# SoftBank Robotics documentation What's new in NAOqi 2.8?

# Effector & Chain definitions

This overview points out the relationship between the different names and specifies which model includes which joint:

- Body = all Joints + the 2 Actuators added at the end of the arm links
- Chain = Joints + Actuators
- Effectors = all Chain names + Torso

## Effectors

These Effector names are identical to the Chain name except for “Torso”.

Effector name | Position | End transform
--- | --- | ---
“Head” | At the neck joint | Position3D(0.0, 0.0, 0.0)
“LArm” | Inside the hand | Position3D(HandOffsetX, 0.0, -HandOffsetZ)
“LLeg” | Below the ankle | Position3D(0.0, 0.0, -FootHeight)
“RLeg” | Below the ankle | Position3D(0.0, 0.0, -FootHeight)
“RArm” | Inside the hand | Position3D(HandOffsetX, 0.0, -HandOffsetZ)
“Torso” | A reference point in the torso | Position3D(0.0, 0.0, 0.0)

To see the position of Effectors, see: Links.

For further details, see: Effectors.

## Chains

The table below lists the chains and all the joints included in each chain:

Body is ... | Head + LArm + LLeg + RLeg + RArm
--- | ---
The chain ... | Head | LArm | LLeg | RLeg | RArm
involves the joints ... | HeadYaw | LShoulderPitch | LHipYawPitch1 | RHipYawPitch1 | RShoulderPitch
HeadPitch | LShoulderRoll | LHipRoll | RHipRoll | RShoulderRoll
| LElbowYaw | LHipPitch | RHipPitch | RElbowYaw
| LElbowRoll | LKneePitch | RKneePitch | RElbowRoll
| LWristYaw | LAnklePitch | RAnklePitch | RWristYaw
| LHand | RAnkleRoll | LAnkleRoll | RHand

Note

1 LHipYawPitch and RHipYawPitch share the same motor so they move simultaneously and symmetrically. In case of conflicting orders, LHipYawPitch always takes the priority.

The group “Body” addresses all the joints of the robot.

It is possible to get the list of joints available on your robot using the `ALMotionProxy::getBodyNames` method, described in the section: Case 2: Programmatic access to Joint Names.

### Joint range and direction

- Head joints
- Left Arm joints, Right Arm joints
- Pelvis joints
- Left Leg joints, Right Leg joints

For further details, see: “Body”, chains and joint names.

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