March 10th, 2011 - Fractured Follies

Fracture Types

by DR.

How you break your bone determines what type of fracture you get. Twisting your ankle in a hole will make a different bone break than falling from a roof. Doctors use bone geometry to describe these fracture types. Some geometries are more stable and easier to fix than others.

Fracture Types

1. Transverse fracture - meaning straight across. The two ends tend to stay together i.e. it's a stable fracture.
2. Comminuted fracture - meaning broken into many pieces. This is bad news as the fragments will find it hard to stay together on their own. This generally needs surgery using pins to hold everything together until the bone heals.
3. Displaced fracture - meaning the bone ends are no longer touching. This means they'll have to be reduced back together before healing will occur.
4. Greenstick or crush fracture - meaning the bone has not snapped, it's been stretched or crumpled like soft chalk. Great prognosis and common in kids.
5. Hairline fracture - this is a small crack in the bone from a repetitive action like running which is so tiny you may not see it on X-ray, but it hurts! This has an excellent prognosis if you give the bone a rest from repetitive injury as the damage is mild.

Another broad classification of fracture types is whether the fracture is 'open' or 'closed'. Open fractures mean that the the skin around the broken bone has split open. Closed fractures mean the skin is intact over the fracture. This difference is important because open fractures need antibiotic cover and may also need external fixation to heal.

http://www.doctorsecrets.com/your-bones/type-of-fracture.htm

There are other kinds of  specific fractures as well.  These relate to special parts of the body or bone itself.

Stress fractures - Stress fractures are small and result from repetitive force (eg, from overuse); they occur most often in the metatarsals (usually in runners—see Exercise and Sports Injury: Stress Fractures), followed by the fibula and tibia. Symptoms include gradual onset of intermittent pain that worsens with weight bearing and eventually becomes constant. Sometimes swelling occurs.

Growth plate fractures - Bone grows as tissue is added proximally by the epiphyseal disk (growth plate), which is bordered by the metaphysis proximally and the epiphysis distally. The age at which the growth plate closes and bone growth stops varies by bone, but the growth plate is closed in all bones by the end of puberty. If there is question about a growth plate injury or if a fracture is suspected, opposite side comparison x-rays may be helpful.

Rib fractures - Typically, rib fractures result from blunt injury to the chest wall, usually involving a strong force (eg, from high-speed deceleration, a baseball bat, a major fall); however, sometimes in the elderly, only mild or moderate force (eg, in a minor fall) is required. Pain is severe and is aggravated by movement of the trunk (including coughing or deep breathing), and lasts for several weeks. Inspiratory splinting (incomplete inspiration due to pain) can cause atelectasis and pneumonia, especially in the elderly or those with multiple fractures. Young healthy patients and those with 1 or 2 rib fractures rarely develop these complications.

Clavicle fractures - The usual injury mechanism is a fall on an outstretched arm or a direct blow. About 80% involve the middle ¹⁄₃ of the bone and are immobilized with a sling. Previously used figure-of-eight braces are no more helpful (and are more uncomfortable) than a simple sling. Reduction is not necessary even for greatly angulated fractures. Clavicle fractures that significantly tent the skin or that involve areas other than the middle ¹⁄₃ of the bone may require additional intervention.

Distal radial fractures - The usual injury mechanism is wrist hyperextension, usually during a fall. Dorsally displaced or angulated fractures (sometimes called Colles' fractures) are common. Treatment is reduction and immobilization at 15 to 30° of wrist extension. ORIF may be necessary if the joint is disrupted or if there is excessive impaction or shortening.

For more information concerning the above fractures see  
http://www.merckmanuals.com/professional/sec21/ch309/ch309b.html

Boxer's/brawler's fracture - This type of fracture is defined as a break through the bones of the hand that form the knuckles. Some doctors use the term "brawler's fracture" rather than "boxer's fracture" because a boxer is not likely to get this injury. The less well-trained brawlers have to learn how to punch without hurting themselves.  (Also commonly caused by wall punching.)  http://www.emedicinehealth.com/boxers_fracture/article_em.htm

Fun Fact - Multiple studies have shown a significant difference in the healing time of bone between groups of smokers and non-smokers.  One study showed that the average time until complete healing was over 2 months longer in the smokers.

March 9th, 2011 - Backpacks & Back Pain

http://i.acdn.us/image/A1333/133371/300_133371.gif

Sometimes I think backpacks are one of the biggest mistakes we could have made with respect to children today.  Children, like adults, are prone to fill space.  A large backpack doesn't simply make it easier to move things in and out or provide room for extra pockets and fancy bits.  A large space screams to be filled and then carried (by a sherpa-like 4th grader) from class to class.  Students eschew the use of lockers, preferring to carry all of their worldly possessions throughout the day.  Just ask my son, who must have a 64oz water bottle and a full size stapler with him at all times (for some unexplained reason.)

And, though backpack technology (did I just write that) has come a long way to meet the recommendations of chiropractors and orthopedists, students still labor under packs that weigh as much, or sometimes more than a classroom desk. This is not always an exaggeration -

So what does this do to the spine?  See the study data below taken from -

http://www.webmd.com/back-pain/news/20040813/heavy-backpacks-can-hurt-student-backs

Heavy Backpacks Can Hurt Students' Backs

Lighten the Load to Avoid Pain, Say Experts

WebMD Health News

Aug. 13, 2004 - With back-to-school season here, parents and students should make sure heavy backpacks aren't too much of a burden.

Shouldering a hefty load can cause back pain, according to a study by researchers at the University of California in Riverside.

The study was led by David Siambanes, DO, of the Inland Empire Spine Center in Riverside, Calif. Participants were 3,500 students aged 11 to 15 at four middle schools in Riverside and San Bernardino counties.

Researchers weighed the children's backpacks and asked the kids how often they used their backpacks and how much pain, if any, they felt as a result.

Most students said they hurt, at least a bit, from their backpacks; 64% reported having back pain at some time. Two of every five children said they felt pain while wearing their backpacks. In students reporting pain, about 12% said it was "not bad," while almost 90% said their back pain was "bad" or "very bad."

Of those reporting back pain, 21% said their pain lasted more than six months. About 16% said they had missed school, gym class, or after-school sports because of the pain, and almost 17% said they had seen a doctor for their back pain. Most students with back pain said the pain was recurrent.

Your child’s backpack can hurt his or her spine, resulting in reduced disc height and lumbar asymmetry says Timothy Neuschwander, MD of the Department of Orthopedic Surgery at the University of California, San Diego. Researchers found that heavy backpacks increased curvature and disc compression of the lower spine in what they say is the first study to utilize magnetic resonance imaging (MRI). “Children commonly carry school backpacks of 10 percent to 22 percent [of their] body weight,” wrote the researchers. Not surprisingly, children who carried heavier packs reported significantly greater back pain.
http://calorielab.com/labnotes/20100203/heavy-backpacks-hurt-kids-spines/

The image below shows some of the problems that can emerge during the long years of book 

http://home.earthlink.net/~pnemanic/sitebuildercontent/sitebuilderpictures/bart2-bb.jpg

 The image above shows some of the damage that can be done to a misused spine over time.  A compressed disk and possibly a bulging disk can result from over burdening one's back but other problems may also result.  Abnormal spinal curvatures such as hyper-lordosis or scoliosis may develop or be exacerbated.  Muscular imbalances and postural habits may form especially when a pack is worn over one shoulder instead of both. 

Some tips for minimizing problems: 

http://www.webmd.com/back-pain/news/20040813/heavy-backpacks-can-hurt-student-backs

• Use rolling backpacks.
• Choose backpacks ending above the waist, with padded shoulder straps and a belt.
• Wear backpacks on both shoulders.
• Pull the shoulder straps snug.
• Place heavier books closest to the back.
• Bend your knees when lifting the backpack.
• Get a second set of schoolbooks to keep at home.
• Carry only what's necessary each day.

Additionally you can:

• Use online book access for home when possible. 
• Use a locker when offered to reduce the load
• perform strengthening and stretching exercises to reduce pain

 Fun Facts:  While the concept of the backpack has bee around for a very long time the modern version of the backpack is believed to have been designed/invented in 1920 by Lloyd F. Nelson.  See http://tragerusa.com/look_body.html for more information.

March 2, 2011 - Perfect Posture

Perfect posture is not just about standing/sitting but they are good places to start.  The information below has been gleaned from multiple sources.  While searching I came upon an other blog that I feel is an excellent source of information I highly suggest taking a look at    http://toddhargrove.wordpress.com/
Especially his information on the Feldenkrais Method.
Having excellent posture is paramount to good health, and in some ways, is as important as eating well and exercising.  None of these behaviors alone can provide the same health benefits as a balanced combination of all three.

The following video outlines some good advice about improving your posture.

 Here are some easy ways to check your posture at home:
Stand facing a full length mirror and check the following:
1) Your shoulders are level
2) Your head is straight, not tilted to the side
3) The spaces between your arms and your sides seem equal on both sides
4) Your hips are level, not sloped to one side
5) Your ankles are straight and not turned in or out.
You can also have someone look at you from the side and check the following:
1) Your head is stacked over your body, not jutting forward or pulled back
2) Your chin is parallel to the floor, not tilting up or down
3) Shoulders are in line with ears, not drooping forward or pulled back too far
4) Your hands are in line with hips, not forward or back
5) Your knees are straight, not bent or hyper-extended
6) Your lower back is slightly curved forward, not too flat or curved too much, (creating a swayback)
Do your best to practice these points of posture everyday, and before you know it, your posture will be perfect.
Nancy Wile, Ed.D. is the founder of Yoga To Go - a yoga organization that provides simple and effective yoga programs for busy people around the world. You can subscribe to her free yoga and fitness newsletter at: www.YogaTG.com

        I find that it can be difficult for us (anyone) to check our own posture because of our own self perception.  The body position we use is the one we see in the mirror everyday.  It feels natural and it is difficult to self correct.  When standing in front of the mirror looking for problems we have a tendency to self-correct and make the postural anomalies less significant.  Basically we fool ourselves into thinking that our posture is better than it really is.
       One way to adjust for this is to have someone take a photo of you from the front and from the side while standing in a relaxed position.  It may also help to have a visual aide such as a series of markers behind you for comparisons sake.  I will try to upload some examples before the week's end.

http://i.ehow.com/images/a04/qu/bf/bad-posture-effects-joints-800X800.jpg

Better Posture Made Simple
Follow these simple steps to quickly improve your posture.
1) Bring your feet parallel, not turned out, and about hip width apart. Bringing your feet parallel engages the muscles in the front of your thighs and keeps your hips, knees and ankles in proper alignment.
2) Reach up through the top of your head, feeling your spine lengthen, getting tall.
3) Bring your pelvis to a neutral position. To find this neutral position, place your hands around your hips, then tuck your tailbone slightly until your pelvis is directly over your thighs, so there is no bend in your hip joints, and there's less sway in your low back. As you tuck your tailbone, you should feel your abdominal muscles engage a bit.
4) Draw your shoulders back and relax them down, bringing your hands in line with the seams of your pants.
5) Level your chin, keeping your head directly over the spot between your shoulders, not forward or back.

Read more: http://www.disabled-world.com/artman/publish/posture.shtml#ixzz1FSSrCp00

March 1, 2011 - Spinal Curves

Kyphosis, Lordosis, & Scoliosis

Abnormal Spinal Curvature

Scoliosis (sko-lee-oh-sis) is a term taken from a Greek word meaning curvature. During the 19th Century physicians thought poor posture was the primary cause of scoliosis. Today scoliosis is known to be either congenital (present at birth) or developmental and may be hereditary. The disease causes the spine to curve laterally (to the side) usually in the shape of an "S" or "C". The curve is measured in degrees. Some curves are severe.

Scoliosis 

 Idiopathic Scoliosis (id-dee-oh-path-ick sko-lee-oh-sis) is the childhood version of adult scoliosis. It is hereditary and primarily affects healthy young girls during their early teens. Physical signs may include uneven shoulders, one hip lower than the other, a rib hump when bent over at the waist and leaning to one side. When maturity is reached the disease may stabilize or slowly degenerate over time. In an adult with scoliosis, the curve may have begun to develop during childhood but went unnoticed.

Whatever the patient's age, the goal is to stabilize the spine to prevent additional curvature. Some patients with scoliosis are pain free and do not seek treatment until deformity is noticed. Unfortunately, at that point it may be too late to treat the disease. The size of the curve is measured in degrees on an x-ray. The progression of scoliosis is monitored by periodic x-ray studies. When scoliosis is severe it may cause the spine to rotate, which can cause spinal spacing to narrow on the opposite side of the body.


 Kyphosis (ky-foe-sis) is the normal curvature of the rib-bearing thoracic spine. Excessive kyphosis may develop as a result of poor posture early in life. Kyphosis means the spine is bent forward. Although kyphosis usually affects women, it is found to develop in men too. An excessive form of kyphosis may cause a hump to form in the shoulder blade area of the upper back. Kyphosis may affect men and women with osteoporosis.



Excessive Kyphosis 

Lordosis (lor-doe-sis) is the normal contour of the neck and lower back. Excessive lordosis may cause an extreme inward curve in the lower back. This condition is also called swayback.

Excessive Lordosis (Hyperlordosis)

 

This article is an excerpt from the book Save Your Aching Back and Neck: A Patient’s Guide, edited by Dr. Stewart Eidelson.

Fun Fact: While it used to be generally believed that humans evolved from apes and that our ancestors learned to stand up slowly (see A below), it is now understood that this was not the case.

http://www.custance.org/old/evol/5ch3/huxley.gif

The diagram below (to the trained eye) illustrates that many changes had to happen for humans to "stand erect" during the evolutionary process.

For more information about this image visit : 
http://books.google.com/books?id=LfYirloa_rUC&pg=PA129&lpg=PA129&dq=Spinal+curves+of+great+apes&source=bl&ots=gewb904X0_&sig=5EM-PnPdYV3Nc4VVo3-5IW-vZ_0&hl=en&ei=tFtuTaeRPIX7lwey7-B_&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCMQ6AEwAg#v=onepage&q=Spinal%20curves%20of%20great%20apes&f=false

Feb 28, 2011 - Skull Features and Personality

http://phillips.blogs.com/photos/uncategorized/12phrenology.jpg

  
Phrenology is the science which studies the relationships between a person's character and the morphology of the skull. It is a very ancient object of study. The first philosopher to attempt to (my words) locate mental faculties in the head was in fact Aristoteles.  http://www.phrenology.org/intro.html

In modern terms Phrenology is a spurious method for assessing aspects of character and personality from the physical appearances of certain areas of the cranium. Like physiognomy in general, there was a time when the issues of phrenology were presented as empirical or scientific questions, but as the preposterous claims of practitioners became more obviously bogus, this field was classified with the pseudo-sciences by the end of the 19th century. In the 20th century, these topics have increasingly been associated with the mysterious or occult literature, and have acquired the stigma of this association. Perhaps this shift is an aspect of continuing to market books and other products covering this material.  http://face-and-emotion.com/dataface/physiognomy/phrenology.jsp


In the example from Lehmann below, each numbered area is relevant to a personal characteristic. For example, area 20 is related to how confident or imbued with faith one is. If area 20 is enlarged, the person is confident, but if it is lacking, the person is critical, not confident. Area 27 has to do with the sense of humor. If it is enlarged, the person is easily drawn into laughter, but if it is lacking, the person is too serious to appreciate jokes.

From: Arthur R. H. Lehmann. Krankheit Begabung Verßprechen. Berlin: F. Gnadenfeld co., 1904.

Some phrenologists tried to supply answers to deeper questions and to connect the issues of phrenology to those of physiognomy. Spurzheim saw the angles of the face as an important feature of the face, and he knew that the bony structure of the skull was the basis for these angles and other features. Using such observations, he claimed that four personality types were connected physiologically to how the skull was shaped. The validity of such connections is doubtful, but many subsequent researchers have tried to show how body shapes and sizes are related to personality variables, siting more evidence to support their contention. In general, however, the relationships between body characters, including those of the face and head, and psychological variables have not been systematically compiled and evaluated, and the influence of such approaches has been minimal.

The term "physiognomy" refers to features of the face, especially so when, in the narrow sense, these features are used to infer the relatively enduring character or temperament of an individual. In this discussion, physiognomy connotes a broader meaning, i.e., it refers to relatively unchanging facial features that might convey messages about any inner or hidden aspect of the person. Most of these facial features have as their basis the bony structure of the skull, on which the soft tissues lie. These features include the shapes and positions of major areas and landmarks of the face, such as the forehead, eyebrows, nose, cheeks, and mouth. The important facial features can be fairly accurately reconstructed by experts from the skull alone. A diagram of the human cranium shows the major features of the skull, from which much of the visible appearances of the face can be extrapolated. Other physiognomic features are not directly linked to the bony skull, such as skin texture and coloration, hair placement and texture, and detailed shapes of fleshy features. All of these features change slowly and relatively little over time, and they are the sign vehicles for physiognomic messages. Proposing an association between these facial features and other aspects of the person, including personality, character, outcomes of medical treatment, romantic compatibility,or the destiny of the person, is a physiognomic approach. The validity of the association or inference based on physiognomy is a separate issue that can be established or discredited by empirical evidence. Accurately face reading these signs depends upon knowing which relations are valid and which are spurious.  For more information see the following link http://face-and-emotion.com/dataface/physiognomy/physiognomy.jsp

Fun facts:
- In Bram Stoker's Dracula several characters make phrenological observations in describing other characters.

- Terry Prachett, in his Discworld series of books, describes the practice of Retro-phrenology as the practice of altering someone's character by giving them bumps on the head. You can go into a shop in Ankh-Morpork (a city in the book) and order an artistic temperament with a tendency to introspection. What you actually get is hit on the head with a series of small hammers, but it keeps the money in circulation and gives people something to do.

Feb 18, 2011 Fontanelles & Joining the Cranial Bones

The skull is made up of many bones, 7 in the skull itself and 14 in the facial area. They join together to form a solid, bony cavity that protects the brain and supports the structures of the head. The areas where the bones join together are called the sutures.

The bones are not joined together firmly at birth. This allows the head to pass through the birth canal. The sutures get minerals added to them over time and harden, firmly joining the skull bones together. This process is called ossification.


In an infant, the space where two sutures join forms a membrane-covered "soft spot" called a fontanelle (fontanel). The fontanelles allow for growth of the skull during an infant's first year.
There are normally several fontanelles on a newborn's skull, mainly at the top, back, and sides of the head. Like the sutures, fontanelles ossify over time and become closed, solid bony areas. The fontanelle in the back of the head (posterior fontanelle) usually closes by the time an infant is 1 - 2 months old. The fontanelle at the top of the head (anterior fontanelle) usually closes between 7 - 19 months.
The fontanelles should feel firm and very slightly curved inward to the touch. A tense or bulging fontanelle occurs when fluid builds up in the skull cavity or when pressure increases in the brain (increased intracranial pressure).

      http://en.wikipedia.org/wiki/File:Gray198.png


When the infant is crying, lying down, or vomiting, the fontanelles may look like they are bulging, but they should return to normal when the infant is in a calm, head-up position.
http://www.nlm.nih.gov/medlineplus/ency/article/003310.htm







Many animals are born with fonatanelles. These normally close at various points during maturation.  During the intervening time the brain is not as well protected as it will be and care should be taken when handling very young animals.  Some animals, such as dogs, will have fontanelles that don't close.  Which can cause difficulties for the dog (and the dog owner).  Pressure on the soft spot can cause brain damage and seizures.
                 
Fun fact -  There is no law at the U.S. Federal level prohibiting you from having a human bone in your possession. The fact that some people believe there is or believe there should be such a law is irrelevant. 
For more information go to  http://www.boneroom.com/faqs/bones.html#bonelaws

Feb 17, 2011 Where Man Meets Machine

There seems to be an inborn need in many humans to create things in our likeness.  Novelists and movie directors have taken this endeavor to the extreme in writing stories and creating excellent horror, action, and mystery movies to intrigue us.  Asimov's i,Robot  series (later turned into a movie starring Will Smith) blurs the line between robot and human. 

The Terminator series takes us into the future and back to the present as Arnold Schwarzenegger (along with other actors play robots that are  trying to prevent humanity from defeating them in the future.  By destroying the humans from the past that will eventually defeat them. 

Robin William's take on AI (artificial intelligence) in Bicentennial Man and Star Trek's Data, the android played by Brent Spiner (who does a wonderful job portraying Data's fledgling emotional growth), take a more benign look at the interaction between humans and AI.

These portrayals have always provided us with great entertainment, but as we merge our continuing studies of Anatomy, Physiology, and Neurology with robotics, computer programing, and artificial intelligence we are starting to approach something that might make us consider where this is all headed.

 

These are just two of a large number of videos, quite easily found online, that indicate the direction we are moving in; but why?  There are actually a multitude of applications (far too many to be listed here) ranging from the scary science-fiction-like the Clone Wars' militaristic application to a butler-like human aide as represented in the movie classic Star Wars by C3PO.

If you pay attention to the majority of the stories in which the Robot/Android plays a major role I think you will often find that most of them play out as a look into a long debated question.  

"What is life?"

When does AI cross over from - I think because you ask it of me, to - I think, therefore I am?

Fun fact - Long before Isaac Asimov first touched a typewriter, Walt Whitman's boon companion William Douglas O'Connor toiled over a story of steampunk robots and political intrigue, called "The Brazen Android."

A list of worthwhile Robot/Android stories (some of which are now movies):

• Do Androids Dream of Electric Sheep? (Now called Blade Runner)
• The Terminator Series
• Bicentennial Man
• The i,Robot series by Asimov
• some specific episodes of Star Trek - Next Generation

Please add your favorites in the comment section.

Feb 15, 2011 - The Axial & Appendicular Skeleton

Reminder - Thursday 2/17 is the bone Histology Quiz

The Axial and Appendicular Skeleton together cover the following functions:

1. STRENGTH, SUPPORT AND SHAPE: It gives strength, support and shape to the body. Without a hard and rigid skeletal system, human body cannot stand upright, and it will become just a bag of soft tissues without any proper shape
2. PROTECTION OF DELICATE ORGANS: In areas like the rib cage and skull, the skeleton protects inner soft but vital organs like heart and brain from external shocks. Any damage to these organs can prove fatal, therefore protective function of skeleton is very important
3. LEVERAGE FOR MOVEMENTS: Bones of the human skeleton in all parts of body provide attachment to the muscles. These muscles provide motor power for producing movements of body parts. In these movements the parts of skeleton acts like levers of different types thus producing movements according to the needs of the human body.
4. PRODUCTION OF RED BLOOD CELLS: Bones like the sternum, and heads of tibia have hemopoeitic activity (blood cells production). These are the sites of production of new blood cells.

The Axial Skeleton

 

The axial skeleton:

• is made of the skull, spine, sacrum, and rib cage 
• allows various movements of the torso at the vertebrae but it is primarily for protection 
• has  80 of the 206 bones of the body

The Appendicular Skeleton

http://www.mananatomy.com/wp-content/uploads/2010/12/appendicular-skeleton.jpg

The appendicular skeleton:

• is made of the shoulder girdle, upper limbs (appendages), pelvic girdle,  and lower limbs
• is made primarily for leverage/movement/locomotion
• has  126 of the 206 bones of the body

Fun fact:  A popular theory regarding skeleton bones is that men have one less bone than women, owing to the Bible story that Eve was created from one of Adam's ribs. Both men and women actually possess 12 pairs of ribs. It is interesting to note; however, that should a rib need to be removed, it can regenerate itself within 3 months.

Feb 14, 2011 Happy Valentine's Day or Black Monday (Whichever fits)

Reminder - Thursday 2/17 is the bone Histology Quiz

Today is a departure from strict anatomy. Many students have asked me why we draw a heart the way we do today.  Here is a little information.  I will not venture to say which if any of these are correct.  See the following link for more information. http://www.romancestuck.com/articles/general/history-of-heart-shape.htm

In modern days, the heart symbolizes love, romance, and passion, but where did this come from?

The History of the Heart Shape

The Heart Shape
The heart is traditionally drawn in this shape with a red color.

Colors of the Heart

The color of hearts is generally red colored. Red traditionally represents passion and strong emotions in many cultures.

Heart Theories

From what we could determine, there are three main theories as to where the heart shape originated. None of the three are proven, but all present interesting points:  

1. Modeled after an actual heart.
This theory is actually a pretty well known one. The theory says that the modern drawing of a heart is actually modeled after the actual human heart because the ancients, including Aristotle, and even some today, believe that the heart contains all human passions. However, the traditional heart shape as drawn has very little resemblance to an actual human heart. The drawing more closely matches that of a cattle heart, which was more readily available in sight in past centuries, meaning they modeled it after a cattle heart. However, the resemblance to the cattle heart is still very slight. It's also said that the drawing of a modern heart possibly originated because of botched drawings of the human heart by medieval artists after a philosopher inaccurately described the shape. The medieval tradition of courtly love may have reinforced the shape's association with romance. Hearts can be found on playing cards, tapestries, and paintings.

 Human heart - The most "heart shaped" I could find.

2. Depicts the female body.
Some say that the traditional heart shape actually represents body features of a female, such as the vulva, breasts, or buttocks. The female pelvis is also somewhat heart-shaped. Because the female gives birth to life, this could be the association with the heart-shape and love.

3. Derived from a seed.

A last theory is that the traditional heart came was derived from the plant seed of the Silphium plant. This now extinct (for over two millennia) North African plant was found in the ancient city of Cyrene during the seventh century BC. The plant was most commonly used as a seasoning, but was also widely used as a contraceptive in ancient Egypt. Because of it's importance to their economy, they depicted the shape of the seed on their coins. The seeds and flowers were distinctly heart-shaped. It is said that because of the use of the plant as a contraceptive, the shape of the seeds became associated with sexuality and eventually with romantic love.

Silphium Seed Coin - http://growingupcreative.typepad.com/.a/6a010535781c42970c011278d8daef28a4-pi

Fun Fact -  One of the most ancient of Valentine's Days rituals (dating from at least the Middle Ages and possibly earlier) was the practice of writing the names of young ladies on slips of paper and placing them within a jar or bowl. The lady whose name was drawn by an eligible bachelor became his valentine and he wore the name on his sleeve for one week. It is believed that the saying "to wear one's heart on one's sleeve" (meaning that is is easy for others to know the romantic inclination of an individual) may have originated from this custom.

Valentine Superstition - It was believed that if a lady slept with a sprig of rosemary pinned inside the pillow on the Eve of Valentine's Day it would encourage dreams of a future sweetheart's face.

For more information try the following - http://www.novareinna.com/festive/valrites.html