From the Guidelines
PNF, or Proprioceptive Neuromuscular Facilitation, includes techniques such as hold-relax, contract-relax, rhythmic initiation, rhythmic stabilization, and combination patterns, with a recommended protocol of a 3–6 s contraction at 20%–75% maximum voluntary contraction followed by a 10–30 s assisted stretch for PNF stretching. The main types of PNF stretching are:
- Hold-relax: involves isometric contraction against resistance followed by relaxation to increase range of motion
- Contract-relax: adds active movement after the isometric phase
- Rhythmic initiation: progresses from passive to active-assisted to active-resisted movement to improve motor control
- Rhythmic stabilization: uses alternating isometric contractions of antagonistic muscles to enhance stability
- Combination patterns: involve diagonal and spiral movements that mimic functional activities, such as D1 flexion/extension and D2 flexion/extension patterns for upper and lower extremities, as described in the 2018 EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis 1. These techniques are effective because they utilize neurophysiological principles like reciprocal inhibition and successive induction to facilitate muscle relaxation, improve coordination, and enhance functional movement, with the greatest gains occurring with daily exercise, as stated in the study 1. Key considerations for implementing PNF stretching include:
- Frequency: ≥2–3 day/week is effective in improving joint range of motion
- Intensity: stretch to the point of feeling tightness or slight discomfort
- Time: holding a static stretch for 10–30 s is recommended for most adults
- Volume: a reasonable target is to perform 60 s of total stretching time for each flexibility exercise
- Pattern: repetition of each flexibility exercise two to four times is recommended, with flexibility exercise being most effective when the muscle is warmed through light to moderate aerobic activity or passively through external methods such as moist heat packs or hot baths, as outlined in the study 1.
From the Research
Types of PNF
- Proprioceptive neuromuscular facilitation (PNF) techniques include:
- Assisted hold-relax (HR) on diagonal plane
- Assisted HR
- Self-HR
- Self-contract-relax (CR)
- Assisted CR contract
- Assisted HR contract as mentioned in the study 2
- Theoretical mechanisms of PNF include:
- Autogenic inhibition
- Reciprocal inhibition
- Stress relaxation
- The gate control theory as identified in the study 3
- PNF can be combined with other techniques, such as:
- Robotic-assisted gait training (RAGT) as investigated in the study 4
- PNF can be compared to other forms of training, such as:
- Weight training (WT) as compared in the study 5
- PNF has been applied to various populations, including:
- Individuals with Parkinson's disease as reviewed in the study 6