An exercise apparatus with an adjustable rotating element around which a force transferring material wraps either clockwise or counterclockwise to provide bidirectional rotational resistance for exercising. The force transferring material is preferably guided to remain in close proximity to the rotating element while wrapping around the rotating element. Multiple attachments provide great flexibility in performing exercise or physical therapy.

A bi-directional exercise machine has a work arm, first and second cams coupled to the work arm, a resistance mechanism, and a pulley assembly that couples the resistance mechanism to the work arm via the first and second cams so that movement of the work arm is resisted by the resistance mechanism according to first and second resistance profiles provided by the first and second cams, respectfully. The pulley assembly has a primary pulley cable having a first end coupled to the first cam and a second end coupled to the second cam. When the work arm is in a rest position the first and second ends of the primary pulley cable both extend from cable tracks of the first and second cams, respectively, at a tangent, and in particular so that the resistance mechanism applies a resistance force on the work arm via the pulley assembly immediately upon movement of the work arm out of the rest position.

The apparatus provides an exercise device that is portable, versatile, and enables the user to match the resistance of the device with the normal physiologic length-tension relationship of skeletal muscle. The device adds resistance in the form of cartridges that are stackable to summate resistance and can connect to a variety of attachments for use with arms, legs, or trunk, i.e., handle, bar, loop, etc. Given the device's portability, it can be used freestyle or mounted to various surfaces.

Provided are apparatuses for augmenting human speed, human-driven compliant mechanisms, artificial limbs to augment human movement, and the like. The apparatuses can include variable stiffness mechanisms including springs that can be configured to selectively store and subsequently release energy generated by human movement. The apparatuses can selectively release the captured energy supplied by the human to provide force and power output beyond the physical capability of the human.

A portable lower limb therapy device having a support base and a pulley system. The support base includes an exterior surface suitable to slide on smooth surfaces and an interior surface suitable to receive and conform to a foot of a user. The pulley system defines a closed force transfer system that is integrated with the support base. The pulley system employs a pair of cord members which run along the right and left sides of the support member, a cross member positioned above the support member and connected at each end to one of the cord members, and two adjustable handle mechanisms. The pulley system is configured to transfer force applied behind and above the foot of a user that is in the support base to the support base.

An adjustable resistance exercise machine for providing variable resistance forces on a pull cable extending from the machine. The adjustable resistance exercise machine generally includes a plurality of power springs that may be selectively engaged using an adjustment mechanism. By engaging springs with different forces, the resistance may be adjusted incrementally as preferred for performing different exercises. The adjustable resistance exercise machine may be connected to various structures, either below or above an exerciser, to allow the exerciser to choose whether to pull the pull cable up or down during exercise.

A cam mechanism may include a cam assembly rotatably mounted to an axis shaft and having a profile arc adapted for receiving a belt or cable, a belt adjustment lever pivotally mounted to the cam assembly and having a control bearing, and a cam range slot plate rigidly mounted to the axis shaft and defining a slot in sliding communication with the control bearing of the belt adjustment lever, wherein the belt adjustment lever is connected to one end of a belt or cable, and the opposite end of the belt or cable is connected to a moveable weight stack, and wherein the cam assembly is rotatable relative to the cam range slot plate.

Provided are apparatuses for augmenting human speed, human-driven compliant mechanisms, artificial limbs to augment human movement, and the like. The apparatuses can include variable stiffness mechanisms including springs that can be configured to selectively store and subsequently release energy generated by human movement. The apparatuses can selectively release the captured energy supplied by the human to provide force and power output beyond the physical capability of the human.

Assemblies are for attaching a resistance mechanism to an exercise apparatus. In one example, the assembly has a pulley cable having a first end portion for being coupled to the resistance mechanism and a second end portion coupled to the exercise apparatus; and a plunger device facilitating coupling and uncoupling of the pulley cable to and from the exercise apparatus. The plunger device is movable into a first position in which the plunger device couples the pulley cable to the exercise apparatus and into a second position in which the plunger device uncouples the pulley cable from the exercise apparatus.

An exercise machine comprises an arm support, including: a carriage configured to slide within a track attached to the exercise machine; and a support assembly that floats the carriage relative to the track, wherein the support assembly is disengaged by the application of force via the arm. An exercise machine comprises a rotatable column, wherein the column supports an arm, and a gear detent mechanism to support a discrete number of positions for the rotatable column. An exercise machine comprises a tiltable arm, and a mechanism to support a discrete number of positions for the tiltable arm.