Stretching, when done correctly, increases both the active and passive range of motion of the joints and reduces the resistance in the opposing muscles and joints, which increases the amount of strength that can be translated into speed. In addition, the likelihood of injury is greatly reduced. An imbalance between the flexibility of opposing muscle groups in a joint or between the same muscles on opposite sides of the body can distort bodily movement and render the movement less effective. It can also create a difference in the stresses borne on different parts of the body and lead to overuse injuries or even nerve impingement.
Each sport requires certain levels of flexibility and stability to do the skills required, while avoiding injury. The requirements vary according to the positions the athlete must work from and the forces the body is subjected to. Football players are subject to high forces but aren’t required to achieve unusual positions. The primary requirement is balance of strength and flexibility in each joint, durability and enough flexibility to not hinder speed in running. The “rings” in men’s gymnastics require extreme flexibility and a very high strength-to-weight ratio in the upper body. Wrestlers require a balance of strength and flexibility, especially in the neck and shoulders. Hurdlers and kickers for football require flexibility and strength in the groin and hamstrings, since they generate great force in an extreme range of motion. Martial arts practitioners have the similar requirements, although each martial art differs from the others in the emphasis placed on different methods of fighting and self-defense. Tae Kwan Do emphasizes kicks, while boxing prohibits kicks and depends on punches. Wrestling, Aikido and the various forms of Jiu-jitsu use leverage and joint manipulation to defeat their opponents. Baseball pitchers require great flexibility and strength in the shoulder joint and to a lesser degree in the hip joint.
Marathon runners don’t require much flexibility; they just need to have a normal and pain-free range of motion in the ankle, knee and hip as well as great durability throughout the lower body due to the repetitive stress of running long distances. The foot strikes the ground with three to six times the weight of the body when running. If a 120-pound runner has a stride length of four feet and runs 100 miles per week during peak training for a marathon, the body is jarred with 360 to 720 foot-pounds of force 132,000 times and absorbs 47,520,000 to 95,040,000 foot-pounds of shock each week.
To decide which stretches to use, first observe which, if any, areas are sore subsequent to training. Second, observe videos of the sport and see which areas require excellent range of motion for optimum performance. Of course, athletes who already have a coach can follow his or her directions on which areas to stretch.
More information can be found in training manuals in your sport. A certified personal trainer can provide general guidance on how and which stretches are best. Athletes who are currently injured or still impaired by an old injury should seek the guidance of their physician or a Registered Physical Therapist (RPT). Try to find an RPT who specializes in sports medicine and has some experience with athletes in your sport.
If stretches recommended by your coach or trainer cause pain, tell the coach or trainer. If the pain doesn’t improve, seek medical advice before continuing. For a list of choices for stretching, see the article “Stretches That May Improve a Surfers’ Flexibility” in the water sports section of this Web site.
In conclusion, properly performed stretching is well worth the time and effort required. Stretching regularly prevents injuries and improves performance. Once the correct technique and the appropriate stretches are chosen and learned, they become second nature. As the stretches become easier, it may be wise to progress to more difficult stretches periodically, until the optimum range of motion has been reached. Once flexibility is at the optimum level, then stretching for maintenance is enough.