Proprioceptive neuromuscular facilitation (PNF) is an approach to therapeutic exercise that combines functionally based diagonal patterns of movement with techniques of neuromuscular facilitation to evoke motor responses and improve neuromuscular control and function. This widely used approach to exercise was developed during the 1940s and 1950s by the pioneering work of Kabat, Knott, and Voss. Their work integrated the analysis of movement during functional activities with then current theories of motor development, control, and learning and principles of neurophysiology as the foundations of their approach to exercise and rehabilitation. Long associated with neurorehabilitation, PNF techniques also have widespread application for rehabilitation of patients with musculoskeletal conditions that result in altered neuromuscular control of the extremities, neck, and trunk.
PNF techniques can be used to develop muscular strength and endurance; facilitate stability, mobility, neuromuscular control, and coordinated movements; and lay a foundation for the restoration of function. PNF techniques are useful throughout the continuum of rehabilitation from the early phase of tissue healing when isometric techniques are appropriate to the final phase of rehabilitation when high-speed, diagonal movements can be performed against maximum resistance.
Hallmarks of this approach to therapeutic exercise are the use of diagonal patterns and the application of sensory cues—specifically proprioceptive, cutaneous, visual, and auditory stimuli—to elicit or augment motor responses. Embedded in this philosophy and approach to exercise is that the stronger muscle groups of a diagonal pattern facilitate the responsiveness of the weaker muscle groups. The focus of discussion of PNF in this chapter deals with the use of PNF patterns and techniques as an important form of resistance exercise for the development of strength, muscular endurance, and dynamic stability.
Although PNF patterns for the extremities can be performed unilaterally or bilaterally and in a variety of weight-bearing and non-weight-bearing positions, only unilateral patterns with the patient in a supine position are described below.
DIAGONAL PATTERNS
The patterns of movement associated with PNF are composed of multijoint, multiplanar, diagonal, and rotational movements of the extremities, trunk, and neck. Multiple muscle groups contract simultaneously. There are two pairs of diagonal patterns for the upper and lower extremities: diagonal 1 (D1) and diagonal 2 (D2). Each of these patterns can be performed in either flexion or extension. Hence, the terminology used is D1Flexion or D1Extension and D2Flexion or D2Extension of the upper or lower extremities. The patterns are identified by the motions that occur at proximal pivot points—the shoulder or the hip joints. In other words, a pattern is named by the position of the shoulder or hip when the diagonal pattern has been completed. Flexion or extension of the shoulder or hip is coupled with abduction or adduction as well as external or internal rotation. Motions of body segments distal to the shoulder or hip also occur simultaneously during each diagonal pattern.
As mentioned, the diagonal patterns can be carried out unilaterally or bilaterally. Bilateral patterns can be done symmetrically (e.g., D1Flexion of both extremities); asymmetrically (D1Flexion of one extremity coupled with D2Flexion of the other extremity); or reciprocally (D1Flexion of one extremity and D1 Extension of the opposite extremity). Furthermore, there are patterns specifically for the scapula or pelvis and techniques that integrate diagonal movements into functional activities, such as rolling, crawling, and walking. There are several in-depth resources that describe and illustrate the many variations and applications of PNF techniques.
BASIC PROCEDURES WITH PNF PATTERNS
A number of basic procedures that involve the application of multiple types of sensory cues are superimposed on the diagonal patterns to elicit the best possible neuromuscular responses. Although the diagonal patterns can be used with various forms of mechanical resistance (e.g., free weights, simple weight-pulley systems, elastic resistance, or even an isokinetic unit), the interaction between the patient and therapist, a prominent feature of PNF, provides the greatest amount and variety of sensory input, particularly in the early phases of re-establishing neuromuscular control.
Manual Contacts
The term manual contact refers to how and where the therapist’s hands are placed on the patient. Whenever possible, manual contacts are placed over the agonist muscle groups or their tendinous insertions. These contacts allow the therapist to apply resistance to the appropriate muscle groups and cue the patient as to the desired direction of movement. For example, if wrist and finger extension is to be resisted, manual contact is on the dorsal surface of the hand and wrist. In the extremity patterns one manual contact is placed distally (where movement begins). The other manual contact can be placed more proximally, for example, at the shoulder or scapula. Placement of manual contacts is adjusted based on the patient’s response and level of control.
Maximal Resistance
The amount of resistance applied during dynamic concentric muscle contractions is the greatest amount possible that still allows the patient to move smoothly and without pain through the available range. Resistance should be adjusted throughout the pattern to accommodate to strong and weak components of the pattern.
Position and Movement of the Therapist
The therapist remains positioned and aligned along the diagonal planes of movement with shoulders and trunk facing in the direction of the moving limb. Use of effective body mechanics is essential. Resistance should be applied through body weight, not only through the upper extremities. The therapist must use a wide base of support, move with the patient, and pivot over the base of support to allow rotation to occur in the diagonal pattern.
Stretch stimulus. The stretch stimulus is the placing of body segments in positions that lengthen the muscles that are to contract during the diagonal movement pattern. For example, prior to initiating D1Flexion of the lower extremity, the lower limb is placed in D1Extension.
Rotation is of utmost consideration because it is the rotational component that elongates the muscle fibers and spindles of the agonist muscles of a given pattern and increases the excitability and responsiveness of those muscles. The stretch stimulus is sometimes described as “winding up the part” or “taking up the slack.”
Stretch reflex. The stretch reflex is facilitated by a rapid stretch (overpressure) just past the point of tension to an already elongated agonist muscle. The stretch reflex is usually directed to a distal muscle group to elicit a phasic muscle contraction to initiate a given diagonal movement pattern. The quick stretch is followed by sustained resistance to the agonist muscles to keep the contracting muscles under tension. For example, to initiate D1Flexion of the upper extremity, a quick stretch is applied to the already elongated wrist and finger flexors followed by application of resistance. A quick stretch can also be applied to any agonist muscle group at any point during the execution of a diagonal pattern to further stimulate an agonist muscle contraction or direct a patient’s attention to a weak component of a pattern.
PRECAUTION: Use of a stretch reflex, even prior to resisted isometric muscle contractions, is not advisable during the early stages of soft tissue healing after injury or surgery. It is also inappropriate with acute or active arthritic conditions.
A sequence of distal to proximal, coordinated muscle contractions occurs during the diagonal movement patterns. The distal component motions of the pattern should be completed halfway through the pattern. Correct sequencing of movements promotes neuromuscular control and coordinated movement.
Traction is the slight separation of joint surfaces theoretically to inhibit pain and facilitate movement during execution of the movement patterns. Traction is most often applied during flexion (antigravity) patterns.
The gentle compression of joint surfaces by means of manual compression or weight bearing stimulates co-contraction of agonists and antagonists to enhance dynamic stability and postural control via joint and muscle mechanoreceptors.
Verbal Commands
Auditory cues are given to enhance motor output. The tone and volume of the verbal commands are varied to help maintain the patient’s attention. A sharp verbal command is given simultaneously with the application of the stretch reflex to synchronize the phasic, reflexive motor response with a sustained volitional effort by the patient. Verbal cues then direct the patient throughout the movement patterns. As the patient learns the sequence of movements, verbal cues can be more succinct.
Visual Cues
The patient is asked to follow the movement of a limb to further enhance control of movement throughout the ROM.
Buy the Book that holds this excerpt: Therapeutic Exercise: Foundations and Techniques (Therapeutic Exercise: Foundations & Techniques)
Related Articles
No Comment Received
Leave A Reply