Trigger Points Definition And Types Health And Social Care Essay

Primary trigger points develop independently and non as the consequence of trigger point activity elsewhere. Secondary trigger points may develop in counter musculuss and neighbouring protective musculuss as a effect of emphasis and musculus cramp. It is normally experienced in patients after primary trigger point riddance.

Satellite trigger points may develop in the country of referred hurting as a consequence of relentless resting motor unit activity in the musculus. Generation of trigger points consequences from the development of secondary and satellite trigger points. This concatenation reaction of trigger point generation may be elicited by many factors, including musculus failing, tenseness, and postural abnormalcies. ( 1 )

Active trigger points are considered stamp, painful, and diagnostic with hurting at remainder and during gesture. There are two common reactions seen in patients when feeling active trigger points. The first 1 is a seeable “ local vellication response ” of the musculus or tegument. The 2nd reaction is known as the “ leap response ” , where the patient tends to leap or travel off from the healer ‘s palpating manus during scrutiny. Palpation of a trigger point causes a local or specific referred hurting form, which is limited to primary trigger points. A thorough cognition and apprehension of referred hurting forms are necessary to forestall any errors when handling trigger points ( orbiter ) in the referred hurting countries and neglecting to detect the primary trigger point ( 1 )

Latent trigger points are normally found coincidentally on tactual exploration. They are described as symptomless and do non necessitate intervention unless they are activated. Latent trigger points are stamp and may show a local vellication response. Latent trigger points may be a cause of musculus shortening and failing even though they are non painful. Latent trigger points are largely found in the country of the shoulder girdle, aiming the cowl muscle and levator shoulder blade musculuss. ( 1 )

Gun trigger Points: History and Literature Review

Gun trigger points were first described and mapped by Janet G. Travell, MD in the 1940 ‘s. Later in old ages, Drs. Travell and David Simons both wrote the text edition on Trigger point Therapy: Myofascial Pain and Dysfunction: The Trigger Point Manual. Sixty old ages of medical research has shown that trigger point therapy relieves hurting, nevertheless the medical community has been slow to advance its usage. ( 2 )

In 2007, a reappraisal of diagnostic standards used in surveies of trigger points concluded that there is yet limited consensus on the definition of myofascial trigger point hurting syndrome. Further research is required in order to prove the dependability and cogency of both the diagnostic standards and the effectivity of intervention intercessions. ( 3 )

In 1942, Dr. Janet Travell foremost used the term “ trigger point ” to depict a clinical determination which holds the undermentioned features:

Pain related to a discrete, cranky point in skeletal musculus or facia, non caused by acute local injury, redness, devolution, tumor or infection.

A painful point or a tumour is felt in the musculus that can arouse a vellication response upon stimulation.

Palpation of the trigger point reproduces the patient ‘s symptoms of hurting which can radiate typical of the specific musculus incorporating the trigger point.

Neurological scrutiny findings can non explicate the trigger point hurting behaviour.

The history associated with trigger points suggested many thoughts on how they are formed and why they cause hurting. It was one time believed that trigger points were inflammatory cicatrixs in the musculus. However, biopsies disproved this when they showed no abnormalcies.

More late, it has been claimed that trigger points are spasms or contractures of voluntary musculuss, likely caused by an abnormalcy at the neuromuscular junction where the nervousnesss commanding musculuss connect to the musculus fibres ( Travell & A ; Simons, 1999 ) . However this theory seems dubious since no contractions of voluntary musculus appear to be identified by traditional EMG and since the trigger points are frequently off from the site of the neuromuscular junction. ( 4 )

The most recent suggested mechanism is that trigger points are muscle spindles, which are activated by adrenalin stimulation. These, 1 centimeter in length, musculus fibres, are called intrafusal musculus fibres separating them from the voluntary musculus fibres, which are known as extrafusal musculus fibres. The intrafusal musculus fibres inside the spindle alone are stimulated by epinephrine through the sympathetic nervous system. The “ sympathetic spindle cramp ” theory of trigger points proposes that when spindles are over-stimulated by epinephrine they become painful. The diagrams below illustrate the difference between intrafusal and extrafusal musculus fibres: ( 4 )

Figure1- Muscle spindles: Intrafusal and extrafusal fibres

Figure2- Neural Circiut ( intrafusal/sensory and extrafusal/motor )

The most acknowledged theory that explains the trigger point mechanism suggests that the muscular overload leads to a drawn-out release of Ca2+ ion from the sarcoplasmic Reticulum, storage unit for the musculus cell, ensuing in a sticking of the untrained or overladen cells. This causes a contracture with compaction of capillaries, increasing local energy demand and local ischaemia to the country. This “ energy crisis ” causes the release of chemicals that enhance hurting activity. As a consequence of this activity, the involved musculus is weakened therefore leting the environing musculuss to develop trigger points in a compensatory mode ( 4 )

Gun trigger Points: The Travell and Simons Model

This theoretical account presently represents the most normally recognized account as to the etiology of trigger points. They suggest the followers ( 5 ) :

Dysfunctional end-plate activity occur, largely associated with a strain, taking to an inordinate release of acetylcholine ( Ach ) at the synapse, along with stored Ca

High Ca degrees maintain the calcium-charged Gatess unfastened, while the Ach continue to be released

An oxygen/nutrient shortage is created as a consequence from ischaemia in the country, which in bend leads to a local energy crisis

Without available ATP, the local tissue is unable to rinse out the accrued Ca ions which are ‘keeping the Gatess open ‘ for Ach to go on being released

Washing out the overruning Ca needs more energy than prolonging a contracture, so the contracture remains

The ensuing muscle-fiber contracture ( nonvoluntary, without motor potencies ) is different from a contraction ( voluntary with motor potencies )

The contracture is maintained by the chemical science at the excitation country, non by action potencies from the cord

While the endplate supports bring forthing Ach flow, the actin/myosin fibrils assume a to the full shortened place ( a weakened province ) in the immediate country around the motor end-plate ( at the centre of the fibre )

This knot is the ‘nodule ‘ which is the tangible feature of a trigger point

As this procedure occurs, the balance of the sarcomeres of that fibre are stretched, making the taut nodule, which can normally be palpated ( 5 )

In 2008, a reappraisal in The Archivess of Physical Medicine and Rehabilitation concludes that Travell and Simons incorporate hypothesis is the most sure and most complete suggested etiology of myofascial trigger points. However, the feedback cringle proposed in this hypothesis has some weak links, and surveies by Shah and co-workers peculiarly provide a solid nexus for one of them. The feedback cringle connects the hypothesized energy crisis with the surroundings changes responsible for noxious stimulation of local nociceptors that leads to the local and referred hurting of myofascial trigger points. Shah ‘s studies quantify the presence of non merely 1 noxious stimulation but 11 of them with great concentrations of immune system chemicals. The consequences besides strongly put a important clinical differentiation between active and latent trigger points. Subjects with active trigger points in the musculus have a biochemical surroundings of selected inflammatory go-betweens, neuropeptides, cytokines, and catecholamines unlike those in topics kicking of latent or absent trigger points. ( 6 )

Causes of Trigger Points

Janet Travell and David Simons have confirmed that the undermentioned factors contribute to heightening and keeping trigger point activity:

Nutritional lack, particularly vitamin C, B-complex and Fe

Hormonal instabilities ( low thyroid, menopausal or premenstrual state of affairss, for case )

Infections ( bacteriums, viruses or barm )

Allergies ( wheat and dairy in peculiar )

Low oxygenation of tissues

The reverberations of trigger point activity are far from a simple musculoskeletal hurting. They can be accompanied by hyperventilation and chronic weariness every bit good as evident pelvic inflammatory disease ( 5 )

Gun trigger Points and Breathing Dysfunction:

Trigger point activity is often found in the musculuss of the neckshoulder part which besides act as accessary external respiration musculuss, the scalenes in peculiar. In the event of chronic weariness and increased anxiousness, hyperventilation occurs, which can be associated with a assortment of secondary symptoms including concerns, cervix, shoulder and arm hurting, along with giddiness, palpitation, fainting, and digestive symptoms. ( 5 )

Clinically, where upper thorax fixators of the shoulder and intercostals, thoracic and paraspinal musculuss of the pectoral part are likely to feel as tense, fibrotic, with engagement of active trigger points. Successful take a breathing retraining and standardization of energy degrees seems in such instances to be accelerated following initial standardization of the functional unity of the accessary musculuss of respiration, whether straight or indirectly ( latissimus dorsi, psoas, quadratus lumborum ) ( 5 )

Gun trigger Points and Referred Pain:

Harmonizing to the medical lexicon of Dorland, referred hurting is a term used to depict the phenomenon of hurting perceived at a site next to or at a distance from the site of an hurt ‘s beginning ( 7 ) and harmonizing to physicians Janet Travell and David Simons, referred hurting is the specifying symptom of trigger points. The ground why many conventional interventions of hurting frequently fail is because referred hurting is a deceptive phenomenon. It ‘s a error to presume that the job is precisely at the topographic point that hurts.

Travell and Simons ‘s research has shown that trigger points are the primary cause of hurting 75 % of the clip. Trigger points may do concerns, cervix and jaw hurting, low back hurting, tennis cubitus, and carpal tunnel syndrome. They are oftenly mistaken for arthritis, tendinoses, bursitis, or ligament hurt. Gun trigger points besides cause symptoms every bit diverse as giddiness, otalgias, sinusitis, sickness and pyrosis, every bit good as numbness in the custodies and pess. Even fibromyalgia may hold its beginnings with trigger points. ( 8 )

Referred hurting is often felt as an oppressive profound ache that can be sharpened by motion. Referred myofascial hurting can be every bit unbearable as post-surgical hurting. Muscles that have been subjected to strive or overload are susceptible to develop trigger points.These trigger points will do symptoms of stiffness and joint hurting. ( 8 )

Figure3- A music instrument that causes trigger points and referred hurting

Referred hurting can frequently be triggered by simply pressing on a trigger point that is bad plenty to reproduce portion of its referred hurting behaviour. Since the mechanisms of the human nervous system are so unthinkably little, research on hurting referral is complicated. The bantam electrochemical urges in the nervousnesss can be detected and measured to a certain bound ; nevertheless, it is non with truth or great favoritism. Furthermore, moralss limit how far one can travel in hurting experiments. On the other manus, scientists have come up with a figure of theories explicating how hurting can be referred from its topographic point. The simplest hypothesis to accept refering referred hurting is that the signals fundamentally get assorted in the neurological wiring. Sensory inputs from several beginnings are known to unify into individual nerve cells at the spinal degree, where they are integrated and altered before being transmitted to the encephalon. As one electrical signal may hold possible influence on another, mistaken feelings may ensue. ( 8 )

A Microscopic Position:

The undermentioned drawing is a representation of several musculus fibres within a trigger point. It shows a microscopic position of an existent trigger point. This specific trigger point would do concern over the left oculus and sometimes at the really top of the caput. ( 8 )

Figure4- A microscopic position of a trigger point in a musculus fibre

Letter A is a muscular fibre in its resting province neither stretched nor contracted. The distance between the short intersections lines ( Z bands ) within the fibre characterizes the length of the single sarcomeres. The sarcomeres run along the length of the fibre, perpendicular to the Z sets.

Letter B is a mass of sarcomeres in a musculus fibre which are in their province of upper limit uninterrupted contraction that define a trigger point. The ball-shaped construction of the contraction knot shows how that portion of the musculus fibre has drawn up and go shorter and wider, drawing the Z set closer together.

Letter C is the section of the musculus fibre that originates from the contraction knot and extends to the musculus ‘s fond regard. In the figure, the bigger distance between the Z sets, demonstrates how the musculus fibre is being stretched by tenseness within the contraction knot. These overstretched constituents are what cause stringency and shortness in a musculus.

Normally, the sarcomeres in a on the job musculus act as bantam pumps, which contract and relax in order to assist blood circulate through the capillaries that supply their metabolic demands. When sarcomeres in a trigger point hold their contraction, blood Michigans from fluxing to the country in demand. The ensuing oxygen lack every bit good as the accretion of the waste merchandises of metamorphosis exacerbates the trigger point. Therefore, the trigger point reacts to this crisis by directing out hurting signals ( 8 )

Gun trigger Points vs. Tender Points:

Since referred hurting is an of import feature of a trigger point, it is of import to distinguish between the two. ( 9 )

Trigger Points

Tender Points

Local tenderness, tight set, local vellication response, leap mark

Local tenderness

There possibly remarkable or multiple points

There are ever multiple points

May occur in any skeletal musculus

Occur in specific locations that are symmetrically located

May do a particular referred hurting form

Do non do referred hurting, but frequently cause a entire organic structure addition in hurting sensitiveness

From the old tabular array, it is concluded that stamp points are associated with hurting at the site of tactual exploration merely, are non associated with referred hurting, and arise in the interpolation country of musculuss, non in tight sets in the musculus belly. Tender points occur in braces on different parts of the organic structure ensuing in equal distribution of hurting on equal sides of the organic structure. Tender points of fibromyalgia are present at nine bilateral musculus locations clarified as follows: ( 9 )

Low Cervical Region: at anterior facet of the interspaces between the transverse processes of C5-C7.

Second Rib: at 2nd costochondral junctions.

Occiput: at suboccipital musculus interpolations.

Trapezius Muscle: at center of the upper boundary line.

Supraspinatus Muscle: above the median boundary line of the scapular spinal column.

Lateral Epicondyle: 2 centimeter distal to the sidelong epicondyle.

Gluteal: at upper outer quarter-circle of the natess.

Greater Trochanter: buttocks to the greater trochanteric prominence.

Knee: at the median fat tablet proximal to the joint line.

Figure5 -anterior and posterior position of stamp point ‘s locations


The single demands to be suitably assessed, In order for limitations and instabilities in the musculoskeletal system to be satisfactorily addressed, and perchance treated. Designation of the undermentioned factors is of import in a successful musculoskeletal appraisal ( 5 ) :

Postural instabilities

Forms of functional instability

Forms of abuse

Shortened musculuss

Weakened musculuss

Changes within musculuss and other soft tissues

Joint limitation

Functional instabilities ( for illustration: in respiration and pace )

Palpation trials for Tender and Trigger Points:

In the twelvemonth of 1992, a survey was carried out in order to prove the truth of tactual exploration for both stamp points and trigger points in myofascial tissues. Subjects from three groups were tested- some with fibromyalagia syndrome ( FMS ) , some complaing from myofascial hurting syndrome ( MPS ) and some with no hurting or any other symptoms. The FMS patients were easy identified as 38 % of the FMS patients were identified to hold trigger points. On the other manus, merely 23.4 % of the MPS patients were found as holding trigger points and of the normal topics, less than 2 % had any. Most of the MPS patients had stamp points in sites typically tested in FMS and would hold qualified for this diagnosing every bit good ( 5 ) .

There are a figure of tactual exploration methods by ways of which trigger or stamp points can easy be identified. One simple effectual method is the usage of what is termed as ‘drag ‘ tactual exploration. A light transition of a individual figure, finger or pollex, across the tegument provokes a sense ‘drag ‘ , when the tegument has increased H2O content in comparing with its environing tegument. This increased hydrosis seems to demo a relationship with increased sympathetic activity, which accompanies a trigger point activity. In add-on, the tegument overlying a trigger point will expose reduced snap when mildly stretched apart, compared to the environing tegument. These countries are known as ‘hyperalgesic tegument zones ‘ and identifies a farther characteristic, which is a decreased extent of skin motion over the implicit in facia, tangible when originating a slide or ‘roll ‘ motion on the tegument. These three old features of skin alteration present effectual indexs as to underlying disfunction. Systematic attacks to the graphing of trigger point locations and their inactivation are provided by systems such as neuromuscular technique ( NMT ) , in which a methodical sequence of palpatory geographic expeditions are carried out, based on the trigger point ‘maps ‘ . In order to “ run into and fit ” tissue tenseness, it is indispensable to invariably vary tactual exploration force per unit area when trying to feel for trigger points at deepness, non merely utilizing skin marks. ( 5 )

Figure6- Trigger Point Palpation

Trigger Point Locations:

Gun trigger Points: Head and Neck

Paraspinous Neck Muscles: refer hurting to occiput

Upper Trapezius: refer hurting to make out and temporal brow

Sternocleidomastoid: associated with Otalgia and perchance Vertigo

Clavicle Muscular structure: referred hurting across brow and behind ear

Sternal Muscular structure: referred hurting into occiput, cheek and periorbital

Cervical paraspinous musculus: mention temporal-orbital hurting

Peri-auricular musculuss: referred hurting to teeth and chew the fat

Gun trigger Points: Shoulder, Thorax, and Arm

Serratus Anterior Muscle: referred hurting to sidelong thorax and shoulder blade boundary line

Pectoralis Major Muscle and Pectoralis Minor Muscle: referred hurting to breast and ulnar arm

Levator scapulae Muscle: referred hurting to base of cervix

Infraspinatus Muscle: referred hurting to shoulder articulation and down upper arm

Supraspinatus Muscle: referred hurting to middle deltoid and cubitus

Gun trigger Points: Back and Buttock

Quadratus Lumborum Muscle: referred hurting to moo back

Iliocostalis Muscle: referred hurting to lower quarter-circle of venters and to buttock

Gluteus Maximus Muscle: referred hurting to sacrum and inferior cheek

Gun trigger Points: Thigh, Leg and Foot

Quadricepss Femoris ( anterior thigh quad musculuss )

Rectus femur referred to patella and distal thigh

Vastus intermedius referred to upper thigh

Vastus medialis referred to median articulatio genus ( 10 )

Bicepss Femoris: referred hurting to calf

Gastrocnemius: referred hurting to calf and pes instep

Soleus: referred hurting to list and to sacroiliac articulation ( 10 )

Choice of Trigger Point Treatment

A successful intervention protocol should follow a sequence that begins with properly placing the trigger points, deactivating them, and if all trigger points have been resolved, stretching the constructions affected back to their normal scope of gesture and length. In the instance of musculuss, where most intervention takes topographic point, this involves stretching the musculus utilizing a assortment of inactive, active, active isolated ( AIS ) and muscle energy techniques ( MET ) , every bit good as positional release therapy ( PRT ) , strain/counterstrain ( SCS ) and integrated neuromuscular suppression technique ( INIT ) , along with proprioceptive neuromuscular facilitation ( PNF ) stretching to be effectual. Myofascial release should besides be used to handle fascia environing musculuss in order to stretch and decide strain forms ; otherwise musculuss will merely be returned to places where they are likely to re-activate trigger points. ( 11 )

The manual therapy intervention result is related to the degree of the healer ‘s accomplishment, that is if trigger points are pressed for a short period of clip, they may trip or stay active, and if pressed excessively long or hard, they may be irritated or the kneading force may be difficult plenty to do a muscular contusion. This bruising can last for a period of 1-3 yearss station intervention. Although patients may non truly be overexerting their musculuss, the application of the incorrect intervention methods can do symptoms of hurting similar to person who has been exerting for 24-72 hours. This is known as musculus febrility or delayed onset musculus tenderness ( DOMS ) . Pain can besides happen after a massage if the practician uses force per unit area on unnoticed latent or active trigger points, or is non competent in trigger point therapy ( 11 ) .

Treatment Methods

A broad scope of intervention techniques have been recommended in handling trigger points, including repressive force per unit area methods ( Nimmo, Lief ) stylostixis, working utilizing ultrasound moving ridges ( Kleyhans and Aarons ) , chilling and stretching of the musculus where the trigger point lies ( Travell and Simons ) , certain injections ( Slocumb ) , active or inactive stretching ( Lewit ) , and even surgical intercession ( Dittrich ) . Clinical experience, confirmed by the thorough research of Travell and Simons, has indicated that while all or any of these techniques can successfully suppress trigger point activity impermanent, in order to wholly get rid of their noxious activity, more is frequently needed. Common sense every bit good as clinical experience provinces that the subsequent measure of rectification of such jobs related to trigger points should affect re-education or riddance of factors which contributed to the job ‘s patterned advance. This might every bit good affect ergonomic rating of the person ‘s work environment. Travell and Simons have besides made known that whatever original intervention is offered to suppress the neurological activity of the trigger point, the musculus in which it lies has to make its natural resting length after such intervention, otherwise the trigger point will quickly reactivate. In handling trigger points the technique of chilling the annoyed musculus harbouring the trigger while keeping it at stretch was adopted by Travell and Simons, while Lewit has advocated the Muscle Energy or mutual suppression technique prior to passive stretching. Although a sufficient grade of failure occurs, both techniques are normally successful, which calls for probe of more successful attacks ( 12 ) .

8.2 INIT Hypothesis

Clinical experience shows that by uniting the techniques of direct suppression, which is application of mild uninterrupted force per unit area in a brand and interruption form, along with the construct of strain/ counterstrain and MET, a specific intent can so be achieved ( 12 ) .

Strain/Counterstrain ( SCS ) construct

Jones has indicated that specific painful ‘points ‘ associating to a chronic or acute joint or muscular strain, can be used as ‘monitors ‘ , where force per unit area is being applied to them while the organic structure or organic structure portion is carefully positioned in such a manner as to cut down the hurting felt in the palpated country. When the place of relieve is reached in which pain disappears from the palpated monitoring country, the stressed tissues are felt to be at their most relaxed province, and clinical experience confirmed that this is so because they palpate as ‘easy ‘ instead than holding being tense. SCS is thought to achieve its benefits by ways of an automatic rearranging of musculus spindles, which help to order the length and tone in the tissues. It seems that this rearranging occurs merely when the musculus harbouring the spindle is at easiness and by and large consequences in a release of cramp and decrease in inordinate tone. ( 12 )

INIT Method 1

It would be rational to presume that were a trigger point being palpated by direct force per unit area, and were the underlying tissues in which the trigger point was housed to be gently positioned in such a manner as to cut down the hurting, that the most annoyed fibres in which the trigger point was lying would at that clip be in a place of alleviation or easiness. As a consequence there would be a trigger point under direct inhibitory force per unit area which had been positioned so that the underlying tissues were comparatively or wholly relaxed. ( 12 )

Refering the strain/counterstrain technique, the hurting free place is held for a period of clip between 30 to 90 seconds in order for the musculus spindles to reset themselves and let go of any cramp or contraction. ( 12 )

8.5 Method 2

Sing MET ; isolytic techniques use an bizarre isosmotic motion. The musculus concerned is actively contracted by the patient while a stretch is introduced at the same time, ensuing in the dislocation of hempen adhesions between the musculus and its constructions. In order to present this technique into trigger point therapy, after the application of repressive force per unit area and SCS release, the patient is asked to contract the musculuss around the feeling pollex or finger given that the contraction should non be a maximal force since the healer programs to gently stretch the tissues as the contraction is taking topographic point. This isosmotic bizarre attempt, intended to diminish contractions and interrupt down tissue adhesions, should take specifically at the tissues in which the trigger point being treated prevarications buried. After the isolytic stretch the tissues could profit from the application of hot and cold mode or effleurage massage in order to alleviate any local congestion ; nevertheless a patient is instructed to avoid any active usage of the country for a twenty-four hours or so. ( 12 )

Figure7 Figure8 Figure9

Figure7 illustrates the first phase of INIT in which a trigger point in the supraspinatus musculus is located and intermittently or persistently compressed. ( 5 )

Figure8 illustrates how the hurting is reduced from the trigger point by happening a place of relieve which is held for at least 20 seconds, after which an isometric contraction is attained sing the tissues which involve the trigger point. ( 5 )

Figure9 illustrates the measure after keeping the isometric contraction for an appropriate period of clip, during which the musculus harbouring the point of local soft tissue disfunction is stretched. This completes the INIT rhythm ( 5 ) .


Gun trigger points have been studied and shown to be the most frequent cause of musculoskeletal hurting. Trigger points cause the musculus to stay tight, weak, and stressed, which frequently consequences in hurting in nearby articulations. A alone component that differentiates trigger points from other muscular hurting is that trigger points about invariably refer hurting to other parts of the organic structure, which is why many interventions fail because most interventions assume that the country of hurting is besides the beginning of hurting, yet the existent cause could be in a wholly different topographic point. Trigger points limit motion of the musculuss and lessening circulation, striping the musculus of O and foods, ensuing in a aggregation of metabolic waste that can non be adequately filtered off. Furthermore, trigger points create shortened musculuss which lead to compression on nearby nervousnesss, therefore doing irregular esthesiss such as prickling and numbness. Trigger point therapy can diminish hurting, enhance motion, and let the musculuss to lengthen and go stronger by presenting a figure of methods, including force per unit area, stretching, working massage, and hot and cold modes. Applying force per unit area helps detain the annoying chemical rhythm, therefore alleviating hurting and contractions in the involved musculuss. Hot and cold modes can assist heighten the circulation and extinguish the metabolic waste merchandises. Stretching exercisings after trigger point release is besides shown effectual in maintaining the musculus in a elongated place ; by that, the force per unit area constituent of the hurting rhythm is diminished.