Body Movements Examples Flashcards
Protraction and retraction of the mandible
Anatomical structures: The mandible moves relative to the viscerocranium (fused bones of the skull forming the face).
Reference axes: The movement is primarily of a ‘sliding/gliding’ nature, and occurs in the sagittal plane. A very slight degree of rotation will also occur around a frontal/coronal axis.
Direction: During protrusion, the mandible moves directly anteriorly (think underbite). During retrusion, it moves directly posteriorly (think overbite).
These movements are sometimes interchanged with protraction and retraction. However, the latter pair have an additional movement added to them. Protraction is not only an anterior movement but an anterolateral one as well. This means that the structure moves forwards and laterally. Similarly, retraction also consists of an extra posteromedial movement. The scapulae are the standard example of bones that perform protraction and retraction.
Flexion and extension of the elbow
Anatomical structures: The forearm moves relative to the arm. More precisely, the ulna (one of the two forearm bones) moves relative to the humerus (bone of the arm).
Reference axes: The movement is in the sagittal plane. The fulcrum is provided by the elbow joint, around a frontal/coronal axis .
Direction: During flexion, the forearm moves upwards and ‘closer’ to the arm, resulting in a decreased angle between them. During extension it straightens, increasing the angle relative to the arm.
Flexion and extension of the shoulder
Anatomical structures: The humerus of the arm moves relative to the scapula of the shoulder blade.
Reference axes: The movement is in the sagittal plane. The fulcrum is provided by the shoulder, or glenohumeral joint, around a frontal axis.
Direction: During flexion, the arm moves anteriorly and upwards (in full flexion). During extension of the arm/shoulder joint (from a flexed position), the arm moves posteriorly and downwards, back to the anatomical position. If a full range of motion is performed, it can continue posteriorly, creating an imaginary arc or semicircle.
Flexion and extension of the neck
Anatomical structures: The skull and cervical vertebrae of the neck move relative to the thoracic vertebrae and upper back.
Reference axes: The movement is in the sagittal plane. The ‘fulcrum’ is not fixed due to the anatomy and movement of the cervical vertebrae, but it can loosely be positioned through the upper thoracic vertebrae. Movement occurs around a frontal/coronal axis.
Direction: During flexion, the head and neck move anteriorly and downwards (in full flexion). Essentially, you are looking down. During extension, it moves posteriorly and slightly downwards.
flexion and extension of the vertebral column
Anatomical structures: The vertebral column moves relative to the sacrum and hip bone.
Reference axes: The movement is in the sagittal plane. You can imagine the ‘fulcrum’ as being loosely through the two hip bones and sacrum. Movement occurs around a frontal/coronal axis.
Direction: During flexion, when you are bending forward, the vertebral column moves anteriorly and downwards (in full flexion). During extension, it moves backwards and slightly downwards.
flexion and extension of the knee
Anatomical structures: The tibia of the leg moves relative to the femur of the thigh.
Reference axes: The movement is in the sagittal plane. The fulcrum is provided by the knee joint, through which the frontal/coronal axis passes.
Direction: During flexion, the leg moves backwards (posteriorly). During extension, it moves forwards (anteriorly).
flexion and extension of the foot
In the world of anatomy, flexion of the foot is referred to as dorsiflexion and plantarflexion. Both movements happen at the ankle joint. Dorsiflexion means flexion of the dorsum (top) part of the foot by reducing the angle between it and the anterior surface of the leg. It happens when you lift the front part of your foot while keeping your heel on the ground.
Plantarflexion is flexion of the plantar (underside) part of the foot by moving it down. This movement happens when you are standing on your toes or pointing them.
Elevation and depression of the mandible
Anatomical structures: The mandible moves relative to the viscerocranium (fused bones of the skull forming the face).
Reference axes: The movement is in the frontal plane. It has a ‘fulcrum’ due to the nature of the temporomandibular joint, which is the transverse plane passing through the two respective joints.
Direction: During depression, the mandible moves directly downwards. During elevation, it moves directly upwards. You are performing these two movements when you open and close your mouth or during mastication.
Adduction and abduction of the arms and legs
Anatomical structures: The arm moves relative to the trunk and the shoulder. The leg moves relative to the hip.
Reference axes: The movement is in the frontal plane. You can imagine the ‘fulcrum’ as axes that pierce the shoulder and the hip respectively, each one following in a forward-backward trajectory.
Direction: During abduction, you are moving your arm/leg away from the median plane. During adduction, you are moving them towards the median plane. To picture these movements, imagine a child jumping and flailing his/her arms very excitedly in order to grab your attention.
Adduction and abduction of the digits
Anatomical structures: The digits move relative to the third finger of the hand or the second toe of the foot. These two entities represent the medial planes.
Reference axes: The movement can be in multiple planes, depending on the orientation of the hand or foot.
Direction: During abduction, you are moving the digits away from the third finger or second toe, hence spreading them apart from the medial plane. Adduction is the opposite - the digits are brought closer.
Rotation of the head
Anatomical structures: The head turns relative to the trunk.
Reference axes: The movement is in the transverse plane. The ‘fulcrum’ is the longitudinal/vertical axis passing up and down through the vertebral column and the crown of your head.
Direction: These two movements happen by changing the position the nose is pointing to. Turning your head laterally corresponds to lateral rotation, while turning it back to look straight ahead corresponds to medial rotation.
Rotation of the arms and legs
Anatomical structures: The anterior surface of the arm/leg turns relative to the trunk.
Reference axes: The movement is in the transverse plane. The ‘fulcrum’ is the longitudinal/vertical axis passing up and down through the arm/leg itself.
Direction: These two movements happen by changing the position of their anterior surfaces. By bringing your biceps/vastus muscles towards the midline, you are rotating them medially. If you orientate them in the opposite direction, you are rotating them laterally. For instance, if you are holding a newborn baby, your arms are medially rotated.
Pronation and supination of the forearm
Anatomical structures: The distal part of the radius rotates around the ulna. Its proximal part rotates in place.
Reference axes: The movement is in the transverse plane. The ‘fulcrum’ is the longitudinal axis passing through the ulna.
Direction: Supination is a lateral rotation of the radius, resulting in the palm of the hand facing anteriorly (if in anatomical position) or superiorly (if elbow is flexed). In contrast, pronation is a medial rotation of the radius, with the palm ending in opposite directions compared to supination. You are supinating and pronating when you hold a bowl of soup and when you empty it, respectively.
Inversion and eversion of the foot
The antagonistic movements of inversion and eversion take place relative to the median place and are specific to the foot. In eversion, the plantar side of the foot is moved away from the median plane so that it is turned laterally. In inversion, the plantar side is moved towards the median plane, resulting in a medial turn.
Eversion muscles: peroneus longus, peroneus brevis and peroneus terius
Inversion muscles: tibialis anterior and tibialis posterior
Opposition and reposition of the digits
These two movements are restricted to the digits of the hand. Essentially, they involve pinching, such as when sprinkling salt over food or snapping your fingers. Anatomically speaking, opposition involves touching the pad of any one of your fingers with the thumb of the same hand. Reposition is the reverse, which consists of separating them.
