Position shoulders under padded bars handles. Place feet under bar or just slightly forward. Straighten legs so weight is lifted. Disengage dock lever(s) if available. Place feet slightly forward.
Step back with one leg while bending supporting leg. Plant forefoot far back on floor. Lower body by flexing knee and hip of supporting leg until knee of rear leg is almost in contact with floor. Return to original standing position by extending hip and knee of forward supporting leg and return rear leg next to supporting leg. Repeat movement with opposite legs, alternating between sides.
If available, re-engage dock lever(s) in extended position before dismounting. Keep torso upright during lunge; flexible hip flexors are important. Forward knee should point same direction as foot throughout lunge. A long lunge with feet slightly forward emphasizes Gluteus Maximus; short lunge with feet under the bar emphasizes Quadriceps.