A significant percentage of weight training injuries occurs as a direct result of poor technique when executing specific movements at the shoulder(Mayer et al., 1994). Our focus in this experiment is to pay close attention to the effect of torque on the glenohumeral joint when performing a specific exercise, namely, the flat dumbbell fly, while executing two separate techniques. It is in our interest to analyze and question the possibility of performing this exercise effectively while at the same time taking safety into consideration so that injury may be avoided.
If one observes the movement perpendicular to the transverse plane, it is possible to determine how one repetition performed proximal to the midline of the body compares to one performed distal to the midline of the body. Using kinematics, we will be able to determine the moment arm of the dumbell weight force at the glenohumeral joint. We will also determine the greatest range of motion in the elbow requiring the least amount on torque on the glenohumeral joint. From studying the (2) techniques of the dumbell fly, we will be able to conclude which technique would have more potential to cause injury as related to the applied torque at the glenohumeral joint.