musculoskeletal system

functions of the skeletal system

• support- framework for the body

• movement- provides locomotion with attachment of muscles, ligaments, & tendons

• protection- protects vital organs (heart, liver, brain, lungs)

• hematopoiesis- blood formation (WBCs, RBCs and platelets)

• storage- calcium, phosphorus

“locomotor system”

bones; joints/cartilage; ligaments; muscles; tendons

bones

• 206 bones total (more than half in wrist, hands, feet, and ankles)

• babies born with 300 bones most fused by age 25

• make of calcium, phosphorus, sodium, minerals, protein, collagen

• hyoid bone is only bone not connected to any other bone

• 4 main types of bone: long, short, flat, irregular

long bones

• support/strength

• femur, tibia, radius

short bones

• facilitates movement

• irregular/cube shape

• carpals, tarsals

flat bones

• muscle attachment

• protections

• skull, scapulae, ribs, sternum

irregular bones

• attachment within joints

• pelvis, vertebrae, middle ear

diaphysis~ bone structure

main shaft portion of bone, compact bone

epiphysis~ bone structure

end of bones, spongy bone

epiphyseal plates~ bone structure

growth plates

medullary cavity~ bone structure

contains yellow marrow, in the middle of diaphysis

endosteum~ bone structure

membrane that lines medullary cavity

periosteum~ bone structure

dense white fibrous membrane covering entire surface of bone

articular cartilage

smooth covering over ends, cushions joints

red marrow

found in the ends of long bones. bodies of vertebrae and flat bones. manufactures red blood cells, white blood cells, and platelets (hematopoiesis)

yellow marrow

found in the medullary cavity of long bones mostly fat; no longer produces blood cells

axial skeleton (midline)~ divisions of skeleton

ossicles, skull, hyoid bone, ribcage, vertebral column

appendicular (hangs from) skeleton~ divisions of skeleton

• shoulder girdle; clavicle, scapula

• arm bones; humerus, ulna, radius, carpals, metacarpals, phalanges

• pelvic bone; pubic symphysis, hip bone

• leg bones; femur, patella, tibia, fibula, tarsals, metatarsals, phalanges

spine~ major bones

7 cervical vertebrae > 12 thoracic vertebrae > 5 lumbar vertebrae + sacrum

skull~ major bones

8 cranial bones, 14 facial bones, including mandible

rib cage~ major bones

12 parts of ribs; ribs 11 & 12 are floating

sternum~ major bones

• manubrium

• body

• xiphoid process

joints

classified by

• functional classification

• plus, synovial joints by type of motion

synarthrosis joint

immovable joint

• ex: skull sutures, epiphyseal plates, joint between first rib and manubrium of sternum

ampiarthrosis joint

slightly moveable joint

• ex: vertebral joints, joint of the symphysis pubis

diarthrosis “synovial” joint

freely movable joint

• ex: joints of the extremities, shoulder joints, hip joints

ball and socket~ types of joints and movement

movement in all directions (hip and shoulder)

hinge~ types of joints and movement

bending and straightening in one direction (knee and elbow)

pivot~ types of joints and movement

limited rotation (neck)

saddle~ types of joints and movement

movement back and forth and side to side; no rotation (base of thumb)

condyloid~ types of joints and movement

2 oval shaped bones that fit together. similar to ball and socket but can’t rotate (jaw, finger joints)

gliding~ types of joints and movement

joints glide over each other (carpals and tarsals)

tendon

attaches muscle to bone

injury= strain

ligaments

attach bone to bone

injury= sprain

cartilage

• soft & flexible tissue

• reduces friction in joints

  • slick surface for rotation

• distributes weight bearing

• absorbs shock

bursae

• synovial fluid filled sac

• produces synovial fluid

• reduces friction

• between bone/muscle or bone/tendon

major muscle groups; front view

• A- Deltoids~ shoulder

• B- Pectorals~ chest

• C- Biceps~ arms

• D- Abdominals~ abdomen

• E- Quadriceps~ front thigh

major muscle groups; back view

• F- Trapezius

• G- Triceps

• H- Latissimus Dorsi

• I- Gluteals

• J- Hamstrings

• K- Gastrocnemius

muscles of respiration

• intercostals in between ribs

• diaphragm dome shaped contracts and flattens with breathing

skeletal muscle~ types of muscle

• close to skeletal components

• striated

• voluntary

• locomotory actions~ movement

smooth muscles (visceral muscles)~ types of muscle

• inner walls of hollow organs like alimentary canal

• unstriated

• involuntary~ don’t have to think about digestion

• transportation of food and gametes

cardiac muscles~ types of muscle

• heart

• striated

• involuntary

• pumps heart

contractability~ muscle characteristics

the ability to become shorter/thicker

irritability/excitability~ muscle characteristics

ability to respond to stimulus

extensibility~ muscle characteristics

ability to lengthen or stretch

elasticity~ muscle characteristics

ability to return to original shape

tone~ muscle terms

state of slight tension

fatigue~ muscle terms

when overexerted, loses some power

spasm~ muscle terms

involuntary contraction/sustained contraction

atrophy~ muscle terms

degeneration or loss of muscle fiber due to lack of use/loss of nerve supply

voluntary movement~ functions of muscle

• walking, sitting, standing, maintain upright position

• balance

involuntary movement~ functions of muscle

heart to pump blood, gastrointestinal tract movement, respiration, reflexes

protection~ functions of muscle

• protect body in emergency

• cover, surround, support internal organs

misc.~ functions of muscle

• produce heat

• provides shape to body

• maintains body temp

• shivering, chills, goose flesh

musculoskeletal movements

• ankle bones: inversion~ inward; eversion~ outward

• jaw: protraction~ forward; retraction~ backward/resting

• shoulder: circumduction~ circular movement

• arm: supination~ upward; pronation~ flat down

hip movements

• flexion- forward/upward

• extension- behind your body

• abduction- out/away

• adduction- toward/across midline

• external rotation- outward

• internal rotation- inward

effects of aging on the musculoskeletal system

• bone mass/calcium loss

• vertebral column shortens

• decrease joint flexibility

• muscle cells lost (decrease strength/endurance)

• muscle cell replaced by fat

• elasticity muscle fibers lost

ESR (Erythrocyte Sedimentation Rate)

test for inflammation related to possible infection or inflammatory disorders
(rheumatoid arthritis, polymyalgia rheumatica, osteomyelitis, systemic lupus erythematosus, bone tumors)

CBC (Complete Blood Count)

WBCs, RBCs, platelets, etc.; indication of overall condition of health and musculoskeletal system

RF (Rheumatoid Factor)

measures the amount of rheumatoid factor in blood; indicator for rheumatoid arthritis

uric acid

elevated level indicative of gout

CK (Creatinine Kinase)

an enzyme found in skeletal muscle, cardiac muscle, and brain. Elevated CK indicates muscle cell injury

CRP (C-Reactive Protein)

a protein made by the liver that increases in the blood in response to inflammation, as it binds to damaged cells to mark them for removal

calcium and phosphorus

essential mineral components of bone structure and metabolism

x-ray~ imaging studies

• can diagnose fractures, dislocations, arthritis, osteoporosis, and bone tumors

• non-invasive

CT (computerized tomography)~ imaging studies

• provides 3-dimentional radiographic view diagnosing bone fracture, ligament/tendon injuries, soft tissue damage, tumors, lumbar disc herniation

• does not show nerve roots clearly

MRI (Magnetic Resonance Imaging)~ imaging studies

• magnetic field enables scanning machine to produce detailed 3D images

• does not use x-rays

• shows detail of soft tissues; disc, nerve roots, tumors

ultrasound

• non invasive

• use of sound waves/echoes

• can show soft tissue masses, osteomyelitis, infection, bone mineral density, sports injuries/fracture

• used to guide needle placement for aspiration or injection

myelogram~ diagnostic test

injects dye or air into vertebral column; used for spinal cord/vertebral column diagnostics- lesions on the spine

arthrogram~ diagnostic test

x ray or MRI study of joint; dye is injected into the joint, then a series of x rays or MRI taken; joint diagnostics

bone scan~ diagnostic test

nuclear imaging technique (IV) injection of radioisotope, which accumulates in areas of increased bone activity. A gamma camera is used for visualization.
Diagnose bone tumors, osteomyelitis, osteoporosis, inflammation, bone/joint infections, stress fx

arthroscopy~ diagnostic test

surgeon uses small endoscope, called an arthroscope; has a lens and a light source that transmits a picture to a video monitor. flexible scope used in viewing joints for diagnostic and treatment purposes.~ consider allergy to dye
example: removal of bone spur

arthrocentesis~ diagnostic test

uses needle to aspirate synovial fluid or pus from joint cavity. used to diagnose infection/inflammatory conditions and bleeding.

EMG (Electromyogram)~ diagnostic test

test of electrical conductivity; measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle
the test is used to help detect neuromuscular abnormalities

biopsy~ diagnostic test

bone or soft tissue sample is taken; sent to lab
used for detection of cancer

degenerative disorders

muscular dystrophy
carpal tunnel syndrome

muscular dystrophy~ degenerative disorders

chronic, degenerative disease of skeletal muscles that often inherited. Varying degrees of progressive weakening & muscle wasting

• cause: not known; possibly related to inadequate enzyme production

• there are multiple types that affect different muscle groups

• Duchenne type is caused by mutations on the X chromosome, leading to dysfunction of dystrophin, a protein crucial for maintaining muscle cell integrity. Females are carriers and usually don’t have symptoms. Male children inherit the disease. The condition progresses to loss of ability to walk and heart failure; death usually late teens, early 20s, but new treatment might change that

• tx: support to continue activities as normally as possible

  • exercise programs and splints/braces; can permit ambulation

  • prevent upper respiratory tract infection

Repetitive strain injury: carpal tunnel syndrome~ degenerative disorders

compression neuropathy of median nerve in wrist

• causes: repetitive movements, arthritis, trauma, gout, tumor

• s/s: progressive forearm, wrist pain, numbness, tingling, weak grip, positive Tinel sign

• treatment: wrist splinting, rest, NSAIDs corticosteroid injections, surgery

systemic disorders w/ musculoskeletal manifestation

gout
lupus
scleroderma
rickets & osteomalacia

Gout~ systemic disorders w/ musculoskeletal manifestation

purine rich foods are broken down into uric acid. if the body produces too much uric acid or cannot excrete it, uric acid crystals form in the joints leading to gout attacks. Usually affects big toe, instep, ankle, or knee but may be in any joint

• causes: genetic defects in purine metabolism enzymes or uric acid transporters; eating too much food in high in purines, high fructose diet, dehydration, drinking alcohol (especially beer), surgery, injury, diet, stress

• s/s: joint swelling, redness, severe pain

• Dx: uric acid lab test, joint aspiration for crystals

• tx: diet, avoid alcohol and high purine foods: liver, anchovies, red meat, sardines, salmon, turkey, some shellfish

  • medications (allopurinol, colchicine, corticosteroids, NSAIDs)

  • weight loss, drink plenty of fluids

Lupus~ systemic disorders w/ musculoskeletal manifestation

2 types:
Discoid Lupus Erythematosus is a chronic disease with skin manifestations of disc like patches with raised, reddish edges and depressed centers
Systemic Lupus Erythematosus: SLE (“lupus”) is an autoimmune systemic disorder that affects many body systems

• chronic multisystem autoimmune disorder; effects nearly every organ

• more common in women

• inflammation, tissue injury, organ damage

• s/s: butterfly rash on face, joint pain muscle aches, fatigue, fever, headache, appetite loss

• no cure, NSAIDs, Corticosteroids, immunosuppressive drugs, avoid sun, PT

Scleroderma (“Hard skin”)~ systemic disorders w/ musculoskeletal manifestation

• autoimmune disorder that involves chronic hardening and shrinking of connective tissues (CREST)

• localized: skin, muscle, bone

• generalized: skin, muscles, joints, internal organs

• treatment: symptom management; similar to tx of arthritis conditions

CREST~ symptoms of scleroderma

Calcinosis- calcium deposits in the skin
Raynaud’s phenomenon- spasm of blood vessels in response to cold or stress
Esophageal dysfunction- acid reflux and decrease in motility of esophagus
Sclerodactyly- thickening and tightening of the skin on the fingers and hands
Telangiectasias- dilation of capillaries causing red marks on surface of skin

Rickets & Osteomalacia~ systemic disorders w/ musculoskeletal manifestation

Rickets: caused by vitamin D deficiency in childhood, causing bones to be weak and become bowed when the child starts walking; rare in the U.S. but more common in areas with little sunlight and poor nutrition (Alaska)
Osteomalacia: Vitamin D deficiency in adults (bones softening)

tx: vitamin D, sunshine, mikl

spinal column disorders

chronic back pain; kyphosis; lordosis; scoliosis; spondylolisthesis; spinal stenosis; herniated disc

chronic back pain~ spinal column disorders

nearly 80% of all people have some type of back pain at some point in their lives
8% of Americans have chronic back pain
one of the most common reasons people go to the ER

Causes:

• muscle deconditioning leading to weak back muscles

• herniated or ruptured discs, spinal abnormalities

• trauma, aging process, poor body mechanics

prevention: maintain healthy wt, strengthen core muscles, keep proper posture and body alignment

tx options for chronic back pain

• medication: NSAIDs, muscle relaxants, antidepressants, opioids for severe pain

• epidural steroid injections: reduce inflammation around spinal nerves

• nerve blocks: to block pain signals

• radiofrequency ablation (RFA): to disrupt pain signals

• surgical procedures: used when herniated discs or nerve compression is the cause of the pain

• physical therapy: to retain posture, strengthen core muscles and teach body mechanics

• cognitive behavioral therapy: to change the negative thought patterns that worsen and use relaxation techniques and mental imaging to give a sense of control over the pain

• complimentary treatments: acupuncture, chiropractic care, biofeedback, yoga

• dietary counseling: to lose body weight

kyphosis, lordosis, scoliosis~ spinal column disorders

abnormal curvature of spine

• kyphosis- abnormal bowing of the spine at the thoracic area (hunchback)

• scoliosis- lateral curvature of the back

• lordosis- abnormal inward curvature of the lumbar region (swayback)

treatment: analgesics, NSAIDs, Vitamin D, Physical therapy, weight loss/diet, brace, surgery

spondylolisthesis~ spinal column disorders

one of the vertebrae in the spine slips out of alignment and presses down on the vertebra below it

causes: degeneration or fracture from injury or osteoporosis. can be congenital

s/s: low back pain, sciatica, stiffness, difficult walking or standing, numbness weakness or tingling in feet

tx: NSAIDs, corticosteroids, PT, back brace, surgery

spinal stenosis~ spinal column disorders

narrowing of the spinal canal in the spinal column, causing compression on the spinal cord or roots

causes: bone spurs caused by osteoarthritis, Paget’s disease (excessive bone growth), herniated disks, thick ligaments, tumors, spinal injury

s/s: numbness, tingling or weakness in hand, leg, foot, or arm, problems with walking and balance, neck pain, problems with bowel or bladder continence (L4-5 or L5-S1)

tx: NSAIDs, corticosteroids, PT, surgery

herniated disc~ spinal column disorders

causes: gradual wear and tear; trauma i.e., lifting/twisting

s/s: arm or leg pain; numbness or tingling; weakness

dx: CT, MRI, CT Myelogram; MRI gold standard for dx back pain. Shows nerve roots

tx: PT, lumbosacral brace, antispasmodic, analgesic, heat/ice, surgery, excercises

inflammatory disorders

bursitis, rheumatoid arthritis; osteoarthritis; polymyalgia rheumatica

bursitis~ inflammatory disorders

inflammation of the bursa

causes: mechanical irritation, infection, trauma, gout

s/s: swelling, pain, tenderness, decreased mobility

tx: ice for first 72 hours, then heat, rest, NSAIDs, corticosteroids, drainage of bursa

rheumatoid arthritis~ inflammatory disorders

chronic, systemic, autoimmune inflammatory disorder primarily affecting symmetrical joints; also has systemic effects

• inflammation of synovial membranes leading to pain, swelling, stiffness. Can lead to crippling ulnar drift in hands and hard nodules on joints

• morning stiffness > 30 min

• systemic effects: increased risk of heart disease, pericarditis, interstitial lung disease, pleuritis, muscle weakness, fatigue, osteoporosis, carpal tunnel, peripheral neuropathy, Sjogren’s syndrome (dry eyes, mouth, skin), anemia, Felty’s syndrome (splenomegaly, neutropenia, rheumatoid arthritis), infections

• cause: autoimmune; virus can trigger

• dx: elevated ESR, positive for rheumatoid factor

• tx: heat/ice, PT, NSAIDs, ASA, rest, ROM, steroids, good nutrition

osteoarthritis~ inflammatory disorders

• wear and tear on joint cartilage causes cartilage to wear away, exposing bone; bone ends rub together causing osteophytes to form. Overgrowth of bone causes stiffness, crepitus, restricted ROM

• affects asymmetrical joints

• morning stiffness <30 minutes

• osteophytes in joints of fingers called Heberdon’s nodes

• not systemic

• particles of cartilage break off and float around

• causes: obesity, injury, overuse, genetics

• tx: NSAIDs, ASA, steroids, removal spurs, heat/ice

osteoarthritis vs rheumatoid arthritis

• osteoarthritis: degenerative disease; morning stiffness <30 minutes; Heberden’s nodes; cartilage loss; asymmetrical

• rheumatoid arthritis: autoimmune disease; morning stiffness >30 minutes; extraarticular involvement; inflamed synovium; symmetrical

polymyalgia rheumatica (PMR)~ inflammatory disorders

systemic inflammatory disorder affecting muscles. More common in women

• s/s: muscle pain and stiffness, especially in the shoulders, hips, and neck; difficult raising the arms above the shoulders; systemic s/s include fever, fatigue, weight loss

• cause: unknown, but likely autoimmune with possible environmental triggers (infections, vaccinations, and some medications, such as statins)

• dx: based on s/s, elevated ESR, elevated CRP (C reactive protein, which is a protein produced by the liver in response to inflammation)

• tx: low dose corticosteroids, physical therapy, analgesics, exercise and stress management

• prognosis: most improve within a few months, but some experience relapses or have long term effects

traumatic injuries

sprain/strain; dislocation; fracture; amputation

strains~ traumatic injuries

muscles or tendons

• strains affect muscles or tendons- thick bands that attach muscles to bones

• they occur in reaction to a quick tear, twist, or pull of the muscle

• they usually result from overstretching or over contraction

• typical symptom are pain, weakness, and muscle spasms

sprains~ traumatic injuries

ligaments

• sprains occur in ligaments- thick bands of cartilage that attach one bone to another

• they occur in response to a stretch or tear of ligament

• they usually result from traumas like a fall or an external force that displaces the surrounding joint from its normal alignment

• typical symptoms are bruising, swelling, instability, and painful movement