KineMan

Interactive 3D Articulated Skeleton






FAQ

General

Why is this software called KineMan (and how do you pronounce it)?
Is there a ‘KineWoman’?
What is a degree of freedom (DOF)?

Controls & Indicators

How do I zoom in & out?
What are the red, blue, & green lines for?
Why does the acromio-clavicular joint show 3 sliders, but only 1 works?

Specific Joints

How do I select basic joints like the shoulder or the knee?
Why can't I move individual joints in the hands or feet?
Why can't I move the atlas (Occiput-C1) joint all by itself (instead of moving the entire neck)?
Why can't I move the L5S1 joint all by itself (instead of moving the entire lumbar spine)?
Why can't I select bones or move individual joints in the ribcage (thorax)?
Why can't I move the full skeleton in all 6 degrees of freedom?
Why isn't there a humero-radial joint?
Why can't I move the tibio-fibular joint?
Why can't I move the tempero-mandibular joint in protrusion/retrusion?

Why does the acromio-clavicular joint show 3 sliders, but only 1 works?




General

Why is this software called KineMan (and how do you pronounce it)?

The name KineMan has a double origin:

As such, KineMan software is a tool specialized for demonstrating human motion geometry; it’s not designed to compute muscle forces, joint torques, or the like. It can also serve to replace physical mannequins in many situations, e.g., for ergonomics or artistic modeling.

KineMan rhymes with the phrase ‘spin a man’ (& not with ‘cinnamon’, ‘chinaman’, or ‘fine man’ ! )

Is there a ‘KineWoman’?

Sorry, but not yet. An alternate version of KineMan, which features female-specific anatomy & movement, may be offered in the future. Please stay tuned!

What is a degree of freedom (DOF)?

A degree of freedom refers to one of the 'directions' you can move a joint. Please see the Degrees of Freedom Help Topic for an extended explanation.


Controls & Indicators

Where is the Zoom control?

To increase or decrease the size of the skeleton in the viewing area, KineMan provides a calibrated Distance slider, instead of a conventional Zoom control. Please see the Distance vs. Zoom Help Topic for additional info.

What are the red, blue, & green lines?

The colored lines are rotation axes, which show how & where the body or joint pivots for each rotational degree of freedom. Please see the Rotation Axes Help Topic for further information.

Why does the acromio-clavicular joint show 3 sliders, but only 1 works?

The acromio-clavicular joint nominally presents 3 degrees of freedom, as indicated by the sliders, but 2 degrees of freedom are constrained, to cause the scapula's medial edge to follow the posterior ribs at a fixed distance. This serves to prevent the scapula from 'diving' into the ribs (which of course is completely unrealistic). As such, this scapulo-thoracic constraint serves to define the scapulo-thoracic joint. (As explained in Neumann & other references, this isn't a joint in the conventional sense - it doesn't have a capsule, synovial fluid, etc. But, if you understand a joint as 1 or more constraints, it makes sense).

Note that the scapulo-thoracic joint is not movable in the same way that other joints are - you can't select it by name from the joint menu. Instead, you have to select the acromio-clavicular or the sterno-clavicular joint, to move the scapula relative to the thorax. A future enhancement is planned, whereby you can select the scapulo-thoracic joint independently.


Specific Joints

How do I select basic joints like the shoulder or the knee?

In KineMan, you can't select the shoulder as a separate joint, because it is considered to be a group, of multiple joints:

Instead of selecting the shoulder, you have to choose one of these individual joints to operate.

The knee can be selected, by clicking on the tibia, or by selecting the ‘tibio-femoral’ joint in the menu. Like the shoulder, the knee is a group of joints:

Although the knee is a group, you don’t have to choose between one joint or the other: KineMan allows you to operate both together, with a single control. When you move the tibia, you’ll see that the patella follows along – just as it does in a real knee. (Note that you can alternatively select the patella, and move it – in this case, it will move independently of the tibia).

Why can't I move individual joints in the hands or feet?

If you're using KineMan Basic (our free edition), the joints within the hands and feet are not available. Hands and feet joints are included in KineMan Pro, which is available by subscription.

Why can't I move the atlas (Occiput-C1) joint all by itself (instead of moving the entire neck)?
Why can't I move the L5S1 joint all by itself (instead of moving the entire lumbar spine)?

KineMan makes it possible to move all the bones in the cervical spine (or in the lumbar spine) simultaneously. Currently, the way to do this is to select the bone at the distal end of the spine: the skull or the sacrum, respectively. The regular joints associated with these bones (Occiput-C1 and L5S1) can't be moved individually because they’re used for selecting the entire group. The group selection method may change, in a future edition of KineMan – then it may be possible to operate all spinal joints individually.

Why can't I select bones or move individual joints in the ribcage (thorax)?

Mobile joints in the thorax (e.g., between thoracic vertebrae, or between vertebrae and ribs) are not currently available in KineMan. Owing to their small motion ranges, we’ve regarded these joints to be of lesser importance, compared to the lumbar & cervical spinal joints and appendicular joints. We may offer these joints in the future, if there is sufficient demand.

Furthermore, you can't ‘select’ any of the thoracic bones, i.e. click on them so that they change color to blue. This follows directly from the paragraph above: selecting bones is only possible when movable joints are present.

[This may seem to contradict what happens when you click on a skull bone: there are no movable joints in the skull, yet when you click on any of them, the entire skull turns blue. You’ll note however that when the skull is selected, the Occiput-C1 joint becomes the current joint. This happens because Occiput-C1 is the first movable joint proximal to the skull. In the thorax, on the other hand, there are no proximal joints; it is the base for all other joints, and all joints connecting the thorax to other bones are distal. Without a proximal joint, there is nothing to select!]

Why can't I move the full skeleton in all 6 degrees of freedom?

In general, a rigid body in space has 6 degrees of freedom (DOF): 3 translations and 3 rotations. KineMan represents the position of the full skeleton using 5 or 6 degrees of freedom, depending on which version of KineMan you’re using:

Thus, if you don’t see any slider control for the ‘dial’ degree of freedom, it may be that you’re using the free version of KineMan, or, you’re using the Pro version, but you haven't enabled the 6th DOF. In the latter case, Help for enabling and using the 6th DOF is available here.

Regardless of the version you use, it may be helpful for you to understand that the 5 DOF ‘mode’ may be adequate for many purposes. The 6th DOF doesn’t reveal or obscure any new visual information compared to the 5 DOF case. For example, if you use 5 DOF to orient the body, and then capture that pose as a photograph, the 6th DOF is equivalent to rotating the photograph within its own plane. You don’t see anything new or different, you just see it with a different orientation. Whether that change in orientation is useful depends on your application; for example, it may be useful for showing KineMan in a swimming pose, but it’s not needed for an upright stance. Similarly, if you want to focus on the motion of a particular joint, it’s usually sufficient to view the motion from an upright stance.

Why isn't there a humero-radial joint?

The humero-radial joint has been excluded from KineMan because it’s redundant, in the sense that motion between the humerus and radius can be defined completely by flexion/extension of the humero-ulnar joint, and rotation of the (distal & radial) radio-ulnar joints.

Why can't I move the tibio-fibular joint?
Why can't I move the tempero-mandibular joint in protrusion/retrusion?

Some joints in KineMan present special difficulties, and so they have not been enabled for movement. Some of these are: