Flexibility Exercise

 Flexibility can be defined as the ability of joints to move through a range of motion. The more flexible we are, the greater the range of motion. This joint flexibility depends on the connective tissue and muscles associated with the point. Connective tissue refers to the ligaments that bind bones together and tendons that bind muscle to bone.

 There is little flexibility to connective tissue. Tendons are the least flexible and will tear beyond 4% of stretching.  Ligaments have a bit more flexibility but will tear when stretched beyond 6%. Thus, flexibility exercises are primarily devoted to the muscles attached to the tendons. With stretching exercises, muscles can be stretched 50% or more without tearing.

 The purpose of flexibility is threefold.

 First, by extending the range of joint motion, you reduce the potential of injury when that range is over extended. The ankle and the knee joint are particularly subject to joint injury. When running or just walking on rough ground, the foot can easily be turned by a hidden hole causing a bad sprain. Skiers suffer injury to knees when they fall awkwardly. When ligaments have some range of movement, damage can be avoided or minimized by accidental movement.

 Second, flexibility can reduce the stress on the vertebral column. Much of lower back pain can be caused by excessively tight quadriceps (quads) and hamstrings (hams). These are two of the most powerful muscles in the body, and they can exert powerful stresses on the spinal column. If these muscles are stretched, the level of stress on the back is also reduced.

 Back stress can also be caused by an imbalance between the quadriceps and the hamstrings. Generally the quadriceps are larger and the more powerful of the two. Quadriceps are used (exercised) more often. Every time we raise ourselves from a chair we exercise the quadriceps. Most aerobic exercises utilize the quadriceps more than the hamstrings so balancing the strength is difficult. However, with power exercise, it is possible to set resistance to balance the quads and hams. Both weights and Human Isokinetics can achieve this balance.

 Third, flexibility can reduce the internal resistance of the both the quads and hams. By stretching these muscles, their tension loosens. Not only will this lesson the stresses on back, but also reduce the resistance when running or cycling. This can improve both speed and resistance to fatigue. This is certainly a benefit for runners.

 The primary focus of flexibility exercise is for the muscles associated with the knee joint: the hamstrings and the quadriceps.

 All of the hamstrings stretches involve the straightening of the leg parallel to some surface. The most familiar of these is the runners stretches which there are many variants. The toe-touch stretch which was frequently employed in physical education classes for many years has lost favor because of the potential strain on the lower back.

 Quadriceps stretches are the opposite movement of the hamstring stretches. In these stretches, the leg is flexed backwards and upwards. The stretch requires exercisers to pull the muscle with their hand or use a strap or elastic band.

  Stretching can be broadly categorized into two forms: static and dynamic. As the names imply, dynamic stretching involves movement whereas static refers to holding a certain position. A stretch position can be both dynamic and static. Consider a sprinter's stretch which primarily stretches the hamstrings. The exerciser lowers the torso toward the knee of the leg that is parallel to the ground with the goal of touching the chin to the knee. This movement is dynamic stretching. However, if the chin remains on the knee for an extended time, 30 seconds or more, then that interval is static stretching.

 Static stretching was once a popularized form of exercising, but has recently lost favor especially among athletes. Such stretching has been shown to cause the muscle to lose elasticity and power. If you look at the muscle like a rubber band that has been stretched for a long time, the rubber band has lengthened but has lost its elasticity, and might eventually snap. Static stretching appears to have that effect on muscles.

 There are other variants of stretching such as ballistic, active, an assisted stretching. Once popular, ballistic stretching subjects the muscle to jerky movements. These movements pushes the joints to its limits, and unfortunately sometimes beyond its limits. Active stretching is exaggerating natural movements. Lunges are the most common form of active stretching. These lunges can also be dangerous if not properly executed, and they are especially dangerous when weight is added to the exercise.

 Assisted stretching is the use of some device or person to facilitate the stretching. Exercise bands can be used for this purpose. There are also therapeutic devices that fulfill the same function—some with the assistance of a trainer or therapist.

 For senior exercisers, dynamic stretching is a valuable addition to an exercise regimen especially for those with running as their major aerobic activity.

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