Joints: Movements, Types, and Injuries PDF

Joints Movements Allowed by Synovial Joints Three general types of movements 1. Gliding 2. Angular movements 3. Rotation Range of motion allowed by synovial joints 1. Nonaxial: slipping movements only 2. Uniaxial: movement in one plane 3. Biaxial: movement in two planes 4. Multiaxi...

Joints Movements Allowed by Synovial Joints Three general types of movements 1. Gliding 2. Angular movements 3. Rotation Range of motion allowed by synovial joints 1. Nonaxial: slipping movements only 2. Uniaxial: movement in one plane 3. Biaxial: movement in two planes 4. Multiaxial: movement in or around all three planes Adapted from Pearson Education 1. Gliding Movements One flat bone surface glides or slips over another similar surface Examples ◦ Intercarpal joints ◦ Intertarsal joints ◦ Between articular processes of vertebrae Adapted from Pearson Education 2. Angular Movements Increase or decrease angle between two bones Movement along sagittal plane Angular movements include: ◦ Flexion: decreases the angle of the joint ◦ Extension: increases the angle of the joint ◦ Hyperextension: movement beyond the anatomical position Adapted from Anatomy and Physiology 2e OpenStax.org Angular Movements (cont.) Abduction: movement along frontal plane, away from the midline Adduction: movement along frontal plane, toward the midline Circumduction ◦ Involves flexion, abduction, extension, and adduction of limb ◦ Limb describes cone in space Adapted from Anatomy and Physiology 2e OpenStax.org 3. Rotation Turning of bone around its own long axis, toward midline or away from it ◦ Medial: rotation toward midline ◦ Lateral: rotation away from midline ◦ Examples ◦ Rotation between C1 and C2 vertebrae ◦ Rotation of humerus and femur Adapted from Anatomy and Physiology 2e OpenStax.org Special Movements - Arm Supination and pronation: rotation of radius and ulna ◦ Supination: palms face anteriorly ◦ Radius and ulna are parallel ◦ Pronation: palms face posteriorly ◦ Radius rotates over ulna Adapted from Anatomy and Physiology 2e OpenStax.org Special Body Movements - Foot Dorsiflexion: bending foot toward shin Plantar flexion: pointing toes Inversion: sole of foot faces medially Eversion: sole of foot faces laterally Adapted from Anatomy and Physiology 2e OpenStax.org Special Body Movements - Mandible Protraction and retraction: movement in lateral plane ◦ Protraction: mandible juts out ◦ Retraction: mandible is pulled toward neck Elevation and depression of mandible ◦ Elevation: lifting body part superiorly ◦ Example: shrugging shoulders ◦ Depression: lowering body part ◦ Example: opening jaw Adapted from Anatomy and Physiology 2e OpenStax.org Special Body Movements - Thumb Opposition: movement of thumb ◦ Example: touching thumb to tips of other fingers on same hand or any grasping movement Adapted from Anatomy and Physiology 2e OpenStax.org Selected Synovial Joints Synovial joints are diverse All have general features, but some also have unique structural features, abilities, and weaknesses Five main synovial joints 1. Jaw (temporomandibular joint) 2. Shoulder (glenohumeral joint) 3. Elbow (humeroulnar joint) 4. Hip (acetabulofemoral joint) 5. Knee (tibiofemoral joint) Temporomandibular Joint (TMJ, 1/2) Jaw joint is a modified hinge joint Mandibular condyle articulates with temporal bone Articular capsule thickens into strong lateral ligament Two types of movement 1. Hinge: depression and elevation of mandible 2. Gliding: side-to-side (lateral excursion) grinding of teeth Adapted from Pearson Education Temporomandibular Joint (TMJ, 2/2) Most easily dislocated joint in the body because of shallow socket of joint Almost always dislocates anteriorly, causing mouth to remain open ◦ To realign, physician must push mandible back into place Symptoms: ear and face pain, tender muscles, popping sounds when opening mouth, joint stiffness Usually caused by grinding teeth, but can also be due to jaw trauma or poor occlusion of teeth ◦ Treatment for grinding teeth includes bite plate ◦ Relaxing jaw muscles helps Adapted from Pearson Education Shoulder (Glenohumeral) Joint (1/3) Most freely moving joint in body Stability is sacrificed for freedom of movement Ball-and-socket joint ◦ Large, hemispherical head of humerus fits in small, shallow glenoid cavity of scapula ◦ Like a golf ball on a tee Articular capsule enclosing cavity is also thin and loose ◦ Contributes to freedom of movement Adapted from Pearson Education Shoulder (Glenohumeral) Joint (2/3) Reinforcing ligaments ◦ Primarily on anterior aspect ◦ Coracohumeral ligament ◦ Helps support weight of upper limb ◦ Three glenohumeral ligaments ◦ Strengthen anterior capsule, but are weak support Adapted from Pearson Education Shoulder (Glenohumeral) Joint (3/3) Reinforcing muscle tendons contribute most to joint stability ◦ Tendon of long head of biceps brachii muscle is “superstabilizer” ◦ Travels through intertubercular sulcus ◦ Secures humerus to glenoid cavity ◦ Four rotator cuff tendons encircle the shoulder joint ◦ Subscapularis, Supraspinatus, Infraspinatus, Teres minor Shoulder dislocations are common injuries due to mobility in the shoulder (i.e. in sports) Structures reinforcing this joint are weakest anteriorly and inferiorly, so head of humerus can easily dislocate forward and downward Glenoid cavity provides poor support when humerus is rotated laterally and abducted ◦ ex: when football player uses arm to tackle opponent Adapted from Pearson Education Elbow Joint Humeroulnar joint Humerus articulates with radius and ulna Hinge joint formed primarily from trochlear notch of ulna articulating with trochlea of humerus ◦ Allows for flexion and extension only Anular ligament surrounds head of radius Two capsular ligaments restrict side-to- side movement 1. Ulnar collateral ligament 2. Radial collateral ligament Adapted from Pearson Education Hip (Coxal) Joint (1/2) Acetabulofemoral joint Ball-and-socket joint Large, spherical head of the femur articulates with deep cup-shaped acetabulum Good range of motion, but limited by the deep socket ◦ Acetabular labrum: rim of fibrocartilage that enhances depth of socket (hip dislocations are rare) Adapted from Anatomy and Physiology 2e OpenStax.org Hip (Coxal) Joint (2/2) Reinforcing ligaments include: 1. Iliofemoral ligament 2. Pubofemoral ligament 3. Ischiofemoral ligament 4. Ligament of head of femur (ligamentum teres) ◦ Slack during most hip movements, so not important in stabilizing ◦ Does contain artery that supplies head of femur Greatest stability comes from deep ball-and-socket joint Adapted from Pearson Education  Knee Joint (1/4) Largest, most complex joint of body Consists of three joints surrounded by single cavity 1. Femoropatellar joint ◦ Plane joint ◦ Allows gliding motion during knee flexion 2. Lateral joint and 3. Medial joint 1 ◦ Lateral and medial joints together are called tibiofemoral joint 2&3 ◦ Joint between femoral condyles and lateral and medial menisci of tibia ◦ Hinge joint that allows flexion, extension, and some rotation when knee partly flexed Adapted from Anatomy and Physiology 2e OpenStax.org Knee Joint (2/4) Joint capsule is thin and absent anteriorly Anteriorly, quadriceps tendon gives rise to three broad ligaments that run from patella to tibia ◦ Medial and lateral patellar retinacula that flank the patellar ligament ◦ Doctors tap patellar ligament to test knee-jerk reflex At least 12 bursae associated with knee joint Adapted from Anatomy and Physiology 2e OpenStax.org Knee Joint (3/4) Capsular, extracapsular, or intracapsular ligaments act to stabilize knee joint Capsular and extracapsular ligaments help prevent hyperextension of knee ◦ Fibular and tibial collateral ligaments: prevent rotation when knee is extended ◦ Oblique popliteal ligament: stabilizes posterior knee joint ◦ Arcuate popliteal ligament: reinforces joint capsule posteriorly Adapted from Pearson Education The Knee Joint (4/4) Intracapsular ligaments reside within capsule, but outside synovial cavity Help to prevent anterior-posterior displacement ◦ Anterior cruciate ligament (ACL) ◦ Attaches to anterior tibia ◦ Prevents forward sliding of tibia and stops hyperextension of knee ◦ Posterior cruciate ligament ◦ Attaches to posterior tibia ◦ Prevents backward sliding of tibia and forward sliding of femur ◦ Articular discs (menisci) ◦ Fibrocartilage separates articular surfaces ◦ Improves “fit” of bone ends, ◦ Stabilizes joint and reduces wear and tear Adapted from Anatomy and Physiology 2e OpenStax.org The Knee Joint Injuries Knee absorbs great amount of vertical force; however, it is vulnerable to horizontal blows ◦ Common knee injuries involved the 3 C’s: 1. Collateral ligaments 2. Cruciate ligaments 3. Cartilages (menisci) ◦ Lateral blows to extended knee can result in tears in tibial collateral ligament, medial meniscus, and anterior cruciate ligament ◦ Injuries affecting just ACL are common in runners who change direction, twisting ACL ◦ Surgery usually needed for repairs The “Unhappy Triad:” Ruptured ACL, Ruptured Tibial Collateral Ligament, and Torn Meniscus Adapted from Anatomy and Physiology 2e OpenStax.org Disorders of Joints Common Joint Injuries Cartilage tears ◦ Due to compression and shear stress ◦ Fragments may cause joint to lock or bind ◦ Cartilage rarely repairs itself ◦ Repaired with arthroscopic surgery ◦ Partial menisci removal renders joint less stable but mobile; complete removal leads to osteoarthritis ◦ Meniscal transplant possible in younger patients ◦ Perhaps meniscus grown from own stem cells in future Adapted from Pearson Education Common Joint Injuries (cont.) Sprains ◦ Reinforcing ligaments are stretched or torn ◦ Common sites are ankle, knee, and lumbar region of back ◦ Partial tears repair very slowly because of poor vascularization ◦ Three options if torn completely ◦ Ends of ligaments can be sewn together ◦ Replaced with grafts ◦ Just allow time and immobilization for healing Dislocations (luxations) ◦ Bones forced out of alignment ◦ Accompanied by sprains, inflammation, and difficulty moving joint ◦ Caused by serious falls or contact sports ◦ Must be reduced to treat Subluxation: partial dislocation of a joint Inflammatory and Degenerative Conditions: Bursitis, Tendonitis, and Arthritis Bursitis ◦ Inflammation of bursa, usually caused by 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 those of bursitis Arthritis ◦ >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 joint ◦ Acute forms: caused by bacteria, treated with antibiotics ◦ Chronic forms: osteoarthritis, rheumatoid arthritis, and gouty arthritis Inflammatory and Degenerative Conditions: Osteoarthritis Osteoarthritis (OA) ◦ Most common type of arthritis ◦ Irreversible, degenerative (“wear-and-tear”) arthritis ◦ May reflect excessive release of enzymes that break down articular cartilage ◦ Cartilage is broken down faster than it is replaced ◦ Bone spurs (osteophytes) may form from thickened ends of bones ◦ By age 85, half of Americans develop OA, more women than men ◦ OA is usually part of normal aging process ◦ Joints may be stiff and make crunching noise referred to as crepitus, especially upon rising ◦ Treatment: moderate activity, mild pain relievers, capsaicin creams ◦ Glucosamine, chondroitin sulfate, and nutritional supplements not effective Inflammatory and Degenerative Conditions: Rheumatoid Arthritis Rheumatoid arthritis (RA) ◦ Chronic, inflammatory, autoimmune disease of unknown cause ◦ Immune system attacks own cells ◦ Usually arises between ages 40 and 50, but may occur at any age; affects three times as many women as men ◦ Signs and symptoms include joint pain and swelling (usually bilateral), anemia, osteoporosis, muscle weakness, and cardiovascular problems ◦ RA begins with inflammation of synovial membrane (synovitis) of affected joint ◦ Inflammatory blood cells migrate to joint, release inflammatory chemicals that destroy tissues ◦ Synovial fluid accumulates, causing joint swelling ◦ Inflamed synovial membrane thickens into abnormal pannus tissue that clings to articular cartilage ◦ Pannus erodes cartilage, scar tissue forms and connects articulating bone ends (ankylosis) Inflammatory and Degenerative Conditions: Rheumatoid Arthritis (cont.) ◦ Treatment includes steroidal and nonsteroidal anti-inflammatory drugs to decrease pain and inflammation ◦ Disruption of destruction of joints by immune system ◦ Immune suppressants slow autoimmune reaction ◦ Some agents target tumor necrosis factor to block action of inflammatory chemicals ◦ Can replace joint with prosthesis Adapted from Pearson Education Inflammatory and Degenerative Conditions: Gouty Arthritis Gouty arthritis ◦ Deposition of uric acid crystals in joints and soft tissues, followed by inflammation ◦ More common in men (naturally retain more uric acid) ◦ Typically affects joint at base of great toe (cooler temps cause uric acid to crystalize) ◦ In untreated gouty arthritis, bone ends fuse and immobilize joint ◦ Treatment: drugs, plenty of water, avoidance of alcohol and foods high in purines, such as liver, kidneys, and sardines Inflammatory and Degenerative Conditions: Lyme Disease Lyme disease ◦ Caused by bacteria (Borrelia burgdorferi) transmitted by tick bites (US – deer tick) ◦ Symptoms: skin rash, flu-like symptoms, and foggy thinking ◦ May lead to joint pain and arthritis ◦ Treatment ◦ Long course of antibiotics Adapted from Pearson Education Developmental Aspects of Joints By embryonic week 8, synovial joints resemble adult joints Joint’s size, shape, and flexibility modified by use ◦ Active joints have thicker capsules and ligaments Advancing years take toll on joints ◦ Ligaments and tendons shorten and weaken ◦ Intervertebral discs more likely to herniate ◦ Most people in 70s have some degree of OA Full-range-of-motion exercise key to postponing joint problems Discussion Contrast circumduction and rotation. List the four rotator cuff tendons that encircle the glenohumeral joint. Describe the sequence of injuries that may occur if the extended, weight-bearing knee receives a very strong blow to the lateral side of the knee. 5 minutes to write it down, 5-10 min to discuss, 5-10 min share with class