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Table of Contents
this marker set provides insufficient data to build 6 degree of freedom segments in visual3d, and also provides insufficient data to adequately define 3 dimensional arm movements without adding constraints. it provides, however, more than sufficient information for a 3dsspp model.
the subject may be facing in any direction, so it is recommended that a virtual laboratory be defined to accommodate this.
many landmarks must be created to give this marker set 3d anatomical meaning. the model template is defined as follows:
anatomical measurements
there are several anatomical dimensions that should be measured. this marker set isn't particularly useful for 3d biomechanics but the inclusion of these dimensions makes the model moderately better. the default values will still create an animation of the movement that is representative visually. the default values are listed.
shoulder radius (measured ap) = 0.04 elbow radius (measured ml) = 0.04 wrist radius (measured ap) = 0.04 knee radius (measured ml) = 0.06 ankle radius (measured ml) = 0.06 foot radius (half the distance between first and fifth metatarsal) = 0.07
laboratory landmarks (not calibration only)
| name | starting point | existing segment | offset x | offset y | offset z |
| lab_origin | lab | 0 | 0 | 0 | |
| lab_x | lab | 0.1 | 0 | 0 | |
| lab_y | lab | 0 | 0.1 | 0 | |
| lab_z | lab | 0 | 0 | 0.1 | |
| lab |
virtual laboratory segment
| proximal lateral | proximal joint | proximal medial | proximal radius |
| lab_z | 0.01 | ||
| distal lateral | distal joint | distal medial | distal radius |
| lab_origin | 0.01 | ||
| location | lateral | lab_x | |
| tracking targets | |||
| lab_origin | lab_x | lab_y | lab_z |
static landmarks (calibration only)
| name | starting point | ending point | lateral object | offset ml | offset ap | offset axial |
| right_hip_static | rhip | lhip | 0.25 by percent | |||
| left_hip_static | lhip | rhip | 0.25 by percent | |||
| r_shoulder_static | rsho | lsho | shoulder_radius | |||
| l_shoulder_static | lsho | rsho | shoulder_radius | |||
| r_elbow_static | relb | rsho | lsho | -elbow_radius | ||
| l_elbow_static | lebl | lsho | rsho | -elbow_radius |
pelvis, trunk and head segment (rtk)
the pelvis, trunk and head are represented as one segment. this is perhaps the biggest limitation of creating a 3d biomechanical model using the 3dsspp marker set. note that the 3dsspp model isn't really meant for biomechanics of an individual segment, so this model is simply a visual representation of the movement.
| proximal lateral | proximal joint | proximal medial | proximal radius |
| rhip | lhip | ||
| distal lateral | distal joint | distal medial | distal radius |
| rsho | lsho | ||
| location | lateral | ||
| tracking targets | |||
| l4 | lhip | rhip | neck |
| roff |
four tracking landmarks are created relative to the pelvis, trunk and head segment
| name | starting point | existing segment | offset to existing calibration target or landmark |
| right_hip | rtk | right_hip_static | |
| left_hip | rtk | left_hip_static | |
| r_shoulder | rtk | r_shoulder_static | |
| l_shoulder | rtk | l_shoulder_static |
right thigh (rth)
| proximal lateral | proximal joint | proximal medial | proximal radius |
| rhip | right_hip | ||
| distal lateral | distal joint | distal medial | distal radius |
| rkne | knee_radius | ||
| location | lateral | ||
| tracking targets | |||
| rhip | right_hip | rkne |
one tracking landmark is created relative to the right thigh
| name | starting point | existing segment | ml offset | ap_offset | axial_offset |
| right_knee | rth | 0 | 0 | -1.0 as percent |
left thigh (lth)
| proximal lateral | proximal joint | proximal medial | proximal radius |
| lhip | left_hip | ||
| distal lateral | distal joint | distal medial | distal radius |
| lkne | knee_radius | ||
| location | lateral | ||
| tracking targets | |||
| lhip | left_hip | lkne |
one tracking landmark is created relative to the left thigh
| name | starting point | existing segment | ml offset | ap_offset | axial_offset |
| left_knee | lth | 0 | 0 | -1.0 as percent |
right shank (rsk)
| proximal lateral | proximal joint | proximal medial | proximal radius |
| rkne | right_knee | ||
| distal lateral | distal joint | distal medial | distal radius |
| rank | ankle_radius | ||
| location | lateral | ||
| tracking targets | |||
| rkne | right_knee | rank |
one tracking landmark is created relative to the right thigh
| name | starting point | existing segment | ml offset | ap_offset | axial_offset |
| right_ankle | rsk | 0 | 0 | -1.0 as percent |
left shank (lsk)
| proximal lateral | proximal joint | proximal medial | proximal radius |
| lkne | left_knee | ||
| distal lateral | distal joint | distal medial | distal radius |
| lank | ankle_radius | ||
| location | lateral | ||
| tracking targets | |||
| lkne | left_knee | lank |
one tracking landmark is created relative to the left thigh
| name | starting point | existing segment | ml offset | ap_offset | axial_offset |
| left_ankle | lsk | 0 | 0 | -1.0 as percent |
right foot (rft)
| proximal lateral | proximal joint | proximal medial | proximal radius |
| rank | right_ankle | ||
| distal lateral | distal joint | distal medial | distal radius |
| rfoo | foot_radius | ||
| location | lateral | ||
| tracking targets | |||
| rank | right_ankle | rfoo |
one tracking landmark is created relative to the right thigh
| name | starting point | existing segment | ml offset | ap_offset | axial_offset |
| right_ankle | rsk | 0 | 0 | -1.0 as percent |
left foot (lft)
| proximal lateral | proximal joint | proximal medial | proximal radius |
| lank | left_ankle | ||
| distal lateral | distal joint | distal medial | distal radius |
| lfoo | foot_radius | ||
| location | lateral | ||
| tracking targets | |||
| lank | 'left_ankle | lfoo |
one tracking landmark is created relative to the left thigh
| name | starting point | existing segment | ml offset | ap_offset | axial_offset |
| left_ankle | lsk | 0 | 0 | -1.0 as percent |
right arm (rar)
if the elbows are flexed during the standing trial, we can use the plane defined by the shoulder, elbow, and wrist markers to determine the calibration_only elbow joint center
| name | starting point | ending point | lateral object | offset ml | offset ap | offset axial |
| r_elbow_static | relb | rsho | rhan | 0 | elbow_radius | 0 |
the right arm segment includes the right hand.
| proximal lateral | proximal joint | proximal medial | proximal radius |
| r_shoulder_static | shoulder_radius | ||
| distal lateral | distal joint | distal medial | distal radius |
| r_elbow_static | elbow_radius | ||
| location | anterior | rhan | |
| tracking targets | |||
| r_shoulder | 'rsho | relb |
one tracking landmark is created relative to the right arm
| name | starting point | existing segment | ml offset | ap_offset | axial_offset |
| right_elbow | rar | 0 | 0 | -1.0 as percent |
left arm (lar)
if the elbows are flexed during the standing trial, we can use the plane defined by the shoulder, elbow, and wrist markers to determine the calibration_only elbow joint center
| name | starting point | ending point | lateral object | offset ml | offset ap | offset axial |
| l_elbow_static | lelb | lsho | lhan | 0 | -elbow_radius | 0 |
the right arm segment.
| proximal lateral | proximal joint | proximal medial | proximal radius |
| l_shoulder_static | shoulder_radius | ||
| distal lateral | distal joint | distal medial | distal radius |
| l_elbow_static | elbow_radius | ||
| location | anterior | lhan | |
| tracking targets | |||
| l_shoulder | lsho | lelb |
one tracking landmark is created relative to the left arm
| name | starting point | existing segment | ml offset | ap_offset | axial_offset |
| left_elbow | lar | 0 | 0 | -1.0 as percent |
right forearm (rfa)
the right forearm segment includes the right hand.
| proximal lateral | proximal joint | proximal medial | proximal radius |
| right_elbow | elbow_radius | ||
| distal lateral | distal joint | distal medial | distal radius |
| rhan | wrist_radius | ||
| location | posterior | relb | |
| tracking targets | |||
| right_elbow | relb | rhan |
left forearm (lfa)
the left forearm segment includes the left hand.
| proximal lateral | proximal joint | proximal medial | proximal radius |
| left_elbow | elbow_radius | ||
| distal lateral | distal joint | distal medial | distal radius |
| lhan | wrist_radius | ||
| location | posterior | lelb | |
| tracking targets | |||
| left_elbow | lelb | lhan |