Ballistic
This form of stretching involves quick, repetitive bouncing or bobbing actions. It is undertaken in order to increase the stretch beyond the muscle’s normal range using momentum and body weight. It is generally considered unacceptable for the average exerciser, due to the intramuscular damage that may occur as a result of the stretch reflex. These stretching exercises can produce muscle soreness and even losses in resilience and elasticity. However, they are sometimes necessary as a more radical method of stretching adhesions and stubborn fibrous tissue in physiotherapy and rehabilitation.
Dynamic
This is similar to ballistic stretching, however, the limb movements do not end with bouncing or jerky movements, but instead, are performed under control (Alter, 1998). These stretches should mimic the movements of the following sport or activity and act as a kind of rehearsal.
• perform 10-15 repetitions of each stretch under control, gradually increasing the ROM
Static maintenance
Static maintenance stretching is where the muscle is taken to the end of its normal range and held without bouncing. These are short stretches, held for 10-15 seconds (Moffat, 1988), and are used to maintain the normal length of the muscle. Following repeated contractions during exercise, the muscle becomes shorter and thicker and a maintenance stretch is used to return the muscle to its normal length. The following guidelines should be observed:
• take the stretch to the point of bind, maintaining good alignment and posture • hold for 10-15 seconds
• repeat the stretch if desired
Static developmental
These stretches are used in flexibility training to develop the length of the fibres themselves, thereby increasing range of movement at a joint. The following guidelines should be observed:
• take the stretch to the 'point of bind', maintaining good alignment and posture • hold for 10 or more seconds, until the tension within the muscle has
reduced
• relax and passively increase the ROM of the stretch until tension is felt again • again hold for 10 or more seconds, until the tension within the muscle has
reduced
• again increase the ROM of the stretch until tension is felt again
• hold until the tension reduces, then slowly return the limb to its normal position
• repeat the stretch if desired
Muscle energy techniques (METs)
MET is a form of passive stretching from the world of osteopathic technique. According to Chaitow (1996), MET, “…targets the soft tissues primarily, although it also makes a major contribution towards joint mobilisation…”. The technique itself evolved from the rehabilitative technique known as proprioceptive neuromuscular facilitation (PNF), developed by Herman Kabat in the late 1940s and early 1950s. Like PNF techniques, MET commonly uses an isometric contraction of the target muscle before the stretch is applied. MET, unlike PNF (which uses near maximal muscle contractions), uses only minimal force during the isometric phase. The stretching phase is generally, though not always, done passively.
Perhaps the main form in which MET is applied is post isometric relaxation (PIR). The following is an example of a hamstring stretch, utilising PIR:
• under the trainer’s instruction the client should adopt a comfortable and manageable position
• the trainer explains to the client what is to be done and how the technique is to be carried out
• the trainer lifts the leg into hip flexion and takes the passive stretch to the point of bind, maintaining good alignment and posture throughout
• the trainer holds the limb at the point of bind for 10 or more seconds, until the tension within the muscle has reduced
• the client performs an isometric contraction of 20-30% maximum force and holds this for 6-8 seconds. The trainer should direct the client to begin slowly and progressively build the level of contraction
• the client relaxes (this can be aided by a deep inhalation followed by an exhalation as the stretch is administered) while the trainer passively increases the ROM of the stretch (increase hip flexion) until tension is felt again
• this cycle is repeated 2-3 times, always finishing with a stretch and not a contraction
• the trainer slowly returns the limb to its normal position
By isometrically contracting the target muscle (hamstrings in the above example) against the trainer, the client will activate the GTOs in that muscle and stimulate an autogenic inhibition response. This will create the necessary level of relaxation in that muscle to allow it to be stretched.
Since, the technique is very hands on and necessitates the trainer and client communicating clearly to create a stretch, passive stretching using PIR provides an excellent medium for establishing a rapport with the client.
When to apply: PIR based techniques are best suited to the post-exercise period. This will allow the trainer to stretch out the muscles worked during the main session and provides a relaxing ‘wind down’ for the client after their exertions. A good passive stretching session, performed by a competent trainer really embodies the personal, one-to-one nature of personal training.
Safety issues: safety should always be a priority for both the client and the trainer. An awareness of body mechanics and posture are vital for the trainer throughout the PIR protocols, but particularly during the isometric contraction phase. Consequently, the trainer should plan carefully and communicate clearly and freely with the client.
Trainer safety: the trainer may be at risk of injury if they do not take care of themselves during the application of PIR. However, by paying attention to their body mechanics and posture, the risk of injury can be virtually eliminated. Some useful tips for the trainer include:
• if standing, pay close attention to the legs and feet. A wide stance should be used to maintain balance and stability, especially when resisting the isometric contraction of the client
• be conscious of keeping the spine lengthened, rather than flexing and collapsing in on yourself. This will reduce the stress imposed on the spine
• maintain a neutral lumbar spine. This will again reduce the stresses imposed on the back
• brace the abdominals to prevent overarching of the spine
• avoid unnecessary twisting or bending. Instead, the trainer should try and get the client to move to accommodate them
• always try to use the trunk rather than the arms to resist the client’s isometric contractions. For instance, during the hamstring stretch the trainer should block the client’s contraction with their shoulder rather than the arm
• always control the strength of the client’s contraction. The client should be instructed to “slowly build” the level of the contraction
• remain in control at all times. For instance, the client should only contract the target muscles on the trainer’s instruction. In this way, the trainer will be able to prepare, and stabilise themselves effectively
Client safety: the client should be encouraged to play an active role in the application of PIR techniques. They should be encouraged to develop an awareness of the muscles being targeted. Clients should also provide as much feedback as possible; this might include what they are feeling during PIR stretches or their levels of fatigue. To ensure safety clients must:
• ask the trainer to stop if they experience pain at anytime. If the client does experience pain, the trainer should try repositioning the limb or ask the client to exert less force during the isometric contraction. If pain persists, do not continue until the cause of pain has been determined
• follow the trainers instruction at all times • communicate freely with the trainer