Lunges, also called split squats, are a compound, multi-joint, strength exercise that works your thighs and gluteus muscles. Two common lunge variations are the forward lunge and the static lunge. The forward lunge is a more challenging, dynamic and functional strength exercise, but it also comes with higher risk for injury.
The static lunge is so named because you don't move your feet during the movement. Start in a split stance with the working leg in front of the non-working leg. Keep your front foot flat on the floor; lift onto the toes of your back foot. Drop down, bringing your back knee within 2 to 3 inches of the floor. Your front knee forms a 90-degree bend, and your thigh is parallel to the ground. Press through the heel of your front foot to straighten your legs. Maintain an upright torso, and keep 80 percent of your weight on the heel of the working leg; the back leg is mostly for balance.
The forward lunge is an advanced version of the static lunge. You step forward with the working leg and drop down into the lunge position. Push through the heel of your front foot, and propel yourself back into a standing position with your feet next to each other. The forward lunge is more challenging than the static lunge because instead of just straightening your knees, you have to power your body back into a standing position all in one continuous, smooth motion.
The static lunge is appropriate for beginners to learn proper lunging technique. Improper lunging technique can result in knee pain or injury. The static lunge allows you to focus on technique without worrying about balance or coordination.
The forward lunge is a more functional movement; it more closely mimics the dynamics of real life movements. You move through a more complete range of motion during the forward lunge. This dynamic version of the lunge also enhances balance and coordination, along with strength.
The static lunge is a much easier exercise than the forward lunge. However, the drawback of sticking with the static lunge is limited development of the muscles involved. Though the forward lunge is more advanced and challenging than the static lunge,the drawback here is the greater potential for injury. When you step forward, the tendency is to allow your front knee to move past your toes. This places undue stress on the knee joint. Proper form can help avoid injury but the nature of the forward lunge makes it easier to trip or step off-balance, possibly resulting in a fall or sprained ankle. Start with static lunges and progress to forward lunges once you develop sufficient, strength, balance and coordination in the lower body.