Introduction:
Exercise is suitable for a healthy body. However, different exercises have different purposes. Specific exercises increase stamina and cardio-respiratory performance, and certain exercises are beneficial for muscle strength. Understanding the role of different exercises is essential to achieve goals and prevent injury.
What Are Flexibility Exercises?
Stretching and flexibility exercises are essential for lengthening and elongating specific muscle and tendon groups. These exercises improve joint mobility, muscle-tendon flexibility, and overall range of motion.
Movement or locomotion is one of the main physiological functions of living beings. The movement of the joints is aided by bones, skeletal muscles, and tendons. During movements, muscles produce two different types of tension. The neuro-reflexive properties of the muscles generate active tension.
Factors such as contractile effects or the force generated by the interaction of sarcomeres (the contractile unit of muscle) composed of actin and myosin (two types of muscle fibers) filaments, interaction between motor neurons (nerve fibers that send signals to the body), and reflexive activation are also known as dynamic muscle contraction. On the other hand, passive tension is created by structural changes in the connective tissues due to the elongation of the muscle fibers beyond their contractility.
A decrease in these muscle tensions is related to muscle tightness. Also, scar tissue in the muscle fibers may cause muscle shortening and decreased range of motion. Different stretching or flexibility exercises decrease muscle length and increase muscle tension.
There are three types of stretching exercises. In static stretching, a slow-placed passive motion of a large group of muscles is achieved through external forces or gravity. Dynamic stretching utilizes movements specific to the sport to enhance the range of motion of the limbs beyond what static stretching can achieve. It involves swinging, jumping, or exaggerated motions that extend the limbs beyond their normal limits. In pre-contraction stretching, both contraction and stretching of the muscle are observed.
What Are the Recommendations for Stretching Exercises?
According to the guidelines put forth by the American College of Sports Medicine,
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Stretching or flexibility exercises can be performed two to three times a week.
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Each stretch should be held for 15 to 30 seconds and performed three to four times.
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For elderly individuals, relatively longer stretching times are required to achieve flexibility and mobility.
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The type of stretching needed by a particular person is based on sexuality, age, and the body's physiological condition.
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Stretching exercises for flexibility can be performed as part of a warm-up procedure before sports. While static stretching is practical for sports like gymnastics, dynamic stretching is adequate for running and jumping.
What Are the Benefits of Stretching Exercises?
The benefits of stretching exercises include the following;
1. Acute Effects:
- Stretching exercises for flexibility can immediately improve the range of joint motion for 60 to 90 minutes. They also reduce passive tension and enhance joint flexibility.
- Stretching exercises can decrease muscle tension and tendon stiffness, preventing energy loss in muscles and tendons.
2. Chronic Effects:
- Stretching exercises can lead to improved muscle strength and power over time.
- Stretching exercises are beneficial for correcting posture, particularly in neuro-muscular disorders, and can enhance neuro-muscular coordination.
- These exercises effectively treat muscle pain and dysfunction and improve joint stability. Additionally, stretching can increase muscle fiber length and properly orient collagen fibers, aiding rehabilitation.
What Are the Roles of Stretching in Injury Prevention?
According to previous researchers, a temporary or long-lasting increase in tendon flexibility due to short-term or long-term stretching could result in a greater capacity for the tendon to handle energy absorption. When it comes to intense movements (where a significant amount of energy absorption is required), the enhanced energy-absorbing ability of the stretched tendon could theoretically reduce the risk of injury to both the tendon and muscle structures.
This happens because the tendon becomes more adept at absorbing energy. As a result, the intense stress placed on the tendon (often from vigorous movements) is less likely to surpass its maximum energy-absorbing capacity, thus decreasing the incidence of tendon injury. With the stretched tendon better equipped to absorb energy, there is a lower energy transfer to the contractile apparatus, lowering the risk of injury within this muscle component.
However, modern research does not support the previous argument. Increased muscle length is linked to a reduced ability to absorb energy in a muscle at rest, while a contracting muscle is less stretched but can absorb more force.
Therefore, greater change in volume, achieved through stretching, does not necessarily correlate with the tissue's resistance to injury. Another concept presented is the observation that sarcomere length in an active muscle is heterogeneous. This is significant during muscle activity because the actin and myosin filaments do not overlap when some sarcomeres are stretched.
As a result, the force being absorbed is transmitted to the muscle fiber cytoskeleton, resulting in fiber damage. Furthermore, according to the literature, these events can occur within the normal range of motion of the joint. Therefore, muscle compliance may be irrelevant to injury, while the loss of energy-absorbing capacity of overstretched sarcomeres is of greater importance.
According to researchers, stretching a muscle while it is active can lead to injuries. This suggests that increasing the muscle length at rest through stretching does not necessarily decrease the risk of injury when the muscle is active. Scientific studies have demonstrated that even stretching a muscle to just 20 percent of its resting length, which can happen with proper stretching techniques, can cause damage in isolated preparations. These results suggest that identifying the proper stretching techniques to minimize injury prevention may be challenging.
Conclusion:
Stretching is a form of flexibility exercise that increases muscle tension. These exercises increase the range of motion and mobility of the joints. However, the role of stretching in preventing injury is doubtful. According to modern research, stretching exercises do not significantly prevent injuries. Despite this, these exercises are suitable for rehabilitation and mobility.
