Flexibility Training Methods
There are several training methods used to develop flexibility; however, most fall
under the following general categories:- Dynamic
- Static
- Ballistic
- Proprioceptive neuromuscular facilitation (PNF)
Dynamic Stretching
Dynamic stretching (sometimes referred to as active stretching) consists of
controlled movements which increase in range and/or speed so that you gradually reachyour full range and speed of movement (e.g., slow, controlled leg swings or kicks,
controlled arm swings, back bends). This type of stretching often mimics the activity that
is to be performed and prepares the muscles for that activity.
There is some controversy surrounding the effectiveness of dynamic stretching and
its role in the development of flexibility. Some experts believe that the short, intermittentmovements involved in this type of stretching activate the stretch reflex and cause the
stretched muscle to contract. Others maintain that dynamic stretching is beneficial for
quick, explosive activities like gymnastics or martial arts. However, in general, dynamic
stretching should not be used to develop static flexibility or long-standing changes in range
of motion. If used at all, dynamic stretching functions best before exercise to enhance
performance. This type of stretch is often performed after a warm up and prior to an
exercise session in anticipation of a particular activity. Dynamic stretches should mimic the
activity that is to be performed.
Static Stretching
Static stretching (sometimes referred to as passive stretching) develops static
flexibility and uses slow, controlled movements through a full range of motion. This typeof stretch is performed by holding a position using a part of the body, the assistance of a
partner, or some other apparatus such as a pole or the floor (e.g., lifting one leg up and
holding it with the hand, the splits). Slow, static stretching helps relieve muscle spasms due
to exercise, and is used for cooling down after a workout to reduce muscle fatigue and
soreness.
Ballistic Stretching
Ballistic stretching uses the momentum of the body or a limb to force a stretch past
the normal range of motion and then return to the starting position. Ballistic stretching
incorporates bouncing or jerky movements and should not be confused with dynamic
stretching. An example of a ballistic stretch would be bouncing down to touch toes or using
the momentum of the torso to twist the body. Uncontrolled arms swings in which the arms
are thrown backward and then bounce back to the starting position are also an example.
This type of stretching does not contribute to flexibility. Instead, the repeated activation of
he stretch reflex causes muscles to contract which can lead to injury. This type of
stretching is not recommended.
PNF Stretching
Proprioceptive neuromuscular facilitation (PNF) stretching is considered an
advanced stretching technique. It is used extensively by physical therapists or when high
degrees of both passive and dynamic flexibility are required for performance (e.g., martial
arts, ballet, gymnastics, kick-boxing). There are several PNF techniques, but generally,
PNF consists of a passive stretch, followed by an isometric contraction, which is then
followed by another stretch (static or dynamic). By combining passive stretching with
isometric contractions (a contraction in which there is no change in muscle length or joint
movement) with a partner or object for resistance, PNF uses the stretch reflex and
lengthening reaction to achieve a greater range of motion. As described in the section
above, when a muscle is slowly stretched and held, the resulting tension triggers the
lengthening reaction which prevents the stretched muscle fibers from contracting. When
this stretched muscle is then isometrically contracted, the following happens:
- During an isometric contraction, some fibers will contract, but others will
stretch even further. When the contraction is stopped, the contracted fibers
return to their starting position, while the stretched fibers retain their
stretched position (due to muscle spindle accommodation) and are able to
lengthen even further.
- The increased tension within the muscles generated by an isometric contraction
activates the GTO which triggers the lengthening reaction, and inhibits
further contraction. When the isometric contraction is stopped, the muscle is
still inhibited from further contraction and able to lengthen further.
The final stretch, which follows isometric contraction, takes advantage of the
muscle's ability to elongate further, and allows the muscle, tendon, and sense organs to
adapt to greater lengths.
It is best to have a partner help when using PNF techniques.
A common PNF technique is referred to as the “contract-relax method”.
Instructions for and a pictorial representation of this method are provided in Figure 7-2.
This technique uses passive stretch and isometric contractions, followed by muscle
relaxation and passive stretching to the new range of motion. For example, if you are
stretching your hamstrings, you first passively take the stretch to the point of tightness and
hold. Then you isometrically contract the hamstrings by using this muscle to apply force
against an object or partner (See Figure 7-2). Following the contraction, the muscle is
allowed to relax and the muscle is then passively stretched and held. Current
recommendations suggest performing this technique with one to five repetitions, but like
weight training, it needs to be done no more than three to five times a week.
It is interesting to note that many stretches (including some of those illustrated in
this chapter) can be performed statically, dynamically, or using PNF, depending on the
goals of a stretching program.
