by Thomas Kurz
1. Error: Stretching statically before dynamic exercises.
If you try to make a fast, dynamic movement immediately after a static stretch you may injure the stretched muscles and the more strenuous the stretch the more likely the injury. (Stretching is strenuous when you do it at the pain threshold and it is light when you feel a sensation of stretch, but not pain.)
Two good reasons not to do static stretches before exercise according to Shrier (2000):
—Even mild static stretching can damage muscle cells.
—Static stretching increases pain tolerance. In the words of Dr. Shrier (2000), “It does not seem prudent to increase one’s tolerance to pain, possibly create some damage at the cytoskeletal level, and then exercise this damaged anesthetized muscle.”
For a period from several seconds up to five minutes following a static stretch you cannot display your top agility or maximal speed because your muscles are less responsive to stimulation—your coordination is off. Relaxed static stretches decrease strength by impairing activation of the stretched muscles for up to five minutes after the stretch and contractile force for up to one hour (Fowles et al. 2000).
Reduction of muscle activation, or imbalance in activity, that follows static stretching is more likely to cause an injury than a reduction in strength (Murphy 1991). (This applies to a single workout and not to long-term training. A long-term [3–12 weeks] stretching program may improve strength performance [Kokkonen and Lauritzen 1995; Wilson et al. 1992; Worrell et al. 1994].)
As for the claim that static stretching in a warm-up prevents injuries—there is no scientific evidence of that (Shrier 1999).
2. Error: Stretching your sore or even injured muscles strenuously.
Stretching of sore muscles may further damage them. After all, soreness is a sign of muscle tissue damage and Smith et al. (1993) showed that stretching may cause delayed onset muscle soreness. So, if you feel that a stretch may relieve spasms in the sore muscles, to be safe stretch lightly—only as much as it takes to feel relief.
3. Error: Stretching with a partner.
The practice of using partners in stretching is a waste of time, and it is dangerous. The helper is neither stretching nor resting. The danger of using a partner in stretching is obvious. The partner does not feel what you feel. He or she can easily stretch you a bit more than you would like. If you feel pain and let your partner know about it, by the time the partner reacts, it can be too late.
Remember—a partner in stretching can cause an injury. If you need someone’s help in doing any stretches, it means that you are not ready for them. It is better to go slowly but steadily.
4. Error: Stretching without regard for (or knowledge of) the anatomy of the involved joints.
It is an error to stretch your limbs in alignments in which they cannot reach the maximal stretch. For example, if you are an adult and never were able to do the front split with your hips square and the front thigh of the rear leg flat on the ground, forcing such a split will take you forever and likely injure you.
If you started to stretch past the age when elongating ligaments was feasible, you probably have difficulty touching the ground with the front thigh of the rear leg in the front split. What keeps you from doing a front split with hips square is a ligament running in front of your hip joint. This ligament is tightened by moving the thigh straight back or by tilting the pelvis back as when leaning your trunk back and relaxed by the opposite movement—hip flexion (Kapandji 1987). As stretching ligaments is not an option for adults (see explanation in point 5), to achieve a flat front split you need to stretch the hamstring of the front leg and the muscles of the lower back so you can tilt the pelvis forward while keeping the trunk upright. Another method is to both tilt and twist the pelvis and rotate the rear leg so its inner thigh faces the ground rather than its quadriceps.
If you stretch for a side split (lateral split, box split, Chinese split) without tilting your hips and rotating your thighs the right way you will rather inflame your hip joints than reach the side split. You cannot do this split without some combination of rotating your thighs outward and tilting your pelvis forward. Spreading the legs without these additional movements twists and tightens the ligaments of the hip and jams the tops of the necks of your thigh bones against the cartilage collar at the upper edge of your hip socket (Ciszek and Smigielski 1997).
5. Error: Stretching ligaments, especially if your joints have normal range of motion.
Stretching ligaments leads to loose-jointedness and can be effectively applied only with children. In adults, an age-related increase in the rigidity of collagen fibers makes any stretches aimed at elongating ligaments hazardous. When children stretch ballistically or statically, their muscles do not contract as strongly as an adult’s, and their softer ligaments can be stretched (Raczek 1991). If a ligament is stretched more than six percent of its normal length, it tears. There is no need to stretch ligaments to perform even the most spectacular gymnastic or karate techniques. The normal range of motion is sufficient. Stretching ligaments destabilizes joints and thus may cause osteoarthritis (Beighton et al. 1983).
Laxity of the glenohumeral joint (arm joint) predisposes the joint for injuries (Fleisig et al. 1995; McMaster et al. 1998; Pappas et al. 1985).
Overstretched ligaments of the spine may be associated with back pain because of hypermobility of back joints or because of entrapment of the tissues that normally would be kept out of the joint by the ligaments (Hertling and Kessler 1996).
Low back pain may result from laxity of joints other than those of the back—lax ligaments of ankle and knee joints increase the risk of low back pain (Nadler et al. 1998). You can compensate for lax ligaments by strengthening the muscles crossing a given joint (Krivickas 1997; Zelisko et al. 1982).
One can have tight ligaments and good muscle flexibility or loose ligaments and poor muscle flexibility (Krivickas and Feinberg 1996).
6. Error: Forcing the stretch beyond the point at which you can still tense the stretched muscles.
Forced stretching can damage the muscles and even the capsule and ligaments of involved joints, which leads to the joints’ instability and pain (McMaster and Troup 1993; McMaster et al. 1998).
7. Error: Doing ballistic stretches.
In ballistic stretches (bobbing, bouncing, or jerky movements), you use the momentum of a fast-moving body or a limb to forcibly and abruptly increase the range of motion. Ballistic movement cannot be adjusted or corrected once started. Ballistic or bounce stretches may result in immediate as well as residual pain—the symptom of “minute injury to soft tissue involved in the stretching,” which the subsequent strenuous exercises may aggravate “to the point of serious muscle damage” (Logan and Egstrom 1961).
8. Error: Doing many isometric stretches for the same muscle groups.
This is likely to excessively fatigue the stretched muscles and damage them to the point of being sore for several days.
It is enough to do only one isometric stretch per muscle group. To increase your range of motion you have to repeat this stretch two to five times, using several tensions per repetition and that is plenty of work for your muscles.
References are listed in the fourth edition of Stretching Scientifically: A Guide to Flexibility Training.
This article is based on the Stadion book Stretching Scientifically: A Guide to Flexibility Training and on the video Secrets of Stretching: Exercises for the Lower Body. Get them now and have all of the info—not just the crumbs!
If you have any questions on training you can post them at Stadion’s Sports and Martial Arts Training Discussion Forum