Principles of PNF

Principles of PNF

• PNF is a method of enhancing patient outcomes. Its principles maximize effectiveness of treatment by applying neuroscience.
• PNF history: Dorothy Voss, Margaret Knott, and Dr. Herman Kabat observed and developed optimal patterns for application of the PNF techniques. Video resource: https://www.youtube.com/watch?v=RSxPNM1OLVE
• PNF facilitates a maximal response and utilizes repetition or practice. One of its goals is independent and optimal function and movement.

What is PNF

• Proprioceptive involves the proprioceptors in joints, muscles, tendons, ligaments, and skin.
• Neuromuscular pertains to the nerves and muscles.
• Facilitation is to make easier.

PNF Philosophy

• PNF has a positive focus using abilities and strengths.
• PNF is holistic, referring to the treatment of the whole person
• Goal is oriented to harness untapped potentials for the highest level of function.
• PNF continues to evolve to new levels of proficiency through clinical experience and scientific advances.
• Concepts and principles developed by Kabat and Knott have withstood testing and research over time, making PNF principles evidence-based.

Key Principles of PNF

• Research has supported the principles and procedures of PNF, which is used in a framework of motor control and motor learning.
• Key principles include: patterns, position of therapist and patient, normal timing, manual contacts, stretch, vision, verbal cues, resistance, and traction/approximation.

Patterns

• Patterns include functional movement and athletic activities.
• PNF diagonal patterns are based on clinical observation of normal movement.
• Many muscles are arranged in diagonal and rotational patterns.

Diagonal and Rotational Movements

• Functional movement incorporates diagonal and rotational patterns.
• Rotation and diagonal movements are the last to develop and first to disappear in injury, illness and aging.
• PNF diagonal patterns effect on upper extremity muscles shows increased motor evoked potentials and decreased EMG latency.
• Contralateral effect increased compared to sagittal plane movement (23% vs. <13%).

Brain Plasticity and Diagonal Patterns

• Diagonal movement of the upper limb produces greater adaptive plasticity than sagittal plane flexion in the shoulder (2017).
• Diagonal pattern groups have better planning and execution in the dorsal lateral prefrontal cortex.
• They also have a greater control of movement and kinesthetic responses in the primary motor cortex and increased integration of somatosensory information in the parietal cortex.

Therapist and Patient Positioning

• Use tactile input for patient position with supine, prone, and sidelying options.
• Gravity can be used to assist or resist.
• Positioning can increase or decrease challenge.
• Body position of the therapist should be in the diagonal if you want diagonal movement, allowing the patient to move toward the therapist's body. Position yourself for optimal patient response.

Normal Timing of Movement

• This involves the recruitment of motor units that result in continuous, smooth, coordinated movement.
• Postural adjustments precede tasks, like reaching.
• The most coordinated and efficient movement is from distal to proximal such as with gait swing with ankle dorsiflexion.

Manual Contacts

• Manual contacts can facilitate or inhibit, depending on how they're applied.
• Firm pressure over an agonist facilitates the agonist, while firm pressure over an antagonist inhibits the agonist.
• Touching agonist/antagonist stimulates sensory receptors.
• Light touch, rough touch, and vibration improved function in the hemiparetic hand.
• Sensory stimulation can increase the speed of muscle contraction and activity.
• Sensory information is necessary for voluntary movement and stimulates free nerve endings, facilitating movement with touch anywhere on the muscle or dermatome.

Manual Contacts for Stability

• Manual contacts guide patients' movements and stimulates synergists.
• In the presence of pain, place contacts away from the painful area.
• Touch agonist and antagonist simultaneously.
• Place contacts on trunk for proximal stability and limb movement.

Use of Stretching

• Stretching initiates movement and increases strength.
• It also inhibits the antagonist and influences the direction of movement, leading to a quicker response.

Types of Stretching

• Position the patient with muscles on full stretch, using quick or repeated stretches.
• Muscles can be on full stretch in diagonal reaching.

Quick Stretch

• Steps for Quick Stretch
  • Elongate muscles in pattern to "tension" point
  • Tension in all components of diagonal pattern
  • Superimpose a quick, elongation further into direction of movement
• Rotation further elongates the muscle fibers.

Repeated Stretch

• Repeat stretch throughout range as needed when strength decreases

Resistance

• Resistance is used to evaluate, elicit contraction, increase muscle control, strength, and awareness of movement.

Appropriate Resistance

• The patient can reach the goal in a smooth and coordinated fashion with appropriate resistance.
• Resistance can be guided or assisted.
• Maximum effort yields increased strength, but avoid Valsalva and pain.
• Isotonic Muscle Contractions: Concentric (lifting a glass, walking uphill), Eccentric (lowering glass, walking downhill)
• Isometric Muscle Contractions: Stabilizing, it allows patient to hold.

Irradiation

• Irradiation spreads and increases strength of a response.
• Resistance is one way to increase the number and strength of the stimuli.
• Maximal resistance may result in overflow (irradiation) of facilitation to the motor neurons of weaker muscles, and be excitation or inhibition.
• Examples of Specific Patterns of Irradiation: Hip Flexion -> Ankle Dorsiflexion; Pelvic Anterior Elevation -> Hip Flexion; and Hip Flexion -> Trunk Flexion.
• Use a pain-free, strong area to influence painful areas by treating the neck with an indirect approach, with bilateral UE D1 flexion to extension to activate short neck flexors and resisting scapular patterns and lower trunk rotation.

Reciprocal Inhibition

• Reciprocal inhibition is excitation of the agonist causes inhibition of the antagonist and is necessary for smooth and coordinated movement.

Vision

• Vision leads and corrects movement, influencing head, neck, & trunk motion.
• It increases force of muscle contraction
• It improves speed and accuracy.
• Vision improves movement planning and control and has an important role in anticipatory & compensatory corrections while maintaining posture.
• It can result in a better response when the patient has a visual external focus.

Verbal Cues

• Verbal cues identify relationship of body to environment.
• They improves voluntary motor control and motor planning and increases arousal.
• Timing of verbal cue is important and just prior to the stretch.
• Volume of verbal cue is important- loud signifies stronger contraction and soft & calm signifies relaxation and pain control.
• Simple, crisp, clear commands enhance sub-cortical input=more functional.
• Hold when tell patient to hold, and allow movement when you say move.

Traction/Approximation

• Traction/Approximation is directed toward joint receptors, promotes movement and facilitates flexors, but has contraindications.
• Traction/Approximation increases muscular response and promotes stability, especially with weight-bearing postures and extension.

Summary of PNF

• Use a patient's strengths to enhance movement & function (e.g. irradiation).
• Add layers of intervention to promote motor learning, strengthen the normal movement pattern and increase independent function.
• The end goal is for the individual to independently complete tasks without the therapist.