The posterior lat pulldown puts the shoulder complex at risk and should be eliminated from your list of acceptable exercises because the negative consequences outweigh the benefits. But that is not to say you should never ever do a lat pulldown. What is recommended is that this exercise be replaced with the anterior lat pulldown, which is more practical in function. The posterior lat pulldown involves pulling the bar down behind the head whereas the anterior lat pulldown involves pulling the bar down in front of the head. Every other aspect of the exercise remain basically the same.
Why Change? By changing the position of the pulldown from posterior to anterior will result in fewer injuries to the shoulder complex. From a practical point of view, everyday activities do not usually require pulling a resistance down behind the head. But day in and day out you can find yourself pulling down or pushing up a resistance in front of the body. Therefore, when putting a training routine together you should try and include exercises that would mimic daily functional movements you generally perform.So What's Really Going On? Even though the shoulder is considered a ball and socket joint it isn't actually an encapsulated ball inside of a socket. The head of the humerus actually glides underneath the acromion process. Because of the mechanics of this joint stabilization is particularly important within and around the shoulder. Furthermore, the articular capsule, which completely surrounds the joint, is not a rigid structure and allows for a significant separation of the articulating surfaces during anterior and inferior humeral displacement. Structurally, the joint is protected superior by the coracoacrmial arch and anterior by the glenohumeral ligament. Because of this all the major ligaments cross the superior or top portion of the shoulder joint and no major ligaments or muscle are associated with the inferior or underside.
That Means What Biomechanically? A posterior lat pulldown requires torso and cervical spine flexion during the concentric phase of the exercise in order to accommodate placement of the bar behind the head. As a result, three planes of motion simultaneously occur at the joint: adduction, external rotation, and horizontal hyper abduction. This situation places force on the humeral head, encouraging displacement anterior and inferior out of the joint capsule.Placing the upper extremity in concurrent abduction and external rotation (as with the posterior pulldown position) adds stress to the inferior glenohumeral ligament, which is the primary static stabilizer of the shoulder joint.
Go ahead and add some heavy weight, a few extra repetitions and maybe an improper hand placement to this posterior exercise and you have just created a recipe for major overuse injuries. Rarely can victims of an overuse injury recall an acute event that prompted the trauma rather, they notice that their "symptoms" become gradually more debilitating.
So How Bad Can It Really Be? The following is a short list of some injuries commonly associated with the shoulder joint from the at-risk position of the posterior lat pulldown.
Subluxation: Subluxation is a partial anterior-inferior displacement of the humeral head from the glenoid fossa due to tears of the labrum, anterior ligaments, and joint capsule.
Dislocation: Dislocation is a total anterior-inferior displacement of the humeral head to a greater degree than subluxation.
Impingement: This injury commonly occurs in the tendons of the supraspinatus and the long head of the biceps, as well as the subacrmial bursa. The coracoacromial arch (coracoid and acromion processes, coracoacromial ligament) is a naturally tight space that allows a specific tendon thickness to pass through it unobstructed. With overuse and repetitive irritation over time, most tissues will respond with inflammation and swelling causing an impingement.
Rotator Cuff Tears: A rotator cuff tear is a strain or complete rupture of one of the rotator cuff tendons (supraspinatus, infraspinatus, teres minor, subscapularis).
Spinous Process Damage: These are bone fractures and soft tissue sprains and bruises due to collision of the bar with the lower cervical region.
Ballistic Potential: The posterior pulldown is often executed with poor technique. For example, the bar may be pulled ballistically toward the body, bounced off the spinous process, and returned to the starting position with a lack of eccentric control. When done properly, a lat pulldown is not ballistic but instead possesses tensile qualities through a controlled full range of motion.
Now Let's Talk Form... To properly accomplish this exercise the feet should be flat on the floor and knees tucked under a padded bar, to keep yourself seated firmly erect. Depending on the desired width of the grasp (moving hands closer, or farther apart will stress different parts of the muscles) grasp the overhead bar in a pronated or overhand grip (palms facing away from you towards the front, knuckles up) pull your shoulders straight down towards the floor and pull smoothly downwards on the bar. The move should be executed by concentrating on attempting to bring the shoulder blades together in the back and your elbows as far towards the floor as possible. Imagine cracking a walnut between your shoulder blades. Do not lean back and use your body weight to pull the bar down. Arch your back in the middle and complete the downward move by touching the center of the bar to the collarbone area or upper chest. Hold in this position briefly, concentrating on form and bringing the shoulder blades close and contracting the lats. Slowly and in a controlled manner, return the bar upward until your arms are straight, then move your shoulder blades wide and shoulders up high as if you are shrugging and allow the pull of the bar to stretch the muscles in your back that were contracted performing the exercise. Relax for a second, pause and repeat the exercise until repetitions are complete or muscle is exhausted, according to your exercise plan.
Other Variations...This exercise can be varied by changing two major positions involving the grip. Different widths of the hands from nearly twice as wide as shoulder width to as close as inside the shoulder, and changing the position of the hands from overhand, to supinated, to parallel will alter the path the elbows take and thus stress different portions of the muscle. In addition, multiple cables may be used by advanced exercisers to escape the motion limitations imposed by the use of a single bar.
To view variations and advanced pulldown exercises click on the following link: http://www.bodybuilding.com/fun/exercises.php?MainMuscle=Lats
Remember no matter what exercise you are performing it is imperative to always concentrate on using proper technique through kinesthetic awareness and visualization of joint movement and muscle fiber contraction. To stave off injury pay attention to how you feel from day to day, workout to workout and listen to what your body is saying to you. Never "work through" chronic pain or any type of discomfort that could be the beginning of an overuse injury . The old adage, "No Pain, No Gain" isn't for you, the educated exerciser of today. Continue to change your exercise routines, live alittle, try something new and by all means....QUESTION EVERYTHING.
In Health,
W
