1. Joints & Joint Movements
Human Anatomy
Sonya Schuh-Huerta, Ph.D.

2. Joints Rigid elements of the skeleton meet at joints or articulations
Greek root “arthro” means joint
Structure of joints
Enables resistance to
crushing, tearing, &
other forces

3. Classifications of Joints
Joints can be classified by function or structure
Functional classification  based on amount of movement
Synarthroses  immovable; common in axial skeleton
Amphiarthroses  slightly movable; common in axial skeleton
Diarthroses  freely movable; common in appendicular skeleton (all synovial joints)

4. Classifications of Joints
Structural classification based on
Material that binds bones together
Presence or absence of a joint cavity
Structural classifications include:
Fibrous
Cartilaginous
Synovial

5. Classifications of Joints

6. Sutures – A Type of Fibrous Joint
Bones are tightly bound by a minimal amount of fibrous tissue
Only occur between the bones of the skull
Allow bone growth so the skull can expand with brain during childhood
Fibrous tissue ossifies in middle age
Synostoses = closed sutures

7. Syndesmoses – A Type of Fibrous Joint
Bones are connected exclusively by ligaments
Amount of movement depends on length of fibers
Tibiofibular joint = immovable synarthrosis
Interosseous membrane between radius & ulna = freely movable diarthrosis

8. Gomphoses – A Type of Fibrous Joint
Tooth in a socket
Connecting ligament  the periodontal ligament

9. Fibrous Joints (a) Suture (b) Syndesmosis (c) Gomphosis
Joint held together with very
short, interconnecting fibers,
and bone edges interlock.
Found only in the skull.
Joint held together by a
ligament. Fibrous tissue can
vary in length but is longer
than in sutures.
Peg-in-socket fibrous joint.
Periodontal ligament holds
tooth in socket.
Socket of
alveolar
process
Suture
line
Fibula
Tibia
Root of
tooth
Dense
fibrous
connective
tissue
Ligament
Periodontal
ligament

10. Cartilaginous Joints Bones are united by cartilage Lack a joint cavity
2 types
Synchondroses
Symphyses

11. Synchondroses Hyaline cartilage unites bones Epiphyseal plates
Joint between first rib & manubrium
(a) Synchondroses
Bones united by hyaline cartilage
Sternum
(manubrium)
Epiphyseal
plate (temporary
hyaline cartilage
joint)
Joint between
first rib and
sternum
(immovable)

12. Symphyses Fibrocartilage unites bones; resists tension & compression
Slightly movable joints that provide strength with flexibility
Intervertebral discs
Pubic symphysis
Hyaline cartilage  present as articular cartilage

13. Symphyses (b) Symphyses Bones united by fibrocartilage
Body of vertebra
Fibrocartilaginous
intervertebral
disc
Hyaline cartilage
Pubic symphysis

14. Synovial Joints Most movable type of joint!!!
All are diarthroses  what does that mean?
Each contains a fluid-filled joint cavity

15. General Structure of Synovial Joints
Articular cartilage
Ends of opposing bones are covered with hyaline cartilage
Absorbs compression
Joint cavity (= synovial cavity)
Unique to synovial joints
Cavity is a potential space that holds a small amount of synovial fluid

16. General Structure of Synovial Joints
Articular capsule  joint cavity is enclosed in a 2-layered capsule
Fibrous capsule  dense irregular connective tissue, which strengthens joint
Synovial membrane  loose connective tissue
Lines joint capsule & covers internal joint surfaces
Makes synovial fluid

17. General Structure of Synovial Joints
Synovial fluid
A viscous fluid similar to raw egg white
A filtrate of blood
Arises from capillaries in synovial membrane
Contains glycoprotein molecules secreted by fibroblasts

18. General Structure of Synovial Joints
Reinforcing ligaments
Often are thickened parts of the fibrous capsule
Sometimes are extracapsular ligaments  located outside the capsule
Sometimes are intracapsular ligaments  located internal to the capsule

19. General Structure of Synovial Joints
Ligament
Joint cavity (contains synovial fluid)
Articular (hyaline)
cartilage
Fibrous
capsule
Articular
capsule
Synovial
membrane
Periosteum
(a) A typical synovial joint

20. General Structure of Synovial Joints
Richly supplied with sensory nerves
Detect pain
Most monitor how much the capsule is being stretched

21. General Structure of Synovial Joints
Have a rich blood supply
Most supply the synovial membrane
Extensive capillary beds produce basis of synovial fluid
Branches of several major nerves & blood vessels

22. Synovial Joints with Articular Discs
Some synovial joints contain an articular disc
Temporomandibular joint & Knee joint
Occur in joints whose articulating bones have somewhat different shapes

23. How Synovial Joints Function
Synovial joints  lubricating devices
Friction could overheat & destroy joint tissue & bone ends
Are subjected to compressive forces
Fluid is squeezed out as opposing cartilages touch
Cartilages ride on the slippery film

24. Bursae & Tendon Sheaths
Bursae & tendon sheaths are not synovial joints
Closed bags of lubricant
Reduce friction between body elements
Bursa = a flattened fibrous sac lined by a synovial membrane
Tendon sheath = an elongated bursa that wraps around a tendon

25. Bursae & Tendon Sheaths
Coracoacromial
ligament
Acromion
of scapula
Subacromial
bursa
Coracoacromial
ligament
Subacromial
bursa
Joint cavity
containing
synovial fluid
Fibrous
articular
capsule
Cavity in
bursa containing
synovial fluid
Humerus resting
Hyaline
cartilage
Bursa rolls
and lessens
friction.
Tendon
sheath
Synovial
membrane
Tendon of
long head
of biceps
brachii
muscle
Fibrous
capsule
Humerus
Humerus head
rolls medially as
arm abducts.
Humerus moving
(a) Frontal section through the right
shoulder joint
(b) Enlargement of (a), showing how a bursa
eliminates friction where a ligament (or other
structure) would rub against a bone

26. Movements Allowed by Synovial Joints
3 basic types of movement
Gliding  one bone across the surface of another
Angular movement  movements change the angle between bones
Rotation  movement around a bone's long axis

27. Gliding Joints Flat surfaces of two bones slip across each other
Gliding occurs between:
Carpals
Articular processes of vertebrae
Tarsals
Gliding
(a) Gliding movements at the wrist

28. Angular Movements Increase or decrease angle between bones
Movements involve:
Flexion & extension
Abduction & adduction
Circumduction

29. Angular Movements Extension Flexion
(b) Angular movements: flexion & extension of the neck

30. Angular Movements Extension Flexion
(c) Angular movements: flexion & extension of the trunk

31. Angular Movements Flexion Extension Flexion Extension
(d) Angular movements: flexion & extension at the shoulder and knee

32. Angular Movements Abduction Circumduction Adduction
(e) Angular movements: abduction, adduction, &
circumduction of the upper limb at the shoulder

33. PLAY
Movement of the glenohumoral joint

34. Rotation Involves turning movement of a bone around its long axis
The only movement allowed between atlas & axis vertebrae
Occurs at the neck, shoulder, elbow, hip

35. Rotation Rotation Lateral rotation Medial rotation
(f) Rotation of the head, neck, & lower limb

36. Special Movements Elevation  lifting a body part superiorly
Depression  moving the elevated part inferiorly
Elevation
of mandible
Depression
of mandible
Elevation
Depression

37. Special Movements Protraction  nonangular movement anteriorly
Retraction  nonangular movement posteriorly
Protraction
of mandible
Retraction
of mandible
Protraction
Moving a body part in the
anterior direction
Retraction
Moving a body part in the
posterior direction

38. Special Movements
Supination  forearm rotates laterally, palm faces anteriorly
Pronation  forearm rotates medially, palm faces posteriorly
Brings radius across the ulna

39. Special Movements Pronation (radius rotates over ulna) Supination
(radius and ulna
are parallel)
Pronation (P)
Rotating the forearm so the
palm faces posteriorly
Supination (S)
Rotating the forearm so the
palm faces anteriorly

40. Special Movements
Opposition  thumb moves across the palm to touch the tips of other fingers
Opposition

41. Special Movements Inversion & eversion Special movements at the foot
Inversion  turns sole medially
Eversion  turns sole laterally

42. Special Movements Inversion Eversion Inversion
Turning the sole of the foot
medially
Eversion
Turning the sole of the foot
laterally

43. Special Movements Dorsiflexion & plantar flexion
Up-and-down movements of the foot
Dorsiflexion  lifting the foot so its superior surface approaches the shin
Plantar flexion  depressing the foot, elevating the heel (ballet toe point)

44. Special Movements Dorsiflexion Plantar flexion Dorsiflexion
Lifting the foot so its superior
surface approaches the shin
Plantar flexion
Depressing the foot
elevating the heel

45. PLAY
Eversion of
Ankle joint (5a)

46. Synovial Joints Classified by Shape
Plane joint
Articular surfaces are flat planes
Short gliding movements are allowed
Intertarsal & intercarpal joints
Movements are nonaxial
Gliding does not involve rotation around any axis

47. Plane Joint Nonaxial movement (a) Plane joint Metacarpals Carpals
Gliding
(a) Plane joint

48. Synovial Joints Classified by Shape
Hinge joints
Cylindrical end of one bone fits into a trough on another bone
Angular movement is allowed in one plane
Elbow, ankle, & joints between phalanges
Movement is uniaxial  allows movement around one axis only

49. Hinge Joint Uniaxial movement Humerus Medial/ lateral axis Ulna
Flexion & extension
(b) Hinge joint

50. Synovial Joints Classified by Shape
Pivot joints
Classified as uniaxial – rotating bone only turns around its long axis
Examples
Proximal radioulnar joint
Joint between atlas & axis

51. Pivot Joint
Vertical
axis
Ulna
Radius
Rotation
(c) Pivot joint

52. Synovial Joints Classified by Shape
Condyloid joints
Allow moving bone to travel:
Side to side  abduction-adduction
Back & forth  flexion-extension
Classified as biaxial = movement occurs around 2 axes
Phalanges

53. Condyloid Joint Biaxial movement Phalanges Anterior/ posterior axis
Medial/
lateral
axis
Metacarpals
Flexion &
extension
Adduction &
abduction
(d) Condyloid joint

54. Synovial Joints Classified by Shape
Saddle joints
Each articular surface has concave & convex surfaces
Classified as biaxial joints
1st carpometacarpal joint is a good example
Allows opposition of the thumb

55. Saddle Joint (e) Saddle joint Metacarpal 1 Medial/ lateral axis
Anterior/
posterior
axis
Adduction and
abduction
Flexion and
extension
Trapezium
(e) Saddle joint

56. Synovial Joints Classified by Shape
Ball-and-socket joints
Spherical head of one bone fits into round socket of another
Classified as multiaxial  allow movement in all axes
Shoulder & hip joints are examples

57. Ball-and-Socket Joint
Multiaxial movement
Scapula
Medial/lateral
axis
Anterior/posterior
axis
Vertical
axis
Humerus
Flexion and
extension
Adduction
and abduction
Rotation
(f) Ball-and-socket joint

58. PLAY
Movement of the glenohumeral joint (a)

59. Factors Influencing Stability of Synovial Joints
Articular surfaces
Shapes of articulating surfaces determine movements possible

60. Factors Influencing Stability of Synovial Joints
Ligaments
Capsules & ligaments prevent excessive motions
On the medial or inferior side of a joint  prevent excessive abduction
Lateral or superiorly located  resist adduction

61. Factors Influencing Stability of Synovial Joints
Ligaments (cont…)
Anterior ligaments  resist extension & lateral rotation
Posterior ligaments resist flexion & medial rotation
The more ligaments  usually the stronger & more stable

62. Factors Influencing Stability of Synovial Joints
Muscle tone
Helps stabilize joints by
keeping tension on tendons
Is important in reinforcing:
Shoulder & knee joints
Supporting joints in arches of the foot

63. Selected Joints

64. Selected Synovial Joints
Temporomandibular Joint
Is a modified hinge joint
The head of the mandible articulates with the temporal bone
Lateral excursion is a side-to-side movement
2 surfaces of the articular disc allow:
Hinge-like movement
Gliding of superior surface anteriorly

65. The Temporomandibular Joint
Mandibular fossa
Articular tubercle
Zygomatic process
Infratemporal fossa
Mandibular
fossa
Articular disc
Articular
tubercle
Articular
capsule
External
acoustic
meatus
Superior
joint
cavity
Lateral
ligament
Synovial
membranes
Articular
capsule
Ramus of
mandible
Mandibular
condyle
Inferior joint
cavity
Ramus of mandible
(a) Location of the joint in the skull
(b) Enlargement of a sagittal section through the joint
(arrows indicate movement in each part of the joint cavity)

66. The Temporomandibular Joint

67. Selected Synovial Joints
Shoulder (= Glenohumeral) joint
The most freely movable joint (lacks stability!)
Articular capsule is thin & loose
Muscle tendons contribute to joint stability

68. The Shoulder Joint Acromion of scapula Glenoid labrum Coracoacromial
ligament
Synovial cavity
of the glenoid
cavity containing
synovial fluid
Subacromial
bursa
Fibrous
articular capsule
Hyaline
cartilage
Tendon
sheath
Synovial membrane
Fibrous capsule
Tendon of
long head
of biceps
brachii muscle
Humerus
(a) Frontal section through right shoulder joint

69. The Shoulder Joint Glenoid labrum Synovial cavity of the glenoid
cavity containing
synovial fluid
Hyaline
cartilage
Fibrous capsule
Humerus
(b) Cadaver photo corresponding to (a)

70. Glenohumeral Joint
The rotator cuff is made up of 4 muscles & their associated tendons
Supraspinatus
Infraspinatus
Teres minor
Subscapularis  (= SITS muscles)
Rotator cuff injuries are common shoulder injuries

71. The Shoulder Joint Articular capsule Acromion Coracoid Coracoacromial
process
Coracoacromial
ligament
Subacromial
bursa
Articular
capsule
reinforced by
glenohumeral
ligaments
Coracohumeral
ligament
Greater
tubercle
of humerus
Subscapular
bursa
Transverse
humeral
ligament
Tendon of the
subscapularis
muscle
Tendon sheath
Scapula
Tendon of
long head
of biceps
brachii
muscle
(c) Anterior view of right shoulder joint capsule

72. The Shoulder Joint Acromion Coracoid process Acromion (cut) Articular
capsule
Glenoid cavity
Glenoid
cavity of
scapula
Head of
humerus
Glenoid labrum
Tendon of long
head of biceps
brachii muscle
Capsule of
shoulder
joint
(opened)
Muscle
of rotator
cuff (cut)
Glenohumeral
ligaments
Tendon of the
subscapularis
muscle
Scapula
Posterior
Anterior
(d) Lateral view of socket of right shoulder joint,
humerus removed
(e) Posterior view of an opened left shoulder joint

73. Selected Synovial Joints
Elbow joint
Allows flexion & extension
The humerus’ articulation with the trochlear notch of the ulna forms the hinge
Tendons of biceps & triceps brachii provide stability

74. The Elbow Joint Synovial membrane Humerus Synovial cavity
Articular
capsule
Synovial
membrane
Humerus
Synovial cavity
Articular cartilage
Fat pad
Coronoid process
Tendon of
triceps
muscle
Tendon of
brachialis muscle
Ulna
Bursa
Trochlea
Articular cartilage
of the trochlear
notch
(a) Mid-sagittal section through right elbow (lateral view)

75. The Elbow Joint Annular ligament Radial collateral ligament Humerus
Radius
Lateral
epicondyle
Articular
capsule
Radial
collateral
ligament
Olecranon
process
Ulna
(b) Lateral view of right elbow joint

76. The Elbow Joint Articular capsule Humerus Annular ligament Coronoid
process
Medial
epicondyle
Ulnar
collateral
ligament
Radius
Ulna
(d) Medial view of right elbow

77. Wrist Joint Stabilized by numerous ligaments
Composed of radiocarpal & intercarpal joint
Radiocarpal joint  joint between the radius & proximal carpals (the scaphoid & lunate)
Allows for flexion, extension, adduction, abduction, & circumduction
Intercarpal joint  joint between the proximal & distal rows of carpals
Allows for gliding movement

78. Wrist Joint Radius Ulna Radiocarpal Lunate joint Triquetrum Scaphoid
Pisiform
Capitate
Hamate
Trapezoid
Trapezium
Thumb
(a) Right wrist, anterior (palmar) view

79. Wrist Joint Distal radioulnar joint Articular disc Ulnar collateral
Radiocarpal
joint
Distal
radioulnar
joint
Articular
disc
Radial
collateral
ligament
Ulnar
collateral
ligament
Intercarpal
joint
(b) Wrist joints, coronal section

80. Wrist Joint Palmar radiocarpal ligament Radius Ulna Lunate Radial
collateral
ligament
Ulnar
collateral
ligament
Scaphoid
Intercarpal
ligaments
Pisiform
Hamate
Trapezium
Carpo-
metacarpal
ligaments
Capitate
(c) Ligaments of the wrist, anterior (palmar) view

81. Selected Synovial Joints
Hip joint
A ball-and-socket joint
Movements occur in all axes
Limited by ligaments & acetabulum
Head of femur articulates with acetabulum
Stability comes chiefly from acetabulum & capsular ligaments
Muscle tendons contribute somewhat to stability

82. PLAY
Movement of the hip joint

83. The Hip Joint Acetabular labrum Coxal (hip) bone Articular cartilage
Ligament of the
head of the femur
(ligamentum teres)
Acetabular labrum
Femur
Synovial cavity
Articular capsule
(a) Frontal section through the right hip joint

84. The Hip Joint Iliofemoral Iliofemoral ligament Anterior inferior
iliac spine
Ischium
Ischiofemoral
ligament
Pubofemoral
ligament
Greater
trochanter
Greater
trochanter
of femur
(c) Posterior view of right hip joint, capsule in place
(d) Anterior view of right hip joint, capsule in place

85. Selected Synovial Joints
Knee joint
The largest & most complex joint
Primarily acts as a hinge joint
Has some capacity for rotation when leg is flexed
Structurally considered compound & bicondyloid
2 fibrocartilage menisci occur within the joint cavity
Femoropatellar joint  shares the joint cavity
Allows patella to glide across the distal femur

86. Sagittal Section of Knee Joint
Tendon of
quadriceps
femoris
Femur
Suprapatellar
bursa
Articular
capsule
Patella
Posterior
cruciate
ligament
Subcutaneous
prepatellar bursa
Synovial cavity
Lateral
meniscus
Lateral meniscus
Anterior
cruciate
ligament
Infrapatellar
fat pad
Deep infrapatellar
bursa
Tibia
Patellar ligament
(a) Sagittal section through the right knee joint

87. Superior View of Knee Joint
Anterior
Anterior
cruciate
ligament
Articular
cartilage on
lateral tibial
condyle
Articular
cartilage on
medial tibial
condyle
Medial
meniscus
Lateral
meniscus
Posterior
cruciate
ligament
(b) Superior view of the right tibia in the knee joint, showing
the menisci and cruciate ligaments

88. Anterior View of Knee Quadriceps femoris muscle Tendon of quadriceps
Patella
Medial
patellar
retinaculum
Lateral
patellar
retinaculum
Tibial
collateral
ligament
Fibular
collateral
ligament
Patellar
ligament
Fibula
Tibia
(c) Anterior view of right knee

89. Knee Joint Ligaments of the knee joint:
Become taut when knee is extended
These extracapsular & capsular ligaments are:
Fibular & tibial collateral ligaments
Oblique popliteal ligament
Arcuate popliteal ligament

90. Knee Joint Intracapsular ligaments Cruciate ligaments
Cross each other like an “X”
Each cruciate ligament runs from the proximal tibia to the distal femur
Anterior cruciate ligament (ACL)
Posterior cruciate ligament (PCL)

91. Anterior View of Flexed Knee
Posterior cruciate
ligament
Fibular
collateral
ligament
Medial condyle
Medial femoral
condyle
Anterior cruciate
ligament
Medial meniscus
on medial tibial
Patella
(f) Photograph of an opened knee joint; view similar to (e)
Tibial collateral
ligament
Lateral
condyle
of femur
Anterior cruciate
ligament
Lateral
meniscus
Medial meniscus
Tibia
Patellar ligament
Fibula
Patella
Quadriceps
tendon
(e) Anterior view of flexed knee, showing the cruciate
ligaments (articular capsule removed, and quadriceps
tendon cut and reflected distally)

92. Knee Joint Intracapsular ligaments
Cruciate ligaments  prevent undesirable movements at the knee
Anterior cruciate ligament  prevents anterior sliding of the tibia
Posterior cruciate ligament  prevents forward sliding of the femur or backward displacement of the tibia

93. Stabilizing function of cruciate ligaments1
During movement of the knee the anterior
cruciate prevents anterior sliding of the tibia;
the posterior cruciate prevents posterior
sliding of the tibia. 2
When the knee is fully extended,
both cruciate ligaments are taut and
the knee is locked.
Quadriceps
muscle
Femur
Anterior
cruciate
ligament
Patella
Medial
condyle
Anterior
cruciate
ligament
Lateral
meniscus
Posterior
cruciate
ligament
Posterior
cruciate
ligament
Tibia
(a)
(b)

94. The “Unhappy Triad” Lateral blows to the knee can tear:
Tibial collateral ligament & medial meniscus
Anterior cruciate ligament
Are common sports injuries!

95. Selected Synovial Joint
Ankle joint
A hinge joint between:
United distal ends of tibia & fibula
The talus of the foot
Allows the movements of:
Dorsiflexion & plantar flexion only

96. The Ankle Joint Medially & laterally stabilized by ligaments
Medial (deltoid) ligament
Lateral ligament
Inferior ends of tibia & fibula are joined by ligaments
Anterior & posterior tibiofibular ligaments

97. The Ankle Joint Tibialis posterior muscle Tibia Calcaneal tendon
Ankle (talocrural) joint
Talocalcaneal ligament
Talus
Talonavicular joint
Cuneonavicular joint
Tarsometatarsal joint
Metatarsal bone (II)
Metatarsophalangeal
joint
Interphalangeal
joint
Calcaneus
Subtalar
joint
Navicular
bone
Intermediate
cuneiform bone
Tendon of flexor
digitorum longus
(a) Cadaver photo of ankle and foot, sagittal section

98. Ligaments of the Ankle Joint
Tibia
Medial malleolus
Talus
Medial (deltoid)
ligament
Navicular
Sustentaculum
tali
1st metatarsal
Calcaneus
(b) Right ankle, medial view

99. Ligaments of the Ankle Joint
Fibula
Anterior tibiofibular
ligament
Tibia
Posterior tibiofibular
ligament
Lateral malleolus
Anterior talofibular
ligament
Talus
Lateral
ligament
Posterior talofibular
ligament
Metatarsals
Calcaneofibular
ligament
Calcaneus
Cuboid
(c) Right ankle, lateral view

100. Disorders of Joints
Structure of joints makes them prone to traumatic stress
Function of joints makes them subject to friction and wear & tear
Affected by inflammatory & degenerative processes

101. Joint Injuries
Torn cartilage  common injury to meniscus of knee joint
Sprains  ligaments of a reinforcing joint are stretched or torn
Dislocation  occurs when the bones of a joint are forced out of alignment

102. Inflammatory & Degenerative Conditions
Bursitis  inflammation of a bursa due to injury or friction
Tendonitis  inflammation
of a tendon sheath
Swollen bursa
surrounding
the knee

103. Inflammatory & Degenerative Conditions
Arthritis  describes over 100 kinds of joint-damaging diseases
Osteoarthritis  most common type of “wear & tear” arthritis
Rheumatoid arthritis  a chronic inflammatory disorder
Gouty arthritis (gout)  uric acid build-up causes pain in joints
Lyme disease  inflammatory disease often resulting in joint pain

104. The Joints Throughout Life
Synovial joints develop from mesenchyme
By week 8 of fetal development, joints resemble adult joints
Outer region of mesenchyme becomes fibrous joint capsule
Inner region becomes the joint cavity

105. The Joints Throughout Life
During youth  injury may tear an epiphysis off a bone shaft; breaks near joints; dislocations
Advancing age  osteoarthritis becomes more common
Exercise  helps maintain
joint health!

106. Keeping Your Joints Healthy
Exercise is key –
strengthens the muscles around
the joints & stabilizes them;
decreases injuries, joint disorders,
wear-&-tear, etc.
Also good: proper nutrition, hydration, & vitamins/ supplements (glucosamine a good one)
The journey of a mother & daughter

107. Keeping Your Joints Healthy

108. Questions…. What’s Next
Questions…? What’s Next? Lab: Finish Bones & Joints Wed Lecture: Skeletal muscle Wed Lab: Skeletal muscle tissue
& muscles