Exercise apparatus

A passive exercise apparatus comprising:

• an interface member for coupling to a user's body;
• an arm member coupled to the interface member by a wrist joint, the wrist joint being an unbraked joint having rotational motion about three axes;
• first link coupled to the arm member by a sliding joint, the sliding joint allowing translational motion of the arm member relative to the first link;
• a second link rotatably coupled to the first link by a first rotary joint;
• a third link rotatably coupled to the second link by a second rotary joint;
• a first rotary brake coupled to the first rotary joint for resisting movement of the first rotary joint;
• a second rotary brake coupled to the second rotary joint for resisting movement of the second rotary joint;
• a third rotary brake coupled to the arm member for resisting translational motion of the arm member;
• a first transmission coupled between the first joint and the first brake for reducing torque to the first brake, the first link having an outer periphery, a portion of the outer periphery of the first link forming a pulley that is part of the first transmission;
• a second transmission coupled between the second joint and the second brake for reducing torque to the second brake;
• and
• a third transmission coupled between the arm member and the third brake for reducing torque to the third brake, wherein the user may interface with the apparatus to exercise a six degree of freedom motion, while only three degrees of freedom of the apparatus are braked.

A method of exercising comprising the steps of:

• coupling an interface member of an exercise apparatus to a user's body, the interface member being coupled to an arm member by a wrist joint, the wrist joint providing rotational motion about three axes, the arm member being coupled to a first link by a sliding joint, the sliding joint allowing translational motion of the arm member relative to the first link, a second link being rotatably coupled to the first link by a first rotary joint and a third link being rotatably coupled to the second link by a second rotary joint;
• moving the limb in a desired motion relative to the exercise apparatus;
• resisting movement of the first rotary joint with a first rotary brake coupled to the first rotary joint, a first transmission being coupled between the first rotary joint and the first brake for reducing the amount of torque to the first brake, the first link having an outer periphery, a portion of the outer periphery of the first link forming a pulley that is part of the first transmission;
• resisting movement of the second rotary joint with a second rotary brake coupled to the second rotary joint, a second transmission being coupled between the second rotary joint and the second brake for reducing the amount of torque to the second brake;
• and
• resisting movement of the arm member with a third rotary brake coupled to the arm member, a third transmission being coupled between the arm member and the third brake for reducing the amount of torque to the third brake, wherein the user may interface with the apparatus to exercise a six degree of freedom motion.