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MVN Biomechanical Model

The data from all 17 trackers applied on the participant body is used by MVN Analyze or MVN Animate  to produce movement of an avatar. To do this, a model of the avatar is required. This biomechanical model consists of 23 segments linked through 22 joints. All joints are modeled with 3 degrees of freedom. The MVN biomechanical model, including the definition of the segment axes and origin of the frames, was designed based on the ISB biomechanical model. For the differences between these two models and further information on the axes definition, please check the chapter “23.5 Anatomical Model” and “23.6 Segment Axes Definitions and origin Definitions” in the MVN user manual.

 

Segments

The orientation of most segments is directly determined by the orientation attached to that specific segment. However, the orientation of the segments: L5, L3, T12, Neck, Right Toe and Left Toe, is estimated from sensors placed in other segments since these do not have a sensor attached to them. 

 

Index

Segments

Description

Origin of the segment frame (*)

1

Pelvis

Segment between both hip joints and joint L5S1

Midpoint between right and left hip center of rotation

2

L5

Segment between joints  jL5S1 and jL4L3

jL5S1

3

L3

Segment between joints  jL4L3 and jL1T12

jL4L3

4

T12

Segment between joints  jL1T12 and jT9T8

jL1T12

5

Sternum (T8)

Segment between joints  jT9T8 and jT1C7

jT9T8

6

Neck

Segment between joints  jT1C7 and jC1Head

jT1C7

7

Head

End segment above joint jC1Head.

jC1Head

8

Right Shoulder

Segment between joints  jRightC7Shoulder and jRightUpperArm GH

jRightC7Shoulder

9

Right Upper Arm

Segment between joints  jRightUpperArm GH and jRightElbow

jRightUpperArm

10

Right Fore Arm

Segment between joints  jRightElbow and jRightWrist

jRightElbow

11

Right Hand

End segment after joint jRightWrist.

jRightWrist

12

Left Shoulder

Segment between joints  jLeftC7Shoulder and jLeftUpperArm GH

jLeftC7Shoulder

13

Left Upper Arm

Segment between joints  jLeftUpperArm GH and jLeftElbow

jLeftUpperArm GH

14

Left Fore Arm

Segment between joints  jLeftElbow and jLeftWrist

jLeftElbow

15

Left Hand

End segment after joint jLeftWrist.

jLeftWrist

16

Right Upper Leg

Segment between joints  jRightHip and jRightKnee

jRightHip

17

Right Lower Leg

Segment between joints  jRightKnee and jRightAnkle

jRightKnee

18

Right Foot

Segment between joints  jRightAnkle and jRightToe

jRightAnkle

19

Right Toe

End segment after joint jRightToe.

jRightToe

20

Left Upper Leg

Segment between joints  jLeftHip and jLeftKnee

jLeftHip

21

Left Lower Leg

Segment between joints  jLeftKnee and jLeftAnkle

jLeftKnee

22

Left Foot

Segment between joints  jLeftAnkle and jLeftToe

jLeftAnkle

23

Left Toe

End segment after joint jLeftToe.

jLeftToe

* Check the next table to see the definition of each joint.

 

MVNAVATAR.PNG

Figure 1 - Indication of the different segments in the avatar. The numbers point for the segment with the respective index as state in the segments table above. 

 

Joints

Index

Joints

Description

 

1

jL5S1

Joint between the lumbar spine segment 5 and sacral spine 1

mceclip13.png

2

jL4L3

Joint between the lumbar spine segment 5 and sacral spine 1

mceclip11.png

3

jL1T12

Joint between the lumbar spine segment 1 and thoracic spine segment 12

mceclip10.png

4

jT9T8

Joint between the thoracic spine segment 9 and thoracic spine segment 8

mceclip22.png

5

jT1C7

Joint between the thoracic spine segment 1 and cervial spine segment 7

mceclip19.png

6

jC1Head

Joint between the cervical spine segment 1 and the head segment

mceclip2.png

7

jRightT4 Shoulder

Joint between the thoracic spine segment 4 and the right shoulder MVN segment

mceclip20.png

8

jRight Shoulder

Shoulder joint angle between the MVN shoulder segment and the upper arm, corresponding to the glenohumeral joint (GH).

mceclip17.png

9

jRight Elbow

Joint between the upper arm and the forearm. The joint origin is the midpoint between the epicondyles in MVN.

mceclip4.png

10

jRight Wrist

Joint between the forearm and the hand. In MVN, the joint center is the midpoint between the styloids

mceclip28.png

11

jLeftT4 Shoulder

Joint between the thoracic spine segment 4 and the left shoulder MVN segment

mceclip21.png

12

jLeft Shoulder

Shoulder joint angle between the MVN shoulder segment and the upper arm, corresponding to the glenohumeral joint (GH).

mceclip16.png

13

jLeft Elbow

Joint between the upper arm and the forearm. The joint origin is the midpoint between the epicondyles in MVN.

mceclip3.png

14

jLeft Wrist

Joint between the forearm and the hand.  In MVN, the joint center is the midpoint between the styloids

mceclip27.png

15

jRight Hip

Joint between the pelvis and upper leg. Center of rotation of the right hip joint.

mceclip7.png

16

jRight Knee

Joint between the upper leg and lower leg. Located in between lateral tibial condyle (LC) and medial tibial condyle (MC). Both condyles in MVN are suumed to be at the same height.

mceclip9.png

17

jRight Ankle

Joint between the lower leg and foot. Middle point between the lateral and medial malleoli. The malleoli are assumed to be at the same height in MVN.

mceclip1.png

18

jRight Ball Foot

Joint between the foot and the calculated toe.

mceclip24.png

19

jLeft Hip

Joint between the pelvis and upper leg. Center of rotation of the left hip joint.

mceclip6.png

20

jLeft Knee

Joint between the upper leg and lower leg. Located in between lateral tibial condyle (LC) and medial tibial condyle (MC). Both condyles in MVN are suumed to be at the same height.

mceclip8.png

21

jLeft Ankle

Joint between the lower leg and foot. Middle point between the lateral and medial malleoli. The malleoli are assumed to be at the same height in MVN.

mceclip0.png

22

jLeft Ball Foot

Joint between the foot and the calculated toe.

mceclip23.png

 

 Ergonomic Joint Angles

Head_T8

 

 mceclip5.png

T8_Left_UpperArm

 

mceclip14.png

Pelvis_T8

 

mceclip15.png

Vertical_Pelvis

 

mceclip25.png

Vertical_T8  

mceclip26.png

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