Our joints work hard for us every day. Learn about our joints and what they do for us, and what symptoms may be a result of joint damage.
What is a joint?10
A “joint” is a complex of structures that keeps two or more bone surfaces aligned.
The bone extremities that form joints can be, in relation to one another:
- mobile, such as those in the knee, wrist, shoulder, elbow, ankle, and hip
- semi-mobile, such as the joints in the spine
- fixed, such as the joints in the skull or the pelvis
What is articulation?
The term “articulation” refers to a complex of structures that maintains two or more bone surfaces attached for purposes of motion.
Types of articulation
- moveable, such as those of the knee, wrist, shoulder, elbow, ankle, and hip
- semi-moveable, such as the articulation of the vertebral column
- fixed, as in the case of the bones of the skull or pelvis
Different Joints
Knee
The knee is one of the most complex joints in the human body. On one hand, it is mobile enough to allow the lower part of the leg to move, which is essential to carry out everyday activities such as walking, sitting, running, and standing straight. On the other hand, it is strong enough to bear the body’s weight.
Shoulder
The shoulder is made up of three bones and four ligaments that work together to allow you to position your arm and hand as you wish. Its movements, which are broader and more numerous compared with the ones achievable by other joints, require greater range of motion.
Hip
The hip is one of the most important joints in the human body as it allows us to walk, run, and jump. It bears the weight of the body and the force exerted by the muscles in the pelvis and the legs.
Ankle
The ankle joint, together with the bones of the foot, is responsible for balance and for body propulsion during various activities, such as maintaining an erect posture, jumping, walking, and running. It also bears the entire weight of the body.
Wrist
The wrist is a complex joint that connects the bones of the forearm with the bones of the hand. It allows the hand to flex and extend.
Elbow
The elbow is a complex joint located between the upper and the lower part of the arm and is where the forearm flexes and extends.
Common Joint Concerns
Joint cracking and popping (crepitus) results from the rubbing of articular bony ends in the joints. Crepitus may be frequently accompanied by other symptoms such as joint pain, swelling, redness, or warmth at the affected area, and joint stiffness, especially in the early hours of the day.
Arthrosis is a degenerative alteration of one or more joints, characterized by progressive lesions in the joint cartilage and the underlying bones, which causes a varying degree of function limitation and has a negative effect on the quality of life.
Cartilage covers the articulating ends of bones and allows joints to move normally. When it wears thin, there is increased friction between the bones during movement. This can cause structural damage in the joint.
The results may be pain, swelling, and deformity of the bones and of the joint ligaments. Arthrosis is called idiopathic (primary arthrosis) when there is no known cause. It can also be secondary and derive from traumatic events, endocrine and metabolic diseases, or rheumatic disorders.
Symptoms may include joint pain (exacerbated at first by movement and/or load-bearing but can then become chronic in the later stages of the disease), rigidity (especially in the morning and after a period of inactivity), functional limitation, crepitus, and joint swelling. The most affected joints are the knees, the hips, the small joints in the hands, and in the cervical and lumbar regions of the spinal column.
