HUMAN KNEE ANATOMY

Symptoms of knee arthritis are often painful and debilitating, especially if the problem is left untreated. However, unlike most diseases, symptoms can fade or disappear altogether some days, and strike fiercely and unexpectedly other days.

There are three main types of knee arthritis. Osteoarthritis is the most common form, and generally strikes people who are middle-aged. This type of knee arthritis usually gets worse as time goes on. Gradually, the cartilage that surrounds the knee is worn away, causing your bones to rub together.

Rheumatoid arthritis is an inflammation of the knee that can destroy the cartilage surrounding the knee. This type of knee arthritis can strike at any age, and it generally strikes both knees and not just one.

Post-traumatic arthritis is the final, main type of knee arthritis. As mentioned, this type of knee arthritis occurs after an injury. It may not show up for years after you have sustained an injury to the knee, but once it does, it can be painful.

Symptoms of knee arthritis are different from patient to patient. You may experience "good days", or "bad days". In some cases, knee arthritis sufferers complain that the weather affects their symptoms. If it is damp or cold outside, your symptoms may increase in severity compared to when it is dry and more warm outside.

Symptoms of knee arthritis include:

A weakness in the knee

Joint swelling

Knee area feels stiff

Range of motion is reduced

Knee can become deformed

The knee and surrounding area becomes sore to the touch

Do not allow knee arthritis to ruin your mobility. If you notice any of the symptoms of knee arthritis listed above, see your doctor. The longer you leave it, the worse the symptoms can become.

While visiting with your physician is important there are a number of things you can do to alleviate the pain in your knees, if you are suffering from knee arthritis.

First and foremost, if you are overweight, you should strongly consider losing weight in order to take some of the pressure off your knees.

Staying away from any exercise that may exert extra, unneeded pressure on your knee is also recommended. In extreme cases of knee arthritis, you may be required to undergo knee replacement surgery.

A knee brace can also be used to lend extra support to the knee. If you tend to have more pain when certain knee movements occur you should highly consider the support a knee brace can provide. A low profile knee brace can prevent excessive movements and as a result reduce your pain. This is extremely important when you forget about your arthritic symptoms and make a movement without thinking. This is when the knee brace can be your aid.

If you have osteoarthritis a knee brace can also helpful. If you have malalignment due to arthritic anatomy changes at your knee joint. An "OA" (osteoarthritis) knee brace can help maintain proper alignment, thus reducing your pain.

Standard Anatomical Position

The first thing to be aware of is the standard anatomical position. This is the position all movements are derived from of the human body. This position is important to remember; when we use terms of direction to explain limbs assuming that they're in the standard anatomical position.

In human anatomy 'left' and 'right' refer to the left and right of the topic of observation not the observer, for example if I were to refer to the left arm I would be referring to the arm on our (the observer's) right.

Planes

In human anatomy often hear planes used to describe modes of movement or the location of structures (in relation to other structures). A plane is essentially an imaginary line through the human body. Different planes divide the body into different sections. There are 3 basic planes:

Sagittal (median) Plane

This is any vertical plane which runs from the front of the body to the back. As a result it partitions the body into right (dexter) and left (sinister) sections.

It is important to remember this doesn't just apply to the human body as a whole; it can be applied to the orientation of any individual body part.

Coronal (frontal) Plane

The coronal plane is another vertical plane, but it runs at a right angle to the Sagittal plane. It runs from left to right dividing the body into front (ventral) and back (dorsal) sections.

As with the Sagittal plane, it can be applied to individual body parts as well as the whole body.

Transverse (axial, transaxial) Plane

The transverse plane is a horizontal plane that runs perpendicular to the Sagittal and Coronal planes. It separates the body into upper (superior) and lower (inferior) sections.

As always this plane can be applied to individual body parts.

Glossary of directional terms

Below are listed a number of commonly used directional terms relating to human anatomy. It is important to consider that whilst these terms are commonly used they can vary significantly between disciplines. It should be noted that these terms apply to human (medical) anatomy and physiology not veterinary (or zoological) anatomy.

Proximal and Distal: Proximal and distal are terms used primarily in the description of limbs. Distal means further away from the torso whilst Proximal refers to the point where an appendage or limb attaches to the torso. To connect the two points creates the Proximodistal Axis. It is important to remember that these terms are relative; for example, the elbow is distal to the shoulder but it is proximal to the hand.

Lateral (externo), Medial (interno) and Intermediate: These terms are used in reference to the mid-line of the human body (the line through which the sagittal plane runs). Medial refers to structures closer to the medial line (i.e. the centre) whilst lateral refers to structures further away. Intermediate describes a structure between a medial and lateral structure. It is important to remember these terms are relative. For example, the nose is medial to the eyes. The eyes are medial to the ears. The ears and eyes are both lateral to the nose, and the cheeks are intermediate between the nose and the ears.

Anterior and Posterior: The term anterior (or ventral) refers to the front of the body (as split by the coronal plane). Posterior (or dorsal refers to the back of the body. These terms are generally used in conjunction (i.e. anterior and posterior, not anterior and dorsal). Over the whole of the body these terms can be used interchangeably with the exception of the brain (where dorsal means toward the top of the head and ventral means toward the bottom).

Cephalic and Caudal: The term cephalic (also known as cranial, rostral or superior) means toward the upper section or head whilst Caudal (inferior) refers to the lower part of the structure or away from the head. These terms are used in conjunction (cephalic and caudal, superior and inferior, not cephalic and inferior). They are once again relative and can refer to individual body parts as well as the human body as a whole. For example the knee is inferior to the hip, but superior to the foot.

Superficial: This refers to structures close to the surface of the body. The opposing term is deep. For example the brain is deep to the skull whilst the skull is superficial to the brain.

Types of movement

Flexion and Extension: These terms are used to describe movements in the sagittal plane (i.e. movements forwards and backwards rather than side to side). Flexion decreases the angle between to bones at a joint, an example is when the knee is raised. Extension is the straightening of a limb (it increases the angle between two bones at a joint), for example bringing the hand down from the shoulder.

Additionally, flexion and extension in the ankle are know as Plantarflexion and Dorsiflection

Hyper-extension is the action of extending the joint beyond 180 degrees. Hyper-extension is most commonly associated with joint injury.

Protraction and Retraction: Protraction is the action of moving a part of the body forward along the transverse plane by movement of anterior muscles. Retraction is the exact opposite.

Abduction and Adduction: Abduction is the movement of a limb away from the coronal plane of the body. Raising the arms from the hips so a 'T' shaped is formed is an example of abduction, as is the spreading of the fingers. Adduction is movement of a limb back toward the coronal plane.

Rotation: This is movement around its axis without lateral or medial displacement, for the turning of the head to look left or right.

Circumduction: This term describes the actions of flexion, abduction, extension, adduction performed one after the other. The over all movement means that the proximal end of the limb remains stationary whilst the distal moves in a circel (the limb thus outlines a cone).

Pronation and Suppination: Pronation is the movement of the hand from upward facing palm (anterior position) to a downward facing (posterior) position. The rotation is in no way as a result of movement of the arm. Suppination is the exact opposite movement.

Elevation and Depression: Depression describes the movement at a joint which results in downward (inferior) movement. Elevation is the exact opposite of this and results in superior movement. The action of shrugging the shoulders is an example of elevation followed by depression.

Inversion and Eversion: These terms primarily refer to movements of the feet, often in relation to injury (e.g.sprains). Inversion is the movement in the sole inwards (toward the sagittal plane). Eversion is the movement of the sole to face outward (away from the sagittal plane).

Opposition, Aposition and Reposition: Opposition (a term used expressly to describe the thumb) occurs when the hand assumes a holding position. It is important to consider that this term is used with varying specificity (i.e. some anatomists may use this term only to describe the thumb in contact with the little finger, whilst others may be less specific). Aposition (again unique to the thumb) is a broader term used to describe numerous positions of the thumb whilst holding (some anatomists consider these positions to be covered by opposition). Reposition is the movement back to the standard position.

Testing yourself will speed up how quickly you're able to retain these terms and thus increase your understanding of anatomy.

First of all, both the lower end of the femur and the upper end of the tibia are covered with a layer of cartilage, called articular cartilage. Secondly, there are two ring-like pads of cartilage inserted between the articular cartilage of the femur and the articular cartilage of the tibia. One of these is located between the curved surfaces on the medial side (closer to the midline of the body) of the knee and is called the medial meniscus. The other one is located between the curved surfaces on the lateral side (farther from the midline of the body) of the knee and is called the lateral meniscus. Thirdly, there is synovial fluid lubricating all of these cartilage surfaces.

There are also many ligaments associated with the knee. Ligaments are cords of connective tissue which pass from one bone to another across a joint. Their function is to make the joint stronger. Two of these knee ligaments form an X in the area between the medial meniscus and the lateral meniscus. They are called cruciate ligaments, from the latin word for an X. The anterior cruciate ligament (ACL) begins on the middle of the front of the tibia and attaches near the back of the femur. The posterior cruciate ligament (PCL) begins near the middle of the back of the tibia and attaches near the front of the femur.

Two other ligaments of the knee are called collateral ligaments. The medial collateral ligament (MCL) begins on the medial side of the femur and attaches on the medial side of the tibia. The lateral collateral ligament (LCL) begins on the lateral side of the femur and attaches on the lateral side of the tibia. Two more knee ligaments are called popliteal ligaments. They both begin on the back of the femur and provide strength to the back of the knee. The patellar ligament begins at the patella (knee cap) and attaches to the front of the tibia. It adds strength to the front of the knee. There are also other ligaments associated with the knee.

One type of knee injury is called a torn cartilage. This refers to a tear in either the medial meniscus or the lateral meniscus. The medial meniscus is much more likely to be torn than the lateral meniscus. The reason for this is that the medial collateral ligament (MCL) is actually attached to the medial meniscus. The anterior cruciate ligament (ACL) is also attached to the medial meniscus. If the knee is hit from the side or twisted, the force pulls on the medial collateral ligament (MCL), which in turn pulls on the medial meniscus, which in turn pulls on the anterior cruciate ligament (ACL). As a result, the 2 ligaments may stretch or tear. Since the meniscus is composed of cartilage, it cannot stretch; so it tears.

A torn lateral meniscus is much less likely to occur, but it is not impossible. The lateral meniscus is not attached to the lateral collateral ligament (LCL), but it is attached to the posterior cruciate ligament.

Another type of knee injury is a dislocation. This refers to a situation in which the upper end of the tibia is pushed out of its normal position, directly under the lower end of the femur. The tibia could be displaced in any direction -- forward, backward, to the medial side, or the the lateral side, or it could be twisted in place. With a dislocation, there is the possibility of damage to any of the structures associated with the knee or to any of the blood vessels in the knee area.

We will start from the top to the bottom and I have to say that the head is filled with such places. First of all, the eyes represent one of the weakest points in the human body. It will sound cruel however in a life or death situation you must act. A direct blow with the fingers to the attackers eyes will leave him in extreme pain and complete incapacity. He will most likely run away or collapse from the pain. Also behind the ears there is a bone that in placed directly over the balance center of the body or the inner ear. A direct blow with your palm or elbow to that area will leave an attacker with limited or no balance, causing him to fall.

Another weak point the human body has is located directly under the nose. A cartilage is located there and if receiving a direct blow, that cartilage will send out extreme pain sensations to the brain and activate the tear glands of the eyes, thus the attacker will not see and will be temporarily incapacitated. Also a special spot which only men have is the Adam's apple in the neck. A straight punch to that are will leave a man without breath and can actually be fatal if delivered with too much power.

Moving down a bit on the body, we reach the liver. It is considered to be regenerating organ and filters all the impurities in your body. It is located in the lower right side of the abdominal cavity and when punched properly, can cause the attacker to collapse in extreme pain, have almost total lack of breath and even loss of consciousness.

The last weak point taught by self defence classes on the human body, is represented by the knee. It holds you leg together as a principle joint and is covered by a very hard cartilage known as the patella or the knee cap. Upon receiving a direct blow, this injury can cause an attacker to instantly drop and experience pain. All these techniques may seem cruel and unfair, however they must be used only in critical situations and are only for protection.

One of the main complaints of both first-time runners and their seasoned counterparts is knee pain. Running puts considerable strain on the knee joint. If a runner is new to the sport, it is easy to over-train at the beginning. Take it slow, build your leg and joint strength. Establish a base of knee stability to prevent injury down the road. Experienced runners who are working on adding mileage for a new race distance should also take care: 10-kilometer conditioning and strength needs to be carefully modified if a 26-mile marathon is the goal. Knees will adapt to this new challenge if given the stability to do so. If two miles of moderate running cause pain at first, back off and rest. Give the knees time to stabilize.

Stability is essential to keep the knee working properly. Correct leg muscle development, obtained through gradual increase of mileage and intensity, will create stability. The quadriceps (on the front of the thighs) and hamstrings (on the back of the thighs) work in conjunction with each other, pulling on different areas of the knee at the same time. If these muscles are developed correctly, the knee joint will glide over and under itself without undue strain. Let's not forget the tiny, yet indispensable patella, as well. This engineering marvel glides over the front of the knee, adding stability and providing a liaison between thigh and lower leg bones. Thus the knee has been described by medical literature as being three articulations in one: draw a circle in the air with your toe, and you get the idea.

If more than a casual couple of miles per week are the runner's goal, it is mandatory that he or she invest in correct running shoes. People come in all shapes and sizes. Some people pronate, or roll the weight of their body to the inside edge of the foot. Others supinate, or roll the weight to the outside edge. Men and women even have different angles from hip to knee. This is why there are specific running shoes by gender. The best way to be fitted for running shoes is to visit a store that provides treadmill analysis. A shoe fitter will watch, or even video, the runner's heel strike to determine what kind of shoe is best to support the customer's body and running style. Yes, these shoes will probably be twice as expensive as the bargain-rack pair. However, to a runner, healthy, pain-free knees are well worth the price.

When you learn to ride a bicycle, some one tells you to hold onto the handle bars, sit in the seat and put your feet on the peddles. Horse riding is very much the same. When you are around horses people are going to be using the language of horses including the parts of a horse that make up his anatomy.

The most common ones to know are head, back, tail, hooves. Pretty straight forward, knowing the parts of a horse really pays off in a number of areas. For example when you take riding lessons, the instructor may say to "engage the hindquarters". What are hindquarters exactly?

When you tack up a horse, certain straps and buckles go in specific places on a horse. If you read any book on fitting tack correctly, it will tell you exactly how and where with the use of the parts of a horse. For example a sentence in a book may say something like this: The headpiece should lie comfortably behind the horse's poll. When you are putting on a bridle you do not want the headpiece to go anywhere else, so it helps to know exactly where the poll is.

Anytime your horse injures himself, it is very useful and helpful to be able to tell the veterinarian in horse terms, where on his body he hurt himself. "He hurt himself on his leg"; the foreleg, the hindleg, the knee or the hock; where exactly?

The most significant time to know the parts of a horse is when you are buying a horse. When you buy a horse, you have to look at his conformation. How well is his body put together? Does he have sickle hocks, is he over at the knee?

Conformation goes hand in hand with body parts and the horse's anatomy. If the horse has conformational faults and you can point them out to the owner, with the correct use of 'horse lingo', you may be able to negotiate a lower price.

By no means buy a horse that's anatomy is less than desirable, if his fetlock sinks to the floor when he is walking, walk away from the horse and do not look back. Some conformation faults can be overlooked and forgiven, some must be avoided at all costs. You'll only know what faults to look for and where to look for them by knowing basic horse anatomy - the parts of a horse.

People who are around horses will not think that you are showing off when you start naming or using the names of parts of the horse. In fact more than likely they will expect any horse person simply to know them. When you know the horse, you'll know all the parts that make him whole.

Before exploring ways to prevent ankle sprains it is important to discuss what an ankle sprain is and how it occurs. The ankle joint is unique because it is built to bear and stabilize the majority of the body's weight while still being relatively mobile. This seeming contradiction in requirements for stability and mobility is one reason the ankle can be injured so easily.

To understand the injury one must first understand the anatomy of the joint. There are two bones in the lower leg. The larger of the two bones is called the tibia. This bone goes from the knee joint down to the ankle and makes up the bony knob found on the inside portion of the ankle. The other bone is the fibula, which is a long skinny bone that travels with the tibia from the knee down to the ankle. The fibula, however, is the outer bone in the leg and makes up the outer bony knob of the ankle joint. If you feel your ankle right now you can feel these bones, the tibia on the inside and the fibula on the outside. Each knob is called a malleolus. The tibia and fibula are joined together near the knee joint and also just above the ankle joint. The ligament which attaches the tibia and fibula above the ankle is called the distal tibiofibular ligament.

Anatomically the ankle is classified as a complex joint because it is made up of more than two bones. The first two bones are the tibia and fibula. The third bone is irregularly shaped and called the talus. The talus fits perfectly in the space between the two malleoli (which is the word for more than one malleolus). The talus pivots in this space allowing you to point your toes toward the floor or toward your nose. This is the main motion of the ankle but it also allows for a little bit of turning inward and outward.

There are ligaments that attach each malleolus to the talus so that the talus doesn't come loose and the joint can be stable. On the inside of the ankle there is a series of ligaments that go from the malleolus of the tibia to the talus. These ligaments together are called the deltoid ligament. On the other side of the joint the malleolus of the fibula is connected to the talus by three ligaments: the anterior talofibular ligament (on the front part of the malleolus), the calcaneofibular ligament (on the bottom part of the malleolus) and the posterior talofibular ligament (on the back part of the malleolus).

There are two more ligaments that are important to know about when learning about ankle sprains. These ligaments are bands that wrap around the entire joint called the flexor retinaculum and the extensor retinaculum. These ligaments hold the tendons that travel from the leg to the foot down close to the bones. They also help to stabilize the ankle joint.

The last piece of anatomy to consider is the muscles that control the motion of the ankle. The tendons of several muscles cross the ankle joint. Some of these muscles, like the peronei muscles located on the outer portion of the leg, function mainly to move the foot while others mainly move the toes.

Now that you have a basic understanding of the anatomy involved. The next article in this series will describe the different types and grades of ankle sprain. In addition you will learn how these injuries are caused.