Benefits

• One of the greatest benefits of stretching is that you’re able to increase the length of both your muscles and tendons.
• Additional flexibility throughout the body.
• Increased awareness of muscles and their capabilities during any daily activity or sport.
• Increased coordination or agility.
• Quicker removal of waste products.
• Better posture.
• Increased range of motion available at a joints or joints.
• The development of functional or "usable" flexibility.
• Injury prevention.
• Increased blood supply, nutrients, and joint fluid.
• Reduced muscular soreness, stiffness, tightness, and inflammation.
• Personal enjoyment, relaxation, and reduced stress.
  

 Nine very important reasons for which you should stretch:

• Stretching improves an athlete's physical condition.
• Stretching improves learning, practice, and efficiency of an athlete in many difficult and complex moves.
• Stretching improves an athlete's spiritual and body relaxation.
• Stretching promotes the conception of the body.
• Stretching reduces possibilities of muscular fracture or injury of an athlete's joints.
• Stretching reduces danger of a back injury.
• Stretching reduces muscular suffering.
• Stretching reduces the painful symptoms of dysmenorrhea in women athletes.
• Stretching reduces an athlete's muscular tension.
  

 Warm up

• Four key elements: Light physical activity, Static stretching, the sports specific warm up (specifically preparing their body for the demands of their particular sport), and Dynamic stretching.
• Stretching is not warming up!
• Warm-up before you stretch.
• The general warm-up should begin with joint-rotations, starting either from your toes and working your way up, or from your fingers and working your way down.
• If they are not already warm before you wish to stretch, then you need to warm them up yourself, usually by performing some type of brief aerobic activity.
  

 Warm up benefits

• Increase the temperature of muscles - they work better at a temperature of 40 degrees.
• Increase blood flow and oxygen to muscles.
• Increase the speed of nerve impulses - making you faster.
• Increase range of motion at joints reducing the risk of tearing muscles and ligaments.
  

 When

• Stretch before and after exercising.
• One of the best times to stretch is right after a strength workout such as weightlifting.
• You should preferably wait for 2 hours after a meal before you start exercising.
• Most people are more flexible in the afternoon than in the morning, peaking from about 2:30pm-4pm.
  

 As a general rule, you should usually do the following when putting together a stretching routine:

• Stretch your back (upper and lower) first
• Stretch your sides after stretching your back
• Stretch your buttocks before stretching your groin or your hamstrings
• Stretch your calves before stretching your hamstrings
• Stretch your shins before stretching your quadriceps (if you do shin stretches)
• Stretch your arms before stretching your chest
  

 Facts

• If you are not use to stretching on a regular basis, take it slow and for shorter periods of time.
• Work only the muscles you are trying to stretch.
• Proper breathing control is important for a successful stretch.
• If you stretch properly, you should not be sore the day after you have stretched.
• Individuals that have not stretched or exercised much in the last few months will almost always experience some amount of soreness.
• Stretch until muscle is tight. The stretch should be uncomfortable but never painful.
• Stretch all the muscle groups to be involved in the following activity.
• Stretch muscles gently and slowly.
• Increased water intake is believed to contribute to increased mobility, as well as increased total body relaxation.
• Strength training and flexibility training should go hand in hand.
• Stretching won't cure muscle tightness.
• Stretching is just one piece of the fitness puzzle.
• Stretching isn't a warm-up.
• Stretching is best after you run.
• The older you are, the more important stretching becomes.
• Flexibility is a joint’s ability to move through a full range of motion.
• Flexibility is very specific to the joint. There are specific limitations around a joint and Johns and Wright (1962) determined specific limits of motions of the joint shape 47%, muscle fascia 41%, tendons 10% and the skin 2%. 
  

 Monitoring Systems

• There are two main sensory organs that monitor stretch length, speed, and tension. Sensory organs transfer information from the CNS to determine where an individual’s body is in space. This is also known as kinesthetic awareness. 
• The main sensory organs involved in stretching are the muscle spindles and the Golgi tendon organs.
• The muscle spindles are found in the muscles fibers (cells) and recognize the resting length of the muscle, the changes to length and the speed of lengthening. 
• Muscle spindles help the body: 1) maintain tone and posture and 2) present a defense mechanism called the stretch reflex. 
• The Golgi tendon organs are located in the muscle tendon / musculo-tendinous joint. The G.T.O.’s monitor force production and tension in the muscle.

 How long

• 2-5 repetitions with a 15-30 second rest in between each stretch.
• Many researchers recommend 30-60 seconds.
• A good common ground seems to be about 20 seconds of holding a stretch.
• Various sources seem to suggest that they should be held for as little as 10 seconds to as long as a full minute (or even several minutes), but the truth is that no one really seems to know for sure.
  

 Contraindications

• Avoid having a heavy meal just before exercise.
• Some stretches (many of which are commonly performed) are considered risky.
• One of the easiest ways to "overstretch" is to stretch "cold" (without any warm-up).
• Never bounce, jerk or stretch rapidly.
• Do not hold your breath when stretching, but breathe slowly and easily.
• Do not exercise if you have a fever or do not feel well.
• Excessive flexibility can be just as bad as not enough because both increase your risk of injury.
• Using wrong stretching techniques can cause serious injuries like: muscle tears, joint dislocation, ligament tears, etc.
• If you experience pain during stretching, consult a doctor.
• Too much flexibility could mean less support is given to the joint by its surrounding muscles.
• Muscle soreness will usually occur 24 to 48 hours after the intense exercise.
• It takes 6-10 seconds for the brain and spinal cord to perceive that the stretch is safe and, suddenly, the mild pulling sensation you feel of the muscle shortening to resist the stretch is gone. It is in the next 20-24 seconds that the stretch has the beneficial effects. That is a why a stretch must be held at least 30 seconds.
• Muscles naturally tense during the first few seconds of a stretch, and this effect is only heightened by overanxious efforts to force unwilling muscles to obey.
• Do not try to force flexibility that your muscles aren't ready for.
• Noises that are associated with pain may indicate damage to the articulating surfaces of the joint. Such pops and clicks may be due to tears in the meniscus, but are sometimes just due to an overly large or loose meniscus which may snap over the other structures in the knee as the knee bends and straightens.
  

 Technical

• Golgi tendon receptor is in each tendon. This receptor is sensitive to the build up of tension when a muscle is either stretched or contracted.
• The nerve endings that relay all the information about the musculoskeletal system to the central nervous system are called Proprioceptors.
  

 Cool down

• Three key elements: Gentle exercise, Stretching; and Re-fuel.
• The main aim of the cool down is to promote recovery and return the body to a pre exercise, or pre work out level.
• Stretching is not a legitimate means of cooling down; it is only part of the process.
• The cool-down stage should include 2-3 minutes of easy jogging or walking and 5 minutes of gentle stretching.
  

 Cool down benefits

• Gradually lower heart rate.
• Circulate blood and oxygen to muscles, restoring them to the condition they were in before exercise.
• Remove waste products such as lactic acid.
• Reduce the risk of muscle soreness.
  

Cooperating Muscle Groups

• Agonists - A muscle that causes motion. Muscle group being stretched. These muscles cause the movement to occur. They create the normal range of movement in a joint by contracting. Agonists are also referred to as ‘prime movers’ since they are the muscles that are primarily responsible for generating the movement.
• Antagonists - A muscle that can move the joint opposite to the movement produced by the agonist.
• The muscle group on the opposite side being stretched. These muscles act in opposition to the movement generated by the agonists and are responsible for returning a limb to its initial position.
• Prime mover - The muscle that causes the movement
• Synergists - A muscle that assists another muscle to accomplish a movement.
• These muscles help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion.
• Fixators - These muscles provide the necessary support to assist in holding the rest of the body in place while the movement occurs.
• Target - The primary muscle intended for exercise.
  

• Stabilizer - A muscle that contracts with no significant movement.
• Dynamic Stabilizer - A biarticulate muscle that simultaneously shortens at the target joint and lengthens at the adjacent joint with no appreciable difference in length. Dynamic stabilizion occurs during many compound movements.
• Antagonist Stabilizer - A muscle that contracts to maintain the tension potential of a biarticulate muscle at the adjacent joint. The antagonist stabilizer may be contracted throughout or at only one extreme of the movement.

 You should never attempt stretching if:

• A bone is blocking you.
• You have a recent bone fracture.
• You know or you suspect that you have an acute inflammation or infection near a joint
• You have or suspect that you have osteoporosis.
• You have a recent muscular fracture or muscular distortion.
• You have an acute pain when you move a joint or during a muscular elongation.
• You suffer from a severe skin or arterial illness.
• You have reduced moving amplitude.
  

 The types of muscle contraction is defined as follows (International PNF Association, unpublished handout):

Isotonic (dynamic): The intent of the patient is to produce motion.

Concentric: Shortening of the agonist produces motion.

Eccentric: An outside force, gravity or resistance, produces the motion. The motion is restrained by the controlled by the controlled lengthening of the agonist.

Stabilizing isotonic: The intent of the patient is motion; the motion is prevented by an outside force (usually resistance).

Isometric (static): The intent of both the patient and the therapist is that no motion occurs.

Articulation

Uniarticulate
A muscle that crosses one joint
Biarticulate
A muscle that crosses two joints
Triarticulate
A muscle that can move three joints

 Flexibility is joint specific.

• Joint shape (joint capsule) can limit flexibility up to 47%. The joint cannot be altered unless injury occurs.
• The tendon can limit flexibility up to 10%.
• The muscle fascia can limit flexibility up to 41%.
• The skin can limit flexibility up to 2%.
• However, connective or "soft" tissue can be altered long term. It is elasticity, which means a measure of a soft tissue's resistance to stretch or lack of elasticity that allows improvement in range of motion, or predisposes a client to injury if he engages in improper flexibility training.
  

 Flexibility factors

• Connective tissue elasticity within the muscles
• Genetic inheritance
• Joint structure itself
• Ligaments
• Neuromuscular influence (from sensory organs such as the muscle spindle and Golgi Tendon Organ)
• Skin surrounding the joint
• Tendons
• Tension (partial contraction) in the muscle
• Static flexibility - ability to hold a static stretched position.
• Dynamic flexibility - ability of your muscles to stretch to their maximum range while in motion.

 Contraction

• Concentric Contraction - This is a contraction in which the muscle ‘decreases in length’ (shortens) against an opposing load, such as lifting a weight up.
• Eccentric Contraction - This is a contraction in which the muscle ‘increases in length’ (lengthens) as it resists a load, such as pushing something down. During a concentric contraction, the muscles that are shortening serve as the agonists and hence do all of the work. During an eccentric contraction, the muscles that are lengthening serve as the agonists (and does all of the work).
• Isokinetic Contraction - The contraction of a muscle against concomitant force at a ‘constant speed’. Diagnostic strength equipment implements isokinetic tension to more accurately measure strength at varying joint angles.
• Isometric Contraction - This is a contraction in which ‘no movement’ takes place, because the load on the muscle exceeds the tension generated by the contracting muscle. This occurs when a muscle attempts to push or pull an immovable object.
• Isotonic Contraction (same tension) - This is a contraction in which ‘movement does take place’, because the tension generated by the contracting muscle exceeds the load on the muscle. This occurs when you use your muscles to successfully push or pull an object.

 The same basic principles that apply to Isometric stretching also apply to PNF...

• Leave 48 hours between PNF stretching routines.
• Perform only one exercise per muscle group in a session.
• For each muscle group complete 2-5 sets of the chosen exercise.
• Each set should consist of one stretch held for 10-15 seconds after the contracting and relaxing phases.
• PNF stretching is not recommended for anyone under the age of 18.
• If PNF stretching is to be performed as a separate exercise session, a thorough warm up consisting of 5-10 minutes of light aerobic exercise and some dynamic stretches must precede it.

When you start an everyday stretching program you should:

• Have a positive intention.
• Warm up.
• Isolate the muscular group that you are going to stretch.
  Advance slowly and steadily with the stretch to avoid activation of muscular tension reflexes.
• Use the correct mechanics for every move and follow exactly the instructions for each move.
• Breathe free and normally, but extend the exhale in a extended move.
• Keep the stretch for about 20 or 30 seconds and relax.
• Concentrate and try to feel the stretch.
• Cooperate and communicate with your co-athlete, if you exercise with his help.
  Relax slowly and carefully your muscles.
  

 FITT Principle
The FITT Principle (or formula) is a great way of monitoring your exercise program. The acronym FITT outlines the key components of an effective exercise program, and the initials F, I, T, T, stand for:
• Frequency...refers to the frequency of exercise undertaken or how often you exercise.
• Intensity...refers to the intensity of exercise undertaken or how hard you exercise.
• Time...refers to the time you spend exercising or how long you exercise for.
• Type...refers to the type of exercise undertaken or what kind of exercise you do.

 The following is a list of commonly used agonist/antagonist muscle pairs:

• Pectorals/Latissimus dorsi (pecs and lats)
• Anterior deltoids/Posterior deltoids (front and back shoulder)
• Trapezius/Deltoids (traps and delts)
• Abdominals/Spinal erectors (abs and lower-back)
• Left and right external obliques (sides)
• Quadriceps/Hamstrings (quads and hams)
• Shins/Calves
• Biceps/Triceps
• Forearm flexors/Forearm extensors