PROPRIOCEPTIVE NEUROMUSCULAR FACILITATION (PNF)
Proprioceptive Neuromuscular Facilitation (PNF) is a form of stretching in which a muscle is alternatingly stretched passively and contracted. The technique targets nerve receptors of a muscle to extend its length. This stretching procedure is designed for physical therapist and occupational therapist in the 1940s and 1950s to treat the patients of paralysis. It is usually a combination of passive stretching and isometric contraction. The PNF positions encourage flexibility and coordination in the limbs. It helps to quick gains in range of motion and specially used by atheletes to improve performance. PNF is an advanced form of flexibility training that involves both stretching and contraction of the muscle group being targeted.
Indications of PNF : -
1. Loss of range of motion.
2. Acute and chronic pain.
3. Muscle tightness.
4. Muscle cramp.
5. Loss of flexibility.
Contra-indications : -
1. Post-operative : PNF Stretching is not done after recent post operation because the repairs that were made during surgery can be counteracted like muscle or tendons pulling away from reattachment due to tension stretching implements. Tissue healing must be determined from intense stretching can be performed.
2. Instability of joints : If a person has an unstable joint in the area where stretching is applied, he/she may not be able to control the movement of the stretch and hyper mobility may cause injury.
3. Under age 18 years : PNF stretching is not recommended for anyone below the age of 18 years as intense stretching may disrupt the growth plates and may cause disease like Osgood Schlatter’s disease.
4. Already stretched muscles : PNF is not performed more than once a day due to stress it produces on muscles and tendons.
The Fundamentals of PNF : -
PNF may be categorised in terms of five P-factors: Principles, Procedures, Patterns, Positions and Postures, with joint Pivots and Pacing (Timing) as important sub-categories. The methods comprising these factors were formulated from findings on neuromuscular development, such as the functional evolution of all movement from motor immaturity to motor maturity in the growing child or novice athlete in definite sequences progressing logically from:
* total to individuated
* proximal to distal, distal to proximal
* mobile to stabile
* gross to selective
* reflexive to deliberate
* overlapping to integrative
* incoordinate to coordinate
The Principles of PNF : -The basic principles of PNF may be summarised as follows:
1. Use of spiral and diagonal movement patterns
2. Motion crossing the sagittal midline of the body
3. Recruitment of all movement components (e.g. flexion-extension)
4. Exercising of related muscle groups
5. Judicious eliciting of reflexes
6. Movement free of pain, but not free of effort
7. Comfortable full-range movement
8. Application of maximal resistance throughout the range of non-ballistic movement
9. Use of maximal resistance to promote overflow (irradiation) of muscle activity
10. Use of multiple joint and muscle action
11. Commencement of motion in the strongest range
12. Use of static and dynamic conditions
13. Appropriate positioning of joints to optimise conditioning
14. Exercising of agonists and antagonists
15. Repeated contractions to facilitate motor learning, conditioning and adaptation
16. Selection of appropriate sensory cues to facilitate action
17. Emphasis on visuo-motor and audio-motor coordination
18. Use of distal to proximal sequences in neuromuscularly mature subjects
19. Use of stronger muscles to augment the weaker
20. Progression from primitive to complex actions
21. Planning of each phase to lay foundations for the next phase
22. All activities are integrated and goal directed
23. Use of adjunct techniques (e.g. massage, vibration).
Procedure for PNF : -
Pattern of Motion : Normal motor activity occurs in synergistic and functional patterns of movement. PNF patterns are “spiral and diagonal” in character and combine motion in all three planes flexion/extension, abduction/adduction and transverse rotation.
Neck Patterns : -
1. Neck flexion with rotation to the right.
2. Neck extension with rotation to the left
Upper Extremity : -
Diagonal 1 : – Shoulder Flexion, Adduction, External Rotation (D1 Flexion) and Extension, Abduction, Internal Rotation (D1 Extension); Elbow flexed/extended; Wrist & Fingers Extension to flexion.
Diagonal 2 : – Shoulder Flexion, Abduction, Lateral Rotation (D2 Flexion) and Extension, Adduction and Medial Rotation (D2 Extension); Elbow Extended; Wrist & Fingers Flexion to Extension.
Trunk : -
Upper trunk in sitting position : Flexion with rotation to the left (Chopping), Extension with rotation to the right (Lifting).
Lower Trunk in supine position : Flexion with rotation to the left, Extension with rotation with the right.
Lower Extremity : -
Diagonal 1 : Hip Flexion, Adduction, External Rotation; Knee extended; Foot Dorsi Flexion (D1 Flexion) and Hip Extension, Abduction, Internal Rotation; Knee Extension; Foot Planter Flexion (D2 Extension).
Diagonal 2 : Hip Flexion, Abduction, External Rotation; Knee Extension; Foot Planter Flexion (D2 Flexion) and Hip Extension, Adduction, Interna Rotation; Knee Extension; Foot Dorsi Flexion (D2 Extension).
Timing: In PNF patterns normal timing is from distal to proximal. Distal segments (hand/wrist or foot/ankle) move first followed closely by more proximal components. Rotation occurs throughout the pattern, from beginning to end.
Timing for Emphasis : Maximum resistance is used to elicit a strong contraction and allow overflow to occur from strong to weak components within a synergistic pattern; the strong muscles are resisted isometrically while motion is allowed in the weaker muscles.
Resistance : Resistance facilitates muscle contraction and motor control. Resistance is applied manually and functionally through the use of gravity to all types of contractions.
Overflow or Irradiation : Refers to spread of muscle response from stronger muscles in a synergistic pattern to weaker muscles; maximal resistance is the main mechanism for securing overflow or irradiation. Enhance synergistic actions of muscles, increase strength.
Manual Contacts : Precise manual contacts (grip) are used to provide pressure to tactile and pressure receptors overlying the muscles to facilitate contraction and guide direction of movements; pressure is applied opposite to the direction of the desired motion.
Positioning : Muscle positioning at optimal range of function allows for optimal responses of muscles. The greatest muscle tension is generated in mid-ranges with weak contractile force occuring in the shortened ranges.
Therapist Position and Body Mechanics : Therapist is positioned directly in line with the desired motion in order to optimize the direction of resistance that is applied.
Verbal Commands : Verbal commands allow for the use of well-timed words and appropriate vocal volume to direct the patient’s movement.
Vision : Vision is used to guide the patient’s movements, enhance muscle contraction, and synergistic patterns of movement.
Stretch : The elongated position/lengthened range and the stretch reflex are used to facilitate muscle contraction. All muscles in the pattern are elongated to optimize the effects of stretch. Commands for voluntary movement are always synchronized with the stretch to enhance the response.
Approximation : Approximation is used to facilitate extensor/stabilizing muscle contraction and stability; can be applied manually, functionally through the use of gravity acting on body during upright positions, or mechanically using weights or belts.
Traction : A distraction force is used to facilitate muscle contraction and motion, especially is applied in flexion patterns or pulling motions; force is applied manually during PNF. Gentle distraction force is also useful in reducing joint pain.
PNF Techniques : –
Reversal of Antagonists : A group of techniques that allow for agonist contraction followed by antagonist contraction without pause or relaxation.
* Dynamic Reversals (Slow Reversals) : Utilizes isotonic contractions of first agonists, then antagonists performed against resistance. Contraction of stronger pattern is selected first with progression to the weaker pattern. The limb is moved through full ROM.
* Stabilizing Reversals : Utilizes alternating isotonic contractions of first agonists, then antagonists against resistance, allowing very limited ROM.
* Rhythmic Stabilization : Utilizes alternating isotonic contractions of first agonists, then antagonists against resistance, no motion is allowed.
Repeated Contractions : Repeated isotonic contractions from the lengthened range, induced by quick stretches and enhanced by resistance; performed through the range or part of range at a point of weakness. Technique is repeated during one pattern or until contraction weakens.
Combination of Isotonics : Resisted concentric contraction of agonist muscles moving through the range is followed by a stabilizing contraction and then eccentric contraction, moving slowig back to the start position; there is no relaxation between the types of contractions. Typically used in anti gravity activities/assumption of postures.
Rhythmic Initiation : Voluntary relaxation followed by passive progressing to active-assisted and active-resisted movements to finally active movements. Verbal commands are used to set the speed and rhythm of the movements. Light tracking resistance is used during the resistive phase to facilitate movement.
Contract-Relax : a relaxation technique usually performed at a point of limited ROM in the agonist pattern. Strong, small range isotonic contraction of the restricting muscles (antagonist) with emphasis on the rotators is followed by an isometric hold. The contraction is held for few seconds and is then followed by voluntary relaxation and movement into the new range of the agonist pattern. Movement can be passive but active contraction is preferred.
Hold-relax : A relaxation technique usually performed in a position of comfort and below a level that causes pain. Strong isometric contraction of the restricting muscles (antagonists) is resisted, followed by voluntary relaxation, and passive movement into the newly gained range of the agonist pattern.
Replication (Hold-Relax Active motion) : The patient is positioned in the shortened/end position of a movement and is asked to hold. The isometric contraction is resisted followed by voluntary relaxation and passive movement into the lengthened range. The patient is then instructed to move back into the end position; stretch and resistance are applied to facilitate the isotonic contraction. For each repetition, increasing ROM is desired.
Resisted Progression : Stretch, approximation and tracking resistance is applied manually to facilitate pelvic motion and progression during locomotion; the patient’s momentum, coordination and velocity. It can be applied using elastic band resistance
Rhythmic Rotation : Relaxation is achieved with slow, repeated rotation of a limb at a point where limitation is noticed. as muscles relax the limb is slowly and gently moved into the range, As a new tension is felt, it is repeated. The patient can use active movements for rhythmic rotation or the therapist can perform it passively. Voluntary relaxation when possible is important.