If the downswing is started from a point where the arms are bent incorrectly at the top of the backswing, the tendency is for the arms to straighten out prematurely in the downswing in an effort to generate power instead of letting it happen. This overswinging unfortunately creates maximum clubhead speed prior to impact. The first lever is created when the wrists cock and form a 90-degree angle between the shaft and the left arm at the top. The second lever is also a 90-degree angle created when the right arm is folded at the elbow so the elbow points to the ground while the right palm points toward the sky. When you fail to turn your chest away from the ball in your backswing and use only the arms to take the club to the top, the arms tend to buckle at the elbows and the hands finish too close to the head.
Poor posture is often the culprit when a good body turn is hard to achieve.
When you grip the club too much in the palm of the left hand, it inhibits the proper wrist hinge. Some golfers compensate for this poor grip by improperly hinging at the elbows on the way to the top of the backswing instead of hinging the wrists. Club swings too much around the golfer. Because we stand to the side of the golf ball, it is easy for golfers to get the club traveling too much to the inside and around them on the backswing. This gets the hands too low at the top with the right arm tucked to the side and right elbow stuck behind the body.