• Most Wi-Fi engineers and technicians have some degree of concern about safety issues with RF. However there is something else much more serious that will affect the health of just about every IT/Wi-Fi professional to some degree or another during their career. For some it will have life changing, serious consequences.

    Anyone care to hazard a guess ? When the answer is given, many will say ?What !!!?. However, once a detailed explanation is given as to the ?reasons why?, it may give pause for further thought.

    Anyone care to give it a try ?


  • Lack of sleep.

  • Yes, the ?curse? of all IT people?lack of sleep?. does hit our health, but it?s something we use every day of our lives?. the humble laptop. I?ll put some information up over the next while, showing exactly why IT professionals have now become the fastest growing group of any profession for neck, back, shoulder and wrist pain. Will also put some suggestions up as to how to help prevent some of these problems. We have to ?live? with laptops just as we ?live? with cell phones, but there are many simple things that can be done to help. Those ?little aches? that we all get can lead to the end of a career in IT for a significant number of people. I work as volunteer on back pain forums and have seen some very bad cases indeed. Two of the top specialists in the world with whom I communicate with have said it is becoming an epidemic amongst the young.


  • The following notes are not merely part of an academic exercise. Five years ago I lay completely crippled in a darkened room, having been given up by the multitude of spinal experts who said my life was over. I realised that there was nobody to help me except myself. By studying the body from an engineering point of view, as opposed to a conventional medical view point, I was able to diagnose what had been done to me. This eventually led to my health being restored.

    From doing this for a long time, I have found that there are different reactions to what I write on this subject. Time after time, the readers tend to fall into certain ?reaction groups?. I see this with all sorts of nationalities:

    1. ?What?s that guy on about ?.......Let me see what?s on TV tonight?

    2.?Hmmm??Never thought about it like that before??I?ll read it some other time though?.there?s nothing wrong with me?.I?ve been healthy all my life?.some laptop is not going to cause me problems?..I?m way too busy to read all of this anyways..?

    3. ?Oh?.I wonder if that could be the reason why my neck/shoulder/back/hands are feeling like xyz?..?

    4. ?That?s exactly what I?ve been going through !!?

    Even if you feel that there is nothing here for you. I implore you to please at least make a mental note of this post. I?ve worked with hundreds of individuals and families ( I neither ask for nor expect any financial reward from anyone. Nobody was there to help me when I needed it, so I?m doing what I can to try and provide information to others ) and have seen all sorts of devastation brought to families when the primary "bread winner" suddenly cannot type or sit for long periods.

    I?ll try and put a post each day or every few days on this thread.

    Anyways, off we go??.

    When we travel in the countryside, we often see large radio and TV transmitters, some of which are hundreds of feet high. Many have ?guy wires?attached to them. The purpose of the guy wires is to provide stability and support to the antenna tower. Around the fourth of July, we often see large tents selling fireworks in fields at the side of the road. These tents usually have a central pole in the middle, with a number of ropes which again, act as supports and stabilizing elements.

    In order for the transmitter tower or the tent pole to remain perfectly vertical, there must be equal tension in the supporting elements. Equal tension that is, between the front and back elements, and side to side elements. By this manner, the pole remains vertical with no distortions. Imagine now that we apply extra pressure on one of the guy wires and/or slacken off an opposing guy wire. I think we can mentally imagine that the tower/tent pole will become distorted, with tension applied unequally. At the least this could cause defects to occur in the metal. At worst, it could cause complete failure of the structure.

    Watch what happens to the shape of the tower in the following video as tension is made unequal in the overall guy wire matrix:

    This analogy can be applied to the human body, with the spine representing the tower/pole and the guy wires representing muscles, liagments and tendons ( to be discussed later ). We will discuss the ?ideal spine? and then some factors that cause deviations away from that ideal model ( especially laptops ), the resultant physiological problems that result, as well as some general guidelines on preventing these issues in the first place.
    Knowledge is power to the individual. If you have no idea of the DCF etc mechanisms involved in Wi-Fi communications, then it makes it difficult to properly troubleshoot complex WLAN problems. With just a little knowledge of the mechanics of the back, neck etc., hopefully these posts will empower people to research a little more and/or make some simple changes to their work habits to help prevent problems later on.


  • Imagine that we took a large vertical wire and pressed down on it from above. It wouldn?t take long before the wire buckled and collapsed. Now imagine that we take that same wire and turn and twist it so that it resembles a coil or helix. We can press down on it, and the coil will ?go down? with the pressure. Release that pressure and the coil restores itself to it?s original position. The human spine has four curves in it ( or rather it SHOULD have four curves in it ). More about that in the next post. These curves are put there to allow the spine to absorb compressive forces such as occur when we walk, lift things, bend over etc. Special shock absorbers are fitted between the bones of the spine just as shock absorbers are fitted in vehicles to ?absorb? the variations in the road and try to keep the vehicle on a level keel.

    The spine is a wonderfully designed thing. It not only allows movement up and down, but side to side and in a turning or twisting manner. It can also perform all of these movements simultaneously. Let?s take a more detailed look at the skeleton:

    So, what does your skeleton do ? Well it does many things:

    It provides PROTECTION. For example, the skull acts as a protective holder for your brain. It also protects your middle and inner ears, and parts of your eyes.

    The rib cage provides protection for the heart and lungs etc.

    It allows you to MOVE by using your legs, and allows you to pick up things and move them and let them go using your hands etc.

    Some bones have special names. The bones in your spine are known as VERTEBRAE. A single spine bone is called a VERTEBRA and more than one are called VERTEBRAE.

    These bones join together with little hinges called FACET joints [ These little joints can become stuck, like rusty hinges on a door. I?ll talk more about this later ].

    When you bend forward or backwards or to the side or rotate, these little hinges move. The following picture shows facet joints.

    These little joints are vitally important. If they are unable to move properly due to reasons that will be discussed later, they can cause great pain.

    When you bend forward, doctors, chiropractors, physical therapists etc call this FLEXION. When you bend backwards, doctors call this EXTENSION. When you bend way, way back, doctors call this HYPEREXTENSION.

    Where bones come together and allow a fair bit of movement, we call these JOINTS. There are many types of joints.

    For example, take a look at the picture below:

    This picture shows how your hip bone joins to your hip using a BALL AND SOCKET JOINT.


  • Your SPINE is made up of four different sections.

    There is a section in your neck, another section in your upper back, a third section in your lower back, and a final section at the base of your spine connecting to the tailbone.

    All four of these sections have curves in them.

    The curve in your neck is called the CERVICAL CURVE

    The curve in your upper back is called the THORACIC CURVE

    The curve in your lower back is called the LUMBAR CURVE.

    The curve by the tailbone is called the SACRAL CURVE

    Remember from the previous post that the bones in the back are called the VERTEBRAE.

    There are seven VERTEBRAE in your CERVICAL CURVE. They are numbered C1-C7.

    C1 is at the top of your neck.
    C7 is at the bottom of your neck.

    There are twelve VERTEBRAE in your THORACIC CURVE. They are numbered T1-T12.

    T1 is at the top of your upper back.
    T12 is at the bottom of your upper back.

    There are five VERTEBRAE in your LUMBAR CURVE. They are numbered L1-L5

    L1 is at the top of your upper back.
    L5 is at the bottom of your upper back.

    So, from top to bottom we have C1-C7, T1-T12, L1-L5.

    We also have another item at the bottom of the spine called the SACRUM. Which I will talk about in another posting.

    Take a look at the picture shown below:

    In the picture you can see the three curves.

    An ANTERIOR VIEW means taken from the front.

    A POSTERIOR VIEW means taken from the back.

    Our bodies have been designed so that when we are born properly and naturally, we have three curves all of which are at particular angles, and which can be measured.

    Attached to the vertebrae are several little bones which ?poke out? at different angles.

    These little bones are called PROCESSES. One of their functions is to allow the attachment of MUSCLES and LIGAMENTS [ more on MUSCLES and LIGAMENTS in another post ].

    Imagine you are lying on your belly on the floor.

    Running up and down your spine are a series of PROCESSES called the SPINOUS PROCESSES. These ?stick? straight up.

    Running to the left and to the right of your spine [ sideways ] are another series of PROCESSES called the TRANSVERSE PROCESSES.

    They all help to move the spine in different ways as we will see later.

    Take a look at the picture below ( viewed from the head down to the feet as a cross-section of the spine )

    You can see the SPINOUS PROCESS and the two TRANSVERSE PROCESSES.

    I?ll explain in another posting what is happening to the necks of many babies when they are being pulled out with forceps, and what is happening to their necks and spines when they are ?twisted and tugged? on the way out ., especially with respect to their curves.

    Now, why do we have to have curves in our backs and not just have a ?straight back? ?

    During the course of a day, just think of all the things that our bodies have to do:
    We have to bend forwards and backwards, to the sides and in twisting motions.

    It can be shown, using models in a mechanical engineering laboratory that having these three curves ( ignoring the sacral curve for now ) at certain particular angles will allow the body the maximum range of movement. They have tried many, many different combinations of curves and angles, but these three always give the best range of movement.

    So, what happens when we do not have these proper curves ? Many bad things can happen, as I will detail in a further posting.

    For a quick look at what can happen when we do not have the correct curves, take a look at this picture:

    We?ll be covering all of these ?bad things? at the end of the thread, when we put all the individual pieces together to see why we end up with back problems, knee problems, hip pain etc. Then finally we will see just how damaging incorrect, long term use of laptops can be.

    We all remember the old song ?The knee bone is connected to the leg bone, the leg bone is connected to the hip bone etc?.

    That is the way that back pain, neck pain etc should be treated ? as a complete system.

    When I was learning to walk again, after two weeks I developed foot problems which felt like (literally) someone was sticking a knife in my feet ). It was a bitter blow. The foot ?experts? said they wanted to cut the tendons of my feet ( my feet were like ?claws??I was walking on the tips of my toes and my heels ). The therapist who was treating me, Al Meilus ( the former head of robotics engineering at GE ) analyzed my gait (walking ) patterns and found that the problem was actually coming from a muscle at the back of my leg. The SYMPTOM was the pain and distortion in my feet, but the CAUSE came from elsewhere. My feet are now back to normal. It was interesting that in the foot surgeon?s office, he had a model of a foot only. Not a model of the entire leg. The foot does not operate as an individual entity, but rather as part of a complete engineering system.

    You will find later on that the vast majority of back problems do not come from the back itself originally, but as a result of it reacting to changes elsewhere in the system.


  • At the bottom of our spines, there is a triangular shaped ?bone? [ I?ve said ?bone?, because it is actually a series of bones ? more on that in a minute ], called the SACRUM.

    The SACRUM forms part of the PELVIS, something we?ll be talking about in the next posting. SACRUM in Latin means ?sacred stone?. It was called that because just as when we have a ?keystone? in a building structure ( one that ?holds? the structure together ), the sacrum acts as the keystone for our skeleton.

    Take a look at the pictures shown in the link below:

    Attached on to the very end of your sacrum is the COCCYX. This is sometimes called your TAILBONE.

    Note the holes in the sacrum.

    Nerves pass through those holes.

    Those holes are called the SACRAL FORAMEN.

    We?ll see the word FORAMEN used again when we look at how nerves come out from the spine.

    Basically a FORAMEN is just a hole in a bone or between two bones where a nerve can come out.

    When we are born, we actually have five pieces of bone which make up the sacrum. These are joined to each other fairly loosely and can move one relative to the other.

    When we reach our teenage years, these five bones actually ?fuse? together to form the complete sacrum as ?one bone?.

    The angle that the sacrum makes when viewed from the side is very important to how we stand and sit. This factor is often missed by many doctors and therapists. That was one of my main problems.


  • Bye the way, I know this is a lot of material. In order to properly understand why laptops can cause so many problems, it is necessary to go through this. However, at the end, I'll put up another quick post ( linked to this one ) that gives a one or two paragraph summary of the damage that can occur due to improper laptop usage and some simple recommendations about how to minimize the risk of that damage.

    When we are troubleshooting 802.11 networks, we cannot just blindly dive in. Some background knowledge is necessary.

    The main goal of this series of posts is to try and let people know the implications of not using a laptop properly from an engineering point of view. Hopefully then, this will allow them to seek further information on the subject and/or correct their posture when using them.

    I recently contacted several dozen chiropractors and physical therapists whom I know and asked to name the two things that keep them busier than anything else. Unanimously they said "Kid's backpacks and laptops/video games". One said "As long are there are IT people in the world, I'll be able to keep both my houses and go to the Carribean twice a year".


  • Take a look at the picture in the link below:

    This picture is taken from the front of the body, looking down from the head to the feet.

    The PELVIS consists of four main parts:

    1. The SACRUM

    2. The left HIP BONE


    4. Some cartilage like material connecting the left and right hip bones at the front of the body.

    The SACRUM is the triangular shaped bone at the base of the spine. This was discussed in the last tutorial.

    The LEFT and RIGHT HIP BONES are seen in medical books as being referred to as the LEFT ILIUM and RIGHT ILIUM respectively. Sometimes they will be referred to as the INNOMINATE BONES.

    One hip bone is called an ILEUM.

    Two hip bones are called ILEA [ plural ].

    The cartilage like material that joins the left and right ILIUM bones together is called the PUBIC SYMPHYSIS or SYMPHYSIS PUBIS.

    PUBIC meaning around the pubic area

    SYMPHYSIS meaning ?coming together- coming together of the hip bones?. Like a SYMPHONY - a coming together of musical instruments.

    Can you see the ?hoop shaped? bones at the bottom of the pelvis ? These are called the ISCHIAL TUBEROSITIES and are sometimes called your sitting bones.

    At the bottom of the hip bone is a socket called the ACETABULUM. This the place where the thigh bone fits.

    Even though I?ve said that there are only four parts to the pelvis, medical books will refer to many more parts, as the hip bones are considered to be made up of many parts [ even though they are all really one ?big bone? ].

    On the front of each ILEUM is a small bony point known as the ASIS. This point is very, very important, as it allows us to determine accurately when our pelvis is at a neutral position. There are two ASIS points, one on each side:

    Left ASIS

    Right ASIS


    Let?s analyze how they came up with this name:

    Your body has two parts: the front of your body, called the ANTERIOR part, and the back of your body, called the POSTERIOR part.

    SUPERIOR means ?more towards the head? ( there is another part called the AIIS, the ANTERIOR INFERIOR ILIAC SPINE which is more towards the feet ) The ASIS points stick out the most.

    ILIAC means ?of the ILIUM?.

    SPINE here, means a pointy bit of bone.

    So, the ASIS is the pointy bit of bone that sticks out most from the front of the pelvis.

    The pictures in the links below show the ASIS

    Point 6 on the last picture is the ASIS

    There is also a corresponding point at the back of the pelvis called the PSIS or POSTERIOR SUPERIOR ILIAC SPINE.

    In other words, the pointy bit of bone that sticks out most from the back of the pelvis.

    Point 24 on the last picture is the PSIS.

    When a therapist wants to know whether your pelvis is neutral, he will check to make sure that the ASIS points line up with the PSIS points.

    The PUBIC SYMPHYSIS is like a flexible joint and can move a little bit in many directions.

    When you have a totally neutral pelvis:

    1. The ASIS and PSIS points should line up

    2. One hip should not be higher than the other

    3. There should be no twisting of the pelvis.

    It is possible for your pelvis to be tilted forward too much, to be tilted backwards too much, to have the left hip higher than the right, to have the right hip higher than the left, to have twisting from right to left, to have twisting from left to right, or to have any combination of these.

    We will see at the end of the course, how all of these factors can cause great pain, and how the "dreaded laptop" can cause a lot of this.


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