Should We Be Warning People about the Dangers of Their Chair?
Check Out This Great Article from Dr. Craig Liebenson
On September 13, 2010, in Activity & Musculoskeletal Health, by Craig Liebenson ….Pr Janda’s Warning About Modern Lifestyle Proves Prophetic
The great Czech neurologist Pr Vladimir Janda stated that we are designed to take over 20,000 steps/day. Yet the average American takes less than 10,000 steps/day ! In fact, Pr Janda probably underestimated how much humans are designed to walk as the Amish typically take over 30,000 steps a day. We can say with certainty that 200,000 years of evolution have designed us to walk at least 3x as much as we now do. Our modern lifestyles have led homosapian into becoming homosedentarius. Or, as our German colleagues say homo erectus vulgaris.
What are the culprits? According to a recent summary – Too Much Sitting: The Population Health Science of Sedentary Behavior: Objective Assessment of Sedentary Time: New Findings
■Computer or internet useage
What is the effect of all this sitting? How about the big one – increased mortality!
If we look at the different modifiable risk factors that shorten life span –
■high blood pressure
It took billions of years before life on earth was able to evolve an upright species. Just 200,000 years ago that became possible. And, now in just the last few decades we have polluted this!
HOW BIG A PROBLEM?
Sedentarism affects lifespan more than any of the other risk factors! Yet, prevention strategies more frequently focus on the others.
This is inline with the just launched “Designed to Move – A Physical Activity Action Agenda” from which the following are taken.
■”As economies grow, physical activity is systematically designed, innovated and engineered out of daily life.”
■World Health Organization’s definition of physical inactivity: “Percent of defined population attaining less than 5 times 30 minutes of moderate activity per week, or less than 3 times 20 minutes of vigorous activity per week, or equivalent.”
■2X the Federal Budget of DOE is spent on costs associated w/ inactivity.
■“Betz cells in the brain are essential to the development of fine motor skills” Between ages 7-11 we lose 50% of them!
■“Human beings are designed to move and be active. Our bodies evolved to meet the demands of human existence. And yet, research shows us that, as economies develop, their populations’ levels of activity become dangerously low. The human and economic costs of progress are staggering. Physical inactivity is a looming and dangerous threat to everyone’s health, well-being and quality of life. But most importantly it results in an erosion of human potential. Now, more than ever before, it is time for urgent action.”
■ China’s 1.3 billion citizens are becoming less physically active, at a higher rate, than any other nation: in less than a generation—only 18 years—physical activity declined by 45 percent.
■ “Today, physical inactivity is linked to approximately 5.3 million premature deaths worldwide each year— more than tuberculosis, lung cancer, HIV/AIDS or traffic accidents.”
■“Physical Activity: An Underestimated Investment in Human Capital?” by Bailey, Hillman, Arent and Petitpas (forthcoming, 2012).
■Compared to their inactive peers, physically active childrenwill be significantly healthier and wealthier.
■ Increased physical activity has been shown to lead to reductions in functional decline (frailty), coronary heart disease (CHD), and disability prior to death along with increased life expectancy have all been demonstrated.
■The Surgeon General has reported that only 22% of adults in the United States are active enough to derive benefits from activity. Inactive men 60 years of age who become active have a mortality rate 50% lower than their peers who remain inactive. A study of Harvard University alumni confirmed this result. Men who were initially sedentary, but later began engaging in vigorous sports had a 23% lower rate of mortality than their inactive counterparts (Paffenberger, 1993). A Honolulu Heart program found that retired men who walked >2 miles/day had half the mortality rate (22%) than those who walked <1 mile/day (43%) (Hakim).
■Many physicians counsel patients about smoking and body weight, but not about inactivity (Caspersen, 1985).
What is the primary function of human beings?
WHAT ARE SOME OTHER EFFECTS OF PROLONGED SITTING?
A Pain In Your Neck?
When we sit our muscles are active at about 4% of their maximum voluntary contraction ability (MVC). Yet, if maintained for over 10 minutes a negative metabolic state is established (Andersson, Sato). Such low levels of muscle contractions during static work loads can trigger fatigue and pain in the neck. (Hamilton, Jensen, Veiersted). Jensen suggested that any sustained static work load of greater than 10 minutes should not exceed 2% of MVC (Jensen).
Andersson GBJ. Occupational biomechanics in Wienstein JN, Wiesel SW, eds. The lumbar spine: the international society for the study of the lumbar spine. Philadelphia, WB Saunders, 1990 p 213.
Back Pain From Just Sitting?
Prolonged sitting is one of the most deleterious activities most people engage in. After only 3 minutes of full flexion of the spine ligamentous creep or laxity occurs which persists even after 30 minutes of rest! (Gunning, McGill). These ligaments are responsible for protecting our discs so it is no wonder that trivial early morning flexion (putting on socks) or bending after sitting for a prolonged period (picking up a pencil) can lead to a severe disc problem with nerve irritation (Adams and Hutton)
According to Bogduk and Twomney, “After prolonged strain ligaments, capsules, and IV discs of the lumbar spine may creep, and they may be liable to injury if sudden forces are unexpectedly applied during the vulnerable recovery phase.” Once a tissue is strained, it has difficulty returning to its original length.
Wilder showed that the motor control signature associated with low back pain involves – a slow reaction time, decreased peak torque output (power), and increased after discharges when irregular load is handled (sustained elevated muscle tension). Prolonged sitting was shown to further disturb these variables and a brief walking break to improve them again.
Solomonow et al have demonstrated that the creep reaction may be much more stubborn than previously believed. Reduced muscle activity with spasms were found during static flexion periods during a 7 hour recovery period. Multifidus spasm and acute inflammation of ligaments were noted. The dysfunction was reported to outlast the period over which strain occurred by 60X!
ACTIVITY THROUGHOUT THE LIFESPAN
Most people when they have a problem or as they age tend to associate activity with risk. Yet, doing “too little too late” is often more dangerous than doing “too much too soon”. If a person has a problem with activity they should seek a health care professionals advice. But, when people are sedentary they often do not have symptoms until it is too late.
Fall prevention is an obvious example. The mortality risk in an elderly person is greater than from cancer or heart disease! Simple exercises such as basic Tai Chi have been shown to reduce fall risk and thus mortality in the coming year in seniors.