An elliptical exerciser includes a frame, first and second magnetic control wheel units, first and second swing levers, first and second transmission rods, first and second guiding mechanisms, first and second pedal rods, and a magnetic mechanism. When the first and second swing levers and the first and second transmission rods are swung forward and rearward synchronously and the first and second pedal rods are pedaled up and down to slide forward and rearward, the first and second pedal rods pivotally connected with bottom ends of the first and second swing levers are to do a tread motion of an elliptical trajectory.

A pedal assembly for electromechanical exercise or rehabilitation of a user is disclosed and can include pedals to engage appendages of a user. A spindle supports each pedal and has a spindle axis. A pedal arm assembly is located between the spindle and an axle. The pedal arm assembly is radially offset from the spindle axis to define a range of adjustability for the pedal relative to the axle. The pedal arm assembly can include an electrically-actuated coupling assembly to adjust the position of the pedal in response to a control signal, and regulate motion of the user engaged with the pedals.

A hand-held gyroscope toy or gyroscopic muscle conditioning device with an outer shell containing a drive assembly with a spring-loaded drive button at one end that charges and discharges the gearing inside to provide an accelerated rate of rotation to a flywheel inside the outer shell. The resulting high-speed rotation causes a gyro effect that can be employed as either a fidget-type toy or a resistance device for fine motor or muscle development.