Stretching

The responsibilities of the massage practitioner may not end with practical applications on the massage couch. In conjunction with athletic trainers, coaches and medical professionals, the massage practitioner will often become involved in implementing warm-up, cool-down and stretching programs.

The post-massage advice given by the sports massage practitioner is therefore essential to the athlete in maintaining and improving their ability to perform sporting and everyday activities. Muscles in particular must be maintained in optimum condition. Thus, it is critical that the sports massage practitioner has the knowledge to give the right advice and the ability to give clear instruction on how best to prepare the athlete for exercise and how to aid recovery. This means having a scientific understanding of, and practical skills relating to, the benefits of warming up, cooling down and stretching. The athlete may then enjoy the benefits of sports massage in helping restore normal function, as well as following up with the right programme to prepare the body for rigorous and competitive activity.

The Warm-up

Light exercise undertaken in preparation for training or competition stimulates blood flow to the soft tissues, which increases the temperature and pliability of ligaments, tendons and muscles. This also helps to reduce muscle tension and may reduce the risk of injuring muscles while exercising. Finally, the warm-up allows the athlete to prepare mentally for the session.

The warm-up session should last between 15 and 20 minutes. Where replication of the activity to follow is not possible, an activity such as jogging or the use of stationary rowing or cycling machines may be used. It should gradually increase in pace to prepare the body’s systems for the intensity of the exercise in the main training session or competition.

The Cool-down

All periods of intense physical exercise should finish with a cool-down that slowly decreases the intensity of the exercise before the athlete stops completely. A runner, for example, would cool down by jogging at a moderate pace for a few minutes, gradually slowing down to a walk before stopping and finishing the exercise session. As with the warm-up, the cool-down process should take 15 to 20 minutes.

Allowing the heart rate and circulation to slow down gradually prevents the pooling of blood and waste products in the muscles of the extremities. An abrupt halt after sustained exercise, may result in dizziness as blood pools in the legs. On rare occasions, elevated post-exercise levels of catecholamine (an adrenaline-like substance) may lead to dangerous heart arrhythmia, or abnormal rhythm, which may be avoided by a suitable cool-down. Stretching muscles during a cool-down is also important to improve flexibility, and may also reduce muscle soreness as discussed later in this chapter.

Stretching – Some General Principles

Flexibility and range of motion
Flexibility is the range to which our muscular and connective tissues will allow a joint or group of joints to move in the ‘absence of pain’. While there may be some mild discomfort at the extremes of a joint’s action, pain is the body’s way of saying that something has been, or is about to be, damaged. Stretching may therefore be considered to exist at the balance point between discomfort and damage.

Range of motion (ROM) is determined by the extensibility of muscular and connective tissues. Stretching soft tissue that is limiting the range of motion can improve flexibility and may help reduce the risk of injury. Hypermobility and laxity are terms used in relation to flexibility to describe a joint with an abnormal ROM. Hypermobility describes the non-detrimental (either in terms of discomfort or performance), excess ROM beyond the accepted norm. Laxity describes the relative instability of a joint, regardless of its ROM, and the detrimental effect that this may have on comfort and/or performance.

Why is flexibility important for sports performance?
Healthy, supple muscle tissue that allows maximum ‘normal’ mobility contributes to optimum performance. This is because muscles in this condition are less prone to injury and facilitate greater ROM about the joints at which they act therefore enabling enhanced performance. What ‘normal’ is in specific sports is determined by the demands of competition, and may often be considered abnormal in everyday life. For example, gymnasts may often be considered to be hypermobile, but their sport demands this for successful performance. Bear in mind, too, that tendons to which muscles attach have important recoil properties that generate considerable power, adding to ordinary muscle contraction. It may therefore be detrimental to have muscles that are too flexible.

If a muscle or joint is tight, it will progressively restrict motion as it approaches its maximum range. If an athlete’s competitive actions requires that they approach this maximum range then their performance will not be optimal as they will be hampered at the extremes of their ROM. If they were more flexible they could perform with optimal speed and co-ordination throughout the desired ROM without approaching their maximal range. Second to this, it can be argued that most muscle injuries occur either during supramaximal loading or in supramaximal ranges of motion; extend the ROM, and the risk of exceeding it with any given action is reduced.

What happens to soft tissue when we stretch?
When soft tissue is stretched it changes shape. When the stretch is released, the soft tissue usually returns to its normal form. In these cases, and within the range that this occurs, the soft tissue is said to be elastic since it is capable of re-forming. This is particularly true of elastin fibres within the sarcolemma of the muscle. If the tissue is stretched beyond the elastic range (i.e. the elastic limit), the soft tissue does not re-form and will be permanently deformed. When the soft tissue loses its elasticity it is said to be plastic, and in the plastic range, the more the tissue is stretched, the greater the chance that any deformation will result in permanent damage. However, the collagen fibres of the muscles and connective tissues are plastic by nature. As such, they respond most readily to a static stretch of long duration (minimum 20–30 seconds) and low load (the stretch should not cause any pronounced discomfort).

Muscle reflexes
The body has mechanisms, called muscle reflexes, which help to prevent tissue deformation resulting from stretching overload, as described above. These are reciprocal inhibition, the myotatic stretch reflex and the inverse stretch reflex.

Reciprocal inhibition
In order that the body can move in a co-ordinated manner, the agonist and antagonist muscles must communicate with one another in harmony. When the excitatory motor neurons of the agonist muscle initiate a given muscle action, an inhibitory impulse in the motor neurons of the antagonist muscle is triggered - so-called reciprocal inhibition. For example, during elbow flexion, the biceps contract and almost instantaneously the triceps relax. Thus, the active triceps stretch in resulting from contraction of the biceps, is enhanced by the neurological inhibition of the triceps motor neurons.

The myotatic stretch reflex
Stretching a muscle lengthens both the muscle fibres and special receptors within the muscle called muscle spindle fibres. The muscle spindle fibres serve a protective function and respond to two sets of stimuli:

• how quickly the fibre is being stretched
• how far the fibre is being stretched.

If a muscle is contracting too fast or too hard, it is the muscle spindle fibres of the antagonist muscle that are activated. For example, if the hamstrings are contracting rapidly towards full knee flexion then the muscle spindle fibres of the quadriceps will respond by contracting to prevent potential damage. It is therefore helpful to think of the myotatic stretch response as saving the active joint from damage as a result of rapid, forceful deformation at the end of its ROM.

A classic example of this is the knee jerk reflex: when the patellar tendon is tapped, the muscle spindle fibres of the quadriceps, located parallel to the muscle fibres, are stretched, causing them to deform. This causes the muscle spindles to fire, sending a message to the spinal cord. The brain returns an impulse to the quadriceps, causing them to contract to prevent any further stretching of the fibres. However, in a sporting environment it is usually the agonist–antagonist pairs that set up the tension rather than an external force. The stretch reflex is likely to be activated during certain types of stretching, such as ballistic stretching, discussed later in this chapter.

Inverse stretch reflex
The inverse stretch reflex – also called autogenic inhibition – involves sensory receptors called Golgi tendon organs (GTO), which monitor degrees of tension within the skeletal muscle unit.  Rather than being located within the tendon itself, the vast majority of GTO are actually situated within the musculo-tendinous junction of the muscle unit – its weakest point because this is where two tissue types merge, and therefore a common site of injury.

As the muscle fibres contract, an increasing amount of tension is built up in the tendon as it delivers force to the bone. GTO register this contractile tension in the agonist musculo-tendinous junction. The GTO initiate inhibitory impulses and these cause the agonist muscle to relax, releasing the tension in the musculo-tendinous junction, hence, avoiding injury of the associated muscles, tendons, ligaments and joints. The inverse stretch reflex is thought to contribute to the effectiveness of proprioceptive neuromuscular facilitation (PNF) stretching, as discussed later in this chapter.

What are the benefits of stretching to the athlete?

Mental relaxation
Stretching during the warm-up and cool-down allows the athlete time to mentally relax and prepare or recover from the demands of physical activity.

Muscular relaxation
When the muscles are relaxed through stretching, tension is released and neuromuscular functioning is improved, possibly reducing the chances of injury.

Increased flexibility
Increasing flexibility and joint range of motion through a stretching programme can contribute to better sports performance.

Improved posture and balance in the musculo-skeletal system
Good posture is an important factor for healthy everyday living and optimum performance in sport. By adhering to a good stretching programme you may achieve better symmetry and a healthy balance throughout the musculo-skeletal system, which improves posture.

Prevention of lower back pain
After extensive study, Cailliet (1988) asserts that a ‘mobilised, flexible and strengthened lumbar spine may help prevent lower back pain’.

Improved fitness
Supple muscles, healthy joint functioning, good range of motion and overall mobility all contribute to improved fitness, and all are improved by stretching.

Relief of muscle soreness
While the exact cause of delayed onset of muscle soreness (DOMS) is under investigation, Tillman and Cummings (1992) suggest that slow stretching exercises may reduce its effects. Following Howell et al. (1985), stretching may be most effective where DOMS is secondary to inflammatory or oedaemic response, rather than microtrauma to the protein myofilaments described in the sliding filament theory.

Relief of cramp
Involuntary muscle contraction of an already shortened muscle, commonly known as cramp, may be relieved by passively stretching the cramped muscle.

Improved motor skills
Stretching improves motor skills by increasing flexibility, which is essential for skilled movement and conditioning – particularly in contact sports, dance and gymnastics.

Injury prevention
Weldon and Hill (2003) indicate that there is little conclusive research to support the contention that stretching reduces the occurrence of injury. However, the volume of observational data generated over the years by athletes, coaches and therapists has made the contention widely accepted, so much so that it is now deemed to be unethical to ask a control group to participate in an activity study and not allow them to stretch. So in considering why flexibility is important for sports performance, it becomes evident that injury prevention is an intuitively sound concept and that the muscles, tendons, ligaments and other joint structures can all be protected to some degree by a comprehensive stretching program.

Factors limiting flexibility

There are a variety of factors that may limit flexibility.

• The bony, ligamentous and capsular elements of the joint may define ROM.
• Skin, and especially scar issue, may limit the comfortable ROM of an activity. It is not uncommon to see ‘stretch marks’ on the skin of the axillary regions of the pectorals of weightlifters. As much as they wish it were simply the muscles growing faster than the skin, it is more commonly over-stretching of the skin through ‘flye’-type exercises that are to blame for the blemishes.
• In an increasingly sedentary population, where obesity is becoming prevalent, health professionals are finding it more and more difficult to take standard ‘sit-and-reach’ flexibility measures as pot-bellies get in the way of trunk flexion.
• Most relevant to the sports massage practitioner are the limits of the muscle, fascia and tendons – the soft tissues with which they largely deal. These are discussed below.

Review of the structures of the sliding filament theory will show the sarcomere to be the basic unit of muscular contraction. The protein myofilaments of the sarcomere can only be stretched so far before they can no longer engage functionally or are damaged. The elastin fibres of the sarcolemma are highly resilient, but they too may be torn if stretched too far. At the higher levels of organisation in the skeletal muscle unit, the plastic nature of the collagen fibres of the tendon, fascia/epimysium, perimysium and endomysium limit flexibility. One area of muscular limitation that is often overlooked is that of simple mechanical block – the muscle mass is such that it prevents other limitations from being reached. Think of a sprinters calves and hamstrings meeting on a forced knee flexion, stopping that motion well before the joint capsule is stressed.

The processes of muscle atrophy through decreased activity, immobilisation due to injury, or ageing can all negatively affect flexibility. The atrophy of the muscle tissue is accompanied by inclusion of collagen fibres in areas previously dominated by elastin fibres. Consequently, the plastic nature of collagen replaces the elastic properties of elastin and the flexibility of the skeletal muscle unit decreases to reflect this change.

Fundamentals of Stretching

How to stretch
At its simplest, stretching can be thought of as moving the point of insertion of a muscle or muscle group as far as possible from its origin.  Keeping this in mind, the sports massage practitioner can assist their athletes to learn where the target of the stretch should be felt.

Duration of the stretch
Short-duration (6–10 seconds) stretching is referred to as ‘maintenance stretching’ and is used most commonly during a workout to return the muscle to its pre-activity length. Long duration (20–30 seconds) stretching is referred to as ‘developmental stretching’ and is most commonly incorporated into the cool-down to increase muscle length beyond its usual range of motion – thus progressively increasing flexibility. For example, during a workout an athlete may do a standing hamstring maintenance stretch between sprints; while at the end of the session, they may do a lying hamstring developmental stretch as it would be easier to hold the stretch while comfortably on the ground.

There is an increasing benefit in holding the developmental stretch for longer duration, but there is also a point of diminishing returns where the time spent simply does not justify the almost immeasurable extra gains in flexibility. Similarly, repeated stretches to the same muscle will give diminishing returns. A good balance between time and results is three stretches of 30 seconds per muscle. A rest of 10–15 seconds between stretches is sufficient.

Types of Stretching

The following section introduces seven major types of stretching. Of these, only the assisted and PNF stretches require the physical assistance of the massage practitioner. The remaining types require that the practitioner instruct and observe to ensure that the athlete performs the stretches safely and accurately. Once proper stretching techniques are ingrained in the athlete, the massage practitioner may occasionally reassess the athlete to determine that good form has been maintained – adjusting the exercises of the stretching programme to meet their current needs.

Static stretching
Static stretching involves taking a joint through its range to a point where the soft tissue is comfortably stretched and then holding the position for a period of time. This may be done three ways: positional, active or passive.

Positional-static stretching
This is what we generally think of when we hear the term static stretching.  The body is positioned in such a way that the mass of the limb or the body is acted on by gravity to elicit the elongating stretch of the target muscle. All static stretching works largely by mechanical means affecting the elastin and collagen fibres of the skeletal muscle unit.

Active-static stretching
Whilst appearing a contradiction in terms, in active static stretching the client activates an isometric contraction (where force is exerted but muscle length does not change) at the full inner position of the joint – promoting the static stretch, at extension, of the antagonist muscle or group. For example, fully contracting the hamstrings to full knee flexion will encourage a mechanical stretch of the quadriceps which will be enhanced by reciprocal inhibition. This type of stretching is useful for dancers and martial artists or others who need strength at extreme ranges of motion.

Passive-static stretching
Passive-static stretching is distinguished from assisted stretching (see below) by the absence (passive-static stretching) or presence (assisted stretching) of the sports massage practitioner applying force. It will be further differentiated from positional- or active-static stretching by the addition of external ‘prop’ or force. In passive-static stretching the client uses a prop to resist a force in order to extend or deepen a stretch. The prop may be as simple as using hand and arm strength to deepen a hamstring stretch, or a towel hooked over the heel to draw the leg into a deeper hamstring stretch. This is an effective way to deepen a positional static stretch, as the client is in control at all times.

Assisted stretching
Assisted stretching is where the client is instructed to relax the muscles and the practitioner moves the joint through its range to its comfortable limit. This is particularly useful when used in conjunction with sports massage to assess periodically the effects of massage, as well as to improve flexibility. It is most important to give clear instructions and request feedback from your client to ensure that no harm is done during the stretch.  We have concerns over the safety of assisted stretching in any environment and feel it is most appropriate in a clinical setting – as such we recommend the use of PNF-type stretches (see below) in the training environment in preference to assisted stretching.

Dynamic stretching
Dynamic stretching is a controlled, rhythmic, repeated motion to the point of tension and return to full inner position. For example, from a seated position, extend one leg in front of you and draw the toes towards the knee (dorsiflexion) until tension is felt; return to full toe point (plantarflexion) and repeat 10 times. Each motion should take at least three seconds. By using controlled movements, this type of stretching also lubricates the joints by stimulating the production of synovial fluid. The combination of light activity, musculotendinous stretching, and joint lubrication produces a combination of warm-up and stretching that is known as mobilisation.

Ballistic stretching
Ballistic stretching refers to a rapid, accelerative, repeated action beyond normal ROM with a slow return to the start position. It is the most controversial form of stretching, as it can inappropriately trigger myotatic stretch reflexes and/or cause damage to the skeletal muscle unit or associated joint structures. It is necessary only in sport-specific instances where the decelerative muscle is at risk of injury in explosive activities – for example, the hamstrings are at risk of injury when they decelerate the knee as it approaches full extension during hurdling activities. Sprinters, hurdlers, martial artists and throwers are athletes who may need to incorporate ballistic stretching into their routines. This would follow other warm-up and stretching activities to prepare the tissue.

Proprioceptive neuromuscular facilitation (PNF)
There are several methods of PNF, based on the theory that a muscle will be most effectively stretched if neurological stimuli are fully integrated into the mechanical aspects of stretching. At least nine forms of PNF are described in the literature, with hold–relax (HR), contract–relax (CR) and contract–relax–antagonist–contract (CRAC) being the most widely practised.

It is strongly recommended that a practitioner undertake supervised instruction in the ‘art and science’ of PNF, as it is very easily misunderstood and ineffectively applied when taken directly from a book. That being said, a brief introduction to the three  common forms of PNF follows.

Duration of contraction
Unless otherwise stated, we recommend that all muscular contractions made by the athletes develop progressively, rather than being applied aggressively.  For example, when a twelve second contraction is requested the athlete would build the tension over the first five seconds and then hold the contraction for the remaining seven – instruct the athlete; build, 2, 3, 4, 5, hold, 7, 8, 9, 10, 11, 12.

Force of contraction
The force of contraction that we recommend is dependent on the status of the athlete – ‘post-injury’ or ‘full training’.  When the athlete is in a rehabilitation situation, we ask them to build up to a contraction force of ‘7 out of 10 on the pain scale’.  This is the level of discomfort that they would normally elicit during a hard training session.  At level eight they would be thinking about trying to avoid the pain; at nine they are visibly in pain – gritting teeth, eyebrows twitching, other body parts moving in ‘sympathy’.  Avoid going beyond level seven!  We generally feel the athlete’s force of contraction increasing across a series of sessions even though they remain at ‘7 out of 10’ on the pain scale.  This suggests the tissue is regaining its integrity.  Where the athlete is in a training environment and the target tissue to be stretched is healthy, we ask for build-up to a peak contraction of 70% of maximal voluntary contraction.

Hold–relax (HR) PNF
This method is based on a combination of active-static and assisted stretching (see above). For example, to stretch the hamstrings, the client actively stretches (holds) the hamstrings via the contraction of the quadriceps and hip flexors for 12 seconds. The client then relaxes as the practitioner assists the limb to its new maximum ROM over the course of  five seconds and holds it at the new point of bind for a further seven seconds. Three repetitions of the 12+12 cycle will suffice.

This type of PNF is most effective when the client has limited and/or painful ROM. The client will often be sedentary, elderly or in injury rehabilitation. Advantages include the strengthening of the antagonist muscle during the active/hold portion of the stretch;  increased flexibility and muscular co-ordination is also encouraged through the activation of reciprocal inhibition via reciprocal innervation (see p. 126). Risks are related to the assisted portion of the stretch.

Contract–relax (CR) PNF
This method is based on a combination of isometric resistance and assisted stretching (see above). As an example we will again look at the hamstrings. From the first point of tension, the client applies pressure against the practitioner who resists the hamstrings’ attempts to flex the knee and extend the hip. Over the course of five seconds the client builds from 30% to 70% of maximal contraction and then holds for a further seven seconds. As the client relaxes, the practitioner assists the limb to its new maximum ROM over the course of five seconds and holds it at the new point of bind for a further seven seconds. Three repetitions of the 12+12 cycle will suffice.

This type of stretching is most effective when the client has limited, but pain-free ROM. The client will often be sedentary, elderly or at a late stage in injury rehabilitation. Advantages include the strengthening of the stretched muscle during the contract portion of the stretch, and increased flexibility encouraged through the activation of the inverse stretch reflex via the Golgi tendon organs (see p. 127). Risks are related to the assisted portion of the stretch.

Contract–relax–antagonist–contract (CRAC) PNF
This method is based on a combination of isometric resistance and active-static stretching (see above) and is essentially a CR followed by a HR. For consistency in the examples we will again look at the hamstrings. From the point of tension, the client applies pressure against the practitioner who resists the hamstrings’ attempts to flex the knee and extend the hip. Over the course of five seconds the client builds from 30% to 70% of maximal contraction and then holds for a further seven seconds. As the client relaxes, they build to an active-static stretch at the limb’s new maximum ROM over five seconds and then hold for a further seven seconds. The practitioner follows the limb to its new position in preparation for the next resistance of isometric contraction. Three repetitions of the 12+12 cycle will suffice.

This type of stretching is possibly the most effective form of developmental stretching. Advantages include the strengthening of the stretched muscle during the contract portion of the stretch, and increased flexibility  encouraged through the activation of the inverse stretch reflex via the Golgi tendon organs – as well as the activation of reciprocal inhibition via reciprocal innervation. Risks are minimised as the client is in control of the strength of contraction in both the isometric resistance and active stretch portions of the PNF stretch cycle.

from The Complete Guide to Sports Massage

Recommended Further Reading

The Complete Guide to Stretching (2007) by Christopher Norris (3rd ed) ISBN-13: 978-0713683486

Facilitated Stretching (2007) by Robert McAtee (3rd ed) ISBN-13: 978-0736062480