Joints (Articulations) • Functions of joints

• Classifying Joints: Functional or Structural

• Naming Movements of Bones Around Joints

• Types of Joints Based on Movement

• Selected Key Joints: Shoulder, Elbow, Hip, Knee

• Joint Injuries

• Chronic Joint Conditions: Arthritis

Types of Synovial Joints Based on Shape

Types of Synovial Joints Based on Shape

Plain hinge joints pivot on condyloid saddle ball-sockets.

Joints (Articulations) • Functions of joints

• Classifying Joints: Functional or Structural

• Naming Movements of Bones Around Joints

• Types of Joints Based on Movement

• Selected Key Joints: Shoulder, Elbow, Hip, Knee

• Joint Injuries

• Chronic Joint Conditions: Arthritis

Shoulder (Glenohumeral) Joint

• Bones and features involved

• Head of humerus and glenoid fossa of the scapula

• Type of joint

• Ball-and-socket joint

• Stability/strength of joint

• Coracohumeral ligament supports the weight of the upper limb

• Three glenohumeral ligaments—weak anterior reinforcements

• Reinforced by tendon of the long head of biceps and 4 rotator cuff tendons

• Four rotator cuff tendons encircle the shoulder joint:

• Stability is sacrificed for greater freedom of movement

• Allowable movements

• Diarthrotic

• Flexion, extension, adduction, abduction, medial and lateral rotation

Elbow Joint• Bones and features involved

• Radius and ulna articulate with the humerus

• Hinge at trochlear notch of ulna and trochlea of humerus

• Type of joint

• Hinge joint

• Stability/strength of joint

• Anular ligament —surrounds head of radius

• Two capsular ligaments restrict side-to-side movement:

• Ulnar collateral ligament

• Radial collateral ligament

• Allowable movements

• Diarthrotic

• Flexion and extension only

Hip (Coxal) Joint• Bones and features involved

• Head of the femur articulates with the acetabulum of the pelvis

• Type of joint

• Ball-and-socket joint

• Stability/strength of joint

• 4 Reinforcing ligaments:

• Iliofemoral ligament

• Pubofemoral ligament

• Ischiofemoral ligament

• Ligamentum teres

• Allowable movements

• Flexion, extension, rotation, adduction, abduction, circumduction

• Good range of motion, but limited by the deep socket

• Acetabular labrum (ring of cartilage around cavity—enhances depth of socket, difficult to dislocate

Knee Joint• Bones and features involved

• Largest, most complex joint of body• Three joints surrounded by a single joint

cavity: femoropatellar, lateral and medial tibiofemoral joints

• Type of joint

• Femoropatellar joint - plane joint with gliding

• Lateral and medial tibiofemoral hinge joints between the femoral condyles and the C-shaped lateral and medial menisci (semilunar cartilages) of the tibia

• Stability/strength of joint

• Capsule is reinforced by muscle tendons:

• Quadriceps and semimembranosus tendons

• Joint capsule is thin and absent anteriorly

• Anteriorly, the quadriceps tendon gives rise to patellar ligament

• Capsular and extracapsular ligaments prevent hyperextension

• Intracapsular ligaments

• Allowable movements

• Diarthrotic

• Allows flexion, extension, and some rotation when knee is partly flexed

Joints (Articulations) • Functions of joints

• Classifying Joints: Functional or Structural

• Naming Movements of Bones Around Joints

• Types of Joints Based on Movement

• Selected Key Joints: Shoulder, Elbow, Hip, Knee

• Joint Injuries

• Chronic Joint Conditions: Arthritis

Common Joint Injuries• Sprains

• The ligaments are stretched or torn

• Partial tears slowly repair themselves

• Complete ruptures require prompt surgical repair

• Cartilage tears

• Due to compression and shear stress

• Fragments may cause joint to lock or bind

• Cartilage rarely repairs itself

• Repaired with arthroscopic surgery

• Dislocations (luxations)

• Occur when bones are forced out of alignment

• Accompanied by sprains, inflammation, and joint immobilization

• Caused by serious falls or playing sports

• Subluxation—partial dislocation of a joint

Inflammatory and Degenerative Conditions

• Bursitis

• An inflammation of a bursa, usually caused by a blow or friction

• Treated with rest and ice and, if severe, anti-inflammatory drugs

• Tendonitis

• Inflammation of tendon sheaths typically caused by overuse

• Symptoms and treatment similar to bursitis

Joints (Articulations) • Functions of joints

• Classifying Joints: Functional or Structural

• Naming Movements of Bones Around Joints

• Types of Joints Based on Movement

• Selected Key Joints: Shoulder, Elbow, Hip, Knee

• Joint Injuries

• Chronic Joint Conditions: Arthritis

Lyme Disease: Acute Arthritis

• Caused by bacteria transmitted by the bites of ticks

• Symptoms: skin rash, flu-like symptoms, and foggy thinking

• May lead to joint pain and arthritis

• Treatment: antibiotics

Clinical Forms of Arthritis (Three Chronic Types)

1. Osteoarthritis

• Most common chronic arthritis

• Irreversible, degenerative (“wear-and-tear”) arthritis

• 85% of all Americans develop OA, more women than men

• Probably related to the normal aging process

• More cartilage is destroyed than replaced in badly aligned or overworked joints

• Exposed bone ends thicken, enlarge, form bone spurs, and restrict movement

• Treatment: moderate activity, mild pain relievers, capsaicin creams, glucosamine and chondroitin sulfate

•100 different types of inflammatory or degenerative diseases that damage joints

•Most widespread crippling disease in the U.S.

•Symptoms: pain, stiffness, and swelling of a joint

•Acute forms: caused by bacteria, treated with antibiotics

•Chronic forms: osteoarthritis, rheumatoid arthritis, and gouty arthritis

2. Rheumatoid arthritis

• Chronic, inflammatory, autoimmune disease of unknown cause

• Begins 40-50 years of age, more common in women

• Signs and symptoms include joint pain and swelling (usually bilateral), anemia, osteoporosis, muscle weakness, and cardiovascular problems

•RA begins with synovitis of the affected joint

• Inflammatory blood cells migrate to the joint, release inflammatory chemicals, cartilage erodes, scar tissue forms, bone ends connect.

•Treatment: aspirin, long-term use of antibiotics, and physical therapy; anti-inflammatory drugs or immunosuppressants; new biological response modifier drugs neutralize inflammatory chemicals

Clinical Forms of Chronic Arthritis

Clinical Forms of Chronic Arthritis

3. Gouty Arthritis

• Inflammation of joints is caused by a deposition of urate crystals from the blood in joints and soft tissues, followed by inflammation

• Typically affects the joint at the base of the great toe

• Can usually be controlled with diet: drugs, plenty of water, less red meat, avoidance of alcohol

• More common in men

• In untreated gouty arthritis, the bone ends fuse

Joints (Articulations) • Functions of joints

• Classifying Joints: Functional or Structural

• Naming Movements of Bones Around Joints

• Types of Joints Based on Movement

• Selected Key Joints: Shoulder, Elbow, Hip, Knee

• Joint Injuries

• Chronic Joint Conditions: Arthritis