Anatomy of Joints: Types, Structures, and Movements in Human Body

Joint (articulation)

Point where two bones meet

Arthrology

Study of joint structure, function, and dysfunction

Biomechanics

Study of movements and mechanics in body

Kinesiology

Study of musculoskeletal movement

Bony Joints

Synostosis joints that are immovable and where two bones ossified together

Fibrous Joints

Synarthrosis or synarthrodial joints where collagen fibers bind adjacent bones

Sutures

Immobile or slightly movable joints of skull bones

Gomphoses

Joint between tooth and socket held in place by periodontal ligaments

Syndesmoses

Long collagen fibers bind two bones, such as ulna-radius and tibia-fibula

Cartilaginous Joints

Amphiarthrosis or amphiarthrodial joints with two types: synchondroses and symphyses

Synchondroses

Type of cartilaginous joint with hyaline (costal) cartilage

Symphyses

Type of cartilaginous joint with fibrocartilage, such as pubic symphysis and intervertebral discs

Synovial Joints

Diarthrosis or diarthrodial joints that are varied in mobility and structurally complex

Articular cartilage

Covers facing surfaces of bones in synovial joints

Joint capsule

Encloses joint cavity, a narrow fluid-filled space

Synovial fluid

Lubricant resembling raw egg whites produced by the inner synovial membrane

Bursa

Sac of synovial fluid between adjacent muscles, bone, and skin, or tendons passing over bone

Classes of Synovial Joints

Includes ball-and-socket, plane (gliding), condylar (ellipsoid), hinge, saddle, and pivot joints

Flexion

Decreases joint angle

Extension

Straightens joint angle

Abduction

Moves away from midline

Adduction

Moves toward midline

Elevation

Raises body part

Depression

Lowers body part

Protraction

Anterior movement

Retraction

Posterior movement

Circumduction

Distal end of limb makes circle while proximal end is stationary

Rotation

Bone spins on its long axis, with external and medial rotation

Supination

Moves palm to face anteriorly, radius and ulna become parallel

Pronation

Moves palm to face posteriorly, radius crosses ulna

Dorsiflexion

Foot elevates at ankle

Inversion

Soles face medially

Eversion

Soles face laterally

Plantar flexion

Foot points down at ankle

Temporomandibular joint (TMJ)

Mandibular condyle articulates with mandibular fossa of temporal bone

Lateral ligament

Supports the temporomandibular joint

Glenohumeral joint

Shoulder joint

Glenoid labrum

Ring of fibrocartilage that deepens socket

Elbow joint

Two articulations: humeroulnar and humeroradial

Hinge and pivot joint

Functions of the elbow joint

Radial collateral and ulnar collateral ligaments

Stabilize the elbow joint

Coxal joint

Hip joint

Acetabular labrum

Fibrocartilage that deepens socket in the hip joint

Round ligament

Attaches to fovea capitis in the hip joint

Femorotibial joint

Knee joint

Hinge joint

Function of the knee joint

Lateral and medial menisci

Provide padding in the knee joint

Fibular collateral and tibial collateral ligaments

Important ligaments in the knee joint

Talocrural joint

Ankle joint

Anterior and posterior tibiofibular ligaments

Stabilize the ankle joint

Deltoid ligament

Medial multipart ligament in the ankle joint

Arthritis

Inflammation of joint

Rheumatoid arthritis (RA)

Most common crippling disorder in U.S.

Osteoarthritis (OA)

Autoimmune disease that attacks the synovial membrane

Ankylosis

Immobilization due to arthritis

Crepitus

Crunching and cracking sounds of joints

Arthroplasty

Replacement of diseased joint with an artificial device

Total hip replacement (THR)

Most common procedure for elderly, first performed in 1963

Porous-coated prostheses

Infiltrated with patient's bone to create firmer bond