Joint Movements

Range of Motion (ROM)

refers to range, measured in degrees of a circle, through which bones of a joint can be moved

What are some factors that keep articular surfaces in contact and affect ROM?

structure or shape of articulation bones and strength, tension of muscles, and joint ligaments, hormones, and disuse

How do structure and shape of articulating bone affect articular surfaces and ROM?

determines how closely they fit together

How do strength, tension of muscles, and joint ligaments affect articular surfaces and ROM?

they vary to restrict or permit certain positions

How do hormones affect ROM?

relaxin increases flexibility of the pubic symphysis and loosens ligaments between sacrum and zip bone toward end of pregnancy

How does disuse affect ROM?

movement may be restricted if a joint has not been used

What four main categories are joint movements grouped into?

Gliding, angular movement, rotation, and special movements

Gliding

relatively flat bone surfaces move back-and-forth and from side-to-side with respect to one another and is limited in range

angular movement

increase or decrease in the angle between articulating bones

What are the types of angular movements?

flexion, extension, hyperextension, abduction, adduction, circumlocution

flexion

decrease in the angle, involves bending a joint

extension

increase in angle, involves straightening a joint

hyperextension

a continuation of extensions beyond normal extensions

dorsiflexion

involves moving toes or foot upward

plantar flexion

involves moving toes or foot downward

abduction

movement of a body part away from the midline

adduction

movement of a body part toward the midline

circumduction

body part moves in a circle

internal rotation

bone spins towards the body’s midline

external rotation

bone spins away from bodies midline

supination

movement of the forearm that turns the palm upward

pronation

movement of forearm that turns the palm downward

inversion

foot movement (medially) that turns sole immediately towards the other foot

eversion

foot movement that turns the sole laterally away from the other foot

protraction

moves a part forward (anteriorly)

retraction

movement back to normal, moves a part backward