Articulations / Joints

1. Articulations / Joints

2. Joints - Articulations • Where 2 bones meet. Classified by degree of motion (functional) and major connective tissue types that bind the bones together (structural) • Fibrous joints – united by fibrous tissue and has little to no movement. Example – Sutures, gomphosis (teeth), syndesmosis –tibia / fibula distal articulation • Cartilaginous joints – united by cartilage. Only slight movement. Synchondrosis – epiphyseal plate, Symphysis - pubic • Synovial joint – freely moveable contains synovial fluid in a cavity surrounding bones. Examples – shoulder, knee

3. Function classification • Synarthrosis – immovable joint • Amphiarthrosis – slightly movable • Diarthrosis – freely movable. • -sis is replaced with –ses for the plural form

4. Capsular nature of a synovial joint Cavity (synovial joint) enclosed by a capsule (2 layers) • Fibrous cartilage – dense irregular, encloses cavity • Ligaments – connects bone to bone • Tendons – connect muscles to bone • Articular cartilage – hyaline cartilage at ends of bones • Synovial membranes –areolar, produced synovial fluid for lubrication, nutrients, and metabolic waste removal

5. Capsular nature of a synovial joint • Articular disc / meniscus – pads of fibrocartilage that lie between the articular surfaces of the bones (lateral and medial) • Bursae – closed sacs, with a synovial lining. Subcutaneous (patella), subfascial – between muscles, Subtendinous – tendon and process or tendon

6. Synovial joint

7. The knee joint • Patellar ligament – patella to tibia, anterior • Oblique popliteal ligament - posterior surface • Acruatepopliteal ligament – lower later post. • Medial collateral ligament – medial (inside) • Lateral collateral ligament – lateral (outside) • Anterior cruciate ligament – tibia, post and laterally to the femur, 70% serious injury • Posterior cruciate ligament – tibia, anterior and medial to the femur • (menisci, bursae)

8. Knee joint

9. Synovial joints

10. Major joint movement • Flexion – decrease in the angle • Extension – increase in the angle • Hyperextension – extension beyond position • Abduction – away from midline • Adduction – toward midline • Pronation – palm down • Supination – palm up • Eversion – foot out • Inversion – foot in • Dorsiflexion – foot up • Plantar flexion – foot down

11. Major joint movement con’t • Rotation – turn around long bone axis • Protraction – structure glides to anterior (front) • Retraction – structure glides to posterior (back) • Elevation – move structure superior (up) • Depression – move structure inferior (down) • Excursion – move one side to another • Opposition – move of thumb to pinky • Reposition – return thumb / pinky to normal • Circumduction – arm / hip circles

12. Aging and joints • Decreased synovial fluid • Articular cartilage thins (glucosamine chondroitin / shark cartilage) • Ligaments shorten and lose flexibility • Degenerative changes in vertebral column, hunched – over posture Stretching and aerobic exercise that help with range of motion, help to minimize aging effects

13. Joint Disorders • Bursitis – inflammation of bursa (elbow and shoulder) • Arthritis – inflammation of the whole joint • Rheumatoid arthritis – connective tissue disorder (excess growth) with severe inflammation of small joints • Rheumatic fever – bacterial (strep) infection that causes RA if left undetected. • Fibrositis – inflammation of fibrous connective tissue in a joint; “rheumatism,” lumbago – lower back • Osteoarthritis – Degenerative joint, elderly, weight – bearing joints

14. Joint disorders continued • Gout – uric acid crystals in joint at large toe base • Sprain – twisting tears ligaments (ankles and wrists) • Strain – stretched or partially torn muscle • Slipped Disk – intervertebral disk protrudes or moves out of place, pressure on nerve • Dislocation – temporary displaced bone • Cumulative trauma disorder – ongoing “repetitive” or overuse damage to soft tissue. Carpal tunnel- medial nerve as it passes through the carpal tunnel