Stretching Techniques and Their Definitions
Active stretching eliminates force and its adverse effects from stretching procedures. Before describing the principles on which active stretching is based, the terms agonist and antagonist must be clarified. Agonist refers to actively contracting muscle or muscles while their opposing muscles are termed antagonists. The neuromechanisms conceptualized by Sir Charles Sherrington (1857 - 1956), the philosopher of the nervous system, as applied to active stretching are:
- Reciprocal innervation, While agonist muscles contract, contraction of the opposing antagonist muscles is inhibited. (Such as when alternately flexing and extending one's elbow.)
- Muscle spindles, Sensory nerve endings in muscle detect the change in length of the muscle and its rate of change. Force applied to a muscle stimulates the muscle spindles which activate protective reflexes resulting in contraction of that muscle. (Such as the knee jerk response of neurological testing procedures.) While necessary for sports and ordinary motions, this protective reaction is counterproductive for stretching, i.e., lengthening muscles.
PNF (proprioceptive neuromuscular facilitation) stretching
PNF (proprioceptive neuromuscular facilitation) stretching is a physical therapy procedure designed in the 1940's and 1950s to rehabilitate patients with paralysis. It is often a combination of passive stretching and isometrics contractions. In the 1980s, components of PNF began to be used by sport therapists on healthy athletes. The most common PNF leg or arm positions encourage flexibility and coordination throughout the limb's entire range of motion. PNF is used to supplement daily stretching and is employed to make quick gains in range of motion to help athletes improve performance. Good range of motion makes better biomechanics, reduces fatigue and helps prevent overuse injuries. PNF is practiced by physical therapists, massage therapists, athletic trainers and others.
- Hold Relax: most familiar. Also called Contract-Relax Involves the therapist asking the patient to fire the tight muscle isometrically against the therapist's hand for roughly 20 seconds. Then, the patient relaxes and the therapist lengthens the tight muscle and applies a stretch at the newly found end range. This technique utilizes the golgi-tendon organ, which relaxes a muscle after a sustained contraction has been applied to it for longer than 6 seconds. Verbal cues for the patient performing this exercise would include, "Hold. Hold. Don't let me move you."
- Contract-Relax with Antagonist Contract (CRAC): Also called Hold-Relax Contract. Same as Hold-Relax, patient isometrically contracts the tight muscle against the therapist's resistance. After a 20 second hold has been achieved, the therapist removes his/her hand and the patient concentrically contracts the antagonist muscle (the muscle opposite the tight muscle, the non-tight muscle) in order to gain increased range of motion. At the end of this new range, the therapist applies a static stretch before repeating the process again.
- Hold-Relax-Swing/Hold-Relax Bounce: These are similar techniques to the Hold-Relax and CRAC. They start with a passive stretching by the therapist followed by an isometric contraction. The difference is that at the end, instead of an agonist muscle contraction or a passive stretching, involves the use of dynamic stretching and ballistic stretching. It is very risky, and is successfully used only by people that have managed to achieve a high level of control over their muscle stretch reflex.
- Rhythmic Initiation: Developed to help patients with Parkinsonism overcome their rigidity. Begins with the therapist moving the patient through the desired movement using passive range of motion, followed by active-assistive, active, and finally active-resisted range of motion.
- Rhythmic Stabilization: Also known as Alternating Isometrics, this technique encourages stability of the trunk, hip, and shoulder girdle. With this technique, the patient holds a position while the therapist applies manual resistance. No motion should occur from the patient. The patient should simply resist the therapist's movements. For example, the patient can be in a sitting, kneeling, half-kneeling, or standing position when the therapist applies manual resistance to the shoulders. Usually, the therapist applies simultaneous resistance to the anterior left shoulder and posterior right shoulder for 2-3 seconds before switching the resistance to the posterior left shoulder and the anterior right shoulder. The therapist's movements should be smooth, fluid, and continuous.
Dynamic stretching is a form of stretching beneficial in sports utilizing momentum from form, static-active stretching strength and the momentum from static-active stretching strength, in an effort to propel the muscle into an extended range of motion not exceeding one's static-passive stretching ability. Anything beyond this range of motion becomes ballistic stretching.
Ballistic stretching is a form of passive stretching or dynamic stretching in a bouncing motion. Ballistic stretches force the limb into an extended range of motion when the muscle has not relaxed enough to enter it. It involves fast, "jerky" movements where a double bounce is performed at the end range of movement. Ballistic stretching should only be used by elite athletes with supervision by their trainer.Ballistic stretching has been found to be hazardous towards the body. It can injure vital muscles and nerves with the sharp jerking movements. It is even possible for tissue to be ripped off the bone.