Harrison
01-02-2006, 11:16 AM
A trigger point in a muscle is a warning sign of a possible serious injury. Here we explain what TPs are, how they happen and what to do about them
Picture a rubber band with a small section that has lost its elasticity, and instead has become hardened and rather brittle. That's what a trigger point is like: the muscle is tighter, stiffer, will often be weaker and yet very tense at the same time. A TP will be sore when you push on it, and you may feel a thick band that you can flick over with your fingers.
A vast number of sports injuries of all kinds have their genesis in the development of a TP in the muscle or fascia. This TP is very commonly the first sign of overload, and from then on, cause and effect begin to domino: one tissue breaks down, causing another to be overloaded and then break down, and so on. Trigger points lead to inflammation, then pain, then weakness, then joint and nerve dysfunction, and finally structural breakdown of tissues and a severe sports injury that can keep you out of action for weeks, months or even years, depending on how long you attempt to struggle on without treating the original TP.
A TP is thus an alarm bell - a first warning sign that things are not well within your biomechanical system. Learning to listen to your body's alarm bells is a critical skill that can avoid many injuries. Often athletes, with their enhanced overall body sense, become aware of TPs before they are significant enough to cause actual pain(32), when the only complaint is 'tightness' or the joint or muscle doesn't 'feel right'(20).
Arguably, all sports people will develop TPs at some stage in their sporting career. These may hamper our performance and slow us down for a while, or they may blow out to cause a severe injury. They are a normal part of training and competing because our bodies are biomechanically imperfect and our environments more random than we would like them to be. In a perfect world, our bodies would not break down when overloaded - and the football pitch would be just soft enough to prevent stress fractures, yet hard enough to prevent ligament tears when we run over a pothole in the grass. But it just isn�t so!
To all intents and purposes, a TP is simply a thick knot in the muscle - a way the muscle reacts to being overloaded. In some ways, a TP is the equivalent of a stress fracture in a bone. More specifically, a TP is a palpable, tender, nodal point of muscle or fascia. It may also be found in skin, where scar tissue is present, in old ligament injuries or, occasionally, in periosteum (the lining of bone). Under a microscope, TPs appear darker, straightened out and thicker, ranging in diameter from 1-4mm. If located in muscle, they cause it to form taut bands or become 'ropey'. A focal area of inflammation develops fairly early on and a collagen matrix forms; scar tissue is laid down to bridge the weak link, and can become quite thickened and tough, depending on how long it has been present(3,7,8,19,20,23,28). The muscle in which a TP is found will usually be weakened and shortened. The muscle - or the part containing the TP - is commonly in a state of involuntary tension, or increased 'tone'. At worst, muscle spasm will present around a very nasty and inflamed TP, which can result in cramping(21).
The trigger point presents as either active/'alive' or latent/'sleeping', depending on whether or not it 'refers' pain(3,11,30,32). With an active trigger point (ATP), when you push on the point and try to elicit the 'local twitch response' (an involuntary twitch from the pain of pressing on a sensitive spot), it will begin to cause pain somewhere else in your body on a consistent basis. Latent trigger points (LTPs), on the other hand, are painful only in the area around the TP. The more intense the pain when pressing on the TP, and the more obvious the local twitch response, the greater the likelihood of referred pain being present(12). Sometimes an ATP can even set up 'satellite' TPs in the area to which pain is referred(25).
Apart from finding a sore spot, you can identify a TP in one of three ways:
1. Pain - usually you will start to hurt somewhere(2,4,20,26). Pain may appear at quite a distance from the TP (referred pain) (22,30,32) ; it may surface as a significant injury such as Achilles tendonitis or shoulder impingement(14,16,21) or it may simply hurt like hell in the muscle or joint that has been overloaded. Sometimes the first thing that starts to hurt is a joint associated with a certain muscle: for example, patellofemoral joint pain in the knee may be the first signs of TPs in the vastus lateralis and/or vastus medialis (parts of the quadriceps) muscles.
2. Motor pattern change. Your first indication of a TP may be that things just don't feel 'right'; what was once a smooth action, with power behind it, now feels clumsy and uncoordinated(8, 14, 24). Your lap times are down, and your coach has noticed it too. Somewhere along the line your biomechanics have changed and the firing pattern of your muscles has been altered(32) because muscles with TPs may have a lower firing threshold (i.e. overactive) or a higher threshold (i.e. sluggish and late) because of the pain associated with contracting the muscle.
3. Weakness. A muscle with one or more TPs will lose its strength until the TP is treated(8, 14, 20, 24). This is either because its nerve supply is compromised by the TP(14), or because the TP is causing a pain inhibition (i.e. it hurts to contract the muscle or move a joint associated with it). If a joint is not being sufficiently protected from excessive shear forces by a muscle that is too weak, it will send pain messages, become inflamed and soon start to undergo degenerative changes. In this scenario, it is definitely not enough to just get into the gym and 'work through the pain'. Often the pain will get worse unless the TP is being treated at the same time and joint stability and relearning exercises are prescribed.
What causes trigger points?
Broadly speaking, we can divide the causative factors into three categories, as follows:
1. Overuse - extrinsic factors. These include:
Training errors, such as excessive volume or intensity, rapid increase or sudden change, excessive fatigue and inadequate recovery;
Inadequate preparation - including pre-conditioning, warm-up to stimulate blood-flow, appropriate and sport-specific stretch procedures, brain-stimulating movement drills;
Inadequate massage for sore and tired muscles. The benefits of regular massage have been thoroughly proven and one per week is all you need;
Overhard or soft surfaces. The camber of a running track needs to promote balanced muscle development. Moving from outdoor to an indoor track may also have an impact;
Inappropriate/worn out shoes/equipment;
Environmental conditions - too hot, too humid or too cold - can compromise blood and water flow to muscles, thereby affecting their temperature and the flow of minerals required for muscle/nerve function.
2. Overuse - intrinsic factors. These include:
Poor biomechanics. There is no ideal biomechanical system to aim for, but there are principles that allow muscles to remain balanced on either side of a joint. You may have flat feet or poor posture, but the real issue is whether or not your muscles can support that joint. Some of the best sprinters in the world have flat feet, but those feet are extremely well supported to give their muscles a good biomechanical advantage. Having said that, poor foot biomechanics will require good orthotics (arch supports) to prevent TPs developing in the legs or back(24). Good biomechanics will result in proper muscle balance and, consequently, good muscle performance and joint protection. Whenever a muscle or joint is allowed to move repetitively too far beyond its 'neutral zone', TPs will start developing. Thankfully, the body is very receptive to relearning good movement patterns; with concentrated effort, you will be surprised how well it will adapt to moving in a healthier pattern that will maintain muscle balance and keep TPs at bay;
Muscle fatigue. Repetitive movement or loading beyond a certain point will fatigue a muscle and eventually cause it to break down within its structure, allowing a TP to form. This happens regardless of biomechanical issues. Allow time and other helping factors to give the muscle a good chance of recovery;
Muscle weakness. As above, except that endurance is not the issue but rather the muscle's capacity to produce sufficient force under loading. When you are performing a movement pattern under load, e.g. sprinting from a start, you may not be aware that your gluteus medius isn't strong enough to keep your pelvis in a stable position, so that it is contracting beyond its capacity and developing TPs within it. The first you know about it might be a sore low back or tight, achy hamstrings. Specific strengthening of stability muscles (e.g. abdominals, glutes and scapular and rotator cuff muscles) as well as the more obvious prime mover muscles (e.g. pecs, lats, quads and hams) is essential;
Joint instability/hypermobility. If a joint is no longer constrained by non-contractile tissue (e.g. an ankle that has had a ligament tear) then muscles supporting that joint will be required to overwork to protect the joint from damage. TPs will then develop in that muscle(18, 20, 28);
Lack of muscle flexibility. Generalized muscle tightness will tend to increase the chances of TPs forming(10, 16, 20), but this again has more to do with muscle imbalance around a particular joint. Tightness in specific muscles that are required to be flexible for the demands of the sport - e.g. hamstrings in rugby goal-kickers - will definitely lead to TPs.
3. Non-overuse factors. These include:
Trauma. Muscle trauma such as a partial or full thickness tear of the calf muscle tissue will inevitably cause widespread TPs. They will also need treatment in the process of rehabilitating the muscle tear;
Post-operative factors. TPs often form during rehabilitation after surgery, as a strengthening regime is carried out. This is due to weakness resulting in muscle imbalance. In a recent study(6), 10 patients with ongoing pain after significant surgery to their knee noticed significant improvement after TP treatment;
Nutritional and health factors(8,20,27). Hypothyroidism, folic acid and iron insufficiency are repeatedly cited in TP literature. A host of vitamin and mineral deficiencies may also have an impact (the Bs,Vit C, Ca, K and Mg). It is logical to assume that unhealthy muscle tissue will have poorer regenerative powers and be more susceptible to breakdown;
Psychological factors. Impaired sleep, excessive stress and depression can be related via psychosomatic pathways (i.e. body-brain connections). However, TPs also have an impact on your autonomic nervous system and can themselves cause emotional distress(20).
How to find your own TPs
Make sure you and the affected muscle are completely relaxed, not on stretch, then use one of the following techniques to palpate the TP(20,30):
Flat Palpation. This involves simply moving the fingertip(s) transversely across the muscle fibers with some pressure until a 'taut band' is located. Having found this tight section of the muscle, explore along its length to locate the spot of maximum tenderness with minimum pressure: that is the TP. With some practice it doesn't take long to find the taut bands in a muscle. Don't be too worried about the pain you might elicit, because you can't do yourself any harm here!
Pincer Palpation. Some muscles - e.g. the upper trapezius (neck) or gastrocnemius muscle (calf) - can be lifted from surrounding tissue between the thumb and forefinger to locate the TP. The muscle will usually contain a 'taut band' which contains the TP within it(13,20); if you flick over the right area it should cause a twitch in the muscle or that part of the body, known as the 'local twitch response' (LTR)(3,12,13). If there is no LTR the TP may be more chronic, in which case a part of the muscle will feel like a lumpy rope or knot.
To determine whether the TP is active or latent, apply some firm pressure to the sore area: an ATP will be extremely tender compared to a LTP but, more importantly, it should refer pain to another area in the body. While different TPs refer to different areas, the referred pain pattern is quite similar from person to person. Sometimes a TP needs to be pressed or flicked over for up to 10 seconds before the referred pain becomes evident.
Direct treatment of the TP (as opposed to treating the whole problem, of which the TP is just a part) is relatively straightforward and relies mostly on having 'good hands' that can feel what is happening to the muscle. A muscle that has been released from a TP will feel softer, more malleable and 'loose' to the touch. In this respect, TP treatment is more of an art than a science, in that it relies on the instinct and sensitivity of the therapist as he or she works with the patient. For the same reason, many people end up only 80% better after a course of treatment: it takes persistence and patience (and strong hands!) to stick at it until the TPs are released enough to stop causing pain.
The hands-on treatments
Let's deal first with the different hands-on techniques that can work wonders in easing the pain and stiffness in muscles.
1. Ischemic compression
TPs can be 'deactivated' by temporarily occluding their blood supply and causing a reactive increase in blood supply, effectively flushing out the muscle of inflammatory exudate and pain metabolites, breaking down scar tissue, and reducing muscle tone. The muscle is nourished by the extra flow-through of blood, nerve endings are desensitized, and scar tissue is broken down so that the muscle fibers can move better.
Essentially, this involves applying sustained pressure to the TP with sufficient force and for long enough to slow down the blood supply and force the tension out of the muscle(30). The muscle should be placed in a position of mild stretch, with little or no pain present. The patient must be comfortable and relaxed, and the compression gradually applied with the finger, thumb, or elbow. Such pressure should be relative to how much pain the patient can tolerate, since too much pain will tend to cause tension in the muscle and negate the treatment.
The pressure is gradually applied, maintained, and then gradually released. It can be held for as long as 60 seconds, but the desired effect is usually achieved in 10-20 seconds. The therapist should then pause before gradually reapplying pressure three or four more times, perhaps moving to another part of the muscle if the treated area feels 'looser' or softer to the touch. Initiating pressure on a TP must be done gradually in an effort to minimize increases in tone, and so get closer to the core of the TP. It is important to reproduce the LTR for optimum treatment result(13).
Ischemic compression can be used as a prophylactic (preventive) measure(32) in athletes with LTPs that affect their performance, although the technique must be used carefully in pre-race massage as it can lead to soreness. In a treatment situation, it is my experience that ischemic compression is better for dealing with acute (recently developed, inflamed) TPs than more entrenched and chronic ones, which will need a more vigorous approach.
Most TPs will need a number of treatments to deactivate them(9) and deal with related causal factors. As the TP settles, there will be an accompanying decrease in referred pain and an improvement in other related issues such as weakness, muscle spasm, joint impingement etc. The TP itself should become less sensitive, and it will become harder to find a painful spot.
2. Specific soft tissue mobilizations (SSTM)
SSTM is another manual technique used by physiotherapists to restore a tissue's ability to cope with the loading placed upon it. It uses graded and progressive applications of force, matched as closely as possible to the stage of the healing process, to return the tissue to its previous tensile strength.
This approach has been designed by Glen Hunter(33) to facilitate healing in tissues that have broken down; however, it is my experience that SSTMs can also be effectively used in later stage and chronic TP treatment because of the large stiffness component that characterizes the late stage of TP development.
Following a thorough assessment, an oscillatory force is applied to the site of the lesion or TP, in a direction perpendicular to and on the same plane as the line of its fibers. As with ischemic compressions, the force of the pressure used is dependent on the stage of healing.
3. Frictions
These can be used in the same context as SSTMs - i.e. for later stage treatment when multiple cross-linkages between collagen fibers results in considerable stiffness or scar tissue(7,19,28). Frictions 'free up' scar tissue within a TP, allowing muscle fibers to move more normally, increasing blood flow through the tissue and decreasing nerve sensitivity.
Frictions are performed transversely across the top of the tissue, with some compressive force, for some minutes at a time. Initially pain levels will be quite high, but as the friction progresses it eases off.
4. Massage
The overall treatment of a tight or sore muscle and its TPs can include any or all of the above treatments, as well as more standard massage techniques, such as deep tissue massage (strong longitudinal strokes designed to promote length of tissue) or effleurage (wide sweeping movements that clear the tissue of excess lymphatic fluid). Together they have a rich variety of effects that combine first to treat TPs, then loosen muscle fibers bound by scar tissue, improve overall muscle flexibility, clear any oedema (fluid) collected and restore good nutrition to the muscle via an improved blood supply. A regular sports massage is a superb way to overhaul the muscular system and gain many of these effects, albeit in smaller doses.
Other approaches to TP treatment
1. Stretching. This is a huge topic in itself, but one that must at least be touched on here. There is no doubt that stretching helps prevent TPs from two perspectives:
Warm-up routines. After doing some muscle-warming activity, some sports-specific stretching and drills (call it 'dynamic stretching' if you like), there is no question that you will significantly minimize the formation of TPs through the increased blood flow and consequent malleability and better alignment of muscle fibers and fascia;
Flexibility. Regular 'static stretching' will mean you have that much more 'give' in the joints and soft tissues, reducing the risk of TPs. Conversely, stiff joints will frustrate the muscles operating around them - and that's when muscle or tendon breakdown occurs.
What about stretching to repair the actual TP? This is a tricky one: we know from one study(9) that ischemic compression with stretching is more effective than just doing mobility exercises, and from another(11) that stretching is second only to ischemic compression in its ability to treat TPs. But it can be very difficult to isolate a stretch to a specific portion of the muscle where the TP is located. The conclusion would seem to be that stretching is best used as an adjunct to ischemic compression.
2. Spray and stretch.(30) This involves placing the muscle on stretch and applying cold spray to the length of the muscle in order to reduce the spasm, tension and inflammation that accompanies TP formation.
3.Electrotherapy. Physiotherapists may use ultrasound to improve the rate of healing of the TP(11,30), or they may use 'TENS' or other electrical machines to achieve the same effects. However, all of these therapies are best used as adjuncts to hands-on treatment.
4. Injecting / needling. Relevant literature speaks volumes about the highly effective use of TP injections to achieve the most complete level of resolution of TPs(1,3,5,6,12,20). However, this is the domain of only a few specializing musculoskeletal physicians and sports doctors. First, the point of the needle is directed into the centre of the TP, where it gently divides muscle fibers and scar tissue bound together within the TP; then various mixtures can be injected to produce added benefits - the most notable being 0.5% lidocaine to reduce post-treatment soreness(13).
In one study(15) comparing TP injections with heat, electric stimulation, stretching and relaxation exercises for sufferers of plantar fasciitis (heel pain), treatment time was reduced by a massive 83.9%, and the effects persisted for two years after the treatment.
The bottom line is that some treatments are vastly superior to others. As far as self-treatment is concerned, the most effective technique would be ischemic compression, as it doesn't require too much movement.
While you really cannot go wrong with self-treatment of TPs, always go gently at the start until you have done it a few times and know what to expect. Remember that the pain felt during treatment may be quite strong, but should never be sharp and debilitating. If there is swelling in the area, or if it is warm inside or any nerve problems are present (i.e. pins and needles, numbness or weakness), do not try to treat the injury yourself.
If the history of your injury suggests a muscle tear (i.e. strong sharp pain, swelling/bruising, that occurred suddenly with rapid movement or exertion), you will need to let the injury settle right down and have professional treatment for 2-3 weeks before you begin self-treatment.
Other precautions include making sure you are not pressing on to a major nerve (resulting in pins and needles and, later, numbness and weakness) and not moving too much when the pressure is on the muscle, which can aggravate the problem.
You may be able to obtain a specific device for self-treatment, but for most sports people a tennis or golf ball will easily suffice(10). You treat yourself by lying, rolling, or leaning on the device, as described below, allowing your body weight to help put pressure on the muscle.
If there is stronger or sharper pain with any swelling, the TP is probably an acute one, and 15 minutes of ice wrapped in a damp towel will be of added benefit in helping to prevent further inflammation, numbing nerve endings and reducing muscle spasm.
Light exercise or a brief warm-up is a good prelude to self-treatment with ischemic compression, especially for the more chronic TPs. After the treatment, you can then use heat treatment (a hot water bottle, a warm moist towel or even a soak in the bath) to prevent soreness and promote blood flow(11).
Self-treatment exercises
Low Back Pain. Take an object with which to exert pressure (e.g. a tennis ball) and place it under your back as you lie on the floor facing the ceiling with your knees bent and feet flat on the floor. Make sure the object is in the soft muscular areas on either side of the spine and above the bony edge of the pelvis. Feel it sink into the tight and sore area. Take the same-side knee and hold it with both hands. Now use this as a lever to press your back gently down on to the object as you pull your knee up slowly towards your chest. Spend 10 minutes pressing into all the tight TPs and it should make a huge difference to how loose the area feels. You might even get closer to touching your toes immediately!
Calf pain or cramps(21). Sitting in a chair, cross the sore leg over the other knee but stop when the sore calf rests directly on the other kneecap. Hold the knee of the sore leg with both hands, and allow the sore calf to sink into the other kneecap. Now search for tender and tight bands up and down your calf, spending time putting deep pressure into those you find. Every now and then move your foot around to help pump the blood out of the lower leg.
Heel pain(15,29). I recently read of the idea of sticking a Coke can in the freezer and rolling it under the arch to relieve the pain of plantar fasciitis. Has anyone tried freezing a golf ball (or near equivalent) and using that instead? It would be worth a try because it would be much more specific to treating the TPs in the plantar fascia and intrinsic muscles of the foot.
Hamstring soreness and tightness. Sitting on the edge of a bed or chair so your knees are at the edge, place massage object under your affected hamstring near where it is sore. While not letting your pelvis roll backwards, slowly straighten out the same knee until you feel the object under your hamstring dig deep into the sore area. In this manner treat and explore for other TPs.
NB: If the pain is severe or doesn't abate after a couple of attempts, you'll need an assessment by a physiotherapist because something a little more complex is probably going on.
Summary
So there you have it - the story of trigger points and how they relate to your injuries or lagging performance. Now it is up to you to try some of the ideas for yourself. And when you find a TP and hit the pain barrier at some stage in your home treatment, remember that you are targeting the bulls-eye centre of the problem. Just relax into the 'good pain' and feel the muscle tight spot let go gradually.
Persist with it and you will have learnt the magic key to releasing your muscles to new levels of looseness and power.
Ulrik Larsen
References/ further reading
1. Baldry PE, 'Acupuncture, Trigger points and Muskuloskeletal Pain', 1989
2. Bloomfield et al Editors, 'Science and Medicine in Sport', 2nd, 1995
3. Borg S et al, 'Trigger points and tender points. One and the same? Does injection treatment help?' Rheum Dis Clinics of North America 1996 22(2)
4. Brukner & Khan, 'Clinical Sports Medicine', 1995
5. Esenyel M et al, 'Treatment of Myofascial Pain', Am Jour of Phys Med & Rehab 2000 79(1)
6. Feinberg BI, 'Persistent Pain after total knee arthroplasty: Treatment with manual therapy and trigger point injections', J of Muskuloskeletal Pain 1998 6(4)
7. Formby & Mellion, 'Identifying and Treating Myofascial Pain Syndrome', The Physician & Sports Med Vol 25 No2 1997
8. Gerwin R, 'The management Myofascial Pain Syndromes', J Muskuloskeletal Pain 1993 1(3-4)
9. Hanten WP et al, 'Effects of active head retraction with retraction/extension and occipital release on the pressure pain threshold of cervical and scapular trigger points', Physiotherapy Theory and Practice 1997 13(4)
10. Hanten WP, 'Effectiveness of a home programme of ischaemic pressure followed by sustained stretch for treatment of myofascial trigger points', Physical Therapy 2000 80(10)
11. Hong CZ et al, 'Immediate effects of various physical medicine modalities on pain threshold of an active myofascial trigger point', J of Muskuloskeletal Pain 1993 1(2)
12. Hong CZ et al, 'Referred pain elicited by palpation and by needling of myofascial trigger points: A comparison', Arch Phys Med &Rehab 1997 78(9)
13. Hong CZ, 'Lidocaine injection versus dry needling to myofascial trigger point: the importance of the local twitch response', Am J of Physical Med & Rehab 1994 73(4)
14. Hoven et al, 'Management of peroneal nerve entrapment in an elite skier: A Case Report', J of Sports Chiropractic and Rehab 2000 14(3)
15. Imamura et al, 'Treatment of myofascial pain components in plantar fasciitis speeds up recovery', J of Muskuloskeletal Pain 198 6(1)
16. Ingber RS, 'Shoulder Impingement in tennis/racquetball players treated with subscapularis myofascial treatments', Arch of Physical Med & Rehab 2000 81(5)
17. Lew et al, 'Inter-therapist reliability in locating latent myofascial trigger points using palpation', Manual Therapy 2(2)1997
18. Lewit K, 'Manipulative Therapy in rehabilitation of the motor system', 1985
19. Manheim C, 'The Myofascial Release Manual', 1994 2nd Ed
20. Perle DC, 'Clinicians Corner: Myofascial Trigger points', Chir Sports Med Vol 9 No3,1995
21. Prateepavanich P et al, 'The relationship between myofascial trigger points of gastrocnemius muscle and nocturnal calf cramps', Jour of the Med Assoc of Thailand 1999 82(2)
22. Quinter JL, 'Referred pain of peripheral nerve origin: An alternative to the 'myofascial pain' construct', Clin Jour of Pain 1994 10(3)
23. Ruscoe G, 'Trigger points and Muskuloskeletal Pain', 1996
24. Saggini R et al, 'Myofascial Pain syndrome of the peroneus longus : A biomechanical approach', Clinical Jour of Pain 1996 12(1)
25. Schneider MJ, 'Snapping hip syndrome in a marathon runner: Treatment by manual trigger point therapy. A Case study', Chiropractic Sports Med 1990 4(2)
26. Sheon, Moskowitz & Goldberg, 'Soft Tissue Rheumatic Pain', 1987
27. Sonkin LS, 'Therapeutic Trials with thyroid hormone in chemically euthyroid patients with myofascial pain and complaints suggesting mild thyroid insufficiency', J of Back & Muskuloskeletal Rehab 1997 8(2)
28. Stoddard A, 'Manual Of Osteopathic Practice', 1974
29. Tillu A, 'Effect of acupuncture treatment on heel pain due to plantar fasciitis', Acupuncture in Medicine 1998 16(2)
30. Travell & Simons, 'The Trigger Point Manual', 1983
31. Vanderween et al, 'Pressure algometry in manual therapy', Manual Therapy 1(5)1996
32. Vecchiet L et al, 'Latent myofascial trigger points: Changes in muscular and subcutaneous pain thresholds at trigger point and target level', J of Manual Medicine 5(4) 1990
33. Hunter G, 1998. 'Specific soft tissue mobilization in the management of soft tissue dysfunction.' Manual Therapy 3(1) 2-11
Courtesy of http://www.pponline.co.uk/
Picture a rubber band with a small section that has lost its elasticity, and instead has become hardened and rather brittle. That's what a trigger point is like: the muscle is tighter, stiffer, will often be weaker and yet very tense at the same time. A TP will be sore when you push on it, and you may feel a thick band that you can flick over with your fingers.
A vast number of sports injuries of all kinds have their genesis in the development of a TP in the muscle or fascia. This TP is very commonly the first sign of overload, and from then on, cause and effect begin to domino: one tissue breaks down, causing another to be overloaded and then break down, and so on. Trigger points lead to inflammation, then pain, then weakness, then joint and nerve dysfunction, and finally structural breakdown of tissues and a severe sports injury that can keep you out of action for weeks, months or even years, depending on how long you attempt to struggle on without treating the original TP.
A TP is thus an alarm bell - a first warning sign that things are not well within your biomechanical system. Learning to listen to your body's alarm bells is a critical skill that can avoid many injuries. Often athletes, with their enhanced overall body sense, become aware of TPs before they are significant enough to cause actual pain(32), when the only complaint is 'tightness' or the joint or muscle doesn't 'feel right'(20).
Arguably, all sports people will develop TPs at some stage in their sporting career. These may hamper our performance and slow us down for a while, or they may blow out to cause a severe injury. They are a normal part of training and competing because our bodies are biomechanically imperfect and our environments more random than we would like them to be. In a perfect world, our bodies would not break down when overloaded - and the football pitch would be just soft enough to prevent stress fractures, yet hard enough to prevent ligament tears when we run over a pothole in the grass. But it just isn�t so!
To all intents and purposes, a TP is simply a thick knot in the muscle - a way the muscle reacts to being overloaded. In some ways, a TP is the equivalent of a stress fracture in a bone. More specifically, a TP is a palpable, tender, nodal point of muscle or fascia. It may also be found in skin, where scar tissue is present, in old ligament injuries or, occasionally, in periosteum (the lining of bone). Under a microscope, TPs appear darker, straightened out and thicker, ranging in diameter from 1-4mm. If located in muscle, they cause it to form taut bands or become 'ropey'. A focal area of inflammation develops fairly early on and a collagen matrix forms; scar tissue is laid down to bridge the weak link, and can become quite thickened and tough, depending on how long it has been present(3,7,8,19,20,23,28). The muscle in which a TP is found will usually be weakened and shortened. The muscle - or the part containing the TP - is commonly in a state of involuntary tension, or increased 'tone'. At worst, muscle spasm will present around a very nasty and inflamed TP, which can result in cramping(21).
The trigger point presents as either active/'alive' or latent/'sleeping', depending on whether or not it 'refers' pain(3,11,30,32). With an active trigger point (ATP), when you push on the point and try to elicit the 'local twitch response' (an involuntary twitch from the pain of pressing on a sensitive spot), it will begin to cause pain somewhere else in your body on a consistent basis. Latent trigger points (LTPs), on the other hand, are painful only in the area around the TP. The more intense the pain when pressing on the TP, and the more obvious the local twitch response, the greater the likelihood of referred pain being present(12). Sometimes an ATP can even set up 'satellite' TPs in the area to which pain is referred(25).
Apart from finding a sore spot, you can identify a TP in one of three ways:
1. Pain - usually you will start to hurt somewhere(2,4,20,26). Pain may appear at quite a distance from the TP (referred pain) (22,30,32) ; it may surface as a significant injury such as Achilles tendonitis or shoulder impingement(14,16,21) or it may simply hurt like hell in the muscle or joint that has been overloaded. Sometimes the first thing that starts to hurt is a joint associated with a certain muscle: for example, patellofemoral joint pain in the knee may be the first signs of TPs in the vastus lateralis and/or vastus medialis (parts of the quadriceps) muscles.
2. Motor pattern change. Your first indication of a TP may be that things just don't feel 'right'; what was once a smooth action, with power behind it, now feels clumsy and uncoordinated(8, 14, 24). Your lap times are down, and your coach has noticed it too. Somewhere along the line your biomechanics have changed and the firing pattern of your muscles has been altered(32) because muscles with TPs may have a lower firing threshold (i.e. overactive) or a higher threshold (i.e. sluggish and late) because of the pain associated with contracting the muscle.
3. Weakness. A muscle with one or more TPs will lose its strength until the TP is treated(8, 14, 20, 24). This is either because its nerve supply is compromised by the TP(14), or because the TP is causing a pain inhibition (i.e. it hurts to contract the muscle or move a joint associated with it). If a joint is not being sufficiently protected from excessive shear forces by a muscle that is too weak, it will send pain messages, become inflamed and soon start to undergo degenerative changes. In this scenario, it is definitely not enough to just get into the gym and 'work through the pain'. Often the pain will get worse unless the TP is being treated at the same time and joint stability and relearning exercises are prescribed.
What causes trigger points?
Broadly speaking, we can divide the causative factors into three categories, as follows:
1. Overuse - extrinsic factors. These include:
Training errors, such as excessive volume or intensity, rapid increase or sudden change, excessive fatigue and inadequate recovery;
Inadequate preparation - including pre-conditioning, warm-up to stimulate blood-flow, appropriate and sport-specific stretch procedures, brain-stimulating movement drills;
Inadequate massage for sore and tired muscles. The benefits of regular massage have been thoroughly proven and one per week is all you need;
Overhard or soft surfaces. The camber of a running track needs to promote balanced muscle development. Moving from outdoor to an indoor track may also have an impact;
Inappropriate/worn out shoes/equipment;
Environmental conditions - too hot, too humid or too cold - can compromise blood and water flow to muscles, thereby affecting their temperature and the flow of minerals required for muscle/nerve function.
2. Overuse - intrinsic factors. These include:
Poor biomechanics. There is no ideal biomechanical system to aim for, but there are principles that allow muscles to remain balanced on either side of a joint. You may have flat feet or poor posture, but the real issue is whether or not your muscles can support that joint. Some of the best sprinters in the world have flat feet, but those feet are extremely well supported to give their muscles a good biomechanical advantage. Having said that, poor foot biomechanics will require good orthotics (arch supports) to prevent TPs developing in the legs or back(24). Good biomechanics will result in proper muscle balance and, consequently, good muscle performance and joint protection. Whenever a muscle or joint is allowed to move repetitively too far beyond its 'neutral zone', TPs will start developing. Thankfully, the body is very receptive to relearning good movement patterns; with concentrated effort, you will be surprised how well it will adapt to moving in a healthier pattern that will maintain muscle balance and keep TPs at bay;
Muscle fatigue. Repetitive movement or loading beyond a certain point will fatigue a muscle and eventually cause it to break down within its structure, allowing a TP to form. This happens regardless of biomechanical issues. Allow time and other helping factors to give the muscle a good chance of recovery;
Muscle weakness. As above, except that endurance is not the issue but rather the muscle's capacity to produce sufficient force under loading. When you are performing a movement pattern under load, e.g. sprinting from a start, you may not be aware that your gluteus medius isn't strong enough to keep your pelvis in a stable position, so that it is contracting beyond its capacity and developing TPs within it. The first you know about it might be a sore low back or tight, achy hamstrings. Specific strengthening of stability muscles (e.g. abdominals, glutes and scapular and rotator cuff muscles) as well as the more obvious prime mover muscles (e.g. pecs, lats, quads and hams) is essential;
Joint instability/hypermobility. If a joint is no longer constrained by non-contractile tissue (e.g. an ankle that has had a ligament tear) then muscles supporting that joint will be required to overwork to protect the joint from damage. TPs will then develop in that muscle(18, 20, 28);
Lack of muscle flexibility. Generalized muscle tightness will tend to increase the chances of TPs forming(10, 16, 20), but this again has more to do with muscle imbalance around a particular joint. Tightness in specific muscles that are required to be flexible for the demands of the sport - e.g. hamstrings in rugby goal-kickers - will definitely lead to TPs.
3. Non-overuse factors. These include:
Trauma. Muscle trauma such as a partial or full thickness tear of the calf muscle tissue will inevitably cause widespread TPs. They will also need treatment in the process of rehabilitating the muscle tear;
Post-operative factors. TPs often form during rehabilitation after surgery, as a strengthening regime is carried out. This is due to weakness resulting in muscle imbalance. In a recent study(6), 10 patients with ongoing pain after significant surgery to their knee noticed significant improvement after TP treatment;
Nutritional and health factors(8,20,27). Hypothyroidism, folic acid and iron insufficiency are repeatedly cited in TP literature. A host of vitamin and mineral deficiencies may also have an impact (the Bs,Vit C, Ca, K and Mg). It is logical to assume that unhealthy muscle tissue will have poorer regenerative powers and be more susceptible to breakdown;
Psychological factors. Impaired sleep, excessive stress and depression can be related via psychosomatic pathways (i.e. body-brain connections). However, TPs also have an impact on your autonomic nervous system and can themselves cause emotional distress(20).
How to find your own TPs
Make sure you and the affected muscle are completely relaxed, not on stretch, then use one of the following techniques to palpate the TP(20,30):
Flat Palpation. This involves simply moving the fingertip(s) transversely across the muscle fibers with some pressure until a 'taut band' is located. Having found this tight section of the muscle, explore along its length to locate the spot of maximum tenderness with minimum pressure: that is the TP. With some practice it doesn't take long to find the taut bands in a muscle. Don't be too worried about the pain you might elicit, because you can't do yourself any harm here!
Pincer Palpation. Some muscles - e.g. the upper trapezius (neck) or gastrocnemius muscle (calf) - can be lifted from surrounding tissue between the thumb and forefinger to locate the TP. The muscle will usually contain a 'taut band' which contains the TP within it(13,20); if you flick over the right area it should cause a twitch in the muscle or that part of the body, known as the 'local twitch response' (LTR)(3,12,13). If there is no LTR the TP may be more chronic, in which case a part of the muscle will feel like a lumpy rope or knot.
To determine whether the TP is active or latent, apply some firm pressure to the sore area: an ATP will be extremely tender compared to a LTP but, more importantly, it should refer pain to another area in the body. While different TPs refer to different areas, the referred pain pattern is quite similar from person to person. Sometimes a TP needs to be pressed or flicked over for up to 10 seconds before the referred pain becomes evident.
Direct treatment of the TP (as opposed to treating the whole problem, of which the TP is just a part) is relatively straightforward and relies mostly on having 'good hands' that can feel what is happening to the muscle. A muscle that has been released from a TP will feel softer, more malleable and 'loose' to the touch. In this respect, TP treatment is more of an art than a science, in that it relies on the instinct and sensitivity of the therapist as he or she works with the patient. For the same reason, many people end up only 80% better after a course of treatment: it takes persistence and patience (and strong hands!) to stick at it until the TPs are released enough to stop causing pain.
The hands-on treatments
Let's deal first with the different hands-on techniques that can work wonders in easing the pain and stiffness in muscles.
1. Ischemic compression
TPs can be 'deactivated' by temporarily occluding their blood supply and causing a reactive increase in blood supply, effectively flushing out the muscle of inflammatory exudate and pain metabolites, breaking down scar tissue, and reducing muscle tone. The muscle is nourished by the extra flow-through of blood, nerve endings are desensitized, and scar tissue is broken down so that the muscle fibers can move better.
Essentially, this involves applying sustained pressure to the TP with sufficient force and for long enough to slow down the blood supply and force the tension out of the muscle(30). The muscle should be placed in a position of mild stretch, with little or no pain present. The patient must be comfortable and relaxed, and the compression gradually applied with the finger, thumb, or elbow. Such pressure should be relative to how much pain the patient can tolerate, since too much pain will tend to cause tension in the muscle and negate the treatment.
The pressure is gradually applied, maintained, and then gradually released. It can be held for as long as 60 seconds, but the desired effect is usually achieved in 10-20 seconds. The therapist should then pause before gradually reapplying pressure three or four more times, perhaps moving to another part of the muscle if the treated area feels 'looser' or softer to the touch. Initiating pressure on a TP must be done gradually in an effort to minimize increases in tone, and so get closer to the core of the TP. It is important to reproduce the LTR for optimum treatment result(13).
Ischemic compression can be used as a prophylactic (preventive) measure(32) in athletes with LTPs that affect their performance, although the technique must be used carefully in pre-race massage as it can lead to soreness. In a treatment situation, it is my experience that ischemic compression is better for dealing with acute (recently developed, inflamed) TPs than more entrenched and chronic ones, which will need a more vigorous approach.
Most TPs will need a number of treatments to deactivate them(9) and deal with related causal factors. As the TP settles, there will be an accompanying decrease in referred pain and an improvement in other related issues such as weakness, muscle spasm, joint impingement etc. The TP itself should become less sensitive, and it will become harder to find a painful spot.
2. Specific soft tissue mobilizations (SSTM)
SSTM is another manual technique used by physiotherapists to restore a tissue's ability to cope with the loading placed upon it. It uses graded and progressive applications of force, matched as closely as possible to the stage of the healing process, to return the tissue to its previous tensile strength.
This approach has been designed by Glen Hunter(33) to facilitate healing in tissues that have broken down; however, it is my experience that SSTMs can also be effectively used in later stage and chronic TP treatment because of the large stiffness component that characterizes the late stage of TP development.
Following a thorough assessment, an oscillatory force is applied to the site of the lesion or TP, in a direction perpendicular to and on the same plane as the line of its fibers. As with ischemic compressions, the force of the pressure used is dependent on the stage of healing.
3. Frictions
These can be used in the same context as SSTMs - i.e. for later stage treatment when multiple cross-linkages between collagen fibers results in considerable stiffness or scar tissue(7,19,28). Frictions 'free up' scar tissue within a TP, allowing muscle fibers to move more normally, increasing blood flow through the tissue and decreasing nerve sensitivity.
Frictions are performed transversely across the top of the tissue, with some compressive force, for some minutes at a time. Initially pain levels will be quite high, but as the friction progresses it eases off.
4. Massage
The overall treatment of a tight or sore muscle and its TPs can include any or all of the above treatments, as well as more standard massage techniques, such as deep tissue massage (strong longitudinal strokes designed to promote length of tissue) or effleurage (wide sweeping movements that clear the tissue of excess lymphatic fluid). Together they have a rich variety of effects that combine first to treat TPs, then loosen muscle fibers bound by scar tissue, improve overall muscle flexibility, clear any oedema (fluid) collected and restore good nutrition to the muscle via an improved blood supply. A regular sports massage is a superb way to overhaul the muscular system and gain many of these effects, albeit in smaller doses.
Other approaches to TP treatment
1. Stretching. This is a huge topic in itself, but one that must at least be touched on here. There is no doubt that stretching helps prevent TPs from two perspectives:
Warm-up routines. After doing some muscle-warming activity, some sports-specific stretching and drills (call it 'dynamic stretching' if you like), there is no question that you will significantly minimize the formation of TPs through the increased blood flow and consequent malleability and better alignment of muscle fibers and fascia;
Flexibility. Regular 'static stretching' will mean you have that much more 'give' in the joints and soft tissues, reducing the risk of TPs. Conversely, stiff joints will frustrate the muscles operating around them - and that's when muscle or tendon breakdown occurs.
What about stretching to repair the actual TP? This is a tricky one: we know from one study(9) that ischemic compression with stretching is more effective than just doing mobility exercises, and from another(11) that stretching is second only to ischemic compression in its ability to treat TPs. But it can be very difficult to isolate a stretch to a specific portion of the muscle where the TP is located. The conclusion would seem to be that stretching is best used as an adjunct to ischemic compression.
2. Spray and stretch.(30) This involves placing the muscle on stretch and applying cold spray to the length of the muscle in order to reduce the spasm, tension and inflammation that accompanies TP formation.
3.Electrotherapy. Physiotherapists may use ultrasound to improve the rate of healing of the TP(11,30), or they may use 'TENS' or other electrical machines to achieve the same effects. However, all of these therapies are best used as adjuncts to hands-on treatment.
4. Injecting / needling. Relevant literature speaks volumes about the highly effective use of TP injections to achieve the most complete level of resolution of TPs(1,3,5,6,12,20). However, this is the domain of only a few specializing musculoskeletal physicians and sports doctors. First, the point of the needle is directed into the centre of the TP, where it gently divides muscle fibers and scar tissue bound together within the TP; then various mixtures can be injected to produce added benefits - the most notable being 0.5% lidocaine to reduce post-treatment soreness(13).
In one study(15) comparing TP injections with heat, electric stimulation, stretching and relaxation exercises for sufferers of plantar fasciitis (heel pain), treatment time was reduced by a massive 83.9%, and the effects persisted for two years after the treatment.
The bottom line is that some treatments are vastly superior to others. As far as self-treatment is concerned, the most effective technique would be ischemic compression, as it doesn't require too much movement.
While you really cannot go wrong with self-treatment of TPs, always go gently at the start until you have done it a few times and know what to expect. Remember that the pain felt during treatment may be quite strong, but should never be sharp and debilitating. If there is swelling in the area, or if it is warm inside or any nerve problems are present (i.e. pins and needles, numbness or weakness), do not try to treat the injury yourself.
If the history of your injury suggests a muscle tear (i.e. strong sharp pain, swelling/bruising, that occurred suddenly with rapid movement or exertion), you will need to let the injury settle right down and have professional treatment for 2-3 weeks before you begin self-treatment.
Other precautions include making sure you are not pressing on to a major nerve (resulting in pins and needles and, later, numbness and weakness) and not moving too much when the pressure is on the muscle, which can aggravate the problem.
You may be able to obtain a specific device for self-treatment, but for most sports people a tennis or golf ball will easily suffice(10). You treat yourself by lying, rolling, or leaning on the device, as described below, allowing your body weight to help put pressure on the muscle.
If there is stronger or sharper pain with any swelling, the TP is probably an acute one, and 15 minutes of ice wrapped in a damp towel will be of added benefit in helping to prevent further inflammation, numbing nerve endings and reducing muscle spasm.
Light exercise or a brief warm-up is a good prelude to self-treatment with ischemic compression, especially for the more chronic TPs. After the treatment, you can then use heat treatment (a hot water bottle, a warm moist towel or even a soak in the bath) to prevent soreness and promote blood flow(11).
Self-treatment exercises
Low Back Pain. Take an object with which to exert pressure (e.g. a tennis ball) and place it under your back as you lie on the floor facing the ceiling with your knees bent and feet flat on the floor. Make sure the object is in the soft muscular areas on either side of the spine and above the bony edge of the pelvis. Feel it sink into the tight and sore area. Take the same-side knee and hold it with both hands. Now use this as a lever to press your back gently down on to the object as you pull your knee up slowly towards your chest. Spend 10 minutes pressing into all the tight TPs and it should make a huge difference to how loose the area feels. You might even get closer to touching your toes immediately!
Calf pain or cramps(21). Sitting in a chair, cross the sore leg over the other knee but stop when the sore calf rests directly on the other kneecap. Hold the knee of the sore leg with both hands, and allow the sore calf to sink into the other kneecap. Now search for tender and tight bands up and down your calf, spending time putting deep pressure into those you find. Every now and then move your foot around to help pump the blood out of the lower leg.
Heel pain(15,29). I recently read of the idea of sticking a Coke can in the freezer and rolling it under the arch to relieve the pain of plantar fasciitis. Has anyone tried freezing a golf ball (or near equivalent) and using that instead? It would be worth a try because it would be much more specific to treating the TPs in the plantar fascia and intrinsic muscles of the foot.
Hamstring soreness and tightness. Sitting on the edge of a bed or chair so your knees are at the edge, place massage object under your affected hamstring near where it is sore. While not letting your pelvis roll backwards, slowly straighten out the same knee until you feel the object under your hamstring dig deep into the sore area. In this manner treat and explore for other TPs.
NB: If the pain is severe or doesn't abate after a couple of attempts, you'll need an assessment by a physiotherapist because something a little more complex is probably going on.
Summary
So there you have it - the story of trigger points and how they relate to your injuries or lagging performance. Now it is up to you to try some of the ideas for yourself. And when you find a TP and hit the pain barrier at some stage in your home treatment, remember that you are targeting the bulls-eye centre of the problem. Just relax into the 'good pain' and feel the muscle tight spot let go gradually.
Persist with it and you will have learnt the magic key to releasing your muscles to new levels of looseness and power.
Ulrik Larsen
References/ further reading
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2. Bloomfield et al Editors, 'Science and Medicine in Sport', 2nd, 1995
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4. Brukner & Khan, 'Clinical Sports Medicine', 1995
5. Esenyel M et al, 'Treatment of Myofascial Pain', Am Jour of Phys Med & Rehab 2000 79(1)
6. Feinberg BI, 'Persistent Pain after total knee arthroplasty: Treatment with manual therapy and trigger point injections', J of Muskuloskeletal Pain 1998 6(4)
7. Formby & Mellion, 'Identifying and Treating Myofascial Pain Syndrome', The Physician & Sports Med Vol 25 No2 1997
8. Gerwin R, 'The management Myofascial Pain Syndromes', J Muskuloskeletal Pain 1993 1(3-4)
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10. Hanten WP, 'Effectiveness of a home programme of ischaemic pressure followed by sustained stretch for treatment of myofascial trigger points', Physical Therapy 2000 80(10)
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13. Hong CZ, 'Lidocaine injection versus dry needling to myofascial trigger point: the importance of the local twitch response', Am J of Physical Med & Rehab 1994 73(4)
14. Hoven et al, 'Management of peroneal nerve entrapment in an elite skier: A Case Report', J of Sports Chiropractic and Rehab 2000 14(3)
15. Imamura et al, 'Treatment of myofascial pain components in plantar fasciitis speeds up recovery', J of Muskuloskeletal Pain 198 6(1)
16. Ingber RS, 'Shoulder Impingement in tennis/racquetball players treated with subscapularis myofascial treatments', Arch of Physical Med & Rehab 2000 81(5)
17. Lew et al, 'Inter-therapist reliability in locating latent myofascial trigger points using palpation', Manual Therapy 2(2)1997
18. Lewit K, 'Manipulative Therapy in rehabilitation of the motor system', 1985
19. Manheim C, 'The Myofascial Release Manual', 1994 2nd Ed
20. Perle DC, 'Clinicians Corner: Myofascial Trigger points', Chir Sports Med Vol 9 No3,1995
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22. Quinter JL, 'Referred pain of peripheral nerve origin: An alternative to the 'myofascial pain' construct', Clin Jour of Pain 1994 10(3)
23. Ruscoe G, 'Trigger points and Muskuloskeletal Pain', 1996
24. Saggini R et al, 'Myofascial Pain syndrome of the peroneus longus : A biomechanical approach', Clinical Jour of Pain 1996 12(1)
25. Schneider MJ, 'Snapping hip syndrome in a marathon runner: Treatment by manual trigger point therapy. A Case study', Chiropractic Sports Med 1990 4(2)
26. Sheon, Moskowitz & Goldberg, 'Soft Tissue Rheumatic Pain', 1987
27. Sonkin LS, 'Therapeutic Trials with thyroid hormone in chemically euthyroid patients with myofascial pain and complaints suggesting mild thyroid insufficiency', J of Back & Muskuloskeletal Rehab 1997 8(2)
28. Stoddard A, 'Manual Of Osteopathic Practice', 1974
29. Tillu A, 'Effect of acupuncture treatment on heel pain due to plantar fasciitis', Acupuncture in Medicine 1998 16(2)
30. Travell & Simons, 'The Trigger Point Manual', 1983
31. Vanderween et al, 'Pressure algometry in manual therapy', Manual Therapy 1(5)1996
32. Vecchiet L et al, 'Latent myofascial trigger points: Changes in muscular and subcutaneous pain thresholds at trigger point and target level', J of Manual Medicine 5(4) 1990
33. Hunter G, 1998. 'Specific soft tissue mobilization in the management of soft tissue dysfunction.' Manual Therapy 3(1) 2-11
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