By – Scott Weiss MS PT ATC CSCS & Jamie Bernal SPTProprioceptive neuromuscular facilitation (PNF) was developed in the late 1940s and early 1950s as a means of rehabilitation for neurological disorders such as multiple sclerosis, cerebral palsy and poliomyelitis. The PNF method is a holistic approach; elements of motor development, anatomy, neuro-physiology and kinesiology are used.The basic principle is that movements of the body are the combination of spiral and diagonal patterns. It is in these patterns that muscles function most effectively and naturally. Another basic premise of PNF is that weak muscles can be facilitated, or activated through specific patterns in order to produce irradiation.Irradiation is an overflowing contraction to another weaker muscle. Furthermore, resistance and stretch to a stronger muscle can produce irradiation. This allows greater movement and now the patient can assist in their own recovery. These patterns are effective because the motions require muscles to work in multiple planes and to contract over two or more joints at once. This has great importance due to the fact that these are the motions that occur everyday with functional activities as well as during our activities of daily living.In addition to using specific patterns of movement, PNF also utilizes several techniques to facilitate movement. Manual contact, appropriate resistance, verbal commands, vision and timing are some of the basic techniques, while rhythmic stabilization, combination of isotonics (a combination of eccentric and concentric muscular contractions) and the contract-relax method are some special, more functionally-based techniques.PNF employs several types of muscle contractions, all of which are required during a person’s daily activities. An isotonic contraction is the active voluntary shortening of a muscle; this occurs in the quadriceps muscle while walking up a flight of stairs or in the biceps when performing arm curls.An isometric contraction is a static hold against a maintained resistance; this occurs when trying to push or move a stationary object, or when an ice skater balances his partner up in the air without seeming to move a muscle. An eccentric contraction is the active voluntary lengthening of a muscle; this occurs in the quadriceps muscle while going down stairs or in the triceps muscle when you lower your body during a pushup.During all these contractions, the force capabilities and the length of the muscle are constantly changing attempting to adapt to an external force. PNF training involves these types of contractions either in isolation or in combination because whether you are doing daily chores around the house or playing a competitive game of soccer, your body will naturally contract your muscles in this manner.The law of specificity of training states that a muscle or movement will progress in the manner in which it is trained. If the body and muscles are trained to contract isotonically, isometrically and eccentrically, then your ability to contract your muscles and transition among all three types of contractions will increase and become more natural.PNF began as an effective way to treat several different diagnoses in a rehabilitation setting, allowing patients with severe injuries to become more independent. For example, rolling is an important activity that is utilized while getting in and out of bed. To the average person, this seems like an easy task and we rarely even think about it. To someone with a spinal cord injury, it becomes much more difficult and an obstacle every day.Using the PNF approach, appropriate resistance and manual contact to the front of the pelvis promotes rolling forward, while resistance to the back of the pelvis promotes rolling backward. These skills help patients with poor bed mobility and can be applied in various therapeutic environments.Balance issues are another serious concern for neurological patients. A PNF technique called rhythmic stabilization can assist in increasing trunk, arm and leg control. In this technique, which can be done sitting, standing knealing or during movement, a person tries to maintain their balance while the therapist applies gentle perturbations in numerous angles.This increases the patient’s ability to move without fear that they will be thrown off balance and fall, such as reaching for an object on a high shelf or bending down to pick up an object off the ground.Walking is a task that many people take for granted. After a cerebral vascular accident (CVA) or stroke, this task becomes a challenge. Gait training using the PNF approach may be beneficial. Resistance can be applied via the combination of all muscular contractions to the trunk or lower extremities while walking or while standing, depending on the patient’s specific needs or present ambulatory state.This teaches the patient to transition from all types of contractions, which occurs during walking. By giving appropriate resistance to stronger muscles and allowing irradiation to contract weaker muscles, people can become more independent walkers. Although PNF began as a treatment for neurological patients, its use is becoming more popular in a sports and fitness setting.Several sports employ the use of PNF diagonals already. A tennis serve, a soccer kick or a football toss all represent movements that are within the PNF diagonal. In the example below, a tennis serve begins with the arm stretched over the head, away from the body with the palm up, which is the D2 (diagonal 2) flexion pattern, and ends in a follow-through consisting of the arm coming down and across the body, with the palm down, which is the D2 extension pattern. Therefore an injured athlete will benefit from training specifically following PNF techniques.www.oxfordshirelta.co.uk/ oldnews.html PNF stretching or specifically, the contract-relax method, is a popular technique utilized in sports settings. In this technique, you contract the muscle you are trying to stretch and then relax it. The theory is that when the muscle is released, there will be less resistance, so you can get a better stretch.This is due to the phenomenon of auto genic inhibition, in which the golgi tendon organ (GTO) (a receptor located near the junction of the muscle and tendon) is stimulated, causing muscular relaxation. In recent studies, the contract-relax method was found to be superior to a regular static stretch.This method can also be used without a physical therapist, personal trainer or work-out buddy. For example, a regular hamstring stretch can be turned in to a more dynamic PNF stretch. First, position yourself in the traditional stretch position (foot elevated on a stool, knee straight).Lean your trunk over your leg to get a stretch. Second, contract your hamstrings by pushing your foot into the stool. Hold for 3-5 seconds, release, reach further and then relax. You should now be able to lean your trunk further and get a better stretch.The “chop” and “lift” techniques of PNF began in the rehab setting to facilitate upper extremity reaching and trunk rotation. Now, this technique is being used in a more dynamic approach for core stability and strengthening. A chop and lift exercise can strengthen your abdominal and back musculature, while promoting balance and coordination.With this exercise, your arms start at a diagonal across your body. Then twist your trunk to the opposite side and end with you arms over your opposite shoulder. This can be done with weights or a medicine ball as shown below.http://www.sissel-online.com/exercise/seated reverse wood chop with medicine ball.php PNF is a great way of treating patients for improvements with daily tasks or with athletes during sports specific training.