pyCGM_Single.pyCGM.hipJointCenter

pyCGM_Single.pyCGM.hipJointCenter(frame, pel_origin, pel_x, pel_y, pel_z, vsk=None)

Calculate the hip joint center.

Takes in a dictionary of x,y,z positions and marker names, as well as an index. Calculates the hip joint center and returns the hip joint center.

Other landmarks used: origin, sacrum

Subject Measurement values used: MeanLegLength, R_AsisToTrocanterMeasure, InterAsisDistance, L_AsisToTrocanterMeasure

Hip Joint Center: Computed using Hip Joint Center Calculation [1].

Parameters

framedict

Dictionaries of marker lists.

pel_originarray

An array of pelvis origin, (pel_x, pel_y, pel_z) each x, y, z position.

pel_x, pel_y, pel_zint

Respective axes of the pelvis.

vskdict, optional

A dictionary containing subject measurements.

Returns

hip_JCarray

Returns a 2x3 array that contains two 1x3 arrays containing the x, y, z components of the left and right hip joint centers.

References

1

Davis, R. B., III, Õunpuu, S., Tyburski, D. and Gage, J. R. (1991). A gait analysis data collection and reduction technique. Human Movement Science 10 575–87.

Examples

>>> import numpy as np
>>> from .pyCGM import hipJointCenter
>>> frame = None
>>> vsk = {'MeanLegLength': 940.0, 'R_AsisToTrocanterMeasure': 72.51,
...        'L_AsisToTrocanterMeasure': 72.51, 'InterAsisDistance': 215.90}
>>> pel_origin = [ 251.60, 391.74, 1032.89]
>>> pel_x = [251.74, 392.72, 1032.78]
>>> pel_y = [250.61, 391.87, 1032.87]
>>> pel_z = [251.60, 391.84, 1033.88]
>>> hipJointCenter(frame,pel_origin,pel_x,pel_y,pel_z,vsk).round(2) 
array([[181.71, 340.33, 936.18],
[307.36, 323.83, 938.72]])