human body bones and joints BY : Masoud mirmoezi

Joint is a point of connection between two bones Strands of connective tissue, ligaments, hold the bones together and ensure the stability of joints joints of human body

Functions of the joints: 1)Allowing movements of body segments by providing the bones with a mean of moving or rather of being moved. 2) Providing stability without interfering with the desired motion. The function of the joints depends upon: A.The shape of the contours of the contacting surfaces. B.How well it fits together.

motion Joints are classified according to their motion capabilities: – Synarthroses Immovable – Amphiarthroses Slightly movable – Diarthroses Allow the greatest amount of motion

material Joints are further classified by the material : – Fibrous joint Allow no movement E.g. sutures of the scull – Cartilaginous joints Allow limited movement E.g. intervertebral discs – Synovial joints Allow large range of movements E.g. hip joint

Synovial Joints includes : Hyaline cartilage – A protective layer of dense white connective tissue that covers the ends of the articulating bones Joint cavity Synovial membrane – Covers joint cavity, except over the surfaces of the articular cartilages – Secretes the lubrication fluid Synovial fluid – Lubricates the joint Capsule – May or may not have thickenings called intrinsic ligaments Extrinsic ligaments – Support the joint and connect the articulating bones of the joint

Joints are classified According to the degree of freedom of movement One degree of freedom of movement. Two degree of freedom of movement. Three degree of freedom of movement. According to the number of axis of rotation: According to the number of axis of rotation: Uniaxial. Biaxial. Multiaxial.

Types of synovial joints ExampleMechanical Classification Anatomical classification Elbow joint UniaxialHinge joint Atlanto axial joint, Superior radio-ulnar joint UniaxialPivot joint Knee joint BiaxialCondyloid joint Carpometacarpal joint of the thumb BiaxialSaddle joint Wrist joint TriaxialEllipsoid joint hip joint and shoulder joint TriaxialBall and socket Midtarsal joints of foot NonaxialGliding joint

Movements of Synovial Joints Flexion and extension Abduction and adduction Elevation and depression Protractions and retraction Circumduction Rotation Pronation and supination

Joint Capsule Also called the articular capsule Forms an envelope surrounding synovial joints Made of two layers – Outside layer of dense fibrous tissue – Inside layer of loose fibrous tissue Lined with a synovial membrane – Secretes synovial fluid that lubricates the joint

Help to hold bones together across synovial joints Fairly tough and inelastic Loose enough so as not to restrict normal joint movement joint capsule articular cartilage

Capsule : The joint capsule is vital to the function of synovial joints It seals the joint space passive stability by limiting movements active stability via its proprioceptive nerve endings It varies in thickness according to the stresses to which it is subject The capsule is often injured, leading to laxity, constriction and/or adhesion to surrounding structures

Intraarticular disc (menisci) are found in several synovial joints of body Tibiofemoral Distal radioulnar Sternoclavicular Acromioclavicular Temporomandibular

Articular labrum : Ring of fibrocartilage that attaches to the edge of one of the two joint surfaces. Is found around both the acetabulum (hip joint) and the glenoid (shoulder joint). Its mission is to expand the joint surface, preventing dislocation of the femoral or humeral head.

In medicine, a ring of fibrocartilage (fibrous cartilage) around the edge of the articular (joint) surface of a bone. cartilage The term labrum is used in anatomy to designate a lip, edge, or brim. Plural: labra

Two large synovial joints of the body posses a pevipheral labrum of fibrocartilage The labrum extends from the bony rims of both the glenoid cavity of the shoulder and the acetabulum of the hip These specialized structures deepen the concave member of these joints and support and thicken of the attachment of the joints capsule

kinematic chain… osteokinematics…

kinematic chain… osteokinematics…

arthrokinematics… Fundamental movements…

clavicle & scapula joints

The Shoulder Joint

The Glenohumeral Joint (Superior View, Horizontal Section)

Glenohumeral Joint Connects the upper limb and the scapula A typical multiaxial joint has a wide range of movement at this joint compromise = relative lack of stability

The "joint capsule" of the shoulder is attached along the outside ring of the genoid cavity and the anatomical neck of the humerus humerus scapula joint capsule labrum articular cartilage

Bursae in the Shoulder Bursae (plural for bursa) act as the lubricant between areas in your body where friction (rubbing) is greatest. in the shoulder there are 8 bursae The major bursae in your shoulder include: the subscapular bursa, the subdeltoid bursa, the subacromial bursa, and the subcoracoid bursa.

Scapulothoracic joint:

open vs. closed kinetic chain for the shoulder Joint open chain movements (distal on proximal) rolling Slide closed chain movements (proximal on distal) rolling Slide

Elbow Joints Humerus Ulna Radius Humero-Radial Joint Humero-Ulnar Joint Radio-Ulnar Joint

The Elbow Joint Figure 9–10

There are three joints at the elbow: – humero-ulnar joint ( Hinge joint) medial (with respect to anatomical position) between the trochlea of the humerus and the olecranon process of the ulna – humero-radial joint ( Condyloid joint) lateral between the capitulum of the humerus and the head of the radius – radio-ulnar joint ( Pivot joint) between the radius and the ulna

The Elbow Joint (X-ray, Sagittal View, and Articular Surfaces) Fig 8.12

joint capsule The joint capsules surrounding a joint function to enclose the articulating bones in order to create an envelope.

open vs. closed kinetic chain for the Shoulder Joint open chain movements (distal on proximal) rolling Slide closed chain movements (proximal on distal) rolling Slide

Wrist joints

The Joints of the Wrist and Hand

open vs. closed kinetic chain for the wrist Joint open chain movements (distal on proximal) rolling Slide closed chain movements (proximal on distal) rolling Slide

lower limbs anatomy

Joints of the Pelvic Girdle

Sacroiliac joint The sacroiliac joint or SI joint is the joint in the bony pelvis between the sacrum and the ilium of the pelvissacrum ilium the SI joints connect the spine to the pelvis. The main function of the sacroiliac joints is to transmit forces between the upper body and the lower limbs. They are designed to withstand large stresses.

The Hip Joint

Hip Joint - Between the head of the femur and the cup (acetabulum) of the hip bone (os coxae) – Like shoulder joint, hip joint is: ball and socket joint multiaxial joint that allows flexion- extension, abduction-adduction and circumduction

Hip Joint unlike shoulder joint, hip joint is very stable in fact it is the body’s most stable synovial joint due to: – deepened socked (via lip or fibrocartilaginous labrum ) – an intrinsic and very strong extrinsic ligaments dislocation in sports is not common, but can occur in car collisions dislocate the head posteriorly or drive it through the posterior lip of the actetabulum

open vs. closed kinetic chain for the hip Joint open chain movements (distal on proximal) rolling Slide closed chain movements (proximal on distal) rolling Slide

The Knee Joint

Knee Joint Knee Joint however, the knee joint is relatively stable due to additional structural supports from: – menisci shock-absorbing fibrocartilaginous discs – anterior and posterior cruciate ligaments in the centre of the joint – lateral and medial collateral ligaments extending from the sides of the femur to the tibia and fibula – the musculature that surrounds it

The articular disks of the knee-joint are called menisci because they only partly divide the joint space. These two disks, the medial meniscus and the lateral meniscus, consist of connective tissue with extensive collagen fibers containing cartilage-like cellsarticular disksmeniscimedial meniscuslateral meniscus

The Knee Joint, Part II (Anterior Views, Flexed Knee)

The Knee Joint, Part I (X-ray, Partially Flexed Knee)

Knee bursae: are the fluid sacs and synovial pockets that surround and sometimes communicate with the joint cavity.joint cavity Thin-walled and filled with synovial fluid, they represent the weak point of the joint, but also produce enlargements to the joint spacesynovial fluid

Patella Bone Anatomy The knee patella bone is a firm small triangular bone The function of the patella cartilage is to protect the front part of the knee. The knee joint undergoes a lot of stress on a daily basis. The knee is utilized in almost every type of activity such as walking, leaping, running, jogging, lifting and so on. The patella located just in front of the knee joint bears the brunt of the stress, serving as a physical barrier

open vs. closed kinetic chain for the knee Joint open chain movements (distal on proximal) rolling Slide closed chain movements (proximal on distal) rolling Slide

The Ankle Joints

Ankle Joint talocrural or ankle joint involves several bones: – medial and lateral malleoli of the tibia and fibula – head of the talus – calcaneus (heel bone) Medial malleolus Lateral malleolus Talus Calcaneus

The Joints of the Ankle and Foot, Part II (Medial Views)

The Joints of the Ankle and Foot

open vs. closed kinetic chain for the Shoulder Joint open chain movements (distal on proximal) rolling Slide closed chain movements (proximal on distal) rolling Slide

The Joints of the Ankle and Foot, Part II (Superior Views)

Articulations of the Axial Skeleton

Joints in the skull immovable or synarthrotic joint The suture and synchondrosis actually become more stable

The Temporomandibular Joint (hinge joint)

Atlanto-occipital joint The Atlanto-occipital joint (articulation between the atlas and the occipital bone) consists of a pair of condyloid joints. The atlanto-occipital joint is a synovial joint. atlasoccipital bone condyloid synovial joint

The atlanto_axial joint The Atlanto-axial joint (articulation of the atlas with the axis) is of a complicated nature.atlasaxis It consists of no fewer than four distinct joints. Type is pivot joint

Chest

The Sternoclavicular Joint

Articulations of the Appendicular Skeleton

Articulations and Movements of the Axial Skeleton