PNF Techniques PDF

PROPRIOSEPTIVE NEUROMUSCULAR FACILITATION TECHNIQUES SENIOR LEC. HAVVA GOZGEN History 1948 → Kabat defined the principles of the Knott PNF for the first time 1953 → Kabat, Knott EMG studies 1956 → Kabat, the importance of sense in movement Definitions Proprioceptive: Having to do with...

PROPRIOSEPTIVE NEUROMUSCULAR FACILITATION TECHNIQUES SENIOR LEC. HAVVA GOZGEN History 1948 → Kabat defined the principles of the Knott PNF for the first time 1953 → Kabat, Knott EMG studies 1956 → Kabat, the importance of sense in movement Definitions Proprioceptive: Having to do with any of the sensory receptors that give information concerning movement and position of the body Neuromuscular: Involving the nerves and muscles Facilitation: Making easier Basic neurophysiologic principles The work of Sir Charles Sherrington was important in the development of the procedures and techniques of PNF. The following useful definitions were abstracted from his work: Afterdischarge: The effect of a stimulus continues after the stimulus stops. If the strength and duration of the stimulus increase, the afterdischarge increases also. The feeling of increased power that comes after a maintained static contraction is a result of afterdischarge. Temporal summation: A succession of weak stimuli (subliminal) occurring within a certain (short) period of time combine (summate) to cause excitation.  Spatial summation: Weak stimuli applied simultaneously to different areas of the body reinforce each other (summate) to cause excitation. Temporal and spatial summation can combine for greater activity. Irradiation: This is a spreading and increased strength of a response. It occurs when either the number of stimuli or the strength of the stimuli is increased. The response may be either excitation or inhibition.  Successive induction: An increased excitation of the agonist muscles follows stimulation (contraction) of their antagonists. Techniques involving reversal of antagonists make use of this property (Induction: stimulation, increased excitability.). Reciprocal innervation (reciprocal inhibition): Contraction of muscles is accompanied by simultaneous inhibition of their antagonists. Reciprocal innervation is a necessary part of coordinated motion. Relaxation techniques make use of this property.  PROPRIOSEPTIVE NEUROMUSCULAR FACILITATION (PNF) It is referred to as "Proprioceptive Neuromuscular Facilitation (PNF)", which is to facilitate the responses of the neuromuscular mechanism by stimulating proprioceptors.  BASIC MECHANISMS BASED ON PNF TECHNIQUES Basic principle; It is based on the principle that physiological movements in the human body have rotational and oblique character and that a greater response can be obtained with the movement against maximum resistance. It is aimed to improve posture and movement ability by using various techniques through hand contact, visual and verbal stimulation.  The theoretical basis of the facilitation and inhibition techniques is based on Sherrington's findings on the spinal reflex arch. Sherrington showed that peripheral receptors and impulses originating from peripheral nerves increase the excitability of the spinal alpha motor neuron.  While the impulses generated by each stimulus affecting the motor neuron stimulate a limited number of motor neurons, it also creates a subthreshold stimulus on some other motor neurons in the environment. Overlapping subthreshold impulses reduce the excitation threshold of the neuron and cause it to discharge. ▫ The increase in extensibility creates a facilitator effect. ▫ Any effect that increases the stimulation threshold of the neuron creates an inhibitory effect by reducing extensibility.  The reduction in synaptic resistance with such repetitive stimulation of a pathway in the central nervous system is thought to be the basis for learning. Pavlov demonstrated the effect of these mechanisms in the formation of new synaptic connections.  Any stimulus travels through different levels of the nervous system to the alpha motor neuron. Sensory- motor organization  Facilitation techniques are based on facilitating the voluntary effort of the patient by applying peripheral stimulation. Peripheral stimulation spinal motor neurons discharge more quickly for voluntary movement, depending on the stimuli coming through the descending paths. Facilitation techniques not only produce FACILITATOR effects. The response to stimuli in the central nervous system is the sensory- motor organization.  The contraction force of the muscle depends on the number of motor units that are stimulated. The number of motor units that are stimulated increases with the decrease of the synaptic threshold. This increase also increases the contraction force of the muscle. Stimulations originating from muscle, tendon, and pain receptors increase the extensibility of the alpha motor neuron.  These mechanisms, defined by Sherrington and known to have spatiotemporal summation effect on alpha motor neurons, form the theoretical basis of PNF techniques.  The concentration of peripheral and central impulses in the same neuron or interneurons with this summation mechanism increases the excitability of these neurons. Neurons Circuits Voluntary effort of the person Stimulation of peripheral structures by the therapist Muscle contraction Spatiotemporal summation effect  Motor neuron discharges can be facilitated by peripheral stimulation, through afferent fibers and their excitatory connections, or inhibited through inhibitory connections and mechanisms. Kabat developing the PNF method Neurophysiology Motor learning Motor behavior Kabat and Knott emphasized the application of maximum resistance when they first defined the principles of PNF. The increase in proprioceptive stimulation with maximum resistance creates an over-threshold stimulus through summation. Purpose of PNF; to develop voluntary control at the central level. The methods that can be used to increase central stimulation, thus achieving voluntary movement even in the paralytic muscle; ▫ Maximal resistance ▫ Reflexes ▫ Force spread ▫ Induction These mechanisms form the basis of PNF techniques. They are used individually or in combination for the summation of the warning.  Reflex and voluntary movements are tightly linked with these mechanisms. Reflexes can inhibit voluntary movement as well as facilitate. Voluntary movement can also inhibit or facilitate reflex activity. The basic procedures for facilitation are: Resistance: To aid muscle contraction and motor control, to increase strength, aid motor learning. Irradiation and reinforcement: Use of the spread of the response to stimulation. Manual contact: To increase power and guide motion with grip and pressure. Body position and body mechanics: Guidance and control of motion or stability. Verbal (commands): Use of words and the appropriate vocal volume to direct the patient. Vision: Use of vision to guide motion and increase force. Traction or approximation: The elongation or compression of the limbs and trunk to facilitate motion and stability. Stretch: The use of muscle elongation and the stretch reflex to facilitate contraction and decrease muscle fatigue. Timing: Promote normal timing and increase muscle contraction through “timing for emphasis”. Patterns: Synergistic mass movements, components of functional normal motion. Combine these basic procedures to get a maximal response from the patient. Resistance The amount of resistance provided during an activity must be correct for the patient’s condition and the goal of the activity. This we call optimal resistance. Types of muscle contraction; Isotonic (dynamic): The intent of the patient is to produce motion. ▫ Concentric: Shortening of the agonist produces motion. ▫ Eccentric: An outside force, gravity or resistance, produces the motion. The motion is restrained by the controlled lengthening of the agonist. ▫ Stabilizing isotonic: The intent of the patient is motion; the motion is prevented by an outside force (usually resistance). Isometric (static): The intent of both the patient and the therapist is that no motion occurs. The resistance to concentric or eccentric muscle contractions should be adjusted so that motion can occur in a smooth and coordinated manner. The antagonists of the facilitated muscles allow a coordinated activity and therefore they are sufficiently inhibited to allow that activity. Resistance to a stabilizing contraction must be controlled to maintain the stabilized position. When resisting an isometric contraction, the resistance should be increased and decreased gradually so that no motion occurs. Types of muscle contraction of the patient. a Isotonic concentric: movement into a shortened range; the force or resistance provided by the patient is stronger. b Isotonic eccentric: the force or resistance provided by the therapist is stronger; movement into the lengthened range. c Stabilizing isotonic: the patient tries to move but is prevented by the therapist or another outside force; the forces exerted by both are the same. d Isometric (static): the intent of both the patient and the therapist is that no motion occurs; the forces exerted by both are the same. Irradiation and Reinforcement We define irradiation as the spread of the response to stimulation. This response can be seen as increased facilitation (contraction) or inhibition (relaxation) in the synergistic muscles and patterns of movement. The response increases as the stimuli increase in intensity or duration. Kabat (1961) wrote that it is resistance to motion that produces irradiation, and the spread of the muscular activity will occur in specific patterns. Increasing the amount of resistance will increase the amount and extent of the muscular response. Changing the movement that is resisted or the position of the patient will also change the results. The therapist adjusts the amount of resistance and type of muscle contraction to suit 1) the condition of the patient, for example, muscle strength, coordination, muscle tone, pain, different body sizes, and 2) the goal of the treatment. Because each patient reacts differently, it is not possible to give general instructions on how much resistance to give or which movements to resist. By assessing the results of the treatment, the therapist can determine the best uses of resistance, irradiation, and reinforcement. Manual Contact  The therapist’s grip stimulates the patient’s skin receptors and other pressure receptors. This contact gives the patient information about the proper direction of motion. The therapist’s hand should be placed to apply the pressure opposite the direction of motion. The sides of the arm or leg are considered neutral surfaces and may be held. To control movement and resist rotation the therapist uses a lumbrical grip. In this grip the pressure comes from flexion at the metacarpophalangeal joints, allowing the therapist’s fingers to conform to the body part. The lumbrical grip gives the therapist good control of the threedimensional motion without causing the patient pain due to squeezing or putting too much pressure on bony body parts.  If the patient has no or decreased control over an eccentric muscle activity, for example, going from standing to a sitting position, the therapist can give the patient the kinesthetic information for this goal-oriented movement by putting his hands on the top of the iliac crest and applying pressure down and backward. If some muscles show too little synergistic activity, we can facilitate the desired muscle activity by giving a tactile stimulus. The therapist should give tactile stimuli when and where the patient needs it but only as long as the patient needs it to increase the patient’s independence and promote motor learning.  The goal is for the patient to be able to control the activity by himself. Normally the therapist has one hand distally and the other hand also distally or proximally when treating patients with extremity activities. If it is necessary to solve the patient’s problem in another way, the therapist can change the normal grips. Body Position and Body Mechanics More effective control of the patient’s motion came when the therapist was in the line of the desired motion. As the therapist shifted position, the direction of the resistance changed and the patient’s movement changed with it. The therapist’s body should be in line with the desired motion or force. To line up properly, the therapist’s shoulders and pelvis face the direction of the motion. The arms and hands also line up with the motion. If the therapist cannot keep the proper body position, the hands and arms maintain alignment with the motion  The resistance comes from the therapist’s body while the hands and arms stay comparatively relaxed. By using body weight the therapist can give prolonged resistance without fatiguing. The relaxed hands allow the therapist to feel the patient’s responses. Not only are the body position and body mechanics of the therapist important, but also the position in which the patient is treated. The treatment goal as well other factors influence this position. The functional activity that the patient needs, muscle tone, muscle strength, pain, and stability of the patient and therapist are some of the factors that need to be considered when choosing the appropriate position in which to treat patients. Verbal Stimulation (Commands) The verbal command tells the patient what to do and when to do it. The therapist must always bear in mind that the command is given to the patient, not to the body part being treated. Preparatory instructions need to be clear and concise, without unnecessary words. They may be combined with passive motion to teach the desired movement. The timing of the command is important to coordinate the patient’s reactions with the therapist’s hands and resistance. It guides the start of movement and muscle contractions. It helps give the patient corrections for motion or stability. Timing of the command is also very important when using the stretch reflex. The initial command should come immediately before the stretch the muscle chain to coordinate the patient’s conscious effort with the reflex response. The action command is repeated to urge greater effort or redirect the motion.  In reversal techniques, proper timing between verbal commands and muscle activity is important when we change the direction of the resistance. A preparatory command should be given with the therapist changing hand and an action command should be given with the therapist applying resistance in the new direction. The volume with which the command is given can affect the strength of the resulting muscle contractions. The therapist should give a louder command when a strong muscle contraction is desired and use a softer and calmer tone when the goal is relaxation or relief of pain. The command is divided into three parts: 1. Preparation: readies the patient for action 2. Action: tells the patient to start the action 3. Correction: tells the patient how to correct and modify the action. For example, the command for the lower extremity pattern of flexion-adduction-external rotation with knee flexion might be [preparation] “ready, and”; [action] “now pull your leg up and in”; [correction] “keep pulling your toes up” (to correct lack of dorsiflexion). Vision The feedback (and –forward) system can promote a much stronger muscle activity. For example, when a patient looks at his or her arm or leg while exercising it, a stronger contraction is achieved. Using vision helps the patient control and correct his or her position and motion. Moving the eyes will influence both the head and body motion. For example, when patients looks in the direction they want to move, the head follows the eye motion. The head motion in turn will facilitate larger and stronger trunk motion.  Eye contact between patient and therapist provides another avenue of communication and helps to ensure cooperative interaction. For elderly patients the visual input can be of more importance than the verbal input. Traction and Approximation Traction is the elongation of the trunk or an extremity. Knott, Voss, and their colleagues theorized that the therapeutic effects of traction are due to stimulation of receptors in the joints. Traction also acts as a stretch stimulus by elongating the muscles. Apply the traction force gradually until the desired result is achieved. The traction is maintained throughout the movement and combined with appropriate resistance. Traction of the affected part is helpful when treating patients with joint pain.  Approximation is the compression of the trunk or an extremity. The muscle contractions following the approximation are thought to be due to stimulation of joint receptors. Another possible reason for the increased muscular response is to counteract the disturbance of position or posture caused by the approximation. Given gradually and gently, approximation may aid in the treatment of painful and unstable joints. There are two ways to apply the approximation: Quick approximation: the force is applied quickly to elicit a reflex- type response. Slow approximation: the force is applied gradually up to the patient’s tolerance.  The approximation force is always maintained, whether the approximation is done quickly or slowly. The therapist maintains the force and gives resistance to the resulting muscular response. An appropriate command should be coordinated with the application of the approximation, for example “hold it” or “stand tall.” The patient’s joints should be properly aligned and in a weight-bearing position before the approximation is given. When the therapist feels that the active muscle contraction decreases the approximation is repeated and resistance given.  While traction usually facilitates motion and approximation facilitates isometric or stabilizing activity, the therapist should use the one which is most effective. For example, using PNF activities in an upright position and combining them with approximation together with concentric and eccentric muscle activity may be the most effective treatment. Using arm activities against gravity can be combined with approximation instead of traction when this promotes a better function. Stretch The response to a stretch of the muscle chain given by the therapist can lead to a stretch reflex or only to stimulation of these muscles. Giving a stretch to muscles should only be done when the therapist expects to facilitate the dynamic muscle activity. Sometimes a stretch activity is contraindicated when the muscles, tendons, bones, or joint are injured.  The stretch stimulus occurs when a muscle is elongated. Stretch stimulus is used during normal activities as a preparatory motion to facilitate the muscle contractions. The stimulus facilitates the elongated muscle, synergistic muscles at the same joint, and other associated synergistic muscles. Greater facilitation comes from lengthening all the synergistic muscles of a limb or the trunk. For example, elongation of the anterior tibial muscle facilitates that muscle and also facilitates the hip flexor-adductor-external rotator muscle group.  If just the hip flexor-adductor-external rotator muscle group is elongated, the hip muscles and the anterior tibial muscle share the increased facilitation. If all the muscles of the hip and ankle are lengthened simultaneously, the excitability in those limb muscles increases further and spreads to the synergistic trunk flexor muscles. The stretch reflex is elicited from muscles that are under tension, either from elongation or from contraction. The reflex has two parts. The first is a short latency spinal reflex that produces little force and may not be of functional significance. The second part, called the functional stretch response, has a longer latency but produces a more powerful and functional contraction. Timing  Timing is the sequencing of motions. Normal movement requires a smooth sequence of activity, and coordinated movement requires precise timing of that sequence. Functional movement requires continuous, coordinated motion until the task is accomplished.  Normal timing of most coordinated and efficient motions is from distal to proximal. The evolution of control and coordination during development proceeds from cranial to caudal and from proximal to distal. In infancy the arm determines where the hand goes, but after the grasp matures the hand directs the course of the arm movements. The small motions that adults use to maintain standing balance proceed from distal (ankle) to proximal (hip and trunk). To restore normal timing of motion may become a goal of the treatment. Normally the timing of an activity is from distal to proximal. Moving an extremity presupposes that the central part of the body is stabilized. Moving the leg forward in gait requires that the trunk and opposite hip and leg have enough stability to move the leg. Central stability is needed to move an extremity. However, studies showed that timing can be changed according to the functional task. There are two ways the therapist can alter the normal timing for therapeutic purposes By preventing all the motions of a pattern except the one that is to be emphasized. By resisting an isometric or maintained contraction of the strong motions in a pattern while exercising the weaker muscles. This resistance to the static contraction locks in that segment, so resisting the contraction is called “locking it in.” INTERACTION BETWEEN REFLEXES AND VOLUNTARY MOVEMENTS 1. Facilitation of voluntary movement with reflexes; stretching reflex, postural reflexes (tonic neck reflex, flexion and extension posture) 2. Inhibition of voluntary movement by reflexes; stretching reflex in spastic muscle, pain reflex in resistance exercise 3. Inhibition of one reflex by another reflex; spastic muscle ice application facilitates a voluntary movement and another voluntary movement; the force propagation principle is inhibited by another reflex by voluntary movement.  4. Facilitation of other voluntary movement by voluntary movement 5. Induction of another movement by voluntary movement: Immediately after the voluntary movement of the agonist, the antagonist movement is revealed more strongly.  Muscle, tendon and joint receptors in skeletal muscles, tendons and joints; ▫ Muscle spindle ▫ Golgi tendon organ ▫ Some receptors found in the fascia of muscles and joints and connective tissue (pacinian capsules)  When the muscle spindle is stimulated, excitation in the muscle leads to facilitation in the synergist muscle and inhibition of the antagonist. There are afferent and efferent endings in the muscle spindle. It activates the stretching muscle spindle, resulting in reflex contraction in the related muscle. The role of the gamma motor neuron in controlling the muscle spindle is to regulate contraction.