Posted by William on August 31, 2012
One example of what not to do that is seen in gyms is people who stand up and push a barbell or dumbbells forward from the shoulders and back to the start. These people are under the mistaken impression that the Pectoralis muscles (chest) are being used while the body is standing erect, as in some sports, such as football. Unfortunately, the muscles being used are the anterior deltoids, since the direction of motion is horizontal, while direction of resistance is straight down. The Pectoral muscles are only used when bringing the upper arms closer together in front of the chest directly against resistance. In addition, some people may find this movement irritates the lateral epicondyles at the outside of the elbows.
If one were trying to simulate pushing forward with the hands while standing erect, a better movement would use a pair of cable pulleys at chest height and at least as far apart as the elbows are when they are at chest height.
Simulating the paddling motion is probably the most applicable type of sport-specific movement for surfing. Use a cable pulley and either two single handles or a pull-down bar to provide resistance throughout the range of motion as the angle of the arm changes. The single handles are attached to either two chains or a single longer chain attached in the middle to the cable loop.
One method is to begin standing with your back against the front of a pull down machine and grasp the bar as wide as you normally keep your arms while paddling. Do not bring the hands back farther than the shoulders. Pull the bar down, with elbows locked, in an arc until the bar reaches the legs.
If you cannot do that without leaning over, reduce the weight. Be sure the bar is grasped with the each hand an equal distance from where the cable attaches to the bar. This exercise may irritate the medial epicondyle of the humerus (upper arm). This is located at the side of the elbow closest to the body. If this irritation occurs, slightly bend the elbow rather than locking it straight.
The greatest perceived resistance in the aforementioned exercise is when the bar is at shoulder height. This approximates the middle of the paddling stroke. Since paddling is most effective when force is generated throughout the stroke, this would not appear to be ideal. When moving in water, resistance is generated in opposition to the motion of limbs. The amount of resistance is directly proportional to the speed of movement and the size of the surface area of the limb.
Many exercises using free-weights or isotonic machines (isotonic means “equal weight”) have one point in the range of motion where the movement is most difficult and where the lifter usually fails in the exercise. This is called the sticking point. The other angles in the range of motion can handle greater resistance, which is one reason many people “cheat” or use other muscles to heave the weights up through that position. If the weight is cheated through the weakest angle, that area of contraction is not stressed and remains weak. In addition, jerking or heaving the weights can cause injuries.
That problem is what prompted manufacturers to develop “isokinetic” machines. Isokinetic means “equal speed,” Isokinetic machines use a fluid or air to provide resistance that equals the amount of resistance the user exerts against the handle of the machine and maintains a constant speed. The controversy about machines versus free-weights or isokinetic machines versus isotonic is too involved to be discussed here. Those issues will be discussed in another article.
Whether or not you agree with the advocates of isokinetic machines, these machines are not always available. However, the issue of developing strength though the entire range of motion remains.
Laying on your back (supine) on the ground and using a pulley at ground level behind your head will cause the greatest degree of difficulty at the start of the range of motion, which approximates the position of the arms just after they enter the water when paddling.