A passive power-conservative artificial knee comprising: a first link; a second link rotatably coupled to said first link at a knee joint, wherein the first link is one of a thigh link or a shank link, and wherein the second link is another one of the thigh link or the shank link; a passive compressive force generator, comprising a first end and a second end, said passive compressive force generator rotatably coupled to said second link from the first end, characterised in that said passive power-conservative artificial knee is further comprising: a release mechanism, coupled to said first link, wherein said release mechanism comprises a first operational mode and a second operational mode, wherein, in the first operational mode, said release mechanism is configured to couple the second end of said passive compressive force generator to said first link, and, in the second operational mode, said release mechanism is configured such that said second end of said passive compressive force generator is not coupled to said first link, and wherein said release mechanism is configured to move into the first operational mode, thereby causing the passive compressive force generator to resist flexion of said first link relative to said second link when an angle of said knee joint is less than a toggle angle, and wherein said passive compressive force generator is configured to encourage flexion of said first link relative to said second link while said release mechanism is in said first operational mode; when said knee joint is larger than said toggle angle, and wherein said release mechanism is configured to move into the second operational mode when a compressive force of the passive compressive force generator is substantially small and when said passive compressive force generator is substantially extended. a first link; a second link rotatably coupled to said first link at a knee joint, wherein the first link is one of a thigh link or a shank link, and wherein the second link is another one of the thigh link or the shank link; a passive compressive force generator, comprising a first end and a second end, said passive compressive force generator rotatably coupled to said second link from the first end, characterised in that said passive power-conservative artificial knee is further comprising: a release mechanism, coupled to said first link, wherein said release mechanism comprises a first operational mode and a second operational mode, wherein, in the first operational mode, said release mechanism is configured to couple the second end of said passive compressive force generator to said first link, and, in the second operational mode, said release mechanism is configured such that said second end of said passive compressive force generator is not coupled to said first link, and wherein said release mechanism is configured to move into the first operational mode, thereby causing the passive compressive force generator to resist flexion of said first link relative to said second link when an angle of said knee joint is less than a toggle angle, and wherein said passive compressive force generator is configured to encourage flexion of said first link relative to said second link while said release mechanism is in said first operational mode; when said knee joint is larger than said toggle angle, and wherein said release mechanism is configured to move into the second operational mode when a compressive force of the passive compressive force generator is substantially small and when said passive compressive force generator is substantially extended. a release mechanism, coupled to said first link, wherein said release mechanism comprises a first operational mode and a second operational mode, wherein, in the first operational mode, said release mechanism is configured to couple the second end of said passive compressive force generator to said first link, and, in the second operational mode, said release mechanism is configured such that said second end of said passive compressive force generator is not coupled to said first link, and wherein said release mechanism is configured to move into the first operational mode, thereby causing the passive compressive force generator to resist flexion of said first link relative to said second link when an angle of said knee joint is less than a toggle angle, and wherein said passive compressive force generator is configured to encourage flexion of said first link relative to said second link while said release mechanism is in said first operational mode; when said knee joint is larger than said toggle angle, and wherein said release mechanism is configured to move into the second operational mode when a compressive force of the passive compressive force generator is substantially small and when said passive compressive force generator is substantially extended.