Joints and Movements Nestor T. Hilvano, M.D., M.P.H.

Learning Objectives You should be able to: 1. Name and describe the structural and functional classes of joints and give an examples of each. 2. Describe the anatomy of a synovial joint and its associated structures and functions. 3. Discuss the types of synovial joints and types of movements. 4. Describe the structure and function of the shoulder, elbow, hip, and knee joints. 5. Explain the anatomy and physiology of common joint injuries. 6. Discuss the effects of aging on articulations

Joints and Their Classification Structural categoryStructural typeFunctional category Bony fusionSynostosisSynarthrosis Fibrous jointSuture Gomphosis Syndesmosis Synarthrosis Amphiarthrosis Cartilagenous jointSynchondrosis Symphysis Synarthrosis Amphiarthrosis Synovial jointMonoaxial, Biaxial, TriaxialDiarthrosis Functional classification of joints: ____- immovable joint a. diarthrosis ____- slightly movable joint. b. amphiarthrosis ____- freely movable joint c. synarthrosis

Synarthrosis Sutures - fibrous joint (DCT) Gomphosis - fibrous joint (periodontal ligament) Synchondrosis - cartilagenous joint (between rib and sternum, epiphyseal cartilage of long bones ) Synostosis - bony fusion (epiphyseal lines, metopic suture of skull)

Amphiarthrosis Syndesmosis – fibrous joint ex: interosseous membrane between radius and ulna Symphysis – cartilagenous joint ex. Intervertebral disc, symphysis pubis

Diarthrosis – Synovial Joint Components: Joint cavity – space Synovial fluid – lubrication, nutrient distribution, shock absorption Articular capsule- articulates bones in a joint Articular cartilage- protects the ends of bones within a joint Accessory structures: - Menisci (articular discs) = fibrocartilage pad w/in joint - Fat pad- adipose tissue - Tendons - Ligaments - Bursae = saclike extension (pockets of synovial fluid) that reduce friction and absorb shocks (cushion) where tendons and ligaments rub

Types of Movements ____ - decreases the angle of a joint ____ - straightens or increases the angle _____ - extension beyond 180 degrees _____ - movement of a part away from the midline _____ - movement towards the midline a. adduction b. abduction c. hyperextension d. extension e. flexion

Types of Movements _____ - movement that raises a bone vertically (moves up) _____ - lowering the mandible or the shoulders (moves down) ____ - movement anteriorly on horizontal plane –thrusting the jaw forward, shoulders _____ - movement posteriorly a. retraction b. protraction c. depression e. elevation

Types of Movements ____ - one end of an appendage remains stationary while the other end makes a circular motion (ex. draw a large circle on chalkboard) Rotation - movement on longitudinal axis (trunk, thigh, head or arm); medial and lateral rotations ___- rotation of forearm so that the palm faces forward ___ - rotation of forearm so the palm faces to the rear ___- heel on the ground, toes up (ankle flexion) ___- toes point on the ground, heel up (ankle extension) a. plantar flexionb. dorsiflexionc. medial rotation d. lateral rotation e. circumduction

Types of Synovial Joints Gliding joints (flattened surfaces) - bones slide over each other - limited monoaxial joint - ex: between carpal bones, tarsal bones, vertebrocostal joints Hinge joints - permit angular motion in a single plane - monoaxial joint - ex: elbow joint, knee joint, interphalangeal joints

Types of Synovial Joints Pivot Joints (rotation only) - allow one bone to rotate around another (monoaxial rotation) - ex: atlantoaxial (C1-C2) joint, proximal radioulnar joint Saddle Joints - permit one bone to slide in 2 directions - monoaxial rotation - ex: trapeziometacarpal joint at the base of the thumb

Types of Synovial Joints Ellipsoidal (condyloid) joints - oval convex surface on one bone fits into a similarly shaped depression - Biaxial joints - ex: radiocarpal joint, metacarpophalangeal and metatarsophalangeal joints Ball and socket joints - head fits within a cuplike depression - multiaxial joint - ex: shoulder joint, hip joint

Shoulder joint ball and socket joint Most freely movable joint in the body Supported by ligaments and tendons Supported by rotator cuff musculature 4 Bursae associated with shoulder joint Subscapular bursitis – common in tennis player Shoulder separation – dislocation of acromioclavicular joint * Student’s self-review/ reading

Hip Joint Ball and socket joint Socket deepened by acetabular labrum Blood supply to head of femur found in ligament of the head of the femur Joint capsule strengthened by ligaments transverse acetabular ligament * Student’s self-review/ reading

Hinge and Pivot joints Hinge joint (elbow) -humeroulnar joint is supported by ulnar collateral ligaments. Pivot joint - proximal radioulnar joint, the head of radius is held in place by the annular ligament. * Student’s self-review/ reading

Knee Joint Most complex diarthrosis Joint capsule anteriorly consists of patella and extensions of quadriceps femoris tendon Capsule strengthened by extracapsular and intracapsular ligaments Anterior and posterior cruciate ligaments limit anterior and posterior movement of femur Medial and lateral collateral ligaments prevent rotation of extended knee (prevent knee from bending out/bending in) Medial and lateral meniscus absorb shock and shape joint Most easily injured joint in the body - lat. surface of leg driven medially, tearing medial meniscus Locked knee- occurs when leg is fully extended and fibular collateral ligaments are tight. * Student’s self-review/ reading

Clinical Conditions Arthritis pain and inflammation of joints Osteoarthritis results from years of joint wear, aging Rheumatoid arthritis is autoimmune attack on joint Gouty arthritis crystals of uric acid in synovial joints Hip fractures are associated with osteoporosis

Homework (Self-Review) 1. Define key terms: joint, synarthrosis, amphiarthrosis, diarthrosis, tendon, ligament, bursae, synovial fluid, articular cartilage, menisci, rheumatoid arthritis, gouty arthritis, dislocation, sprain, bursitis, locked knee. 2. Identify the types of movement given below. a) raising the shoulder b) moving shoulder posteriorly or backward c) swinging upper limb laterally to the side d) moving head towards the chest e) moving head side to side as if saying “NO”. 3. Classify the following as to types of synovial joints. a) cuplike depression in hip joint b) oval surface in metacarpophalangeal joint c) saddle shaped in trapeziometacarpal joint d) spine along its longitudinal axis in atlantoaxial joint e) flexion and extension of elbow joint.