weight bearing exercises increase bone mineral density (see Wolff’s Law), inactivity or weight bearing restrictions on long bones decrease bone absorption • Age: (ie: women over the age of 60 (lack of estrogen), men over the age of 70 (lack of testosterone) Joints Joint: a joint, or articulation, is the place where two bones come together (National Association of Orthopaedic Nurses, 2013). Immovable joint (synarthroses) Bones are in very close contact and are separated by a thin layer of fibrous connective tissue. Ex: the suture in the skill between skull bones. Slightly movable joint (amphiarthroses) Characterized by bones that are connected by hyaline cartilage. Ex: the ribs that connect to the sternum Freely movable joint (amphiarthroses) Most of the joints in the adult human body are freely movable, there are 6 types: 1. Ball-and-socket • The ball-shaped end of one bone fits into a cupshaped socket on another, allowing the widest ROM, including rotation. ie: shoulder & hip 2. Condyloid • An oval-shaped condyle of one bone fits into an elliptical cavity of another, allowing angular motion but not rotation. ie: metacarpals (hands & feet), phalanges (fingers & toes) 3. Saddle • The touching surfaces of two bones have both concave and convex regions, with the shapes of the two bones complementing one other and allowing a wide range of motion. ie: thumb 4. Pivot • Rounded or conical surfaces of one bone fit into a ring of another bone or tendon, allowing rotation. ie: axis & atlas in the neck 5. Hinge • A convex projection of one bone fits into a concave depression in another, permitting only flexion and extension. ie: elbow 6. Gliding • Flat or slightly flat surfaces move against each other, allowing sliding or twisting without any circular movement. ie carpals in the wrist & tarsals in the ankle Page 9 of 196 19.26 Types of Synovial Joints by Molnar & Gair is used under a CC BY 4.0 License Clients with the following conditions are at risk for joint stiffness: • Juvenile Arthritis: like adults, children can get arthritis. Arthritis is caused by inflammation of the joints and can cause pain, swelling, stiffness, and loss of motion (National Institutes of Arthritis and Musculoskeletal and Skin Diseases, 2015). • Rheumatoid Arthritis: a chronic, progressive disease that is characterized by inflammation of connective tissue with or without destruction of the joint. Unexplained periods of remissions and exacerbations also occur (Bergeron, et al., 2018). • Osteoarthritis: a joint disease marked by the degeneration of articular cartilage, hypertrophy of bone at the margins, and changes in the synovial Page 10 of 196 membrane accompanied by pain, stiffness and some swelling (Bergeron, et al., 2018). • Polymyalgia Rheumatica: causes muscle pain and stiffness in the neck, shoulder, and hip that often lasts longer than 30 minutes. Usually occurs in the morning or after periods of no movement. This condition typically develops gradually and generally goes away within one year (National Institute of Arthritis and Musculoskeletal and Skin Diseases, 2016). • Rheumatic Fever (Group A Strep): it is an acute multi-system inflammatory disease that occurs as a delayed result of pharyngeal infection with streptococcal bacterial. It can affect the heart, joints, skin, and brain. It is not directly contagious but the streptococcal infection that triggers rheumatic fever can be highly contagious (National Association of Orthopaedic Nurses, 2013). • Gout: a type of arthritis that causes painful and stiff joints that often starts in the big toe. Uric acid crystallizes and becomes supersaturated in joint fluid, especially in peripheral joints. Could cause kidney stones and/or lumps under the skin (National Institutes of Arthritis and Musculoskeletal and Skin Diseases, 2016). • Lyme disease: it is a tick-born multi-system inflammatory disease. It is also referred to as the “great imitator” because its symptoms can mimic those of mononucleosis, meningitis, multiple sclerosis, and other diseases. It is caused by the spirochete Borrelia burgdorferi transmitted by a bite from an infected tick. Person-to-person transmission does not occur. 60% of affected people experience joint pain and swelling and knees and hips are typically affected. Antibiotic treatment is critical (National