Annotation -- Trunk posture

Group: Trunk posture

General definition posture: A posture represents the general alignment of one or a set of articulators (head, trunk, arms) to a particular resting configuration, which shows periodic changes known as posture shifts. Posture shifts (labelled as posture transitions) are movements associated with positioning the body.

Postures are different from actions because a) postures are less subject to frequent change and thus have larger durations, b) postures are robust (small movements do not change or distort the posture), c) whereas actions may or may not be displayed, the body is continually in one or another postural alignment. This means that when a body part is not involved in an action, it is always in a particular posture (but not vice versa, see remark below).

Definition of trunk: The trunk, or torso, is the upper body excluding the head, neck and upper limbs. It includes the thorax (chest) and abdomen (belly). The thorax extends from the neck to the diaphragm, and does not include the upper limbs. The abdomen constitutes the part of the body between the thorax and pelvis (hip area). Remark: the shoulder belongs to the category of upper limbs (arms).

Trunk posture units (-PU) are defined for each direction (e.g. left, right) and anatomical articulation (e.g. lean, rotation) separately. Direction is coded using an anatomical frame of reference, which is independent of any external observer. The direction of the movement is respective to three orthogonal planes that are defined relative to the anatomical standard position of the body (following kinematic standards). The direction coded for postures (e.g. trunk lean to left) refers to the end position.

Segmentation rules: A posture unit (-PU) is segmented in a transition and configuration phase. The posture transition phase (-PT) (posture shift) is the time segment where the articulator performs the movements for obtaining the end position. During the configuration phase (-PC) the end position of the coded articulator is maintained for the coded direction. This does not imply the obtained posture is static.

The transition onset is the starting point of the movement needed to achieve the end position, or the starting frame of the video when the movement onset is cut off. The transition offset is the time point where the transition described in the particular category is ended, or the last frame of the video if the movement offset is cut from the video. The frame following the transition offset is coded as the onset of the posture configuration. The offset of the configuration phase is the time point when the coded end position is broken off by the beginning of a new positioning movement or by an action behavior of same body part. Note: the transition phase can overlap with the retraction of an action. Remark. Not all action behaviors interrupt an ongoing position. It is thus possible that a position of a body part (e.g. head forward) is not broken off by an action by that body part (lateral head shake). When the end of the posture is cut off by the video boundary, the last frame has to be coded as the offset.

Nodes
TLF-PU
Container
Trunk lean towards a forward position. The upper body leans forward relative to the anatomical standard position.
TLF-PT
Container
Transition phase of trunk lean towards a forward position.
TLF-PC
Container
Configuration phase of trunk lean towards a forward position.
TLB-PU
Container
Trunk lean towards a backward position. The upper body leans backward relative to the anatomical standard position.
TLB-PT
Container
Transition phase of trunk lean towards a backward position.
TLB-PC
Container
Configuration phase of trunk lean towards a backward position.
TLMF-PU
Container
Trunk lean towards the frontal middle position. The upper body moves along the sagittal axis (forward or backward) that results in the anatomical standard position.
TLMF-PT
Container
Transition phase of trunk lean towards the frontal middle position.
TLMF-PC
Container
Configuration phase of trunk lean towards the frontal middle position.
TLL-PU
Container
Lateral trunk lean towards a left position. A lateral flexion of the trunk that results in the upper body leaning laterally to the left relative to the anatomical standard position.
TLL-PT
Container
Transition phase of lateral trunk lean towards a left position.
TLL-PC
Container
Configuration phase of lateral trunk lean towards a left position.
TLR
Container
Lateral trunk lean towards a right position. A lateral flexion of the trunk that results in the upper body leaning laterally to the right relative to the anatomical standard position.
TLR-PT
Container
Transition phase of lateral trunk lean towards a right position.
TLR-PC
Container
Configuration phase of lateral trunk lean towards a right position.
TLML-PU
Container
Lateral trunk lean towards the lateral middle position. A lateral flexion of the trunk (left or right) that results in the anatomical standard position.
TLML-PT
Container
Transition phase of lateral trunk lean towards the lateral middle position.
TLML-PC
Container
Configuration phase of lateral trunk lean towards the lateral middle position.
TRL-PU
Container
Lateral trunk rotation towards a left position. A rotation of the trunk around the vertical axis that results in a left alignment of the upper body relative to the anatomical standard position.
TRL-PT
Container
Transition phase of lateral rotation lean towards a left position.
TRL-PC
Container
Configuration phase of lateral rotation lean towards a left position.
TRR-PU
Container
Lateral trunk rotation towards a right position. A rotation of the trunk around the vertical axis that results in a right alignment of the upper body relative to the anatomical standard position.
TRR-PT
Container
Transition phase of lateral rotation lean towards a right position.
TRR-PC
Container
Configuration phase of lateral rotation lean towards a right position.
TRM-PU
Container
Lateral trunk rotation towards the lateral middle position. A rotation of the trunk around the vertical axis that results in the standard anatomical position.
TRM-PT
Container
Transition phase of lateral rotation lean towards the lateral middle position.
TRM-PC
Container
Configuration phase of lateral rotation lean towards the lateral middle position.
SE-PU
Container
Spine movement towards an erected position. The spine is straightened so the trunk is more erect or upright relative to the anatomical standard position.
SE-PT
Container
Transition phase of spine movement towards an erected position.
SE-PC
Container
Configuration phase of spine movement towards an erected position.
SB-PU
Container
Spine movement towards a bent position. The spine is bent so the trunk is less erect or upright relative to the anatomical standard position.
SB-PT
Container
Transition phase of spine movement towards a bent position.
SB-PC
Container
Configuration phase of spine movement towards a bent position.
SS-PU
Container
Spine movement towards the standard position. The spine takes a normal curvature associated to the anatomical standard position by bending (when was erect) or straightening (when was bent).
SS-PT
Container
Transition phase of spine movement towards the standard position.
SS-PC
Container
Configuration phase of spine movement towards the standard position.
CU-PU
Container
Chest movement towards an upward or forward position. The chest is lifted up or turned outward relative to the anatomical standard position by any combination of lifting the sternum, straightening the spine or bending it backward, pulling the shoulers backward.
CU-PT
Container
Transition phase of chest movement towards an upward or forward position.
CU-PC
Container
Configuration phase of chest movement towards an upward or forward position.
CD-PU
Container
Chest movement towards a downward or inward position. The chest is lowered or turned inward relative to the anatomical standard position by any combination of lowering the sternum, bending the spine forward and pulling the shoulders forward.
CD-PT
Container
Transition phase of chest movement towards a downward or inward position.
CD-PC
Container
Configuration phase of chest movement towards a downward or inward position.

Annotation -- Trunk posture