Which of the following describes the movement of a bone away from the midline?

In anatomy and physiology terms, movement can be described as a result of contraction or relaxation of the muscles that are attached to the bones across joints. The type of movement depends on the mobility of the joint and the position of the muscles in relation to the joint.

There are plenty of examples of the action of muscles on bones that create a movement - the most obvious ones occur at the joints of the limbs. The less obvious include less freely movable bones, like the vertebrae’s movements when bending to one side. In general, the movements are described concerning the anatomical position of the body - an upright stance, with upper limbs to the side of the body and palms facing forward.

The most common types of body movements include:

1. Flexion
This movement decreases the angle of the joint and brings two bones closer together. Example: bending the elbow or bending forward

2. Extension
The movement that is opposite to the flexion - it increases the distance between two bones or parts of the body. Example: straightening the knee or elbow.

3. Abduction
Abduction happens when there is a movement of a limb away from the midline, or median plane, of the body. Example: raising the arm or fanning the fingers.

4. Adduction
The opposite movement to abduction makes the limb move towards the body midline, just like ‘adding’ a body part by bringing it closer to the trunk. Example: lowering down a raised arm.

5. Rotation
Rotation describes a movement of a bone around its longitudinal axis, very common for ball-and-socket joints. Example: shaking the head in a ‘no’ gesture.

6. Circumduction
The combination of flexion, extension, abduction, and adduction movements, where the proximal end of the limb is stationary, and its distal end moves in a circle. The movement of the limb outlines a cone. Example: doing big arm circles

Figure 1: Most common types of body movements.

The human skeleton is made up of different shaped bones that align with each other.  The point where bones align (articulate) is called a joint.

It is the joints within our bodies that allow movement to occur so that we can sit, walk, run, talk etc.  However before we look at the joints of the body in closer detail there are some movment terms that a;; personal trainers need to know (and occasionally 'refresh' their knowledge of).

The planes of movement

Movements of the human body are often described in terms of the ‘plane’ in which they pass through.  There are three planes of the human body, these planes are shown in the following  table.

Frontal

Transverse

Sagittal

Description

The frontal plane passes through the body from left to right, dividing the body into anterior and posterior portions.

Description

The transverse plane passes through the body in a line parallel to the floor, dividing the body into top and bottom portions. 

Description

The sagittal plane passes through the body from front to back, dividing the body into left and right portions.

Example

Side to side movements occur in the frontal plane, such as raising your arms or legs out to the side like in a star jump.

Example

Twisting or rotational movements occur in the transverse plane, such as twisting your head from side to side. 

Example

Front to back movements occur in the sagittal plane, such as walking, pushing, pulling and squatting.

Joint actions

Knowing how the body moves and the actions that various joints allow is crucial for safe and effective exercise instruction.  Some of the key joint actions that you should know are detailed in the following tables.

Flexion:

Refers to movement where the angle between two bones decreases.  Flexion is commonly known as bending. 

Extension: 

Refers to movement where the angle between two bones increases.  Extension is otherwise known as straightening.  

Horizontal flexion: 

Refers to movement where the angle between two bones decreases and on the horizontal plane.

Horizontal extension: 

Refers to movement where the angle between two bones increases and occurs on the horizontal plane.

Lateral Flexion:

Refers to movement of the spine laterally away from the midline of the body.  This can be seen when we bend to one side.

Abduction: 

Is movement of a body segment away from the midline of the body.

Adduction: 

Is movement of a body segment toward the midline of the body.

Circumduction:

This is a movement where the joint is the pivot and the body segment moves in a combination of flexion, extension, adduction and abduction.

Protraction:  

This is forward movement of the scapula that results in ‘hunching’ of the shoulders.

Retraction: 

This is backward movement of the scapula as they pull together to ‘square’ the shoulders and push the chest out.

Elevation: 

Refers to the raising of the scapula to a more superior level (shrugging the shoulders). 

Depression: 

Refers to the scapula moving to a more inferior position as they are pulled downwards.

Supination: 

Hand – movement so the palm of the hand faces upward or forward (anteriorly).

Foot – combination of inversion, plantar flexion and adduction of the foot occurring at the same time.

Pronation:

Hand – movement so the palm of the hand faces downward or backward (posteriorly).

Foot – combination of eversion, dorsiflexion and abduction of the foot occurring at the same time.

Plantar flexion: 

Is moving the top of the foot away from the shin or ‘pointing’ the toes.

Dorsiflexion: 

Is moving the top of the foot toward the shin or ‘raising’ the toes.

Eversion: 

Is the movement of the foot to bring the sole of the foot to face outward. 

Inversion: 

Is the movement of the foot to bring the sole of the foot to face inward.

Rotation: 

Refers to a pivoting or ‘twisting’ movement.  Rotation is broken down further into medial and lateral rotation.

What is the movement of a bone away from the midline?

Which of the following properly describes the movement of an extremity away from the midline?

What is the medical term for movement away from the midline of the body?

Which of the following actions of the muscle that move away from the midline?