Resistance therapy

1. An exercise device, comprising:

first and second flexible bladder portions each having a stiffness and being in fluid connection with each other; and

at least one of said first and second bladder portions contains an electro-rheological fluid therein;

said first or second bladder portions being configured to overly a muscle when the muscle is in a substantially relaxed state and apply a lower pressure against the muscle when the muscle is substantially relaxed; and

said first or second bladder portions being configured to be compressed when the muscle is flexed and apply a higher pressure against the muscle when the muscle is flexed.

2. An exercise device, comprising:

first and second flexible bladders each having a modulus of elasticity;

said first and second bladders configured to contain a fluid and pass the fluid between said first and second bladders;

means for changing the modulus of elasticity of the first bladder relative to the second bladder;

said first bladder configured to overlie a first muscle when the first muscle is in a substantially relaxed state and to apply a lower pressure against the first muscle when the first muscle is substantially relaxed; and

said second bladder configured to overlie a second muscle different than the first muscle;

wherein said first bladder is compressed when the first muscle is flexed to apply a higher pressure against the first muscle when the muscle is flexed, the pressure of said first bladder determined at least in part by said second bladder.

3. An exercise device as set forth in claim 2 , further comprising a control system associated with the first and second bladders to selectively control a fluid pressure within at least one of the bladders.

4. An exercise device as set forth in claim 2 , wherein a plurality of bladders, including said first and second bladders, are serially connected in fluid communication.

5. An exercise device as set forth in claim 4 , wherein tube members are interposed between and fluidly connect adjacent bladders.

6. An exercise device as set forth in claim 4 , further comprising a control valve associated with a tube member to selectively control an inner diameter of the tube member.

7. An exercise device as set forth in claim 5 , wherein the flow of fluid through the tube members provides a resistance in response to muscle expansion.

8. An exercise device as set forth in claim 2 , wherein at least one of said bladders is adjustably positionable about the respective first and second muscles.

9. The exercise device according to claim 2 , wherein at least one of said bladders does not overlap either the first or second muscles.

10. The exercise device according to claim 2 , wherein said means for changing the modulus of elasticity comprises a band configured to overly at least one of said bladders and encircle at least one of said first and second muscles.

11. The exercise device according to claim 2 , wherein at least one of said bladders is configured to encircle at least one of said first and second muscles.

12. The exercise device according to claim 2 , wherein at least one of said bladders tends to push at least one of said first and second muscles from a flexed position to a relaxed position.

13. The exercise device according to claim 2 , wherein said fluid moves from at least one of said bladders when at least one of the first and second muscles is flexed.

14. The exercise device according to claim 2 , wherein at least one of said bladders or said fluid is compressible enough to allow at least one of the first and second muscles to move from a relaxed position to a flexed position.

15. The exercise device of claim 2 , wherein the fluid is an electro-rheological fluid.

16. The exercise device of claim 2 , wherein the means for changing the modulus of elasticity is selected from the group consisting of interchangeable band, shape memory alloy, and replaceable bladder.

17. The exercise device of claim 2 , wherein the means for changing the modulus of elasticity includes means for replacing the second bladder with a bladder having a different resistance.

18. The exercise device of claim 2 , wherein the rate at which fluid is passable between said first and second bladders changes as the first muscle is flexed.

19. An exercise device comprising:

a flexible first bladder having a first modulus of elasticity, said first bladder configured to overlie a muscle when the muscle is in a substantially relaxed state and applying a lower pressure against the muscle when the muscle is substantially relaxed;

said first bladder configured to contain a fluid;

a second bladder having a second modulus of elasticity, said second bladder operative to overlie an antagonist muscle of the muscle being overlain by said first bladder; and

means for changing the modulus of elasticity of said second bladder;

said first bladder being compressed when the muscle is flexed and applying a higher pressure against the muscle when the muscle is flexed,

wherein the fluid is movable between said first and second bladders.

20. The exercise device according to claim 19 , wherein a valve is configured to adjust movement of fluid between said first and second bladders.

21. The exercise device according to claim 19 , wherein a valve is positioned between the first and second bladders.

22. The exercise device of claim 19 , wherein the means for changing the modulus of elasticity is selected from the group consisting of interchangeable band, shape memory alloy, and replaceable bladder.