Glossary: Joints

abduction: movement in the coronal plane that moves a limb laterally away from the body; spreading of the fingers

acetabular labrum: lip of fibrocartilage that surrounds outer margin of the acetabulum on the hip bone

adduction: movement in the coronal plane that moves a limb medially toward or across the midline of the body; bringing fingers together

amphiarthrosis: slightly mobile joint

annular ligament: intrinsic ligament of the elbow articular capsule that surrounds and supports the head of the radius at the proximal radioulnar joint

anterior cruciate ligament: intracapsular ligament of the knee; extends from anterior, superior surface of the tibia to the inner aspect of the lateral condyle of the femur; resists hyperextension of knee

anterior talofibular ligament: intrinsic ligament located on the lateral side of the ankle joint, between talus bone and lateral malleolus of fibula; supports talus at the talocrural joint and resists excess inversion of the foot

articular capsule: connective tissue structure that encloses the joint cavity of a synovial joint

articular cartilage: thin layer of hyaline cartilage that covers the articulating surfaces of bones at a synovial joint

articular disc: meniscus; a fibrocartilage structure found between the bones of some synovial joints; provides padding or smooths movements between the bones; strongly unites the bones together

articulation: joint of the body

atlanto-occipital joint: articulation between the occipital condyles of the skull and the superior articular processes of the atlas (C1 vertebra)

atlantoaxial joint: series of three articulations between the atlas (C1) vertebra and the axis (C2) vertebra, consisting of the joints between the inferior articular processes of C1 and the superior articular processes of C2, and the articulation between the dens of C2 and the anterior arch of C1

ball-and-socket joint: synovial joint formed between the spherical end of one bone (the ball) that fits into the depression of a second bone (the socket); found at the hip and shoulder joints; functionally classified as a multiaxial joint

biaxial joint: type of diarthrosis; a joint that allows for movements within two planes (two axes)

bursa: connective tissue sac containing lubricating fluid that prevents friction between adjacent structures, such as skin and bone, tendons and bone, or between muscles

calcaneofibular ligament: intrinsic ligament located on the lateral side of the ankle joint, between the calcaneus bone and lateral malleolus of the fibula; supports the talus bone at the ankle joint and resists excess inversion of the foot

cartilaginous joint: joint at which the bones are united by hyaline cartilage (synchondrosis) or fibrocartilage (symphysis)

circumduction: circular motion of the arm, thigh, hand, thumb, or finger that is produced by the sequential combination of flexion, abduction, extension, and adduction

condyloid joint: synovial joint in which the shallow depression at the end of one bone receives a rounded end from a second bone or a rounded structure formed by two bones; found at the metacarpophalangeal joints of the fingers or the radiocarpal joint of the wrist; functionally classified as a biaxial joint

coracohumeral ligament: intrinsic ligament of the shoulder joint; runs from the coracoid process of the scapula to the anterior humerus

deltoid ligament: broad intrinsic ligament located on the medial side of the ankle joint; supports the talus at the talocrural joint and resists excess eversion of the foot

depression: downward (inferior) motion of the scapula or mandible

diarthrosis: freely mobile joint

dorsiflexion: movement at the ankle that brings the top of the foot toward the anterior leg

elbow joint: humeroulnar joint

elevation: upward (superior) motion of the scapula or mandible

eversion: foot movement involving the intertarsal joints of the foot in which the bottom of the foot is turned laterally, away from the midline

extension: movement in the sagittal plane that increases the angle of a joint (straightens the joint); motion involving posterior bending of the vertebral column or returning to the upright position from a flexed position

extrinsic ligament: ligament located outside of the articular capsule of a synovial joint

femoropatellar joint: portion of the knee joint consisting of the articulation between the distal femur and the patella

fibrous joint: joint where the articulating areas of the adjacent bones are connected by fibrous connective tissue

fibular collateral ligament: extrinsic ligament of the knee joint that spans from the lateral epicondyle of the femur to the head of the fibula; resists hyperextension and rotation of the extended knee

flexion: movement in the sagittal plane that decreases the angle of a joint (bends the joint); motion involving anterior bending of the vertebral column

fontanelles: expanded areas of fibrous connective tissue that separate the braincase bones of the skull prior to birth and during the first year after birth

glenohumeral joint: shoulder joint; articulation between the glenoid cavity of the scapula and head of the humerus; multiaxial ball-and-socket joint that allows for flexion/extension, abduction/adduction, circumduction, and medial/lateral rotation of the humerus

glenohumeral ligament: one of the three intrinsic ligaments of the shoulder joint that strengthen the anterior articular capsule

glenoid labrum: lip of fibrocartilage located around the outside margin of the glenoid cavity of the scapula

gomphosis: type of fibrous joint in which the root of a tooth is anchored into its bony jaw socket by strong periodontal ligaments

hinge joint: synovial joint at which the convex surface of one bone articulates with the concave surface of a second bone; includes the elbow, knee, ankle, and interphalangeal joints; functionally classified as a uniaxial joint

humeroradial joint: articulation between the capitulum of the humerus and head of the radius

humeroulnar joint: articulation between the trochlea of humerus and the trochlear notch of the ulna; uniaxial hinge joint that allows for flexion/extension of the forearm

hyperextension: excessive extension of joint, beyond the normal range of movement

hyperflexion: excessive flexion of joint, beyond the normal range of movement

iliofemoral ligament: intrinsic ligament spanning from the ilium of the hip bone to the femur, on the superior-anterior aspect of the hip joint

inferior rotation: movement of the scapula during upper limb adduction in which the glenoid cavity of the scapula moves in a downward direction as the medial end of the scapular spine moves in an upward direction

interosseous membrane: wide sheet of fibrous connective tissue that fills the gap between two parallel bones, forming a syndesmosis; found between the radius and ulna of the forearm and between the tibia and fibula of the leg

intracapsular ligament: ligament that is located within the articular capsule of a synovial joint

intrinsic ligament: ligament that is fused to or incorporated into the wall of the articular capsule of a synovial joint

inversion: foot movement involving the intertarsal joints of the foot in which the bottom of the foot is turned toward the midline

ischiofemoral ligament: intrinsic ligament spanning from the ischium of the hip bone to the femur, on the posterior aspect of the hip joint

joint cavity: space enclosed by the articular capsule of a synovial joint that is filled with synovial fluid and contains the articulating surfaces of the adjacent bones

joint interzone: site within a growing embryonic limb bud that will become a synovial joint

joint: site at which two or more bones or bone and cartilage come together (articulate)

lateral (external) rotation: movement of the arm at the shoulder joint or the thigh at the hip joint that moves the anterior surface of the limb away from the midline of the body

lateral excursion: side-to-side movement of the mandible away from the midline, toward either the right or left side

lateral flexion: bending of the neck or body toward the right or left side

lateral meniscus: C-shaped fibrocartilage articular disc located at the knee, between the lateral condyle of the femur and the lateral condyle of the tibia

lateral tibiofemoral joint: portion of the knee consisting of the articulation between the lateral condyle of the tibia and the lateral condyle of the femur; allows for flexion/extension at the knee

ligament of the head of the femur: intracapsular ligament that runs from the acetabulum of the hip bone to the head of the femur

ligament: strong band of dense connective tissue spanning between bones

medial (internal) rotation: movement of the arm at the shoulder joint or the thigh at the hip joint that brings the anterior surface of the limb toward the midline of the body

medial excursion: side-to-side movement that returns the mandible to the midline

medial meniscus: C-shaped fibrocartilage articular disc located at the knee, between the medial condyle of the femur and medial condyle of the tibia

medial tibiofemoral joint: portion of the knee consisting of the articulation between the medial condyle of the tibia and the medial condyle of the femur; allows for flexion/extension at the knee

meniscus: articular disc

multiaxial joint: type of diarthrosis; a joint that allows for movements within three planes (three axes)

opposition: thumb movement that brings the tip of the thumb in contact with the tip of a finger

patellar ligament: ligament spanning from the patella to the anterior tibia; serves as the final attachment for the quadriceps femoris muscle

periodontal ligament: band of dense connective tissue that anchors the root of a tooth into the bony jaw socket

pivot joint: synovial joint at which the rounded portion of a bone rotates within a ring formed by a ligament and an articulating bone; functionally classified as uniaxial joint

plane joint: synovial joint formed between the flattened articulating surfaces of adjacent bones; functionally classified as a multiaxial joint

plantar flexion: foot movement at the ankle in which the heel is lifted off of the ground

posterior cruciate ligament: intracapsular ligament of the knee; extends from the posterior, superior surface of the tibia to the inner aspect of the medial condyle of the femur; prevents anterior displacement of the femur when the knee is flexed and weight bearing

posterior talofibular ligament: intrinsic ligament located on the lateral side of the ankle joint, between the talus bone and lateral malleolus of the fibula; supports the talus at the talocrural joint and resists excess inversion of the foot

pronated position: forearm position in which the palm faces backward

pronation: forearm motion that moves the palm of the hand from the palm forward to the palm backward position

protraction: anterior motion of the scapula or mandible

proximal radioulnar joint: articulation between head of radius and radial notch of ulna; uniaxial pivot joint that allows for rotation of radius during pronation/supination of forearm

pubofemoral ligament: intrinsic ligament spanning from the pubis of the hip bone to the femur, on the anterior-inferior aspect of the hip joint

radial collateral ligament: intrinsic ligament on the lateral side of the elbow joint; runs from the lateral epicondyle of humerus to merge with the annular ligament

reposition: movement of the thumb from opposition back to the anatomical position (next to index finger)

retraction: posterior motion of the scapula or mandible

rotation: movement of a bone around a central axis (atlantoaxial joint) or around its long axis (proximal radioulnar joint; shoulder or hip joint); twisting of the vertebral column resulting from the summation of small motions between adjacent vertebrae

rotator cuff: strong connective tissue structure formed by the fusion of four rotator cuff muscle tendons to the articular capsule of the shoulder joint; surrounds and supports superior, anterior, lateral, and posterior sides of the humeral head

saddle joint: synovial joint in which the articulating ends of both bones are convex and concave in shape, such as at the first carpometacarpal joint at the base of the thumb; functionally classified as a biaxial joint

subacromial bursa: bursa that protects the supraspinatus muscle tendon and superior end of the humerus from rubbing against the acromion of the scapula

subcutaneous bursa: bursa that prevents friction between skin and an underlying bone

submuscular bursa: bursa that prevents friction between bone and a muscle or between adjacent muscles

subscapular bursa: bursa that prevents rubbing of the subscapularis muscle tendon against the scapula

subtalar joint: articulation between the talus and calcaneus bones of the foot; allows motions that contribute to inversion/eversion of the foot

subtendinous bursa: bursa that prevents friction between bone and a muscle tendon

superior rotation: movement of the scapula during upper limb abduction in which the glenoid cavity of the scapula moves in an upward direction as the medial end of the scapular spine moves in a downward direction

supinated position: forearm position in which the palm faces anteriorly (anatomical position)

supination: forearm motion that moves the palm of the hand from the palm backward to the palm forward position

suture: fibrous joint that connects the bones of the skull (except the mandible); an immobile joint (synarthrosis)

symphysis: type of cartilaginous joint where the bones are joined by fibrocartilage

synarthrosis: immobile or nearly immobile joint

synchondrosis: type of cartilaginous joint where the bones are joined by hyaline cartilage

syndesmosis: type of fibrous joint in which two separated, parallel bones are connected by an interosseous membrane

synostosis: site at which adjacent bones or bony components have fused together

synovial fluid: thick, lubricating fluid that fills the interior of a synovial joint

synovial joint: joint at which the articulating surfaces of the bones are located within a joint cavity formed by an articular capsule

synovial membrane: thin layer that lines the inner surface of the joint cavity at a synovial joint; produces the synovial fluid

talocrural joint: ankle joint; articulation between the talus bone of the foot and medial malleolus of the tibia, distal tibia, and lateral malleolus of the fibula; a uniaxial hinge joint that allows only for dorsiflexion and plantar flexion of the foot

temporomandibular joint (TMJ): articulation between the condyle of the mandible and the mandibular fossa and articular tubercle of the temporal bone of the skull; allows for depression/elevation (opening/closing of mouth), protraction/retraction, and side-to-side motions of the mandible

tendon sheath: connective tissue that surrounds a tendon at places where the tendon crosses a joint; contains a lubricating fluid to prevent friction and allow smooth movements of the tendon

tendon: dense connective tissue structure that anchors a muscle to bone

tibial collateral ligament: extrinsic ligament of knee joint that spans from the medial epicondyle of the femur to the medial tibia; resists hyperextension and rotation of extended knee

ulnar collateral ligament: intrinsic ligament on the medial side of the elbow joint; spans from the medial epicondyle of the humerus to the medial ulna

uniaxial joint: type of diarthrosis; joint that allows for motion within only one plane (one axis)

zygapophysial joints: facet joints; plane joints between the superior and inferior articular processes of adjacent vertebrae that provide for only limited motions between the vertebrae