Foot prosthesis

1. A foot prosthesis, comprising:

an upper part,

a lower part that is placed on the ground when walking,

an elastic damping element connecting the upper part and the lower part, the elastic damping element arranged in a heel area,

the upper part is connected to the lower part in a forefoot area so as to form a spring,

the upper part extending above the lower part and spaced apart from each other,

at least one filling piece positioned between the upper part and the lower part and positioned between the damping element and the forefoot area,

the filling piece increasing flexural stiffness of the upper part and the lower part during walking,

a first securing portion on the damping element between the upper part and the lower part,

a second securing portion on the filling piece at a heel end of the filling piece, the second securing portion releasably engaging the first securing portion so as to releasably engage the filling piece between the upper part and the lower part.

2. The foot prosthesis according to claim 1 , wherein the filling piece is a planar component with at least one adhesive contact surface.

3. The foot prosthesis according to claim 1 , wherein

the first securing portion is a groove, which is open toward the forefoot area and has an undercut and elongate holding projection inside the groove, and

the second securing portion is a holding claw, which is shaped to complement the groove and the holding projection and engages around the holding projection.

4. The foot prosthesis according to claim 3 , wherein the second securing portion can be pushed sideways into engagement with the first securing portion.

5. The foot prosthesis according to claim 3 , wherein locking elements are provided on the first and second securing portions which locking portions cooperate in the insertion position and prevent lateral slipping.

6. The foot prosthesis according to claim 1 , wherein the upper part and the lower part are longitudinally slit in the forefoot area so as to form two adjacent longitudinal portions.

7. The foot prosthesis according to claim 6 , wherein the filling piece has an area in the forefoot area, which is arranged between two mutually superposed longitudinal portions of the upper part and lower part, and the area of the filling piece has a width that is substantially a width of the two mutually superposed longitudinal portions.

8. The foot prosthesis according to claim 1 , wherein

the filling piece has a width that corresponds substantially to a width of the upper part and lower part, or

the filling piece has at least in some areas a smaller width than the width of the upper part and lower part.

9. The foot prosthesis according to claim 1 , wherein filling pieces with different Shore hardnesses can be used.

10. The foot prosthesis according to claim 1 , wherein the filling piece is made of several materials having different Shore hardnesses or has several areas having different Shore hardnesses.

11. The foot prosthesis according to claim 10 , wherein the portions made of different materials or the areas of different Shore hardness are arranged alongside each other in the transverse direction or in the longitudinal direction.

12. The foot prosthesis according to claim 1 , wherein the filling piece has a thickness varying over its length and/or width.

13. The foot prosthesis according to claim 1 , wherein the filling piece is formed as a solid material component made of an elastic plastic, or is formed as a foamed material component made of a foamed elastic plastic.

14. The foot prosthesis according to claim 1 wherein the upper part and the lower part are formed integrally with each other.

15. The foot prosthesis according to claim 1 , wherein the upper part is connected to the lower part in the forefoot area by a connecting means.

16. The foot prosthesis according to claim 1 , wherein length markings are provided on at least one side of the filling piece.