Normal Data

Based on motion phases defined in single trials, mean and standard deviation can be determined for a set of normal subjects. Typically one or more files in the .d3d format are used as input and one .d3d file including the normalized and averaged data is written in the projects "normdata" folder also in the .d3d file format. 

The normal data can be visualized as gray bands behind the single trials in the Plot Diagrams components.

Two step procedure via GUI

This procedure is not recommended but it explains, what is done internally in the autmated process configuration based procedure.

1.Step:

You have to select some input .d3d files each representing the data of a single session of a subject. It has the following hierarchically structure:

1: <subject>/<session>/<group>/<phase>/<original trial name>_<phase number>
2: <subject>/<session>/<group>/<phase>/<original trial name>_<phase number>
3: <subject>/<session>/<group>/<phase>/meanStd
4: ...
5: <group>/meanStd

The phase numberst starts with "0". At least the last line "5" must be included. The other lines are optional but needed for determination of coefficients of multiple correlations (CMC) to describe the "qualtity" of the normal data. Input files with this structure can be exported from a gait data sheet to the output folder of the project.

2.Step:

The normal data file can then be created from selected input files via the context sensitive "create normal data" action. The normal data file is automatically written in the normalData folder of the project.

The hierarchically structure of the output is the same as for the input files. The default behavoir is that parts of the hierarchy (of the input files) of the form

<subject>/<session>/<group>/<phase>/meanStd

are averaged inclusive determination of the standard deviation. This results in the output of the form:

<norm>/<group>/<phase>/meanStd

If optional data is available this is simple copied to the output.

Configuration via process configuration file

The normal data determination can be configured in the process configuration file as following example shows:

<NormalData phases="LStride Rstride"
 frames="101"
 basedOnSessionMeans="true"
 sessionSet="abc.set"
 groups="normal/>

Attribute Name	Default	Description	Required
phases	LStrides RStrides	blanc seperated list of phase type names	No
frames	101	Number of frames all of the phases are resampled to.	No
basedOnSessionMeans	true	If set to false, all single trials are averaged. If not set or set to true the sessions means are averaged.	No
sessionSet		File, which includes a set of volunteers measurement sessions (inter subject) saved in the session set file format.	Yes
groups	all defined groups	A blanc seperated list of calc group names. For each normal data are determined.	No
intraSubjectSessionSet		If CMC value should be calculated an additional set of sessions with measurement repetitions of the same subject is needed.	No

If such a definition is available the normal data file can be determined by a single activation of the action "create normal data" in the main menu or the context menu of the project node.

Normal Gait data

For gait data the normal data is determined for both sides together with the consequence that the events and phases must be renamed in a side independend manner before averaged.

Mapping of the events:

Original names	Description	Side independend name
RHS|LHS at the beginning and at the end of the stride	right or left foot strike	No name, since these events are deleted
RHS|LHS inside the stride	right or left opposite foot strike event	OHS
RTO/LTO first occurance	right or left opposite foot off event	OTO
RTO|LTO second occurance	right or left opposite foot off event	TO
RG|LG	right or left general event for indication of force data (one or 3 events are set) and additional subphases	G

Mapping of the phases:

Original names	Description	Side independend name
RForefootOnly|LForefootOnly		ForefootOnly or OForefootOnly for the opposite foot.
RForefoot|LForefoot		Forefoot or OForefoot for the opposite foot.
LPostFootFlat|RPostFootFlat		PostFootFlat or OPostFootFlat for the opposite foot.
RInitialDoubleSupport|LInitialDoubleSupport		InitialDoubleSupport or OInitialDoubleSupport for the opposite foot.
RSwing|LSwing		Swing or OSwing for the opposite foot.
DoubleSupport		(no change)
SingleSupport		SingleSupport or OSingleSupport for the opposite foot
LSingleSupport|RSingleSupport		OSingleSupport for the opposite foot.
LFootFlatOnly|RFootFlatOnly		FootFlatOnly or OFootFlatOnly for the opposite foot.
LTerminalDoubleSupport|RTerminalDoubleSupport		TerminalDoubleSupport or OTerminalDoubleSupport for the opposite foot.
LStride|RStride		Stride
LFootFlat|RFootFlat		FootFlat or OFootFlat for the opposite foot.

Graphical user interface (GUI)

The GUI presents the normal data as gray bands based on the data of the corresponding group (same group name). This default behavoir can be overwritten by setting a normal data group name explicitly in the <CalcGroup> by the attribute "normaldatagroup". 

Typically the normal data variables have the same names than the trials data variables. But if this it not the case, in the sheet definition explicit variables names can overwrite the default. See the <Norm>-element in the following example labelset fragment as an example.

Example Labelset fragment

<Diagram name="RPelvisAngle_X" 
                   column="0"
                   row="0"
                   unit="deg" 
                   diagramDescriptionDown="post" 
                   diagramDescriptionUp="ant" 
                   plane="s" 
                   diagramType="xt" 
                   diagramTitle="Becken Kippung">
          <Norm name="NORMPelvisAngles"
                component="0"
                mean="NORMPelvicTilt"
                std="NORMStdPelvicTilt"/>
          <Label name="RPelvisAngles"
                 component="0"
                 side="right"/>
          <Label name="LPelvisAngles"
                 component="0"
                 side="left"/>
</Diagram>