The gluteus maximus is utilized most in the beginning of the movement when there is a large degree of hip flexion. The glutes work in unison with the hamstring to extend the hips. The hamstrings, located on the back of the upper thigh, become more involved as you begin to decrease the degree of hip flexion as you raise the weight. The erector spinea, which run the length of your spine on both sides, are statically contracted throughout most of the movement keeping the normal curvature of the spine. A static contraction of the rhomboids and the trapezius muscles help maintain the shoulders. The quadriceps muscles are involved with knee extension.

Extension of the body occurs when the upper body, torso and pelvis rotate up and back. In a properly performed deadlift, this will happen simultaneously with the hips moving forward and the knees extending. Two of the biggest mistakes I see when this movement is performed are locking the knees out before the upper body is extended or allowing the back to “round” and magnifying the kyphotic (upper back) curvature while de-emphasizing the lordotic (lower back) curvature. I need to add that a slight curve of the upper back will present no danger and will happen to most while using heavy weight, but if you look like the hunch back of Notre Dame while performing the exercise that’s a different story.

The main reason your lower back would round, which could cause devastating trauma to the lumbar area, is weak erector muscles. There are various exercises you can use to strengthen your lower back like good mornings, arched back good mornings, arched back stiff legged deadlifts, and reverse hyperextensions, but good mornings and its variation in my opinion are probably the best exercise for this purpose.??????

The Dead lift

HOW IT’S DONE
Stand with your feet about hip-width apart, your toes facing straight ahead. Squat down and grab the bar with an outside-shoulder-width, palms-down grip [1]. Keep your lower back in its natural arch, and drive your heels into the fl oor and push your hips forward, lifting the bar as you rise until it’s in front of your thighs [2]. Reverse the motion and return the bar to the fl oor. That’s one rep.

THE TEST
Estimate your deadlift one-rep max?the most weight you can lift for one rep?and compare it to the calculations below.

Your 1RM (one-rep max) is…
? Less than your body weight = Damn, you’re weak
? 1.25 x your body weight = You’re average
? 1.5 x body weight = You’re pretty strong
? 2 x body weight = You’re a beast!

A 200-pound guy who can deadlift 300 pounds for one rep is pretty strong. If your number falls in the weak or average categories, see below for tips on how to bring it up.

Click here to see MF.com?s guide to deadlifting more weight.