Not all exercises are created equal. Unfortunately many of the traditional exercises that were learned in high school, discovered at fitness class or seen in a book have the potential to cause injury. While there tends to be controversy among professionals, biomechanical research has definitely identified some specific do's and don'ts. The following exercises are generally considered to have the greatest potential for causing injury.
There are a variety of exercises, including back arches, that involve hyperextending the low back. These movements tend to place excessive strain on the lower back and can be particularly dangerous if performed in a bouncing fashion.
Suggestion: There is no doubt that ensuring some extension in the low back is important. Stretching and strengthening should be done in a more passive (slow and controlled) manner.
Straight Leg Sit-Ups
There are several risks associated with this exercise. By keeping the legs straight, the individual exercises the hip flexors, as well as the abdominals. When the hip flexors contract they tend to cause a hyperextension of the lower back and a forward tilt of the pelvis. Therefore, the hip flexors are primarily strengthened and the abdominals remain relatively weak. In addition, this exercise puts excessive pressure on the lower back.
Suggestion: A curl-up, on the other hand, is performed with the knees bent and is performed as a partial sit-up. In this manner, the abdominals can be exercised safely and efficiently and strong abdominal muscles can help in relieving low back pain.
Standing Straight-Leg Toe Touch
Although toe-touching is performed as a hamstring stretch, it is relatively ineffective and places undue strain on the spine and lower back muscles. In general, it is wise to avoid positions that require maintaining a bent forward position when standing.
Suggestion: In order to stretch the Hamstring more effectively lay on your back and raise one leg straight in the air. Put your hands around the raised leg (on the lower part of the hamstring) and gently pull towards your chest. Ensure that the raised leg is maintained close to straight throughout to maximize the stretch.
Rolling the head/neck around in circles puts undue stress on the uppermost part of the spine in the neck, particularly if this movement is done quickly and/or forcefully. Neck hyperextensions can cause compression of the nerve roots in the neck, and are especially risky for those individuals who already have degenerative disk-disease.
Suggestion: Whenever moving your head to loosen up your neck do so in a slow and controlled fashion.
This exercise is performed sitting on the floor with both legs apart and one leg tucked behind and outward while the individual reaches forward to touch the toe of the extended leg. This exercise places a great deal of stress on the ligaments in the knee joint of the bent leg.
Suggestion: Perform this exercise on a raised bench or the side of a firm bed or couch. This will allow for the leg not being stretched to remain in a comfortable neutral position. Also, when bending forward, bend from low in the back and not from the mid-back this will maximize the stretch on the hamstring.
The full squat, or the "duck walk" also places a tremendous amount of pressure on the knees. Not only is this exercise ineffective, the knee ligaments and cartilage are placed in an extremely vulnerable position.
Suggestion: Partial squats will give the stretch in the muscle required without putting an over-stress on the ligaments and cartilage.
Exercising safely means avoiding potentially dangerous exercises and choosing exercises that are appropriate for one's level of fitness. Ensuring proper technique is critical and an exercise routine should be started at an appropriately slow pace taking care not to increase the level of difficulty and intensity too rapidly.
The importance of individualizing an exercise program cannot be overemphasized. Some exercises are risky for individuals with back problems, and others with knee problems. Always examine an exercise routine to determine whether the risks of doing the exercises outweigh the expected benefits. Your family physician or local sports physiotherapist can be helpful in assisting you in this regard.