US Patent 7267641 Muscle training device

A muscle training device includes a base seat, a first support arm connected pivotally to the base seat, a second support arm connected pivotally to an impeding unit, and two supporting cushions connected respectively to the support arms. The impeding unit has a housing fixed to the first support arm, a piston unit, first and second fluid chambers formed on two opposite sides of the piston unit, a fluid filled in the first and second fluid chambers, and a passage unit that is in fluid communication with the first and second fluid chambers. The second support arm is turnable toward or away from the first support arm.