(Biomechanics and Stroke)
It has been known for about fifty years that strokes are more common in some south-eastern states, an area known as the “Stroke Belt”, where strokes are substantially higher than in the rest of the country.
The “Stroke Belt” is usually defined as an 11-state region including Virginia, North Carolina, South Carolina, Georgia, Alabama, Mississippi, Louisiana, Arkansas, Tennessee, Kentucky and Indiana.
Incidences of strokes in these states are 50% higher than in the West and in the Northeast of the US and 30% higher than in the Midwest of the US.
We can see that not only is the “Mystery of Southeast Stroke Belt” a reality, but they’re also exists a “Mystery of Midwest Stroke” because, for unknown reasons, the Midwest of the country has a higher incidence of strokes than the West and Northeast of the country.
By comparing the incidence of strokes between the West and the Northeast of the country with New York, we can see that the incidence of strokes is much higher in the West and Northeast than in New York, and because of this fact, we can call it the “Mystery of Northeast and West Stroke”.
Actually, any incident of stroke, it doesn’t matter if it is in the Southeast the country or in the Northeast of the country or anywhere in the world, it is a mystery because to this day, no one knows why some people are affected by strokes, and others are not.
It led to the conclusion that understanding why the incidence of stroke is more common in some regions than another will enable us to make the first step in understanding the real cause of stroke anywhere in the world.
By comparing the incidence of strokes between different regions, we can see that geographical factors play an important role in the incidence of strokes.
To discover how geographical factors determine the incidences of strokes is the best way to start with the region where the incidences of strokes are the most common in the US, and that is the Southeast region, known as the “Stroke Belt”.
If we take a look at the map of this area, we can see that a significant part of all these state territories is that they have flat surfaces of the ground.
The available biostatistics evidence leads us to make a conclusion that physical geography is responsible for the high number of stroke incidences in this area and that people who live in hills and in the mountains are less prone to stroke.
One more contributing fact to making such a conclusion is that this stroke belt has a “buckle” — a zone-within-a-zone that has stroke death rates “substantially higher” than the stroke belt itself and twice as high as the rest of the country.
Reporting in the May issue (1997) of the American Heart Association journal “Stroke”, the scientists identify the “buckle” as the coastal plain sectors of North Carolina, South Carolina and Georgia. In this 153-county area, the new study shows, stroke deaths are 2.1 times higher than the rate of the nation’s average among people aged 35 to 54 and 1.7 times greater for people between the ages of 55 to 74. We can see that this “simple conclusion” about the importance of the geographical factor as a contributing factor to increased and decreased incidences of stroke is actually based on hard facts. Population living in the coastal plain in those three states is more prone to stroke than people who live in the mountains region in the same state.
It shows that people living in flat areas or plain areas are more prone to stroke than people who live in mountains and hilly areas, but the question is why geographical-environmental factor is to some extent responsible for the incidence of stroke?
Now it is left to explain why people who live in these plain areas are more prone to stroke than people who live in areas where there are hills and mountains.
People who live in areas with hills and mountains are more frequently forced to use and challenge their motor skills because they are more often confronted with activities like walking up the hill, walking down the hill, diagonally up the hill, and walking diagonally down the hill etc.
The diversity of physical activity positively affects neuromuscular control. The diversity of physical activity has consequences of providing mental stimulation to the neuromuscular control centre.
On the other side, the people who live in flat areas do not have the chance to walk downhill or up the hill; most of their lives walk only on flat surfaces.
Most of the time, walking on a flat surface has a consequence that habitually gait is used to a greater extent than by people who live in hilly and mountainous areas.
We can conclude that people who live in hills and mountain areas, in general, are more frequently confronted with activities that force mental awareness during the time of doing this particular physical activity.
The physical activities that obligate us to some extent or full mental awareness provide mental stimulation to the central nervous system, and at the same time, those physical activities force us to exercise our existing motor skill ability, and that provides mental stimulation to the neuromuscular control centre.
Habitual walking alone doesn’t provide enough mental stimulation to the neuromuscular control centre and after a prolonged time of doing physical activity mainly on habitually way the motor skill deteriorates.
The fact that in mountain areas, the geographical environment more frequently forces physical activity by increased mental effort and that has consequences of providing mental stimulation to the central nervous system that explain why people in mountainous regions are less prone to stroke than people who live in flat areas.
But in the state of Florida, we have a completely different situation. If we take a look at the physical geography of Florida, we can see that the whole area is flat, as same as the coastal plain sectors of Georgia, South Carolina and North Carolina and this area is known as a “Buckle” of the “Stroke Belt”- an area within the area.
The south part of Florida has one of the lower incidences of strokes in the US. The question is, why?
People who live in the south part of Florida, like those living in the coastal plain sectors of Georgia, South Carolina and North Carolina, do not have the opportunity to walk on uneven ground like up and down a hill.
But people in the south part of Florida have more opportunities to walk with bare feet. Walking with bare feet has consequences of increased sensory contact between feet and the ground, providing stimulation for the peripheral nervous system (PNS) and central nervous system (CNS). Because of the warm climate for most of the year, people spend more time on the beaches or swimming pools. From a biomechanical point of view, swimming alone provides diverse workouts that enhance motor skill ability. The sensory contact between the body surface and the water provides stimulation for the central and peripheral nervous systems.
Everything that positively affects motor skills at the same time positively affects the neuromuscular control centre.
Walking with bare feet on the sandy beaches and in the water is an effective way of maintaining and improving the sense of balance and motor skill ability in general, and people living in the southern part of Florida have plenty of opportunities to do that.
Walking with bare feet demands an increased level of mental awareness about the surface and small objects on the ground like sharp stones etc, which is a factor that demands constant mental awareness for the time of doing this activity.
Walking by wearing footwear doesn’t demand us to take care of where we are stepping and how we are stepping, and because of that fact, we can do locomotion by using a habitual gait.
In the south part of Florida, the great majority of people live in the coastal areas near the beaches, and a reason for this is that the inland of south Florida is mainly a swamp.
In the north part of Florida, much more people live in the inland area, and because of that, people in the north part of Florida have much fewer opportunities to walk with bare feet and less opportunity to be engaged in water sports than the people in south Florida.
They can be more physically active, but this kind of activity is mostly habitual and doesn’t sufficiently contribute to maintaining and improving motor skill ability.
That explains why people in the south part of Florida are less prone to strokes than people living in the north part of Florida and people living in the rest of the US, excluding New York.
The New York metropolitan area has the lowest stroke rates in the country. The question is, why?
If we take a look at the map of this area, we can see that the entire New York metropolitan area is located on flat surfaces similar to the coastal plain sectors of Georgia, South Carolina and North Carolina, where the incidence of strokes is the highest in the US.
The people living in the New York metropolitan area have much fewer opportunities to walk with bare feet compared to people living in the coastal plain sectors in Georgia, South Carolina and North Carolina, and far fewer than those living in the south of Florida.
All physical geographical factors contributing to lower stroke incidences in states located on the hills and mountains like the states in the West and Northeast or states in the Southeast like Florida (Southern part of Florida), in the New York metropolitan area are non-existent.
This all tells us that in the New York metropolitan area, the incidences of strokes should be higher than in the coastal plain sectors of Georgia, South Carolina and North Carolina, but contrary, they are far lower than anywhere in the US.
One important factor which makes the New York metropolitan area different from any other part of the country is that people are using the public transport system like nowhere else in the US.
Every weekday, four and half million people use the subway alone.
How the use of the public transport system (contributing) causes lower incidences of strokes will be understood by understanding firstly how using the public transport system affects our sense of balance, postural stability and motor skill.
One thing is that people who use private cars usually walk at the usual speed (habitually walking). For example, they do not need to hurry to catch their own car, the car always waits for them (contrary to the train or public buses), it is always at home or in the parking place, and they always can afford to walk at their usual speed. (Usual speed is the speed of habitual walk). People who use public transportation often come to a situation to increase their speed of the walk to catch the train or bus, and sometimes they decrease their speed below the speed of their usual (habitual) walk to avoid waiting long at the station for the train or bus.
Each time we change the speed of the usual (habitual) walk to a slow or brisk walk, we are challenging our own postural stability, and any challenge for postural stability is simultaneously a challenge for motor skill ability.
Each time when we challenge our own postural stability, we are at the same time improving our own postural stability.
Improvement in postural stability will positively affect motor skill ability and habitual gait patterns, and at the same time, it will revitalize the entire nervous system.
The next important factor which is contributing to the improvement of postural stability and motor skill ability when travelling on the train is the effect of speeding and slowing on the people inside the train.
For example, if we stand or walk on the platform of a train which moves at a constant speed, we need the same level of postural stability as we need when we are standing or walking on flat ground.
But if we are standing or walking on the train at a time when the train is increasing speed and at the time when the train is decreasing speed, we need to put more effort into avoiding falling on the floor of the train (loss of balance). Each time when we put more effort than usual into maintaining balance, it positively affects postural stability and motor skill and everything that positively affects motor skills at the same time positively affects neuromuscular centres.
Another fact is that the time between speeding and slowing the train is only a few minutes long because, in the city area, the distance between the stations is short. For example, by travelling on the intercity train, we are spending much more time travelling at a constant speed. The time between speeding and slowing on an intercity train is much longer because the distance between stations is much bigger.
In the case when we are travelling by subway, we are affected every few minutes by the effects of speeding and every few minutes we are affected by the effects of slowing.
Most of the time on the train, we are sitting, but we still spend plenty of time standing and walking on a slowing and speeding train, for example, when we are entering a train, and before we have the chance to reach the available seat, the train already starts to leave the station, and in this short time we are exposed to the effects of a speeding train, and at the time when the train is slowing down before it stops at the station, many times we have to leave the seat and walk towards the exit door because the time the train spends at the station is very short, just enough for some passengers to leave and for some passenger to enter in the train.
In these situations, people are forced to put more effort than usual to maintain the required level of postural stability that enables them to avoid falls.
Another situation when we unintentionally exercise our motor skills is when we walk in a crowded area, like; an underground station or in a busy street, shopping centre etc. In this case, we frequently were forced to change speed and direction to make way through the crowd.
In other words, anywhere were surrounded by a geographical or man-made environment like a subway or a man-caused environment like a crowd demands us frequently to change the speed and direction of the walk, people are less prone to stroke than people who live in geographical, and man-made environments that do not demand frequently change of the speed and direction of the walk. (Diversity of motion stimulates the brain. Diversity of motion causes us to be more frequently mentally involved in what we are doing. Mental involvement in physical activity is the factor that provides mental stimulation to the central nervous system, and diversity of motion (diversity of physical activity) provides mental stimulation to the neuromuscular control centre.
Habitually physical activity doesn’t provide mental stimulation for the neuromuscular control centre.
We can conclude that, in general, people who live in the New York metropolitan area are more frequently forced to put mental effort into doing every day’s walk compared to people who live in the rest of the country, and that has the consequence of lower incidence of strokes in the New York metropolitan area than anywhere else in the US.
One thing left to explain is why African Americans are more prone to stroke in the United States than white Americans.
One fact is that a big percentage of African Americans live in an area known as the “Stroke Belt”.
For example, African American men and women in the “Stroke Belt” area have a higher stroke death rate than their racial counterparts in other regions of the country.
This means that African Americans living outside the “Stroke Belt” area have a lower stroke death rate than African Americans living inside the “Stroke Belt” area.
In this case, we can conclude that somehow, the difference in the physical geography of these regions is responsible for the difference in the rates of stroke incidents among African Americans living in different parts of the country.
The next question is why African Americans have a higher rate of stroke incidence than White Americans.
The answer is that they are more prone to stroke because they generally have fewer opportunities to do physical activity that contributes to maintaining their own motor skill ability.
One reason is that African Americans, in general, have a lower socioeconomic status compared to White Americans, and that has the consequence that proportionally, much fewer African Americans have houses near the beach or have swimming pools at home, and in the towns and the city all over the country in flat areas or in areas with hills and mountains, African American mostly have houses on the flat ground.
This and similar other factors cause African Americans to have less opportunity to exercise their motor skill, which negatively affects the neuromuscular control centre and has the consequence of higher susceptibility to strokes.
In general, they have less opportunity every day of life to challenge their own motor skill and postural stability, and because of this factor, they, in general, less frequently provide mental stimulation to the neuromuscular control centre than White Americans.
By doing the same level of activity that positively affect their sense of balance and motor skill, we can conclude that African Americans and White Americans are equally prone or not prone to strokes.
One more convincing fact is that after age 55, the stroke mortality rate for White Americans increases and is equal to that of African Americans. Increased incidence of stroke after age 55 by White and Afro Americans can be attributed to a decrease in diversity of physical activity on one side and on the other side to a prolonged period of doing habitually physical activities.
An African American who more frequently comes into a situation to do physical activity that forces them to exercise their own sense of balance, postural stability and motor skill ability is much less prone to strokes compared to a White American who less frequently came to the situation to do physical activity that force exercise own sense of balance, postural stability and motor skill ability.
An optimal level of sense of balance, postural stability, postural strength and motor skill will enable us to win the battle against stroke, obesity and many other illnesses.
By exercising on exercise machines or most exercises designed for so-called “burning calories,” we are not providing mental stimulation to the brain. In general, this type of exercise produces negative health consequences.
The muscle and bones lose strength and mobility by prolonging the physical inactivity.
By exercising motor skill ability, the neuromuscular control centre is active. By habitually doing the physical activity, the neuromuscular control centre is to some degree inactive.
The neuromuscular control centre is not used to the extent necessary to maintain optimal condition by prolonging the time of habitually doing physical activity.
For example, running and walking on the treadmill, we do not propel ourselves with legs and feet, but to a greater extent, we habitually maintain the lifting motion of the legs, and to some extent, we fall from one leg to another.
Habitual walking and running for prolonged periods don’t give the central nervous system sufficient mental stimulation.
In some cases, in a geographical and/or man-made environment where we are living obligated to do common activities in such a way that our mind is in the present. For example, when we are going downhill, we have to take care not to fall down. And all time by doing this activity, our mind is in present. We can’t walk down the hill with habitual gait patterns. Unexpected obstacles on our way by walking or running are factors that obligate us to keep our minds in the present.
The sense of balance is entwisted with postural stability, strength, and motor skill ability. Improvement in postural stability is bound with the improvement of the sense of balance, postural strength and motor skill ability. We can challenge our own motor skills and postural stability as far as we can maintain a sense of balance. Improvement in motor skill ability positively affects postural stability; on the other hand, improvement in postural stability positively affects motor skill ability.
Each time when we are exercising our own motor skill ability, we are exercising a neuromuscular control centre, and at the same time, we are providing mental stimulation for the neuromuscular control centre and for the entire nervous system.
Much evidence shows that an increase in body weight increases the chance of suffering from a stroke. It is enough to take a look at the obesity map and stroke map, and we will notice that regions with higher obesity rates have a higher incidence of stroke compared to states with lower obesity rates.
It clearly shows that rates of obesity are correlated with the incidence of stroke. Natural geographical-environmental and man-made environmental factors play important roles in obesity prevalence and incidences of stroke. It shows that not every physical activity is beneficial for physical and mental health, and not every physical activity is beneficial for weight control.
The same level of physical activities done on (plain area) even ground will produce different outcomes for health and weight and shape of the body compared to physical activity done on (mountains and hilly area) uneven ground.
Occasionally, using conscious effort to maintain optimal body posture and balanced gait will reduce the risk of stroke. By using conscious effort, we are putting more mental effort than usual.
Incorporating some simple, non-strenuous but mental effort demanding and at the same time enjoyable physical activity and/or postural and motor skill exercise in everyday life will be the most effective measure to ward off stroke and many common diseases and health conditions. For example, habitually walking doesn’t demand mental effort, but slow walking or brisk walk and change of the speed of the walk demand mental output. It needs to take into consideration that slow walking or brisk walking for a prolonged period of time is not beneficial for mental and physical health because, after some period of walking at the same speed, this type of walk starts to become habitual. The best way is to frequently change the speed of the walk.
In general, regardless of intensity level, every physical activity (excluding physical activities on an exercise machine) contributes to the maintenance or improvement of existing motor skills, sense of balance and postural stability. At the same time, it contributes to the effective prevention of stroke.
Physical activities that have a protective role against stroke are at the same time highly effective as means to achieve effective recovery after stroke.
Copyright © 2007 – 2021 LT All right reserved
Luka Tunjic is the Author of the book “Mechanical Stimulation Low-Grade Inflammation Weight Gain” published in 2021.
References:
Geographic Variation in Stroke Mortality in Blacks and Whites in the United States
(Stroke. 1997;28:1639-1647.)
© 1997 American Heart Association, Inc.
http://stroke.ahajournals.org/cgi/content/full/strokeaha;28/8/1639
Stroke-Belt “Buckle” Has Death Rates Twice As High As Rest Of U.S.
Doctor’s Guide – DALLAS — May 21, 1997
http://www.pslgroup.com/dg/29566.htm
A ‘Buckle’ of Death Rates for the Stroke Belt
New York Times
Thursday, May 15, 2008
http://query.nytimes.com/gst/fullpage.html?res=9A01E4D61E39F937A25756C0A961958260
Acute Stroke Treatment, Thrombolysis {(5) Are age or race factors in strokes?}
University of RochesterMedicalCenter
http://www.urmc.rochester.edu/smd/Rad/stroke.htm
Copyright © 2007 – 2021 LT All right reserved
Biomechanics and Health 