JOINTS AND BONE INJURIES

Articular System

Series of joints that allow for movement of the human body

Joint articulation Two bones come into contact May be immoveable, slightly moveable, or freely

moveable Arthrology is the study of joint structure and

function Types of joints

Synarthroses – immovable Amphiarthroses – slightly moveable Diarthroses – freely moveable

Synarthroses

Lack a synovial cavity Held together by fibrous connective tissue Sutures

Ex. Joints between skull bones Fuse together after birth

Syndesmoses Connected by

ligaments are very slightly moveable

Ex. between the tibia and the fibula

Gomphoses Joint which a

conical process fits into a socket and is held by ligaments

ex. teeth held to the jaw bones

Amphiarthroses

Connected by hyaline cartilage or fibrocartilage Ex. Ribs

connected to sternum

Ex. Between pubic bones

Diarthroses(synovial joints)

Ends of bones are covered with articular cartilage and separated by the joint cavity

Within joint is a capsule Outer layer is made of ligaments Inner layer is a synovial membrane that secretes

synovial fluid for lubrication

Types of Diarthroses joints

Pivot joint Bone moves around

a central axis Ex. joint between

the radius and ulna of the lower arm

Gliding joint Bones move in a sliding

motion Ex. between the

carpals in the hand

Hinge joint Allows only flexion and

extension Ex. the knee and elbow

Condyloid or ellipsoidal joint Bones can move in

many directions but cannot rotate

Ex. between the metatarsals and the phalanges

Saddle joint Two bones have

both concave and convex regions

Allows the thumb to touch each of the fingertips

Ex. the thumb

Ball – and – socket joint Bone’s rounded end fits

into a concave cavity on another bone

Provides the widest range of motion possible

Ex. femur connecting to the hip bones

Joint Injuries

Subluxation Occurs when bone

displaces, then returns to normal position

Dislocation Occurs when

significant force displaces bone so that the two bone ends in a joint no longer add up

JOINTMOVEMENTS

Movements of Diarthroses

Flexion Extension Hyperextension Abduction Adduction Rotation Circumduction Supination Pronation Plantar flexion Dorsiflexion

Inversion Eversion Protraction Retraction Elevation Depression Internal Rotation External Rotation Radial Deviation Ulnar Deviation Opposition

Flexion/Extension

Flexion Decreases the angle between 2

bones Extension

Increases the angle between two bones

Hyperextension Movement that increases the angle

between two bones extends beyond the normal range of motion

Abduction/Adduction

Abduction Describes

movements of the limbs only

The limb moves away from the midline of the body

Adduction Describes

movements of the limbs only

The limb moves toward from the midline of the body

Abduction/Adduction

Rotation Movement that occurs when a bone turns on its axis toward or away from the midline of the body, in the limbs, or between the 1st and 2nd vertebrae of the spine

Circumduction The ability of a limb to move in a circular path around an axis

Supination The action of turning the palm upward

Performed by lateral rotation of the forearm

Pronation The action of turning the palm downward

Performed by medial rotation of the forearm

Supination/Pronation

Foot: Dorsal/Plantar

Plantar Flexion Movement that extends the foot

Pointing toes downwards Dorsiflexion

Movement that flexes the foot Brings toes up toward the lower leg

Plantar Flexion/Dorsiflexion

Plantar Flexion/Dorsiflexion

Inversion Movement that turns the sole of the foot medially

Eversion Movement that turns the sole of the foot laterally

Inversion/Eversion

Protraction/Retraction

Protraction Moving the body part forward

Retraction Moving the body part backward

Both movements occur in the transverse plane

Only performed with the shoulder and mandible

Protraction/Retraction

Elevation/Depression

Elevation Movement that lifts the body part superiorly

Depression Movement of the body part inferiorly

Elevation and Depression occur in the frontal plane

Elevation/Depression

Internal/External Rotation Internal rotation

Movement that occurs when the anterior surface moves toward the midline

aka medial rotation External rotation

Movement that occurs when the anterior surface moves away from the midline

aka lateral rotation

Internal/External Rotation

Hip Internal Rotation

Hand Movements

Radial Deviation Hand moves laterally towards the

thumb side Ulnar Deviation

Hand moves medially toward the little finger

Opposition Moves the thumb to touch the tips of

the other fingers

Hand Movements

Joints of Upper Extremity

Shoulder Joint Glenohumeral Sternoclavicular Acromioclavicular

Elbow Joint Radiohumeral Humeroulnar Radioulnar

Wrist Radiocarpal Intercarpal Carpalmetacarpal

Hand Intermetacarpal Metacarpalphalan

geal Interphalangeal

Shoulder

Glenohumeral Sternoclavicular Acromioclavicular

Glenohumeral joint

shoulder

Elbow

Radiohumeral Humeroulnar Radioulnar

Wrist

Radiocarpal Intercarpal Carpalmetacarpal

Hand

Intermetacarpal Metacarpalphalangeal Interphalangeal

Joints of Lower Extremity

Sacroiliac Acetabulofemoral Patellofemoral Tibiofemoral Tibiofibular

Ankle/Foot Talocural Subtalar Intertarsal Tarsometatarsal Intermetatarsal Metatasophalang

el Interphalangeal

Sacroiliac joint

Tibiofemoral joint

TIBIOFIBULAR JOINT

Foot/Ankle

Synovial Joint Injuries

Acute Sprains Synovitis Subluxations Dislocations

Chronic Osteochondrosis Arthritis Bursitis Capsulitis/

synovitis

Sprains

Injury to ligamentous and capsular tissue

Traumatic joint twist that results in stretching of total tearing of the stabilizing connective tissue

One of most common & disabling sports injuries

General Symptoms: Joint swelling Local temperature

increase Pain Point tenderness Skin discoloration

Sprains Grade 1

Some pain Minimum LOF Mild point tenderness Little or not swelling No abnormal motion

Grade 2 Pain Moderate LOF Swelling Slight to moderate

instability

Grade 3 Severe sprain Extremely painful

initially LOF Severe instability Tenderness Swelling

May represent subluxation that reduced spontaneously

Synovitis

Irritation of synovial membrane

Causes increase in fluid production, swelling

Joint pain during motion, skin sensitivity from pressure

Diminish in few days

Acute Joint Injuries

Subluxation Occurs when

bone displaces, then returns to normal position

Dislocation Occurs when

significant force displaces bone so that the two bone ends in a joint no longer add up

Osteochondrosis

Degenerative changes in the ossification centers of the epiphysis of bones

During periods of rapid growth in children Osteochondritis dissecans Suggested causes—

aseptic necrosis: circulation to epiphysis disrupted

Trauma causes particles of articular cartilage to fx, resulting in fissures that penetrate to subchondral bone

Arthritis Inflammation of an

entire joint Usually involves all

tissues of the joint Most often in WB

joints 100 varieties of

arthritis 10% population No cure

Rheumatoid Arthritis Connective tissue

disorder resulting in severe inflammation of small joints

Cause unknown Severely debilitating Synovial membranes

of joint and connective tissues grow abnormally to form layer in joint capsules destroys cartilage and fuses bones of joint

Osteoarthritis

Osteoarthritis

Bursitis

Inflammation of the synovial cavity caused by excessive stress or tension

Open & Closed Kinematic Chains

Open Kinematic Chain Sequence of action in which the body part

farthest from the trunk is free during movement

i.e. Seated leg extension Closed Kinematic Chain

Sequence of action in which the body part farthest from the trunk is fixed during movement

i.e. In a squat, feet are fixed and the rest of leg chain moves