Table 2 Definitions of the segment anatomical coordinate systems of the Amsterdam Foot Model for the right foot

Shank^a

Origin

Midpoint between LM and MM

O = (LM + MM)/2

Anterior-Posterior axis (x)

⊥ to the plane defined by Y and the vector from LM to origin

X = cross(Y, LM-O^c)

Vertical axis (y)

From origin to projection of TT on the plane defined by the origin, LM and FH

TT_proj = projection (TT,X,LM)Y = TT_proj-O

Medio-Lateral axis (z)

⊥ to the plane defined by X and Y

Z = cross(X,Y)

Hindfoot

Origin

Midpoint between CALD and CALP

O = (CALD+CALP)/2

Anterior-Posterior axis (x)

From Origin to midpoint ST and PT

X = (ST + PT)/2-O

Vertical axis (y)

⊥ to the plane defined by Z and X

Y = cross(Z,X)

Medio-Lateral axis (z)

⊥ to the plane defined by X and the vector from CALD to CALP.

Z = cross(X,CALP-CALD)

Midfoot^b

Origin

Midpoint between NAV and BM5

O = (NAV + BM5)/2

Anterior-Posterior axis (x)

From origin to BM2

X = BM2-O

Vertical axis (y)

⊥ to the plane defined by NAV, BM2, BM5

Y = cross (BM5-NAV^c,BM2-NAV)

Medio-Lateral axis (z)

⊥ to the plane defined by X and Y

Z = cross(X,Y)

Forefoot

Origin

Midpoint between mBM12 and mBM25

O = (mBM12 + mBM25)/2

Anterior-Posterior axis (x)

From origin to midpoint mHM12 and mHM25

X = (mHM12 + mHM25)/2-O

Vertical axis (y)

⊥ to the plane defined by origin, mHM12 and mHM25

Y = cross (mHM25-O^c,mHM12-O)

Medio-Lateral axis (z)

⊥ to the plane defined by X and Y

Z = cross(X,Y)

Medial Forefoot

Origin

mBM12

O = mBM12

Anterior-Posterior axis (x)

From origin to mHM12

X = mHM12-O

Vertical axis (y)

⊥ to the plane defined by X and the vector from BM1 to BM2

Y = cross (BM2-BM1^c,X)

Medio-Lateral axis (z)

⊥ to the plane defined by X and Y

Z = cross(X,Y)

Lateral Forefoot

Origin

mBM25

O = mBM25

Anterior-Posterior axis (x)

From origin to mHM25

X = mHM25-O

Vertical axis (y)

⊥ to the plane defined by X and the vector from BM2 to BM5

Y = cross (BM5-BM2^c),X)

Medio-Lateral axis (z)

⊥ to the plane defined by X and Y

Z = cross(X,Y)

Hallux

Origin

HM1

O=HM1

Anterior-Posterior axis (x)

From origin to HLX

X = HLX-O

Vertical axis (y)

⊥ to the plane defined by X and Z of the medial forefoot

Y = cross (Zmedial_forefoot,X)

Medio-Lateral axis (z)

⊥ to the plane defined by X and Z

Z = cross(X,Z)