Joints of the Human Body

It connects the bones of the human skeleton to other bones and cartilage. This occurs in the knees, elbows, wrists, ankles, shoulders, among others.

Therefore, we can say that the joint is the meeting point between the bones , enabling the body’s movements.

Classification of joints

Joints are classified according to the degree of mobility they offer. They can be of three types:

• Synarthrosis : These are fibrous joints, located between one bone and another, characterized by being inflexible . The two bone surfaces are practically continuous, separated only by a layer of connective or cartilaginous tissue. Examples: the joint of the skull (suture), of the teeth and jaw, of the tibia and fibula.
• Amphiarthrosis : These are semi-mobile , flexible and cartilaginous joints . They have cartilage between the bones and allow movements that prevent excessive wear on the bones, thus helping them to slide over each other during different body movements. Examples: hip bones and vertebrae.
• Diarthrosis : These are flexible joints , characterized by the presence of synovial sacs, which contain synovial fluid or synovia, which prevents wear and tear caused by friction. They are located between the skin and the bones. Examples: shoulder, knee and elbow joints.

Elements of joints

Body movement is produced by communication between the ends of the bones involved, carried out by synovial joints.

Synovial bursae act as shock absorbers in mobile joints. Synovial fluid is viscous, transparent and facilitates movement between two bony parts.

As we age, the production of this fluid decreases, causing joint pain.

To do this, check out some elements that are part of the joints below:

• articular cartilage ( elastic connective tissue);
• the ligaments (fibrous structures);
• the joint capsule (fibrous membrane);
• the synovial membrane (pocket with synovial fluid);
• the menisci (knee joint structure).

Main Joints and Movements

Learn about some of the main joints in the human body and the movements they perform.

Skull Joints

The bones of the skull are connected in such a way that they do not allow movement. It is formed by fixed joints or sutures, characterizing synarthrosis.

Another example is the joint between the ribs and the sternum, where there is almost no movement.

Shoulder Joints

The shoulder joints are Glenohumeral, Acromioclavicular and Sternoclavicular. Together, they allow the movements of gliding, adduction and abduction, flexion and extension, rotation and circumference.

Shoulder dislocations are common, when the shoulder becomes dislocated. The most common cause is during certain sports, such as swimming, basketball and volleyball, or due to an accident.

Elbow Joints

The elbow joints are: humeroulnar, humeroradial and proximal radioulnar. They allow flexion and extension movements.

It connects the arm and forearm, and is essential for movement as it acts as a type of hinge.

Wrist and Hand Joints

The joints of the wrist and hand are: Distal radio-ulnar, Radiocarpal, Carpometacarpal, Metacarpophalangeal, Interphalangeal.

They allow adduction, abduction, flexion, extension and sliding movements. Together, they are responsible for the movement of the wrist and fingers.

Hip Joints

The hip joints are: Sacroiliac and Coxofemoral. The sacroiliac joint only performs the gliding movement.

The movements performed by the coxofemoral are abduction and adduction, flexion and extension, rotation and circumference.

Knee Joints

The knee joints are: Patellofemoral, Tibiofemoral, Tibiofibular. Together, they perform sliding, flexion and extension movements.

It is responsible for making the connection between the tibia and the femur, and also between the femur and the patella.

In addition, it acts on stabilization, biomechanics and impact absorption. In some cases, cartilage wear can occur and impair some movements.

Joints of the Spine

The joints of the spine can be considered one of the most complex, as they are responsible for movements that are extremely important for day-to-day activities.

The movement between two vertebrae is considered small, however, together, they represent movements of large amplitude.

Don’t forget that muscles also play an important role in moving the body.

Joint diseases

Arthritis

Arthritis is characterized by inflammation of the joints . It is associated with excess body weight, repetitive work, advanced age, injuries, among others.

Symptoms caused by arthritis are: difficulty moving the joints, pain, redness and swelling.

Some types of arthritis are: rheumatoid arthritis, gouty arthritis (gout), osteoarthritis (arthrosis), psoriatic arthritis, septic arthritis, among others.

Osteoarthritis

Osteoarthritis or osteoarthritis is a chronic disease that affects the bones and cartilage of the body. It most commonly develops in the joints of the hands, wrists, shoulders, elbows, knees and feet.

It is a type of degenerative arthritis, which normally occurs in people who are overweight, elderly, manual workers, and is more common in women.

Interesting facts about joints

• Arthrology is the science that studies joints.
• Rheumatism is a group of diseases related to the skeleton, muscles and joints. For example, gout, fibromyalgia, arthritis, osteoarthritis, osteoporosis, lupus, among others.