Undergarment

1. A undergarment comprising an upper portion ( 2 ) looped to encircle the waist of a wearer;

a front portion supported by the upper portion ( 2 ) and extending downwards from it;

a rear area ( 5 ) supported by the upper portion ( 2 ) and connected to the front portion, the rear area ( 5 ) extending downwards from the upper portion ( 2 ), and delimiting, with the front portion, a first and a second opening ( 6 , 7 ) for the legs of the wearer and comprising at least one portion ( 5 a , 5 b , 5 c ) made of elastic fabric,

the undergarment also comprising a lower connecting portion ( 8 a ) between the front portion ( 4 ) and the rear area ( 5 ), the lower portion ( 8 a ) forming the crotch ( 8 ) of the undergarment, said undergarment being characterised in that it comprises a system ( 9 ) for confining the elastic stretching of the portion ( 5 a , 5 b , 5 c ) made of elastic fabric, the confining system ( 9 ) comprising at least one first sector ( 14 ) in the rear area ( 5 ) where stretching is reduced compared with the portion ( 5 a , 5 b , 5 c ) made of elastic fabric, wherein the confining system ( 9 ) comprises at least a first seam ( 10 ) extending between the crotch ( 8 ) and a node ( 11 ) located at a predetermined height “h 1 ” from the lower edge ( 3 a ) of the elastic element ( 3 ) and at a middle section (S) of the rear area ( 5 ), and wherein the confining system ( 9 ) comprises a second and a third segment or seam ( 12 , 13 ) extending from the node ( 11 ) towards the upper portion ( 2 ) for delimiting the first sector ( 14 ).

2. The undergarment according to claim 1 , characterised in that the first sector ( 14 ) is located between the node ( 11 ) and the upper portion ( 2 ).

3. The undergarment according to claim 1 , characterised in that the first sector ( 14 ) comprises a fabric whose modulus of elasticity is less than the modulus of elasticity of the portion ( 5 a , 5 b , 5 c ) made of elastic fabric.

4. The undergarment according to claim 1 , characterised in that the portion ( 5 a , 5 b , 5 c ) made of elastic fabric comprises a first and a second half-portion ( 5 b , 5 c ), the first seam ( 10 ) joining the first and the second half-portions ( 5 b , 5 c ).

5. The undergarment according to claim 1 , characterised in that the height “h 1 ” is greater than or equal to 3 cm and is less than or equal to 12 cm, that is to say:

3≦h≦12.

6. The undergarment according to claim 1 , characterised in that the confining system ( 9 ) comprises at least one segment or seam ( 12 , 13 ) for delimiting the first sector ( 14 ).

7. The undergarment according to claim 1 , characterised in that the second and third segments or seams ( 12 , 13 ) are angularly spaced relative to the middle section (S) of the rear area ( 5 ) by the same angle and between them form an angle “α”, the segments or seams ( 12 , 13 ) being straight.

8. The undergarment according to claim 7 , characterised in that the angle “α” is greater than or equal to 75 sexagesimal degrees and is less than or equal to 170 sexagesimal degrees, that is to say:

75°≦α≦170°.

9. The undergarment according to claim 8 , characterised in that the angle “α” is greater than or equal to 95 sexagesimal degrees and is less than or equal to 150 sexagesimal degrees, that is to say:

95°≦α≦150°.

10. The undergarment according to claim 1 , characterised in that second and third segments or seams ( 12 , 13 ) and the upper portion ( 2 ) delimit the first sector ( 14 ).

11. The undergarment according to claim 1 , characterised in that the confining system ( 9 ) comprises a first and a second seam ( 20 , 21 ) for connecting the front portion to the rear area ( 5 ).

12. The undergarment according to claim 1 , characterised in that the first sector ( 14 ) comprises a plurality of seams or needlework making the first sector ( 14 ) stiffer than the portion ( 5 a , 5 b , 5 c ) made of elastic fabric.