Chapter 8 Joints and Movements PDF

- This interdigitation adds CHAPTER 8 considerable stability to sutures....

- This interdigitation adds CHAPTER 8 considerable stability to sutures. The tissue between the bones is dense, 8.1 classes of joints regular collagenous connective tissue, and Joints - articulations, are commonly named the periosteum on the inner and outer according to the bones or portions of bones surfaces of the adjacent bones continues that join together. over the joint. Example: Cranial suture - a type of bony articulation Temporomandibular joint - between the found in the skull; immovable. temporal bone and the mandible. Sutural ligament - formed through the two Cubital joint - joint for elbow joint layers of periosteum plus the dense fibrous connective tissue in between the bones. JOINT CLASSIFICATION (according to Fontanel - the membrane area of some their degree of motion) sutures in newborns; they make the skulls 1. Synarthroses - non movable joints flexible during the birth process and allow 2. Amphiarthroses - slightly movable for growth of the head after birth. joints Synotosis - when a suture becomes fully 3. Diarthroses - freely movable joints ossified; results when when two bones grow together across a joint to form a single JOINT CLASSIFICATION (according to the bone. major connective tissue type that binds the bones together) b. Syndesmoses (syndesmosis) 1. FIBROUS JOINTS - slightly movable type of - the connections between fibrous joint. two bones that are held - The bones are farther apart together by fibrous than in a suture and are connective tissue. joined by ligaments. - No joint cavity - Some movements occur - Little to no movement because ligaments are - Can be synarthroses or flexible. amphiarthroses Example: radioulnar syndesmosis - binds the ulna and radius together Fibrous joints subdivision: Syndesmoses - two parallel bones are a. Sutures - seams found only united with each other by interosseous between the bones of the skull. membrane or ligaments based on the gap - Some sutures may become between the bones; allows movement. completely immovable in c. Gomphoses older adults. - are specialized joints - Few sutures are smooth, and consisting of pegs that fit into the opposing bones often sockets and are held in place interdigitate (have by fine bundles of regular interlocking, fingerlike collagenous connective processes). tissue.  - The only gomphoses in the 2. CARTILAGINOUS JOINTS human body are the joints - hold two bones together by between the teeth and the a pad of cartilage. sockets (alveoli) of the - Little to no movement. mandible and maxillae. Gomphoses - a joint that anchors a tooth to Cartilaginous joints subdivision its socket. a. Synchondroses Periodontal ligaments - The connective - consists of two bones joined tissue bundles between the teeth and their by hyaline cartilage where socket. They allow a slight amount of “give” little or no movement occurs. to the teeth during mastication. - Most synchondroses are Biofilm - the accumulation of plaque and temporary. (ex.: epiphyseal bacteria; consists of a group of microbes plate) embedded within a slime-based - In the case of epiphyseal extracellular matrix. plates, the synchondrosis is Periodontal disease - the accumulation of converted to synostosis as plaque and bacteria can destroy the bone replaces the existing periodontal ligaments and the bones; the cartilage. leading cause of tooth loss. - Other synchondroses can be converted to synovial joints. (example: costochondral joints) Costachondral joints - joints between the ribs and the costal cartilages. These joints begin as synchondroses but, because movement occurs between them and the sternum, all but the first usually develop synovial joints at those junctions. Some synchondroses persist in the adult is the sternocostal synchondrosis. sternocostal synchondrosis - joints between the first rib and the sternum. b. symphyses - consists of two bones joined by a pad of fibrocartilage. - Slightly movable because of the somewhat flexible nature of fibrocartilage. - Example is the intervertebral disk Intervertebral disk - , the junction between the manubrium and the body of the sternum and the pubic symphysis; also acts as a 2 layers of joint capsule shock absorber between the vertebrae. 1. Outer fibrous capsule 3. SYNOVIAL JOINTS 2. Inner fibrous capsule - the synovial - contain synovial fluid and membrane allow considerable - It lines the joint cavity, except movement between over the articular cartilage articulating bones. and articular disks. - anatomically more complex - This thin, delicate membrane than fibrous and cartilaginous consists of a collection of joints. modified connective tissue - Most joints that unite the cells either intermixed with bones of the appendicular part of the fibrous capsule or skeleton are synovial joints, separated from it by a layer reflecting the far greater of areolar tissue or adipose mobility of the appendicular tissue. skeleton compared with the axial skeleton. Fibrous capsule - is the outer layer of the Articular cartilage - thin layer of hyaline joint capsule. cartilage that covers the articular surface of - Consists of dense irregular the synovial joint; provides a smooth connective tissue and is continuous surface where the bones meet. with the fibrous layer of the Articular disk - a flat pad of fibrocartilage, periosteum that covers the bones lies between the articular cartilages of the and united at the joint. bones. - Portions of the fibrous capsule may Meniscus - is a type of articular disk that thicken, and the collagen fibers may only partially spans the synovial cavity such become regularly arranged to form that there is an opening in the center. Joints ligaments. with menisci include the knee and wrist, Fat pads - prominent areas of adipose while the disks in the temporomandibular, tissue in some joints, such as the elbows sternoclavicular, and acromioclavicular and knees. joints span the entire cavity. - They lie between the fibrous capsule and the synovial membrane. Meniscus - a crescent-shaped, cartilaginous - Fat pads help protect the articular band between the medial tibial and medial cartilage by acting as a cushion femoral condyle. around the joints. Bursa - synovial membrane extends as a Joint cavity - The space around the articular pocket. surfaces of the bones in a synovial joint. - can extend for a distance away from the rest of the joint cavity. The joint cavity is filled with synovial fluid Tendon sheaths - formed when bursae and surrounded by a joint capsule. extend along tendons for some distance. Bursitis - inflammation of a bursa, may Joint capsule - helps hold the bones cause considerable pain around the joint together while still allowing for movement. and restrict movement. Cartilage does not contain blood vessels. - Ex,: articular processes Nerves do not enter the cartilage or joint between vertebrae cavity. b. Saddle - consists of two saddle-shaped articulating surfaces Arthritis - inflammation of the joints oriented at right angles to each other Different types of arthritis: so that their complementary a. Osteoarthritis surfaces articulate. - most common type of - Biaxial joints arthritis - Ex.: carpometacarpal joint of - Noninflammatory the thumb - Gradual degradation of the c. Hinge joint - a uniaxial joint in which articular cartilage due to a convex cylinder in one bone is overuse or advancing age. applied to a corresponding concavity Osteoarthritis is a degenerative joint in the other bone. disease, in which the tissues in the joint - Ex.: elbow and knee joints break down over time. d. Pivot joint - consists of a relatively - cylindrical bony process that rotates b. Rheumatoid arthritis (RA) within a ring composed partly of - Second most common type bone and partly of ligament. of arthritis - Uniaxial - general, inflammatory - Ex.: the articulation between connective tissue disorder the head of the radius and that affects the skin, vessels, the proximal end of the ulna. lungs, and other organs, but - Ex.: articulation between the it is most pronounced in dens and the atlas joints. e. Ball-and-socket joint - consists of a Rheumatoid arthritis - a chronic ball (head) at the end of one bone (long-lasting) autoimmune disease that and a socket in an adjacent bone mostly affects joints. into which a portion of the ball fits. c. Gouty arthritis - metabolic.disorder; - Multiaxial swollen joints caused by uric crystals - Ex.: shoulder and hip joints that accumulate in the joint. ball-and-socket is a joint in which the rounded surface of a bone moves within a Movements of synovial joints: depression on another bone, allowing a. Uniaxial - occurring around one axis greater freedom of movement than any b. Biaxial - two axes other kind of joint. c. Multiaxial - several axes f. Ellipsoid joint - (condyloid joint) is a modified ball-and-socket joint. Types of synovial joints: - The articular surfaces are a. Plane joint (gliding joint) - consists ellipsoid in shape, rather than of two flat bone surfaces of about spherical as in regular equal size between which a slight ball-and-socket joints. gliding motion can occur. - Biaxial - Uniaxial - Ex.: atlantaoccipital joint  - Ex.: when a person attempts to break a fall by putting out a hand, 8.2 types of movement the force of the fall can result in Some joints are limited to only one type of hyperextension of the wrist, resulting movement; others can move in several in a sprained joint or broken bone. directions. Flexion of the foot: 3 general types of movement Plantar flexion - Movement of the foot 1. Gliding movements toward the plantar surface, as when - Simplest standing on the toes. - Occur in plane joints Dorsiflexion - movement of the foot toward between two flat or nearly flat the shin, as when walking on the heels. surfaces that slide or glide Ex.: elbow and knee joints over each other. b. Abduction and adduction - often allow only slight Abduction - (to take away) is movement movement, as occurs away from the midline. between carpal bones. Adduction - (to bring together) is movement 2. Angular toward the midline. - involve changes in the angle between the bones at the Abduction adduction joint. - the trunk or a limb bends Upper limb done in the bringing the relative to another part of the outward upper limbs body. step of back toward - Most common angular jumping the body movements: flexion and jacks. extension; abduction and adduction. Hand spreads the Brings them a. Flexion and extension fingers back - Common opposing apart, away together movements from the Flexion - bending movement that decreases midline of the angle of the joint to bring the articulating the hand bones closer together. Thumb moves it Extension - a straightening movement that anteriorly, increases the angle of the joint to straighten away from the articulating bones. the palm. Hyperextension - extension of a joint Wrist (radial (ulnar beyond the anatomical position (180 deviation) deviation) degrees). moves the moves the - can be a normal movement, such as hand away hand away the movement of the neck when from the from the looking up at the stars, but it can midline of midline of also result in injury. the body the body  c. Circumduction Head involves tilting the - a combination of flexion, extension, head to one abduction, and adduction side ( commonly 4. Special movements called - those movements that are unique to lateral only one or two joints and do not fit flexion of the neck) neatly into any of the other categories. a. Elevation and depression Bending at the waist to one side is usually Elevation - moves a structure called lateral flexion of the vertebral superiorly column, rather than abduction. Depression - moves it inferiorly Ex.: shrugging the shoulders and 3. Circular movements opening and closing the mouth - rotation around an axis in a b. Protraction and retraction circular pattern or an arc. Protraction - gliding motion that a. Rotation moves a structure in an anterior - turning of a structure around direction. its long axis, as in rotating Ex.: Jutting out the jaw and the head to shake the head hunching the shoulders. “no” or rotating the arm or the Retraction - gliding motion that entire body. moves a structure in a posterior Medial rotation of the humerus with the direction. forearm flexed brings the hand toward the Ex.: Pulling the jaw back and body. pinching or pulling the scapulae Lateral rotation of the humerus moves the back toward the vertebral column hand away from the body. illustrate retraction. b. Pronation and supination c. Excursion - Unique rotation of the Lateral excursion - moving the forearm mandible to either the right or the left Prone - lying face down of the midline, as occurs when Supine - lying face up grinding the teeth or chewing. Pronation - rotation of the forearm so that Medial excursion - returns the the palm faces posteriorly in relation to the mandible to the midline position. anatomical position. d. Opposition and reposition (The palm of the hand faces inferiorly if the Opposition - a movement unique to elbow is flexed to 90 degrees.) the thumb. It occurs when the thumb Supination - rotation of the forearm so that and the tip of a finger on the same the palm faces anteriorly in relation to the hand are brought toward each other anatomical position. across the palm. (The palm of the hand faces superiorly if the Reposition - returns the thumb to the elbow is flexed to 90 degrees.) neutral, anatomical position e. Inversion and eversion  Inversion - turns the ankle so that Subluxation - a partial dislocation. the plantar surface of the foot faces medially, toward the opposite foot, Dislocations are often accompanied by with the weight on the outside edge painful damage to the supporting ligaments of the foot (rolling out). and articular cartilage. Eversion - turns the ankle so that the plantar surface faces laterally, with Sprain - occurs when ligaments are the weight on the inside edge of the damaged. The degree of damage can range foot (rolling in) from stretched to completely torn ligaments. - often result in inflammation, swelling, and pain. 8.3 range of motion Strain - muscles or tendon (tissues that describes the amount of mobility that attaches to the bone) is stretched too far. can be demonstrated in a given joint. Overstretched or “pulled muscle.” Active range of motion - the amount of movement that can be accomplished by Dislocations and sprains are common contracting the muscles that normally act sports injuries. across a joint. Passive range of motion - the amount of The range of motion for a given joint is movement that can be accomplished when influenced by a number of factors that are the structures that meet at the joint are determined by the properties of the joint and moved by an outside force, as when a surrounding tissue: therapist holds on to a patient’s forearm and 1. Shape of the articular surfaces of the moves it toward the arm, flexing the elbow bones forming the joint joint. 2. Amount and shape of cartilage covering those articular surfaces Passive range of motion for normal joints is 3. Strength and location of ligaments, somewhat greater than active range of tendons, and muscles associated with the motion. However, when comparing range of joint motion of a normal joint to that of an injured 4. Bulk of surrounding tissues, such as joint, such as a dislocation, passive and muscle and adipose tissue active ranges of motion are not dramatically 5. Amount of fluid in and around the joint different. 6. Amount of pain in and around the joint 7. Amount of use or disuse the joint has movement of joints beyond the normal received over time. range of motion can cause dislocations and sprains. 1. TEMPOROMANDIBULAR JOINT (TMJ) Dislocation (luxation) - of a joint occurs - Formed when the mandible when the articulating surfaces of the bones articulates with the temporal bone. are moved out of proper alignment. - a combination plane and ellipsoid Dislocation is the injury in which bones are joint, with the ellipsoid portion disconnected from a joint socket that holds predominating. them in place. The mandibular condyle fits into the The four muscles are referred to collectively mandibular fossa of the temporal bone. as the rotator cuff. Rotator cuff - holds the humeral head tightly Fibrocartilage articular disk - located within the glenoid cavity. between the mandible and the temporal bone, dividing the joint into superior and Dislocation of bones and tears in inferior joint cavities muscles or tendons are the most common traumatic disorders. 2. SHOULDER JOINT (glenohumeral joint) Shoulder - most commonly dislocated joint - located between the in the body. mandible and the temporal Axilla - contains very important nerves and bone, dividing the joint into arteries, severe and permanent damage superior and inferior joint may occur when the humeral head cavities dislocates inferiorly. Glenoid labrum - a fibrocartilage ring to Axillary nerve - most commonly damaged which the joint capsule is attached. nerve. - builds up the rim of the glenoid Chronic shoulder disorders: cavity. a. Tendinitis - inflammation of 2 bursae in the shoulder joint: tendons; overuse of a joint a. Subscapular bursa - opens into Ex.: tennis elbow the joint cavity. b. Bursitis - inflammation of bursae b. Subacromial bursa - near the joint c. Arthritis - inflammation of joints cavity, but separated from the cavity by the joint capsule. Bursitis of the subacromial bursa can The stability of the shoulder joint is become very painful when the large maintained primarily by four sets of shoulder muscle, called the deltoid ligaments and four muscles. muscle, compresses the bursa during shoulder movement Four sets of ligaments: 1. Glenohumeral 3. ELBOW JOINT (cubital joint) 2. Transverse humeral - a compound hinge joint 3. Coracohumeral - Consists of: 4. Coracoacromial a. Humeroulnar joint - between the humerus and ulna b. Humeroradial joint - between the humerus and radius c. Proximal radioulnar joint - between the proximal radius and ulna. Elbow’s two types of movement: crosses the acetabular notch on the inferior - flexion/extension edge of the acetabulum. - pronation/supination Hip - capable of a wide range of movement, Flexion/extension occurs at the including flexion, extension, abduction, humeroulnar and humeroradial adduction, rotation, and circumduction. joints. These joints are limited to flexion Ligaments of the hip joints: and extension because of the shape 1. Transverse acetabular of the trochlear notch and its 2. Iliofemoral ligament - especially association with the trochlea of the strong; supports the body’s weight. humerus. 3. Pubofemoral 4. Ischiofemoral Pronation/supination occurs at the 5. Ligament of the head of the femur proximal radioulnar joint. - round ligament of the femur; is located inside the hip joint between Ulnar collateral ligament - reinforces the femoral head and the humeroulnar joint. acetabulum. Radial collateral ligament - - does not contribute much reinforces humeroradial and toward strengthening the hip proximal radioulnar joints. joint Olecranon bursa - covers the - carry a small nutrient artery proximal and posterior surfaces of to the head of the femur in the olecranon process. about 80% of the population. Olecranon bursitis - inflammation of the olecranon bursa. 5. KNEE JOINT - It can be caused by - modified hinge joint located excessive pressure of the between the femur and the elbow against a hard surface tibia. and is sometimes referred to The knee forms a complex ellipsoid union as student’s elbow. that allows flexion, extension, and a small Nursemaid’s elbow - When the radial head amount of rotation of the leg. is partially separated The distal end of the femur has two large, 4. HIP JOINT ellipsoid surfaces with a deep fossa - Formed when the femoral between them. head articulates with the The femur articulates with the tibia, not with relatively deep, concave the fibula. The fibula articulates only with acetabulum of the hip bone the lateral side of the tibia. (or coxal joint). Acetabular labrum - a lip of fibrocartilage, The proximal end of the tibia is flattened which is incomplete inferiorly and deepens and smooth laterally, with a crest called the and strengthens the acetabulum. intercondylar eminence in the center. Transverse acetabular ligament - further The margins of the tibia are built up by deepens and strengthens the acetabulum; menisci. Menisci - are thick, articular disks of Fibrous capsule - surrounds the joint, with fibrocartilage that deepen the articular the medial and lateral parts thickened to surface. form ligaments. Four major ligaments that provide knee Movements at the ankle joint: joint stability: a. Dorsiflexion a. Anterior cruciate ligament - b. Plantar flexion prevents anterior displacement of c. Limited inversion and eversion the tibia relative to the femur. b. Posterior cruciate - prevents Flat feet or fallen arches- results when foot posterior displacement of the tibia. arch fails to form. The two cruciate ligaments extend between - Where the medial longitudinal arch, the intercondylar eminence of the tibia and is depressed or collapsed. the fossa of the femur - may also occur when the muscles c. Medial collateral ligament and ligaments supporting the arch d. Lateral collateral ligament fatigue and allow the arch, usually the medial longitudinal arch, to The medial (tibial) and lateral (fibular) collapse. collateral ligaments stabilize the medial and - During prolonged standing, the lateral sides, respectively, of the knee. plantar calcaneonavicular ligament may stretch, flattening the medial Popliteal ligaments - (together with the longitudinal arch. tendons of the thigh muscle) provide joint Plantar fascia - is composed of the deep strength to the knee. connective tissue superficial to the Suprapetellar bursa - largest bursa that ligaments in the central plantar surface of surrounds the knee. a superior extension of the foot and the thinner fascia on the medial the joint capsule that allows the anterior and lateral sides of the plantar surface. thigh muscles to move over the distal end of Plantar fasciitis - inflammation of the the femur. plantar fascia, can be a problem for Types of knee bursae: distance runners. a. Suprapatellar bursa b. Subcutaneous Prepatellar bursa Ligaments of the knee joints: c. Deep Infrapatellar bursa a. Anterior cruciate d. Popliteal bursa b. Posterior cruciate e. Gastrocnemius bursa c. Medial (tibial) collateral f. Subcutabeous Infrapatellar bursa d. Lateral (fibular) collateral e. Patellar 6. ANKLE JOINT AND ARCHES OF THE f. Patellar retinaculum FOOT g. Oblique popliteal Ankle joint - (or talocrural) a highly modified h. Arcuate popliteal hinge joint formed by two articulations i. Coronary (medial and lateral) between the distal tibia and fibula with the j. Transverse talus in one joint capsule. k. Meniscofemoral (anterior and posterior) Injuries to the medial side of the knee are Representative diseases and disorders of much more common than injuries to the joints lateral side for several reasons. 1. Arthritis - Inflammation of a joint, a. Lateral collateral ligament - leading to pain and stiffness of the strengthens the joint laterally and is joint stronger than the medial (tibial) 2. Rheumatoid arthritis - General collateral ligament. connective tissue autoimmune b. Severe blows on the medial side is disorder that predominantly affects far less common joints c. Medial meniscus - is fairly tightly 3. Gout - Group of metabolic disorders attached to the medial collateral that lead to increased production ligament and is damaged 20 times and accumulation of uric acid more often in knee injuries than the crystals in tissues, including joint lateral meniscus, which is thinner capsules; can lead to arthritis. and not attached to the lateral 4. Lyme disease - Group of metabolic collateral ligament. disorders that lead to increased Torn meniscus - may cause a “clicking” production and accumulation of uric sound during extension of the leg. acid crystals in tissues, including Anterior cruciate ligament - may be torn if joint capsules; can lead to arthritis. the knee is driven anteriorly or 5. Bursitis - Group of metabolic hyperextended, which makes the knee disorders that lead to increased joints very unstable. production and accumulation of uric Posterior cruciate ligament - may be torn if acid crystals in tissues, including the knee is flexed and the tibia is driven joint capsules; can lead to arthritis. posteriorly. 6. Bunion - deformations of the first - Surgical replacement of a cruciate metatarsal (the great toe); bursitis ligament with a transplanted or may accompany this deformity; artificial ligament repairs the irritated by tight shoes. damage. 7. Tendinitis - Inflammation of tendon Unhappy triad of injuries - Tearing of the sheaths, often from overuse, such medial collateral ligament, medial meniscus, as tennis elbow and anterior cruciate ligament. 8. Dislocation - Movement of bones out of their correct alignment at a joint; a Ligaments of the ankle and arch partial dislocation is a subluxation. a. Medial (deltoid) 9. Sprain - stretching or tearing of b. Anterior talofibular ligaments supporting a joint. c. Calcaneofibular 10. Chondromalacia patellae - d. Long plantar Inflammation under the patella and e. Plantar calcaneocuboid softening of the cartilage; common in f. Plantar calcaneonavicular young athletes, as well as older active adults. \ Effects of aging on the joints Those that occur in synovial joints have the greatest impact and often present major problems for elderly people. as a person ages, the tissues of the body become less flexible and less elastic. the flexibilty and strength of tendons and ligaments decrease with age. Tissue repair slows as cell proliferation rates decline and the rate of new blood vessel development decreases. Muscles also tend to weaken Less physically active, less flexible joints, decreases the range of motion. The most effective preventive measure against the effects of aging on the joints is to strengthen the bones and muscles and maintain flexibility. This can be accomplished through a combination of regular physical activity, stretching, and a healthy diet.