A healthy, fit lower body requires a variety of exercises as well as a healthy diet. Lunges are a standard part of a lower-body workout. However, form is critical to a good lunge. Do a few sets poorly, and your knees may bother you for weeks. Variations of a standard forward lunge make it possible to keep a keen eye on your form to ensure you don't inure your knees.
Lunges
Lunges are a compound exercise that work multiple muscle groups. They work the quadriceps, the muscle group at the front of the thigh, as well as the hamstrings, the muscle group at the back of the thigh. They also engage: the gluteal muscles, which make up your bottom; the muscles of your calf, the gastrocnemius and soleus; and the muscles of your torso, primarily the lower back and abdomen. In a regular lunge, you step forward and descend to the floor, supporting either your body weight or additional weight in the form of a barbell or dumbbell.
Backward Lunge
In a rear lunge, also called a backward or reverse lunge, you engage the same muscles as a normal lunge, but step backward instead of forward. The form is the same. You maintain a straight torso while moving, so your knee, hips and shoulders are aligned. Keep your core engaged as well to support the lower back. The benefit to a rear lunge is the final part of the form — the critical position of the knee in relation to your toes. When lunging, you must keep your knee behind your toes to avoid potential injury. A rear, or backward, lunge allows you to glance down at your toes throughout the exercise as you step back, ensuring the correct position of your knee throughout the exercise.
Differences
With a forward lunge, you don't know how far forward your knee will bend until you've completed your descent. With a backward lunge, because your forward knee remains forward, you know at all times the position of your knee in relation to your toes. This makes rear lunges a good option for those who are struggling with the length of their stance or for those who worry about their knees when lunging.
Considerations
If you're a novice to strength training, use a backward lunge to get a good sense of the width of your stance to assure good form. Once you're comfortable with good lunge form, advance to forward lunges and then walking lunges. However, if you are concerned about your knees, another option is to step back or forward into lunge position and keep your feet in lunge stance, focusing on rising and descending without moving your feet until you complete your set. This type of lunge removes stepping in and out, making it easier to establish a correct stance and maintain it throughout the exercise.
