PNF stretching
PNF (proprioceptive neuromuscular facilitation) is often a combination of passive stretching and isometrics contractions. However, it can also weaken muscles, decrease endurance, slow neuromuscular control and coordination, and decrease joint stability. PNF was developed in the 1940's by Kabat, Knott, and Voss. When resistance is applied, as in the case of Hold-Relax, it should be the maximum amount of resistance that allows for pain-free movement. PNF exercises can be applied to patients of all ages. Research shows it is superior to static stretching.
Techniques include:
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 Agonist 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.