The stiff-leg deadlift is a resistance exercise that targets your hip and trunk extensors, which include the gluteus maximus and hamstring muscles and the erector spinae and deep spinal muscles, respectively. Consult a personal trainer to learn the proper technique and to determine how the exercise should fit into a comprehensive exercise program.
Performing the stiff-leg deadlift regularly -- two to three times per week -- will strengthen the involved muscles, enabling them to function effectively and potentially preventing hip, thigh and lower-back injuries. The exercise may also help prevent or minimize lower-back pain -- a condition that most people experience at some point during their lives, according to Susan Hall, author of "Basic Biomechanics."
Prepare the the stiff-leg deadlift by loading a barbell with your desired amount of weight and clipping the ends so the plates don't slide around as you're performing the exercise. Hold the barbell in front of your thighs with your hands about shoulder-width apart and your palms facing backward, then step onto a sturdy box or platform and position your feet about 6 inches apart with your toes directed forward. Take a deep breath, then, with your next inhalation, bend forward at your hips and lower the barbell slowly along the front of your legs. Stop when the barbell reaches ankle height, then reverse to the starting position as you exhale and repeat. Keep your spine as straight as possible and your knees slightly flexed throughout the movement.
The single-leg stiff-leg deadlift is a variation of the traditional exercise that involves extending one leg at a time backward during the downward-movement phase, and returning to the starting position -- with both feet on the floor -- during the upward-movement phase. You can use a barbell, dumbbells, a cable weight machine or a lever weight machine for either variation of the exercise.
Use a relatively light amount of weight at first, performing three sets of 12 repetitions during each session, and then gradually increase the weight and decrease the number of repetitions. Reduce the weight, however, if you can't complete at least three sets of eight repetitions.
The stiff-leg deadlift puts considerable stress on your lower back, especially if you perform the exercise incorrectly or use too much weight. Consult your physician if you feel any pain other than mild muscle soreness following any workout.