Viscoelastic element including a polyurethane foam, obtainable by reaction of at least the following components: an isocyanate-functional prepolymer obtainable by reaction of at least the following components: V1A) aliphatic diisocyanates with V1B) di- to hexafunctional polyalkylene oxides having an ethylene oxide content of 50 to 100 mol%, based on the total amount of oxyalkylene groups present, in the presence of a polyurethaneurea dispersion, where the polyurethaneurea is obtainable by reacting at least V2A) an aliphatic polyisocyanate component having an average isocyanate functionality of ≥ 1.8 and ≤ 2.6; V2B) a polymeric polyether polyol component; V2C) an amino-functional chain extender component having at least 2 isocyanate-reactive amino groups, containing at least one amino-functional compound C1) that does not have any ionic or ionogenic groups and/or an amino-functional compound C2) that has ionic or ionogenic groups; V2D) optionally further hydrophilizing components different than C2), V2E) optionally hydroxy-functional compounds having a molecular weight of 62 to 399 g/mol, V2F) optionally at least one further polymeric polyol which is different than V2B), V2G) a compound having exactly one isocyanate-reactive group or a compound having more than one isocyanate-reactive group, where only one of the isocyanate-reactive groups reacts with the isocyanate groups present in the reaction mixture under the reaction conditions chosen, and V2H) optionally an aliphatic polyisocyanate component having an average isocyanate functionality of ≥ 2.6 and ≤ 4, wherein the reaction of the prepolymer in the presence of the polyurethaneurea takes place with a medium containing isocyanate-reactive groups. an isocyanate-functional prepolymer obtainable by reaction of at least the following components: V1A) aliphatic diisocyanates with V1B) di- to hexafunctional polyalkylene oxides having an ethylene oxide content of 50 to 100 mol%, based on the total amount of oxyalkylene groups present, in the presence of V1A) aliphatic diisocyanates with V1B) di- to hexafunctional polyalkylene oxides having an ethylene oxide content of 50 to 100 mol%, based on the total amount of oxyalkylene groups present, in the presence of a polyurethaneurea dispersion, where the polyurethaneurea is obtainable by reacting at least V2A) an aliphatic polyisocyanate component having an average isocyanate functionality of ≥ 1.8 and ≤ 2.6; V2B) a polymeric polyether polyol component; V2C) an amino-functional chain extender component having at least 2 isocyanate-reactive amino groups, containing at least one amino-functional compound C1) that does not have any ionic or ionogenic groups and/or an amino-functional compound C2) that has ionic or ionogenic groups; V2D) optionally further hydrophilizing components different than C2), V2E) optionally hydroxy-functional compounds having a molecular weight of 62 to 399 g/mol, V2F) optionally at least one further polymeric polyol which is different than V2B), V2G) a compound having exactly one isocyanate-reactive group or a compound having more than one isocyanate-reactive group, where only one of the isocyanate-reactive groups reacts with the isocyanate groups present in the reaction mixture under the reaction conditions chosen, and V2H) optionally an aliphatic polyisocyanate component having an average isocyanate functionality of ≥ 2.6 and ≤ 4, wherein the reaction of the prepolymer in the presence of the polyurethaneurea takes place with a medium containing isocyanate-reactive groups.