This lunge, in addition to working lower body strength, will challenge your balance more then a traditional lunge.
The action of reaching your leg back and across your body's midline will challenge the strength and stability of your hips. The further you reach your leg back, the deeper your lunge will be and the more strength challenge you will give you lower body.
Bowler's Lunge Exercise
Start by standing tall, feet together. Press your feet into the floor, shoulders relaxed, top of the head to the ceiling to start with tall posture.
Reach one foot back, touching your toes at or across the midline of the body. Your focus will be on maintaining the alignment of the knee of the forward leg.
Note in the picture that the knee and toes on the left leg are pointing forward and the left knee is over the shoelaces/heel.
Also note that when the right leg reaches back, the right arm reaches forward.
Lightly touch the back foot down, then press your front foot into the floor to lift you back up into the start position.
The further back and across you reach your leg, the deeper the lunge will be. This will make the exercise more challenging.
You can experiment with doing a full set of 8 - 15 repetitions on one leg before switching legs, or alternate legs. Either way, come back to tall body alignment between repetitions.