Anyone with a remote interest in workouts should have a basic idea of muscle stretching and its significance. However, answers to the most basic questions on the subject are mostly a matter of speculation. There seems to be a lot of fuzzy areas on the subject, even for the most experienced and enthusiastic. This leaves most beginners in the fog, which eventually leads to treading along in appropriate norms. This article will attempt to address the key questions related to muscle stretching based on what current scientific research evidence suggests.

• What are the best stretching approaches for optimal results?
• How effective and safe are stretching procedures?
• Which principles should one follow?
• Is there any scientific evidence supporting the significance of stretching in physical exercise?

A Few Basics on Stretching

Your ability to move around and achieve daily tasks is influenced by the amount of movement allowed by joints which are primarily involved in basic body movements. In professional circles, this factor is known as joint Range of Motion(ROM).

Two main factors affect this parameter, and these are:

• The joint itself.
• Muscles which exert the necessary force to effect movement in the joint.

Factors which are affect movement at the joint itself include its geometry(the way associated bones and other structures are arranged), and the flexibility offered by intrinsic structures i.e cartilage, and those which assist in keeping the joint together such as the Joint Capsule and Ligaments.

Muscle flexibility is affected by the amount of tension in the muscle itself. Tension can be understood in two forms namely: passive or active tension. Passive muscle tension relates to intrinsic tension generated by the the muscle’s structural components and surrounding structures which assist with maintaining its structural integrity i.e fascia.

Active tension is generated when the muscle is actively contracting due to stimulation by the responsible nerves. This can be voluntary, as in when the muscle is involved in certain physical tasks, or involuntary, as in reflexes or muscle contractions which may occur in the absence of voluntary control i.e muscle cramps or spasms.

Muscle tightness describes a state of sustained active tension of a particular group of muscles which often results in limitation of joint movement or Range of Motion. This tends to affect performance in certain tasks, thus necessitating the use of stretching techniques. It is a result of a variety of passive and active mechanisms.

Passively, a muscle can limit joint movement due to shortening, which can be a result of factors such as injury, and a sustained shortened position. Actively, muscle shortening can be a result of muscle spasms and contraction due to pain and other Biomechanical factors. Stretching techniques aim at improving muscle flexibility and length, as well as extensibility of other structures which are primarily involved in joint movement.

Types of Stretching

Muscle stretching can be done using three main approaches: Static, Dynamic and Pre-contraction.

Static Stretching

This is the most popular approach due to its simplicity and perceived effectiveness. The method is characterized by holding the involved limb in a specific position where a stretch sensation is felt in the target muscle. The stretch is typically held for 15 seconds to 1 minute.

Dynamic Stretching

This involves movement of the involved limbs or body segments. Instead of subjecting the muscle to a constant stretch, the individual performs certain movements which subject the muscle to intermittent stretches over a specified period of time. This can be done in two ways:

• Active: Involves moving a limb or joint to maximum range for a specified number of times, with the aim of applying intermittent tension to the group of muscles in question.
• Ballistic: This involves taking the limb to full range, where alternating bouncing movements are performed to stretch the muscle. This is currently discouraged as its associated with increased risk of injury.

Pre-contraction stretching: This involves contracting/tensioning the muscle to varying degrees before it is stretched. Several special techniques with superior gains and safety have been identified, with good examples including the hold-relax, and contract-relax technique. These techniques are extremely effective. However, they require assistance of appropriately trained personnel for maximal results.

Evidence

Standard guidelines from authoritative bodies such as the American College of Sports Medicine(ACSM) along with extensive research demonstrated in numerous scientific systematic reviews show that both static and dynamic stretching techniques have significant short and long-term effects. A look at studies done by prominent researchers on the subject such as Mchugh and Thacker, not only demonstrate its effectiveness in improving muscle flexibility, but also improving risk of injury in everyday activities and physical exercise.

A good number of authors have been able to show that static stretches of as little as 10-30 seconds per muscle group are capable of inducing significant effects. In fact, the greatest effect is seen within the initial 15-30 seconds of the stretch. Additionally, it seems that by the third or fourth repetition, the muscle has already gained the maximum effect, which implies that one needs 1-2 reps for each muscle group provided that proper technique is used.

However, static stretching has its catch. So far, studies have consistently associated static stretching before exercise with reduced muscle strength and performance during high intensity exercises such as running and jogging. This is fancily called ” Stretch-induced Strength loss”, and it raises questions against the common practice of stretching before engaging in physical exercise.

The exact mechanism by which this happens is still a matter of scientific speculation. However pre-contraction stretches have been shown to reduce the phenomenon. This has led to the discovery of other stretching techniques such as those proposed by Feland and colleagues known as Post-isometric relaxation techniques. The controversy necessitates a look at how current evidence compares the efficacy and safety of the different types of stretches.

Stretching modes compared: key facts

• Both Dynamic and Static stretching techniques are capable of inducing substantial improvements in both muscle tightness and overall joint motion.
• Dynamic stretching has not been associated with complications of stretching such as loss of muscle performance.
• The decreased strength after static stretches seems to depend on the intensity of the stretch. Researchers such as Robin observed that 4 repetitions of 15 second-hold stretches did not have any effect on jumping and running activities in athletes. However, 6 repetitions did have an observable effect on overall performance.

This means that more repetitions/intensity increases the likelihood of strength losses during exercise. Muscle contraction preceding the stretch have a positive impact on the risk of compromised performance during exercise.

General Recommendations

With the wide range of viable options in terms of stretching techniques, the first step towards success is to choose the best option in light of individual factors. The ACSM recommends a static stretching program of 15-30 seconds stretches done for 2-4 times, at a weekly frequency of 3 days per week for the general population.

The reason behind the static stretch recommendation is that static stretches are fairly easier to execute especially for starters. Additionally, it’s easier to modify the stretches in such a way that the risk of complications is reduced. However, with assistance of a professional, a variety of dynamic stretches should be explored due to their superior benefits.

Recommendations for highly active individuals and sports

When it comes to sports, static stretching is considered appropriate for sporting activities which are primarily based on flexibility. Dynamic sports such as basketball and Soccer need Dynamic stretching approaches due to the lower likelihood of negatively affecting performance.