L5: Joints Pt. 1 Flashcards
The joints of the skeletal system contribute to homeostasis by
holding bones together in ways that allow for movement and flexibility.
What does the human skeleton need to do?
Move
Why can’t bones bend without being damaged?
They are too rigid
What holds bones together at points of contact?
Flexible connective tissues
What are points of contact where bones are held together called?
Joints
What do joints permit in most cases?
Some degree of movement
What should one think about regarding the bones of the body moving against one another?
The amazing range of motion and the complexity of coordinated movements
What are examples of complex movements that occur as bones move?
Hitting a golf ball or playing a piano
How do the movements of the human body compare to machines?
They are far more complex than those of almost any machine
How often are many joint actions repeated?
Daily
During what stages of life do joint actions produce continuous work?
From childhood, into adolescence, and throughout adult lives
What is another name for a joint?
Articulation or arthrosis
What is a joint?
A point of contact between two bones, between bone and cartilage, or between bone and teeth
What is the scientific study of joints called?
Arthrology
What is the study of motion of the human body called?
Kinesiology
What are the three principal types of joints based on the type of material or manner in which articulating bones are united?
Fibrous, cartilaginous, and synovial
What are fibrous joints united by?
Dense irregular connective tissue (mainly collagen fibers)
How does the degree of movement in fibrous joints vary?
From immovable to slightly movable
What does the degree of movement in fibrous joints depend on?
The length of the collagen fibers that join the articulating bones
What are the two subtypes of fibrous joints?
Sutures and syndesmoses
What characterizes cartilaginous joints?
The presence of a solid piece of hyaline cartilage or fibrous cartilage that unites the articulating bones
How does the degree of movement in cartilaginous joints vary?
From immovable to slightly movable
What are the two subtypes of cartilaginous joints?
Synchondroses and symphyses
What type of joints make up most of the joints in the body?
Synovial joints
What characterizes synovial joints?
A two-layered articular capsule that unites the articulating bones and surrounds a lubricated space called an articular cavity
What supplies the lubrication in synovial joints?
The inner layer of the articular capsule
How does the degree of movement in synovial joints vary?
From slightly movable to freely movable
What are the various types of synovial joints?
Plane, hinge, pivot, ellipsoid, saddle, and ball-and-socket
How are the joints of the body presented in the following sections?
According to their structural classification
What will also be outlined while examining the structure of each type of joint?
Its various degrees of movement
In fibrous joints, how are articulating bones held together?
By dense irregular connective tissue
How much movement do fibrous joints permit?
Little or no movement
What are the two types of fibrous joints?
Sutures and syndesmoses
What is a suture?
A fibrous joint composed of a thin layer of dense irregular connective tissue
Where do sutures occur?
Only between bones of the skull
What is an example of a suture?
The coronal suture between the parietal and frontal bones
What do the irregular, interlocking edges of sutures provide?
Added strength and a decreased chance of fracturing
When do sutures form?
As the numerous bones of the skull come in contact during development
How movable are sutures in older individuals?
They are immovable
How movable are sutures in infants and children?
They are slightly movable
What roles do sutures play?
They act as sites of growth and help in shock absorption in the skull
What happens to some sutures in adulthood?
They are replaced by bone
What is a synostosis?
A bony joint where there is a complete fusion of two separate bones into one
What is an example of a synostosis?
The frontal bone, which grows in halves that join together across a suture line
By what age is the frontal bone usually completely fused?
By age 6
What is a frontal (metopic) suture?
A suture that persists beyond age 6
How movable is a frontal (metopic) suture?
It is immovable
What is a syndesmosis?
A fibrous joint in which there is generally a greater distance between the articulating surfaces and more dense irregular connective tissue than in a suture
How many types of syndesmoses are there?
Three
How is the fibrous connective tissue arranged in the first two types of syndesmoses?
As either an interosseous ligament or an interosseous membrane
How much movement do interosseous ligaments and interosseous membranes permit?
Limited movement
What is an example of an interosseous ligament?
The anterior tibiofibular ligament
What does the anterior tibiofibular ligament connect?
The distal tibia and fibula at the distal tibiofibular joint
What is an interosseous membrane?
A substantial sheet of dense irregular connective tissue that binds neighboring long bones and permits slight movement
Where do interosseous membranes occur?
Between the radius and ulna in the forearm and between the tibia and fibula in the leg
What roles do interosseous membranes play?
They help hold adjacent long bones together, define the range of motion between neighboring bones, and provide an increased attachment surface for muscles that produce movements of the ankle, wrist, and digits of the hand and foot
What is the third type of syndesmosis?
A gomphosis or dentoalveolar joint
What is a gomphosis?
A joint in which a cone-shaped peg fits into a cavity with a small amount of dense irregular connective tissue
What are the only examples of gomphoses in the human body?
The articulations between the roots of the teeth and their dental alveoli in the alveolar process in the maxillae and mandible
What is the dense irregular connective tissue between a tooth and its dental alveolus?
The thin periodontal ligament
What does a healthy gomphosis permit?
Minute shock-absorbing movements
What is inflammation and degeneration of the gums, periodontal ligament, and bone called?
Periodontal disease
At a ___ the bones are held together by dense irregular connective tissue.
fibrous joint
How much movement does a cartilaginous joint allow?
Little or no movement
How are the articulating bones in a cartilaginous joint connected?
By either a solid piece of hyaline cartilage or fibrous cartilage
What are the two types of cartilaginous joints?
Synchondroses and symphyses
What is a synchondrosis?
A cartilaginous joint in which the connecting material is a solid piece of cartilage that allows little or no movement
How are the articulating bones in a synchondrosis connected?
By hyaline cartilage or fibrous cartilage
What is an example of a synchondrosis?
The joint between the first rib and the manubrium of the sternum
What is another type of synchondrosis?
Epiphyseal cartilage
What are epiphyseal cartilages?
Hyaline cartilage growth centers during endochondral bone formation, not joints associated with movements
What is an example of epiphyseal cartilage?
The epiphyseal (growth) plate that connects the epiphysis and diaphysis of a growing long bone
What does the presence of an epiphyseal plate in a radiograph indicate?
That a person still has the potential for some degree of growth to occur
What can damage to the cartilage of a synchondrosis in the epiphyseal plate cause?
It can affect further growth of the bone, leading to abbreviated development and a bone of shortened length
What type of joint is epiphyseal cartilage?
An immovable joint
What happens when bone elongation ceases?
Bone replaces the hyaline cartilage and becomes a synostosis, a bony joint
What is a symphysis?
A cartilaginous joint in which the ends of the articulating bones are covered with hyaline cartilage, but a broad, flat disc of fibrous cartilage connects the bones
Where do all symphyses occur?
In the midline of the body
What is an example of a symphysis?
The pubic symphysis between the anterior surfaces of the hip bones
Where else is a symphysis found?
At the junction of the manubrium and body of the sternum and at the intervertebral joints between the bodies of vertebrae
What is a portion of the intervertebral disc composed of?
Fibrous cartilage
What type of joint is a symphysis?
A slightly movable joint
At a ____ the bones are held together by cartilage.
cartilaginous joint
What is the unique characteristic of a synovial joint?
The presence of a space between the articulating bones called an articular cavity
What surrounds the articular cavity in a synovial joint?
An articular capsule that attaches the articulating bones and contains a lubricating fluid
What does the presence of an articular cavity permit?
A wide range of movements from slightly movable to freely movable
What is an example of synovial joints with very limited movements?
The synovial joints between some carpal bones
Which synovial joint can move freely in all directions?
The shoulder joint
What is the articular cartilage?
A layer of hyaline cartilage that covers the surfaces of the bones within a synovial joint
What does the articular cartilage reduce?
Friction between bones in the joint during movement
What does the articular cartilage help absorb?
Shock
What is an alternative to partial or total knee replacement for minor damage to articular cartilage in the knee joint?
Autologous chondrocyte implantation (ACI)
What type of damage is ACI used for?
Cartilage damage due to acute or repetitive trauma, not arthritis
Where are healthy chondrocytes taken from in the procedure?
An area of the femoral condyle that is not weight-bearing
How long are chondrocytes cultured in the laboratory?
6 to 8 weeks
How many cells are generated during the culture process?
Between 5 million and 10 million cells
What is done to the damaged area before implantation?
Dead cartilage is removed from the defect, which is covered by a piece of periosteum
Where are the cultured chondrocytes injected after preparation?
Under the periosteum
How long does it take for the patient to put full weight on the knee after ACI?
About 10 to 12 weeks
What surrounds a synovial joint, encloses the articular cavity, and unites the articulating bones?
A sleevelike articular capsule or joint capsule
What is the articular capsule composed of?
Two layers: an outer fibrous layer and an inner synovial membrane
What does the fibrous layer of the articular capsule usually consist of?
Dense irregular connective tissue that attaches to the periosteum of the articulating bones
What is the fibrous layer literally a thickened continuation of?
The periosteum between the bones
What does the flexibility of the fibrous layer permit?
Considerable movement at a joint
What does the fibrous layer’s great tensile strength help prevent?
The bones from dislocating (the displacement of a bone from its joint)
What are the fibers of some fibrous membranes arranged as?
Parallel bundles of fibrous connective tissue that are highly adapted for resisting strains
What are these parallel bundles of fibers called?
Ligaments
What is the principal mechanical factor that holds bones close together in a synovial joint?
The strength of ligaments
What is the inner layer of the articular capsule called?
The synovial membrane
What is the synovial membrane composed of?
Areolar connective tissue with collagen and elastic fibers
What does the synovial membrane often include at many synovial joints?
Accumulations of adipose tissue, called articular fat pads
What is an example of an articular fat pad?
The infrapatellar fat pad in the knee
What does a “double-jointed” person have greater flexibility in?
Their articular capsules and ligaments
What does the greater flexibility in a double-jointed person allow them to do?
Increase range of motion, allowing activities such as touching their thumbs to their wrists and putting their ankles or elbows behind their necks
What is the downside of having flexible joints?
They are less structurally stable and more easily dislocated
The distinguishing feature of a synovial joint is the
articular cavity between the articulating bones
What does the synovial membrane secrete?
Synovial fluid
What is synovial fluid described as?
A viscous (gel-like), clear or pale yellow fluid
What is synovial fluid named for?
Its similarity in appearance and consistency to uncooked egg white
What does synovial fluid consist of?
Hyaluronic acid secreted by synovial cells (synoviocytes) in the synovial membrane and interstitial fluid filtered from blood plasma
Where does synovial fluid form a thin film?
Over the surfaces within the articular capsule
What are the functions of synovial fluid?
Reducing friction by lubricating the joint, absorbing shocks, and supplying oxygen and nutrients to and removing carbon dioxide and metabolic wastes from the chondrocytes within articular cartilage
Why does cartilage not have blood vessels?
Because cartilage is an avascular tissue
What does synovial fluid also contain that helps with joint maintenance?
Phagocytic cells that remove microbes and debris from normal wear and tear in the joint
What happens to the viscosity of synovial fluid when a synovial joint is immobile?
The fluid becomes quite viscous
What happens to the viscosity of synovial fluid when joint movement increases?
The fluid becomes less viscous
What is one of the benefits of warming up before exercise?
It stimulates the production and secretion of synovial fluid
What happens to the joints when there is more synovial fluid?
There is less strain on the joints during exercise
What are the cracking or popping sounds in certain joints caused by?
The formation of bubbles in the articular cavity as gases come out of solution
What makes the popping sound in joints?
The formation of the bubble
Why can’t you usually immediately pop your knuckles again after cracking them?
It takes time for the gases to re-accumulate
What are accessory ligaments in synovial joints called?
Extracapsular ligaments and intracapsular ligaments
Where do extracapsular ligaments lie?
Outside the articular capsule
What is an example of an extracapsular ligament in the knee joint?
The fibular collateral ligament or thickening of the external region of the articular capsule, such as the tibial collateral ligament
Where do intracapsular ligaments occur?
Within the articular capsule but are excluded from the articular cavity by folds of the synovial membrane
What are examples of intracapsular ligaments in the knee joint?
The anterior and posterior cruciate ligaments
What are articular discs or menisci?
Crescent-shaped pads of fibrous cartilage lying between the articular surfaces of the bones and attached to the fibrous capsule
What are the menisci in the knee joint called?
The lateral and medial menisci
What do the menisci do in the knee joint?
They bind strongly to the inside of the fibrous layer and usually subdivide the synovial cavity into two spaces
What are the functions of the menisci?
(1) Shock absorption; (2) A better fit between articulating bony surfaces; (3) Providing adaptable surfaces for combined movements; (4) Weight distribution over a greater contact surface; (5) Distribution of synovial fluid across the articular surfaces of the joint
What is a labrum?
A ring-like fibrous cartilage lip that extends from the circumference of the joint socket
Where is the labrum prominent?
In the ball-and-socket joints of the shoulder and hip
What does the labrum help with in ball-and-socket joints?
It helps deepen the joint socket and increases the area of contact between the socket and the ball-like surface of the head of the humerus at the shoulder joint or the femur at the hip joint
What nerves supply a joint?
The nerves that supply the joint are the same as those that supply the skeletal muscles that move the joint
Where are nerve endings distributed in synovial joints?
The nerve endings are distributed to the articular capsule and associated ligaments
What do some of the nerve endings in synovial joints convey?
Some nerve endings convey information about pain from the joint to the spinal cord and brain for processing
What do other nerve endings in synovial joints respond to?
Other nerve endings respond to the degree of movement and stretch at a joint
How do the spinal cord and brain respond to movement and stretch at a joint?
The spinal cord and brain send impulses through different nerves to the muscles to adjust body movements
What is the vascularization status of the cartilaginous components of synovial joints?
Many of the cartilaginous components of synovial joints are avascular
How do arteries supply oxygen and nutrients to synovial joints?
Arteries in the vicinity send out numerous branches that penetrate the ligaments and articular capsule to deliver oxygen and nutrients
How are carbon dioxide and wastes removed from synovial joints?
Veins remove carbon dioxide and wastes from the joints
Where do the arterial branches from different arteries merge before penetrating the articular capsule?
The arterial branches from several different arteries typically merge around a joint before penetrating the articular capsule
How do chondrocytes in the articular cartilage receive oxygen and nutrients?
The chondrocytes in the articular cartilage of a synovial joint receive oxygen and nutrients from synovial fluid derived from blood
How are all other joint tissues supplied with oxygen and nutrients?
All other joint tissues are supplied directly by capillaries
How do chondrocytes pass carbon dioxide and wastes from articular cartilage?
Carbon dioxide and wastes pass from chondrocytes of articular cartilage into synovial fluid and then into veins
How do carbon dioxide and wastes from all other joint structures pass?
Carbon dioxide and wastes from all other joint structures pass directly into veins
What do the various movements of the body create between moving parts?
The various movements of the body create friction between moving parts
What are saclike structures called that alleviate friction in some joints?
The saclike structures called bursae alleviate friction in some joints
Where are bursae strategically situated to alleviate friction?
Bursae are strategically situated to alleviate friction in joints such as the shoulder and knee joints
Are bursae strictly part of synovial joints?
Bursae are not strictly part of synovial joints
What do bursae resemble?
Bursae resemble articular capsules
What are the walls of bursae made of?
The walls of bursae consist of an outer fibrous layer of thin, dense irregular connective tissue lined by a synovial membrane
What is bursae filled with?
Bursae are filled with a small amount of fluid that is similar to synovial fluid
Where can bursae be located?
Bursae can be located between the skin and bones, tendons and bones, muscles and bones, or ligaments and bones
What do fluid-filled bursal sacs cushion?
The fluid-filled bursal sacs cushion the movement between body parts against one another
What structures also reduce friction around joints?
Tendon sheaths also reduce friction around joints
What are tendon sheaths also known as?
Tendon sheaths are also known as synovial sheaths
What do tendon sheaths resemble?
Tendon sheaths are tube-like bursae
What do tendon sheaths wrap around?
Tendon sheaths wrap around certain tendons that experience considerable friction
What do tendon sheaths pass through?
Tendon sheaths pass through tunnels formed by connective tissue and bone
What is the inner layer of a tendon sheath called?
The inner layer of a tendon sheath is called the visceral layer
What is the outer layer of a tendon sheath called?
The outer layer of a tendon sheath is called the parietal layer
What is between the layers of a tendon sheath?
Between the layers of a tendon sheath is a cavity that contains a film of synovial fluid
What does a tendon sheath protect?
A tendon sheath protects all sides of a tendon from friction as the tendon slides back and forth
Where are tendon sheaths found?
Tendon sheaths are found where tendons pass through articular cavities, such as the tendon of the biceps brachii muscle at the shoulder joint
Where else are tendon sheaths found?
Tendon sheaths are also found at the wrist and ankle, where many tendons come together in a confined space
Where else are tendon sheaths found in the body?
Tendon sheaths are found in the digits of the hand and toes, where there is a great deal of movement
What is the tearing of menisci in the knee commonly called?
The tearing of menisci in the knee is commonly called torn cartilage
Who does the tearing of menisci often occur among?
The tearing of menisci often occurs among athletes
What will happen to damaged cartilage if it is not treated surgically?
Damaged cartilage will begin to wear and may cause arthritis to develop unless treated surgically
What procedure was used years ago to treat torn cartilage?
The procedure used years ago to treat torn cartilage was called a meniscectomy
What was the problem with the procedure used years ago to treat torn cartilage?
The problem was that over time the articular cartilage was worn away more quickly
What is the current procedure performed for torn cartilage?
The current procedure performed is a partial meniscectomy
What is removed in a partial meniscectomy?
In a partial meniscectomy, only the torn segment of the meniscus is removed
What procedure may assist surgical repair of torn cartilage?
Arthroscopy may assist surgical repair of torn cartilage
What is arthroscopy?
Arthroscopy is a minimally invasive procedure that involves examination of the interior of a joint
What joint is usually examined with an arthroscope?
The knee is usually examined with an arthroscope
What is an arthroscope?
An arthroscope is a lighted, pencil-thin fiber-optic camera used for visualizing the nature and extent of damage
What is arthroscopy also used for?
Arthroscopy is also used to monitor the progression of disease and the effects of therapy
What can the insertion of surgical instruments through other incisions do?
The insertion of surgical instruments through other incisions can remove torn cartilage, repair damaged cruciate ligaments in the knee, obtain tissue samples for analysis, and perform surgery on other joints
What joints can surgery be performed on with arthroscopy?
Surgery can be performed on joints such as the shoulder, elbow, ankle, and wrist
What is an acute or chronic inflammation of a bursa called?
An acute or chronic inflammation of a bursa is called bursitis
What usually causes bursitis?
Irritation from repeated, excessive exertion of a joint usually causes bursitis
What other factors can cause bursitis?
Bursitis can also be caused by trauma, by an acute or chronic infection (including syphilis and tuberculosis), or by rheumatoid arthritis
What are the symptoms of bursitis?
The symptoms of bursitis include pain, swelling, tenderness, and limited movement
What may the treatment for bursitis include?
The treatment for bursitis may include oral anti-inflammatory agents and injections of cortisol-like steroids
Who uses specific terminology to designate the movements that can occur at synovial joints?
Anatomists, physical therapists, and kinesiologists use specific terminology to designate the movements that can occur at synovial joints
What do anatomists, physical therapists, and kinesiologists look for ways to improve?
They look for ways to improve the efficiency and performance of the human body at work, in sports, and in daily activities
What do the precise terms used by these professionals indicate?
The precise terms may indicate the form of motion, the direction of movement, or the relationship of one body part to another during movement
How are movements at synovial joints grouped?
Movements at synovial joints are grouped into four main categories: (1) gliding, (2) angular movements, (3) rotation, and (4) special movements
Where do special movements occur?
Special movements occur only at certain joints
What is gliding?
Gliding is a simple movement in which nearly flat bone surfaces move back-and-forth and from side-to-side with respect to one another
Is there any significant alteration of the angle between the bones during gliding?
No, there is no significant alteration of the angle between the bones
What limits the range of gliding movements?
Gliding movements are limited in range due to the structure of the articular capsule and associated ligaments and bones
Can gliding movements be combined with any other movements?
Yes, these sliding movements can also be combined with rotation
What are examples of articulations where gliding movements occur?
The intercarpal and intertarsal joints are examples of articulations where gliding movements occur
consist of side- to- side and back- and- forth motions.
Gliding movements
What is angular movement?
In angular movements, there is an increase or a decrease in the angle between articulating bones
What are the major angular movements?
The major angular movements are flexion, extension, lateral flexion, abduction, adduction, and circumduction
What are flexion and extension?
Flexion and extension are opposite movements.
What happens during flexion?
In flexion, there is a decrease in the angle between articulating bones.
What happens during extension?
In extension, there is an increase in the angle between articulating bones, often to restore a part of the body to the anatomical position after it has been flexed.
What plane do flexion and extension usually occur along?
Both movements usually occur along the sagittal plane.
What type of movement is flexion at ball-and-socket joints?
At ball-and-socket joints, flexion is an anterior movement.
What type of movement is extension at ball-and-socket joints?
At ball-and-socket joints, extension is a posterior movement.
What are some examples of flexion?
• Bending the head toward the chest at the atlanto- occipital joints between the atlas (the first vertebra) and the occipital bone of the skull, and at the cervical intervertebral joints between the cervical vertebrae
• Bending the trunk forward at the intervertebral joints, as in doing a crunch with your abdominal muscles
• Moving the humerus forward at the shoulder joint, as in swinging the arms forward while walking
• Moving the forearm toward the arm at the elbow joint between the humerus, ulna, and radius, as in bending your elbow
• Moving the palm toward the forearm at the wrist or radiocarpal joint between the radius and carpals, as in the upward movement when doing wrist curls
• Bending the digits of the hand at the interphalangeal joints between phalanges, as in clenching your fingers to make a fist
• Moving the femur forward at the hip joint between the femur and hip bone, as in walking
• Moving the heel toward the buttock at the tibiofemoral joint between the tibia, femur, and patella, as occurs when bending the knee
Where does flexion of the thumb occur?
Flexion of the thumb involves movement of the thumb medially across the palm at the carpometacarpal joint between the trapezium and metacarpal of the thumb.
What is the term for movement of the trunk sideways to the right or left at the waist?
The movement of the trunk sideways to the right or left at the waist is called lateral flexion.
What is hyperextension?
Hyperextension is a clinical condition associated with injury and describes a movement beyond the normal range of motion.
Where may hyperextension occur?
Hyperextension may occur at joints such as the elbow, interphalangeal joints, and knee joint.
In ____, there is an increase or decrease in the angle between articulating bones.
angular movements
usually occur along the coronal plane.
Abduction and adduction
What is abduction?
Abduction is the movement of a bone away from the midline.
What is adduction?
Adduction is the movement of a bone toward the midline.
What plane do abduction and adduction usually occur along?
Both movements usually occur along the coronal plane.
What are examples of abduction?
Examples of abduction include moving the humerus laterally at the shoulder joint, moving the palm laterally at the wrist joint, and moving the femur laterally at the hip joint.
What is the movement that returns body parts to the anatomical position after abduction?
The movement that returns each of these body parts to the anatomical position is adduction.
What is radial deviation?
Radial deviation is the movement of the palm laterally at the wrist joint.
What is ulnar deviation?
Ulnar deviation is the movement of the palm medially at the wrist joint.
What is used as a point of reference for abduction and adduction of the digits?
The midline of the body is not used as a point of reference for abduction and adduction of the digits.
What happens in abduction of the fingers?
In abduction of the fingers (but not the thumb), an imaginary line is drawn through the longitudinal axis of the middle (longest) finger, and the fingers move away (spread out) from the middle finger.
How does abduction of the thumb occur?
In abduction of the thumb, the thumb moves away from the palm in the sagittal plane.
What is the point of reference for abduction of the toes?
Abduction of the toes is relative to an imaginary line drawn through the second toe.
What happens in adduction of the fingers and toes?
Adduction of the fingers and toes returns them to the anatomical position.
How does adduction of the thumb occur?
Adduction of the thumb moves the thumb toward the palm in the sagittal plane.
What is circumduction?
Circumduction is movement of the distal end of a body part in a circle.
Is circumduction an isolated movement?
Circumduction is not an isolated movement by itself but rather a continuous sequence of flexion, abduction, extension, adduction, and rotation of the joint (or in the opposite order).
Does circumduction occur along a separate axis or plane of movement?
Circumduction does not occur along a separate axis or plane of movement.
What are examples of circumduction?
Examples of circumduction include moving the humerus in a circle at the shoulder joint, moving the hand in a circle at the wrist joint, moving the thumb in a circle at the carpometacarpal joint, moving the fingers in a circle at the metacarpophalangeal joints, and moving the femur in a circle at the hip joint.
Which joints permit circumduction?
Both the shoulder and hip joints permit circumduction.
Why are flexion, abduction, extension, and adduction more limited in the hip joints than in the shoulder joints?
Flexion, abduction, extension, and adduction are more limited in the hip joints than in the shoulder joints due to the tension on certain ligaments and muscles and the depth of the acetabulum in the hip joint.
is the movement of the distal end of a body part in a circle
Circumduction
What is rotation?
Rotation is when a bone revolves around its own longitudinal axis.
What is an example of rotation?
One example of rotation is turning the head from side to side at the atlanto-axial joint (between the atlas and axis), as when you shake your head “no.”
What is another example of rotation?
Another example of rotation is turning the trunk from side to side at the intervertebral joints while keeping the hips and lower limbs in the anatomical position.
How is rotation defined in the limbs?
In the limbs, rotation is defined relative to the midline, and specific qualifying terms are used.
What is medial rotation?
If the anterior surface of a bone of the limb is turned toward the midline, the movement is called medial (internal) rotation.
How can the humerus be medially rotated at the shoulder joint?
You can medially rotate the humerus at the shoulder joint by starting in the anatomical position, flexing your elbow, and then moving your palm across the chest.
How can the femur be medially rotated at the hip joint?
You can medially rotate the femur at the hip joint by lying on your back, bending your knee, and then moving your leg and foot laterally from the midline.
How can medial rotation of the leg at the knee joint be produced?
Medial rotation of the leg at the knee joint can be produced by sitting on a chair, bending your knee, raising your lower limb off the floor, and turning your toes medially.
What is lateral (external) rotation?
If the anterior surface of the bone of a limb is turned away from the midline, the movement is called lateral (external) rotation.
a bone revolves around its own longitudinal axis.
rotation
occur only at certain synovial joints.
Special movements
What are special movements?
Special movements occur only at certain joints.
What are the examples of special movements?
The examples of special movements include elevation, depression, protraction, retraction, inversion, eversion, dorsiflexion, plantar flexion, supination, pronation, and opposition.
What is elevation?
Elevation is a superior movement of a part of the body, such as closing the mouth at the temporomandibular joint to elevate the mandible or shrugging the shoulders at the acromioclavicular joint to elevate the scapula and clavicle.
What is the opposing movement of elevation?
The opposing movement of elevation is depression.
What is depression?
Depression is an inferior movement of a part of the body, such as opening the mouth to depress the mandible or returning shrugged shoulders to the anatomical position to depress the scapula and clavicle.
What is protraction?
Protraction is a movement of a part of the body anteriorly in the transverse plane.
What is the opposing movement of protraction?
The opposing movement of protraction is retraction.
What is retraction?
Retraction is a movement of a protracted part of the body back to the anatomical position.
What is inversion?
Inversion is movement of the sole medially at the intertarsal joints.
What is the opposing movement of inversion?
The opposing movement of inversion is eversion.
What is eversion?
Eversion is a movement of the sole laterally at the intertarsal joints.
What is dorsiflexion?
Dorsiflexion refers to bending of the foot at the ankle or talocrural joint in the direction of the dorsum (superior surface).
What is the opposing movement of dorsiflexion?
The opposing movement of dorsiflexion is plantar flexion.
What is plantar flexion?
Plantar flexion involves bending of the foot at the ankle joint in the direction of the plantar or inferior surface.
What is supination?
Supination is a movement of the forearm at the proximal and distal radioulnar joints in which the radius and ulna are parallel to one another and the palm is turned anteriorly.
What is the opposing movement of supination?
The opposing movement of supination is pronation.
What is pronation?
Pronation is a movement of the forearm at the proximal and distal radioulnar joints in which the distal end of the radius crosses over the distal end of the ulna and the palm is turned posteriorly.
What is opposition?
Opposition is the movement of the thumb at the carpometacarpal joint in which the thumb moves across the palm to touch the tips of the fingers on the same hand.
Movement of relatively flat bone surfaces back- and- forth and side- to- side over one another; little change in angle between bones.
Gliding
Increase or decrease in angle between bones
Angular
Decrease in angle between articulating bones, usually in sagittal plane or an anterior movement at a ball- and- socket joint.
Flexion
Movement of trunk in frontal plane.
Lateral flexion
Increase in angle between articulating bones, usually in sagittal plane or a posterior movement at a ball- and- socket joint.
Extension
Movement of bone away from midline, usually in coronal plane.
Abduction
Movement of bone toward midline, usually in coronal plane.
Adduction
Flexion, abduction, extension, adduction, and rotation in succession (or in the opposite order); distal end of body part moves in circle.
Circumduction
Movement of bone around longitudinal axis; in limbs, may be medial (toward midline) or lateral (away from midline).
rotation
Occurs at specific joints.
Special
Superior movement of body part.
Elevation
Inferior movement of body part.
Depression
Anterior movement of body part in transverse plane.
Protraction
Posterior movement of body part in transverse plane.
Retraction
Medial movement of sole.
Inversion
Lateral movement of sole.
Eversion
Bending foot in direction of dorsum (superior surface).
Dorsiflexion
Bending foot in direction of plantar surface (sole).
Plantar flexion
Movement of forearm that turns palm anteriorly.
Supination
Movement of forearm that turns palm posteriorly.
Pronation
Movement of thumb across palm to touch fingertips on same hand.
Opposition
Synovial joints are divided into six categories based on type of movement:
plane, hinge, pivot, ellipsoid, saddle, and ball- and- socket.
What are the articulating surfaces of bones in a plane joint like?
The articulating surfaces of bones in a plane joint are flat or slightly curved.
What movements do plane joints primarily permit?
Plane joints primarily permit back-and-forth and side-to-side movements between the flat surfaces of bones, but they may also rotate against one another.
What type of movements can plane joints permit in terms of axes?
Many plane joints are biaxial, meaning that they permit movement in two axes.
What is an axis in terms of plane joints?
An axis is a straight line around which a bone rotates (revolves) or slides.
If plane joints rotate in addition to sliding, what type of movement do they permit?
If plane joints rotate in addition to sliding, then they are triaxial (multiaxial), permitting movement in three axes.
What are some examples of plane joints?
Some examples of plane joints are the intercarpal joints, intertarsal joints, acromioclavicular joints, sternocostal joints, and vertebrocostal joints.
Where are the intercarpal joints located?
The intercarpal joints are between carpal bones at the wrist.
Where are the intertarsal joints located?
The intertarsal joints are between tarsal bones at the ankle.
Where are the acromioclavicular joints located?
The acromioclavicular joints are between the acromion of the scapula and the clavicle.
Where are the sternocostal joints located?
The sternocostal joints are between the sternum and ends of the costal cartilages at the tips of the second through seventh pairs of ribs.
Where are the vertebrocostal joints located?
The vertebrocostal joints are between the heads and tubercles of ribs and bodies and transverse processes of thoracic vertebrae.
What is the shape of the convex surface of one bone in a hinge joint?
The convex surface of one bone fits into the concave surface of another bone.
What type of motion do hinge joints produce?
Hinge joints produce an angular, opening-and-closing motion like that of a hinged door.
In most joint movements, what remains in a fixed position while the other moves around an axis?
In most joint movements, one bone remains in a fixed position while the other moves around an axis.
How are hinge joints classified in terms of axes?
Hinge joints are uniaxial (monaxial) because they typically allow motion around a single axis.
What movements do hinge joints permit?
Hinge joints permit only flexion and extension.
What are examples of hinge joints?
Examples of hinge joints are the elbow, ankle, and interphalangeal joints.
What is another name for a pivot joint?
Another name for a pivot joint is a trochoid joint.
What kind of surface articulates in a pivot joint?
The rounded or pointed surface of one bone articulates with a ring formed partly by another bone and partly by a ligament.
How many axes does a pivot joint allow rotation around?
A pivot joint is uniaxial because it allows rotation only around its own longitudinal axis.
What is an example of a pivot joint?
An example of a pivot joint is the atlanto-axial joint.
What movement does the atlanto-axial joint permit?
The atlanto-axial joint permits the head to turn from side-to-side as when you shake your head “no.”
What is another example of a pivot joint?
Another example of a pivot joint is the radioulnar joints.
What movement do the radioulnar joints enable?
The radioulnar joints enable the palms to turn anteriorly and posteriorly as the head of the radius pivots around its long axis in the radial notch of the ulna.
What is another name for an ellipsoid joint?
Another name for an ellipsoid joint is a condylar joint.
What does the convex oval-shaped projection of one bone fit into in an ellipsoid joint?
The convex oval-shaped projection of one bone fits into the oval-shaped depression of another bone.
How many axes does an ellipsoid joint allow movement around?
An ellipsoid joint is biaxial because the movement it permits is around two axes (flexion–extension and abduction–adduction), plus limited circumduction.
What movements does an ellipsoid joint permit?
An ellipsoid joint permits flexion–extension, abduction–adduction, and limited circumduction.
What is an example of an ellipsoid joint?
An example of an ellipsoid joint is the radiocarpal joint (wrist).
What is another example of an ellipsoid joint?
Another example of an ellipsoid joint is the metacarpophalangeal joints (between the metacarpals and proximal phalanges) of the second through fifth digits.
What is another name for a saddle joint?
Another name for a saddle joint is a sellar joint.
What shape is the articular surface of one bone in a saddle joint?
The articular surface of one bone in a saddle joint is saddle-shaped.
How does the articular surface of the other bone fit into the saddle in a saddle joint?
The articular surface of the other bone fits into the “saddle” as a sitting rider would sit.
What are the movements at a saddle joint?
The movements at a saddle joint are the same as those at a condyloid joint: biaxial (flexion–extension and abduction–adduction) plus limited circumduction.
What is an example of a saddle joint?
An example of a saddle joint is the carpometacarpal joint between the trapezium of the carpus and the metacarpal of the thumb.
What is another example of a saddle joint?
Another example of a saddle joint is the sternoclavicular joint (between the manubrium of the sternum and the clavicle).
are classified into six principal types based on the shapes of the articulating bone surfaces
Synovial joints
What is another name for a ball-and-socket joint?
Another name for a ball-and-socket joint is a spheroidal joint.
What does a ball-and-socket joint consist of?
A ball-and-socket joint consists of the ball-like surface of one bone fitting into a cuplike depression of another bone.
How many axes do ball-and-socket joints have?
Ball-and-socket joints are triaxial (multiaxial).
What movements do ball-and-socket joints permit?
Ball-and-socket joints permit movements around three axes: flexion–extension, abduction–adduction, and rotation.
What is an example of a ball-and-socket joint?
An example of a ball-and-socket joint is the glenohumeral joint.
What is another example of a ball-and-socket joint?
Another example of a ball-and-socket joint is the hip joint.
Where does the head of the humerus fit in the glenohumeral joint?
In the glenohumeral (shoulder) joint, the head of the humerus fits into the glenoid cavity of the scapula.
Where does the head of the femur fit in the hip joint?
In the hip joint, the head of the femur fits into the acetabulum of the hip bone.
No articular Cavity; articulating Bones held together by Dense Irregular Connective tissue.
Fibrous
No articular Cavity; articulating Bones United by hyaline Cartilage or Fibrous Cartilage.
Cartilaginous
Characterized by Synovial Cavity, articular Cartilage, and articular (Joint) Capsule; May Contain accessory Ligaments, articular Discs, and Bursae.
Synovial
Articulating bones united by thin layer of dense irregular connective tissue, found between skull bones; with age, some sutures replaced by synostosis (separate cranial cavity bones fuse into single bone).
Suture
Degree of movement of suture
Immovable and slightly movable.
Example of suture
Coronal suture
Articulating bones united by a varying amount of dense irregular connective tissue, usually a ligament or membrane.
Syndesmosis
Degree of movement of syndesmosis
Slightly movable.
Example of syndesmosis
Distal tibiofibular joint and interosseous membrane between tibia and fibula (anterior tibiofibular ligament).
Connecting material: hyaline cartilage.
Synchondrosis
Degree of movement of Synchondrosis
Slightly movable to immovable.
Example of synchondrosis
Between first rib and manubrium of sternum. Epiphyseal cartilage between diaphysis and epiphysis of long bone
Connecting material: broad, flat disc of fibrous cartilage.
Symphysis
Degree of movement of Symphysis
Slightly movable to immovable.
Example of symphysis
Pubic symphysis and intervertebral joints.
Articulated surfaces flat or slightly curved.
Plane
Degree of movement of plane
Many are biaxial: back- and- forth and side- to- side movements. Some are triaxial: back- and- forth, side- to- side, rotation.
Example of plane
Intercarpal, intertarsal, sternocostal (between sternum and second to seventh pairs of ribs), and vertebrocostal joints.
Convex surface fits into concave surface.
Hinge
Degree of movement of hinge
Uniaxial: flexion– extension.
Example of hinge
Elbow, ankle, and interphalangeal joints.
Rounded or pointed surface fits into ring formed partly by bone and partly by ligament.
Pivot
Degree of movement of pivot
Uniaxial: rotation
Example of pivot
Atlanto- axial and radioulnar joints.
Oval- shaped projection fits into oval- shaped depression.
ellipsoid
Degree of movement of ellipsoid
Biaxial: flexion– extension, abduction– adduction
Example of ellipsoid
Radiocarpal and metacarpophalangeal joints.
Articular surface of one bone is saddle- shaped; articular surface of other bone “sits” in saddle.
Saddle
Degree of movement of saddle
Biaxial: flexion– extension, abduction– adduction.
Example of saddle
Carpometacarpal joint between trapezium and metacarpal of thumb.
Ball- like surface fits into cuplike depression.
Ball- and- socket
Degree of movement of Ball- and- socket
Triaxial: flexion– extension, abduction– adduction, rotation.
Example of Ball- and- socket
Glenohumeral and hip joints.
What do the articular surfaces of synovial joints do?
The articular surfaces of synovial joints contact one another and determine the type and possible range of motion.
What does range of motion (rOM) refer to?
Range of motion (rOM) refers to the amount of movement, measured in degrees of a circle, through which the bones of a joint can move.
What factors contribute to keeping the articular surfaces in contact and affect range of motion?
The following factors contribute to keeping the articular surfaces in contact and affect range of motion:
What is the first factor that contributes to keeping the articular surfaces in contact?
- Structure or shape of the articulating bones.
How does the structure or shape of the articulating bones affect movement?
The structure or shape of the articulating bones determines how closely they can fit together.
What relationship is very obvious at the hip joint?
The articular surfaces of some bones have a complementary relationship. This spatial relationship is very obvious at the hip joint, where the head of the femur articulates with the acetabulum of the hip bone.
What does an interlocking fit allow in the hip joint?
An interlocking fit allows rotational movement.
What is the second factor that contributes to keeping the articular surfaces in contact?
- Strength and tension (tautness) of the joint ligaments.
How do the different components of an articular capsule affect joint movement?
The different components of an articular capsule are tense or taut only when the joint is in certain positions. Tense ligaments not only restrict the range of motion but also direct the movement of the articulating bones with respect to each other.
How does the anterior cruciate ligament affect the knee joint when straightened?
In the knee joint, for example, the anterior cruciate ligament is taut and the posterior cruciate ligament is loose when the knee is straightened.
What happens to the ligaments when the knee is bent?
The reverse occurs when the knee is bent.
How do certain ligaments affect the hip joint when standing?
In the hip joint, certain ligaments become taut when standing and more firmly attach the head of the femur to the acetabulum of the hip bone.
What is the third factor that contributes to keeping the articular surfaces in contact?
- Arrangement and tension of the muscles.
How does muscle tension affect joint movement?
Muscle tension reinforces the restraint placed on a joint by its ligaments, and thus restricts movement.
What is an example of the effect of muscle tension on a joint?
A good example of the effect of muscle tension on a joint is seen at the hip joint.
How is the flexion of the hip restricted when the knee is extended?
When the hip is flexed with the knee extended, the flexion of the hip is restricted by the tension of the hamstring muscles on the posterior surface of the thigh.
Why can most people not raise a straightened leg more than 90 degrees from the floor?
Most of us can’t raise a straightened leg more than a 90-degree angle from the floor.
How does flexing the knee affect the tension on the hamstring muscles?
But if the knee is also flexed, the tension on the hamstring muscles is lessened.
What happens when the tension on the hamstring muscles is lessened?
The thigh can be raised farther, allowing you to raise your thigh to touch your chest.
What is the fourth factor that contributes to keeping the articular surfaces in contact?
- Contact of soft parts.
How does contact of soft parts limit mobility?
The point at which one body surface contacts another may limit mobility. For example, if you bend your arm at the elbow, it can move no farther after the anterior surface of the forearm meets with and presses against the biceps brachii muscle of the arm.
What other factor may restrict joint movement?
Joint movement may also be restricted by the presence of adipose tissue.
What is the fifth factor that contributes to keeping the articular surfaces in contact?
- Hormones.
How do hormones affect joint flexibility?
Joint flexibility may also be affected by hormones.
What is an example of a hormone that increases flexibility during pregnancy?
For example, relaxin, a hormone produced by the placenta and ovaries, increases the flexibility of the fibrous cartilage of the pubic symphysis and loosens the ligaments between the sacrum, hip bone, and coccyx toward the end of pregnancy.
How do these hormonal changes affect the pelvic outlet?
These changes permit expansion of the pelvic outlet, which assists in delivery of the baby.
What is the sixth factor that contributes to keeping the articular surfaces in contact?
- Disuse.
How does disuse affect movement at a joint?
Movement at a joint may be restricted if a joint has not been used for an extended period.
What is an example of restricted movement after a joint is immobilized?
For example, if an elbow joint is immobilized by a cast, range of motion at the joint may be limited for a time after the cast is removed.
How does disuse affect synovial fluid and ligaments?
Disuse may also result in decreased amounts of synovial fluid, diminished flexibility of ligaments and tendons, and muscular atrophy, a reduction in size or wasting of a muscle.
Between skull bones.
Skull
Classification of skull
Fibrous.
Movement of skull
none
Between superior articular facets of atlas and occipital condyles of occipital bone.
atlanto- occipital
Classification of atlanto- occipital
Synovial (ellipsoid).
Movement of atlanto-occipital
Flexion and extension of head; slight lateral flexion of head to either side.
(1) Between dens of axis and anterior arch of atlas; (2) between lateral masses of atlas and axis.
atlanto- axial
Classification of atlanto- axial
Synovial (pivot) between dens and anterior arch; synovial (planar) between lateral masses.
Movement of atlanto- axial
Rotation of head.
1) Between vertebral bodies; (2) between vertebral arches.
Intervertebral
Classification of Intervertebral
Cartilaginous (symphysis) between vertebral bodies; synovial (planar) between vertebral arches.
Movement of Intervertebral
Flexion, extension, lateral flexion, and rotation of vertebral column.
(1) Between articular facets of heads of ribs and costal facets of bodies of adjacent thoracic vertebrae and intervertebral discs between them; (2) between articular facet of tubercles of ribs and transverse costal facet of thoracic vertebrae.
Vertebrocostal
Classification of Vertebrocostal
Synovial(planar).
Movement of Vertebrocostal
Slight gliding
Between sternum and first seven pairs of ribs.
Sternocostal
Classification of Sternocostal
Cartilaginous(synchondrosis) between sternum and first pair of ribs; synovial (plane) between sternum and second through seventh pairs of ribs.
Movement of Sternocostal
None between sternum and first pair of ribs; slight gliding between sternum and second through seventh pairs of ribs.
(1) Between body of fifth lumbar vertebra and base of sacrum; (2) between inferior articular facets of fifth lumbar vertebra and superior articular facets of first vertebra of sacrum.
Lumbosacral
Classification of Lumbosacral
Cartilaginous (symphysis) between body and base; synovial (planar) between articular facets.
Movement of Lumbosacral
Flexion, extension, lateral flexion, and rotation of vertebral column
Between sternal end of clavicle, manubrium of sternum, and first costal cartilage.
Sternoclavicular
Classification of Sternoclavicular
Synovial (plane, pivot).
Movement of Sternoclavicular
Gliding, with limited movements in nearly every direction.
Between acromion of scapula and acromial end of clavicle.
acromioclavicular
Classification of acromioclavicular
Synovial (plane)
Movement of acromioclavicular
Gliding and rotation of scapula on clavicle.
