expensive your shoes or how much ‘support’ they provide, they don’t decrease your injury risk. This is a very strong case for flats/minimalist shoes/barefoot.
This article on the ankles also provides some relevant material to the discussion.
Note: The loss in range of motion from the calves covers why I do not have to mention why high heels are terrible for women. Even though women look good in them. Similarly, in sports with extensive plantar flexion such as pointing the toes in gymnastics and figure skating it is possible to develop similar problems.
Sitting / To the top
Sitting has become a huge problem in modern society. Sitting is obviously common for school and most jobs. However, throw in decreasing amounts of recess and lack of activity for adults as well as obesity and you have a full blown epidemic.
There has not been much talk of this in the media. However, most of the sports communities knows the problems associated with sitting and its detrimental effects on athletic performance. Even so, the effects of sitting are more widespread than just poor athletic ability. Let us analyze why sitting is a problem.
- In sitting, the butt / gluteal muscles are in a stretched position. When a muscle is allowed to be in a stretched position for extended periods of time such as in school or office jobs, the muscle becomes weaker and thus inactivated. This is the opposite of what happens with the calves in their shorter and tighter position. Thus, with sitting the glutes become weak and inactive.
- The hip flexors which are shortened in hip flexion, like the calves, become shorter and tighter. The hip flexors consist of the iliopsoas, rectus femoris, sartorius, tensor fasciae latae (TFL), and adductors longus and brevis.Thus, with sitting the the hip flexors become short and tight.
Photos from blogpost and chiropractic-help
It has been investigated “whether gluteal muscles could be activated more effectively by stimulating the proprioceptive mechanism during walking.” They came to the conclusion that balance shoes help especially with lower back pain helping fire inactivate gluteal muscles. Ironically, you could just walk barefoot and do balance work to stimulate foot proprioceptors as well as do gluteal activation work. We will get to this later.
There are varying degrees of inactivation. Gluteal inactivation does not mean that the glutes fail to activate altogether. Rather they will fire although with decreased intensity or a delayed pattern which may be ineffective during proper recruitment during certain movements.
There is another interesting study done on a variety of subjects.
RESULTS: There were 1832 deaths (759 of cardiovascular disease (CVD) and 547 of cancer) during 204,732 person-yr of follow-up. After adjustment for potential confounders, there was a progressively higher risk of mortality across higher levels of sitting time from all causes (hazard ratios (HR): 1.00, 1.00, 1.11, 1.36, 1.54; P for trend <0.0001) and CVD (HR:1.00, 1.01, 1.22, 1.47, 1.54; P for trend <0.0001) but not cancer. Similar results were obtained when stratified by sex, age, smoking status, and body mass index. Age-adjusted all-cause mortality rates per 10,000 person-yr of follow-up were 87, 86, 105, 130, and 161 (P for trend <0.0001) in physically inactive participants and 75, 69, 76, 98, 105 (P for trend = 0.008) in active participants across sitting time categories. CONCLUSIONS: These data demonstrate a dose-response association between sitting time and mortality from all causes and CVD, independent of leisure time physical activity. In addition to the promotion of moderate-to-vigorous physical activity and a healthy weight, physicians should discourage sitting for extended periods.
The very intriguing thing to note here is that sitting, even when adjusting for smoking, physical activity, and other mortality factors, has a dose-response association (meaning that the more you sit) the higher your risk of death. The P-value for this is <.00001. P-value is used in studies to incidate significance of data — generally anything under .05 is significant which means that 95% (1-.05) of the time this data is unlikely to occur. This data is particularly strong which means that 1-.00001 = 99.999% of the time this data set would not occur. This indicates that sitting is extremely insidious and dangerous the more you do it.
Another study seems to verify this conclusion. After adjusting for physical activity and other factors, those who sat greater than 6 hours per day were 37% more likely to die than those who sat less than 3. With a lack of physical exercise those who sat greater than 6 and less than 3 hours were 94% and 48% respectively more likely to die. Associations were strongest for cardiovascular disease mortality.
Consider that we now all send our kids to school for 7-8+ hours a day for 15+ years, and have desk jobs for much of our adult lives…. this is not a good sign.
Note: there will be more studies to come on gluteal activation; however, as a lot of them relate to the injuries that is specifically why they will be discussed later. I just want you to know that I do have my position on this topic supported at least as much as I have supported my case against shoes.
In conclusion, we learned that shoes and sitting cause many problems. This is a big problem because they are ubiquitous in modern society. Shoes tend to allow the user to run improperly (heel-toe) and hinder proper ankle biomechanics. In addition,
Shoes tends to cause the problems of
- Tight calves resulting in loss of 10-20 degrees of dorsi-flexion ROM in the calves.
- Inactivation of the muscles on the bottom of the foot and the ankle stabilizers.
- Decreased proprioception of the lower limbs.
Sitting tends to cause the problems of
- Inactivation of the gluteal muscles.
- Tight hip flexors (i.e. iliopsoas, rectus femoris, sartorius, tensor fasciae latae [TFL], and adductors longus and brevis).
In the next segment we will discuss look at the systemic biomechanical issues that arise from these deficits. Click below for the next part.