Movements and biomechanics

Anterior (ventral)

A movement towards the front, or a point or
surface in front of

Posterior (dorsal)

A movement towards the rear, or a point or
surface behind

Superior (cephalic)

Positioned above a particular reference point

Inferior (caudal)

Positioned below a particular reference point

Lateral

A point, surface or movement that is away from the midline

Medial

A point or surface close to or movement that is moving towards the midline

Distal

Further away from the trunk or root of the limb

Proximal

Closer to the trunk or root of the limb

Superficia

Closer to the surface of the body or skin

Deep

Further away from the body surface or skin

Flexion

Two adjacent body segments move closer together.

Extension

Two adjacent segments move apart.

Abduction

Movement of a body segment away from the midline of the body

Adduction

Movement of a body segment towards the midline of the body

Medial (internal) rotation

Rotation of a limb segment such that the anterior surface faces towards the midline

Lateral (external) rotation

Rotation of a limb segment such that the anterior surface faces away from the midline

Supination

Movement of the forearm so that the palm of the hand faces forwards or superiorly

Pronation

Movement of the forearm that makes the palm of hand face backwards or inferiorly

Plantar flexion

Moving the top (dorsum) of the foot away from the anterior surface of the leg and the toes point.

Dorsiflexion

Bringing the dorsum of the foot towards the anterior surface of the leg

Inversion

Movement of the foot to make the sole face medially

Eversion

Movement of the foot to make the sole face laterally

Elevation

This is when the shoulders (scapulae) are moved or shrugged superiorly

Depression

The opposite of elevation at the scapulae – inferior or downward movement caused by gravity.

Protraction

Movement of the two scapulae laterally and anteriorly (apart) leading to rounding of the shoulders

Retraction

The opposite of protraction in which the scapulae are moved
medially and posteriorly (towards each other)

Base of support (BOS)

Area beneath a person that includes all points of contact with the supporting surface, and it directly affects balance and stability.

Centre of gravity (COG)

Point in a body where its entire weight can be considered to act, crucial for understanding balance, stability, and motion.

What part of the spine is the COG anterior to?

S2

Line of Gravity (LOG)

Imaginary vertical line that passes downward from the body’s centre of gravity to the ground

How is balance maintained (LOG + BOS)

Balance is maintained when the line stays within the base of support