Proprioceptive neuromuscular facilitation is resistance applied to an extremity with an initial isometric contraction --- a muscle contraction with no movement --- for a minimum of six seconds followed by a complete relaxation of the muscle being stretched, the American Council on Exercise explains. You should repeat this contract-relax stretch several times, and do the same with the opposing muscle group for balanced PNF stretching. PNF stretching can increase physical ability, efficiency, performance and coordination during exercise, improve muscular balance and blood supply to muscles and joints and decrease risk of injury, lower back pain and stress.
Examples of PNF Stretching
PNF stretches can help the hamstrings and quadriceps, for example. To stretch your hamstrings, start by lying on your back with one leg straight and the other raised off the floor extended. Your partner should slightly push against your raised leg. Contract your hamstrings, then stop as your partner attempts to stretch your leg further. To stretch the quadriceps, meanwhile, start by lying on your stomach while your partner bends your knee so that your foot gets closer to your torso. Contract your quadriceps, then stop as your partner attempts to stretch further.
Factors Affecting PNF
Age, inactivity, gender, body type and whether or how you warm up can affect PNF stretching. Age and inactivity both decrease flexibility over time. The greatest increase in flexibility occurs between the ages of 7 and 12 years, the American Council on Exercise explains. After age 25, flexibility may significantly decline. Women tend to have greater flexibility than men, particularly in the pelvic area. Someone who is underweight --- with an ectomorph body type --- might have greater range of motion than an endomorph, someone with a heavier, over-developed body type. Warming up increases blood flow and nutrients to muscles creating an increase of range of motion in the joint --- conditions that need to exist for your PNF stretching to be effective.
Assisted-Stretching Technique
It is best to use a professional partner when performing PNF stretching. If you are older than 50, remember that muscle elasticity --- the capability of a strained body to recover its size and shape after deformation --- decreases with age. Your nerve conduction --- the speed at which nerves carry information in the body --- slows and recovery periods lengthen with age, meanwhile. Assisted static stretching is a safer option for those older than 50.
Time and Frequency
To improve your flexibility, perform PNF stretching most days of the week. Stretching can be done every day. You should see results in four to six weeks. Remember, however, that improvements in flexibility are not permanent and regular stretching is needed to maintain maximum range of motion.
PNF Tips
Use effective communication between your trainer or partner and yourself when engaging in assisted PNF stretching. Include all the major muscle groups such as lower back, thighs, hamstrings, hips and shoulder at least once during the training session. Certain equipment --- bands, towels, ties or even an old T-shirt --- can help make your PNF stretching even more beneficial.
References
- "ACE Personal Training Manual"; American Council on Exercise; 1997
- "ACE Certified News"; Functional Flexibility for Clients Over Age 50; Amy Ashmore, Ph.D.
- MayoClinic.com; Stretching: Focus on Flexibility; Feb. 23, 2011
