Stretching is a common activity used by athletes, older adults, rehabilitation patients, and anyone participating in a fitness program. While the benefits of stretching are known, controversy remains about the best type of stretching for a particular goal or outcome.
The purpose of this clinical commentary is to discuss the current concepts of muscle stretching interventions and summarize the evidence related to stretching as used in both exercise and rehabilitation.
Human movement is dependent on the amount of range of motion ROM available in synovial joints. In general, ROM may be limited by 2 anatomical entities: Joint restraints include joint geometry and congruency as well 2 bbws 1 athletic guy the capsuloligamentous structures that surround the joint. Muscle provides both passive and active tension: Structurally, muscle has viscoelastic properties that provide passive tension.
Active tension results from the neuroreflexive properties of muscle, specifically peripheral motor neuron innervation alpha motor neuron and reflexive activation gamma motor neuron.
Obviously, there are many factors and reasons for reduced joint ROM only one of which is muscular tightness. Passively, muscles can become shortened through postural adaptation or scarring; actively, muscles can become shorter due to spasm or contraction.
Regardless of the cause, tightness limits range of motion and may create a muscle imbalance. Clinicians must choose the appropriate intervention or technique to improve muscle tension based on the cause of the tightness.
Stretching generally focuses on increasing the length of a musculotendinous unit, in essence increasing the distance between a muscle's origin and insertion. In terms of stretching, muscle tension is usually inversely related to length: Inevitably, stretching of muscle applies tension to other structures such as the joint capsule and fascia, which are made up of different tissue than muscle with different biomechanical properties. Three muscle stretching techniques are frequently described in the literature: Static, Dynamic, and Pre-Contraction stretches Figure 2.
The traditional and most common type is static stretching, where a specific position is held with the muscle on tension to a point of a stretching sensation and repeated. This can be performed passively by a partner, or actively by the subject Figure 3. Techniques of Muscle Stretching. Static stretching of the posterior shoulder Used with permission of the Hygenic Corporation. There are 2 types of dynamic stretching: Active stretching generally involves moving a limb through its full range of motion to the end ranges and repeating several times.
Pre-contraction stretching involves a contraction of the muscle being stretched or its antagonist before stretching. The most 2 bbws 1 athletic guy type of pre-contraction stretching is proprioceptive neuromuscular facilitation PNF stretching. Resistance can be provided by a partner or with an elastic band or strap 2 bbws 1 athletic guy 4. Contract-Relax stretching with stretching strap Used with permission of the Hygenic Corporation.
Post-facilitation stretch PFS is a technique developed by Dr. Vladimir Janda that involves a maximal contraction of the muscle at mid-range Figure 5 with a rapid movement to maximal length followed by a second static stretch. Many studies have evaluated various effects of different types and durations of stretching. Outcomes of these studies can be categorized as either acute or training effects.