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Diagnosis of osteochondrosis: the state of the muscular system
Last reviewed: 04.07.2025

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During external examination, the degree and uniformity of muscle development and its relief are noted. The degree of muscle development is assessed as good, satisfactory and weak.
With a small muscle volume, lack of relief (when the “pattern” of muscles is not outlined through the skin) and decreased muscle tone (decreased plastic resistance of muscles during compression and palpation), muscle development is assessed as weak.
Average muscle development is defined as moderate volume, satisfactory muscle tone, and poorly defined relief.
Good muscle development means well-defined muscle relief, volume and tone.
During a clinical examination, it is necessary to note whether the muscles are evenly developed, and to indicate which muscle groups are less well developed and which are better developed.
When assessing the condition of skeletal muscles, along with visual examination, it is necessary to conduct a kinesthetic study, which allows determining muscle tone (T), hypotrophy (GT), the number of palpable painful nodules (KU), tenderness (B), duration of tenderness (DP), and the degree of irradiation of pain during palpation (SI). For quantitative expression of the data obtained during the study, F.A. Khabirov et al. (1995) proposed the muscle syndrome index (MSI), determined by the sum of the points of subjective and objective signs. The quantitative expression of the indicators in points is given in Table 3.1, which is based on the most significant signs in the clinic of muscle syndrome:
IMS = VVS + T + GG + B + PB + SI + KU.
Normally, IMS = 1 (in a healthy person, muscle tone is 1 point). Based on IMS, 3 degrees of severity of muscle syndrome are distinguished: 1st (mild) - up to 8 points; 2nd (moderate) - from 9 to 15 points; 3rd (severe) - more than 15 points (Salikhov I.G. et al., 1987).
It is known that muscles are not strained at the moment of convergence of the attachment points, but on the contrary, when they are stretched, keeping the body from falling. As the torso or head is tilted to 20-30°, the paravertebral muscles become increasingly tense. With pathological impulses, in particular, from the receptors of the posterior longitudinal ligament, joint capsules or other tissues, the density of the muscle (its tone) can be detected already in the resting position. The excitability of these receptors or other parts of the reflex arc can be judged by the density of the muscle at rest and during stretching. The reaction of muscle and fibrous tissues to stretching is the most important indicator of their dystrophic state (Popelyansky Ya. Yu., 1989). In addition to increased density, stretching of the specified tissues is also manifested by pain.
Thus, vertebrogenic dystrophic disorders of muscles and fibrous tissues (neuroosteofibrosis) can be judged, firstly, by the reaction of compaction (muscle tone), by the pain reaction to stretching; secondly, by pain on palpation. Pain on palpation can have varying severity.
Determination of the paravertebral region pain and its palpation are generally carried out with the corresponding muscles relaxed. This is possible in the patient's initial position - lying down, and standing - in the extension position, when the posterior traction is provided by gravitational forces.
Determination of the functional capacity of the organs of support and movement includes the study of muscle strength and endurance. The first impression of the strength of the muscles being studied is created by the doctor when assessing the nature of the active movements performed by the patient. In clinical practice, a 6-point assessment of muscle condition is generally accepted.
The patient's muscle strength is also judged by the strength of the resistance he provides to movement, as well as by the ability to lift and move a load of a certain mass.
Muscle strength is also determined using dynamometry and dynamografy. The greatest value in assessing the hand's performance is measuring the strength of the muscles - the flexors of the fingers of the hand. Dynamometers of various designs are used for this. The most accurate data are obtained when using a manual flat-spring dynamometer (DFSD); it gives readings (in kg) from 0 to 90.
Muscle condition assessment on a six-point scale
Movement performed |
Score in points |
Complete loss of muscle function |
0 |
Muscle tension without any motor effect |
1 |
The ability to perform a specific movement involving the muscle being studied under conditions of facilitated function |
2 |
The movement is performed under normal conditions. |
3 |
The movement is performed under conditions of opposition |
4 |
Muscle strength is normal |
5 |
When studying muscle tone, the greatest interest is not in the absolute data concerning muscle tone at rest, but in the ratio of the readings of the tone of a tense and relaxed muscle, since this to a certain extent characterizes the contractile ability of the muscle. The greater the interval between the readings of the tone of a muscle in a state of tension and the readings of the tone of a muscle in a state of relaxation, the greater its ability to relax and tense and, in connection with this, the higher its contractile ability.
Various designs of tonometers were proposed for the study - the spring tonometer of Sermai and Geller, the electrotonometer, the Efimov sclerometer, the Ufland tonometer, etc. The principle of operation of these devices is based on the depth of immersion of the metal pin into the tissue: the softer and more pliable the tissue, the greater the depth of immersion. This is reflected on the scale of the device.
The research method is as follows: the device is placed on the muscle or group of muscles being examined and the scale readings are determined (the state of relaxation of the muscle or muscles). Then the patient is asked to contract the muscle (the state of muscle tension) and the readings are determined again (in myotons) on the scale of the device. The magnitude of the difference in readings is used to judge the contractility of the muscle. Comparison of the obtained data in dynamics makes it possible to judge the change in the functional state of the muscles.
Muscle tone can also be determined by palpation:
- 1st degree - the muscle is soft;
- 2nd degree - the muscle is dense, the finger palpating it penetrates into it only partially and with difficulty;
- Grade 3 - rocky density muscle.
Endurance, i.e. the ability to maintain working capacity for a long time and increased resistance to fatigue under various loads, improves under the influence of physical activity. The endurance of the neuromuscular system is judged by the duration of maintaining muscle tension or performing any dynamic work with a certain muscular effort. Endurance during static work is studied using dynamographs (VNIIMP-TsITO, etc.). First, the maximum strength of the muscle being studied is determined, and then they are asked to maintain 50-75% of the maximum possible effort until fatigue occurs. In healthy individuals, the duration of retention is inversely proportional to the magnitude of muscle effort. Endurance to dynamic work is determined using an ergograph. The movements of a certain segment of the limb are weighed down with a load of a certain size, the rhythm of the movement is set using a metronome, and the onset of fatigue is judged by the ergogram. If the movements are performed without weights, the frequency or speed of voluntary movement can be assessed using the ergogram. The maximum number of movements of the limb segment are performed over a certain period of time, and then the indicators are compared with the data from the study of the healthy limb.
Electromyographic research method is also used to characterize the neuromuscular apparatus. This method allows to determine changes in the bioelectrical activity of the muscle depending on the level of damage, the type of immobilization, it also serves as an objective criterion for the positive effect of physical exercises on the muscular apparatus.
Manual muscle testing (MMT), introduced into practice at the beginning of this century by R. Lovett, despite the introduction of modern electrodiagnostic and tensodynamic methods of assessing the state of muscles, has not lost its significance for the clinic, and especially for rehabilitation therapy.
In muscle testing, a specific movement called a test movement is used for each muscle or muscle group. The MMT method is a developed and systematized movement for individual muscles and muscle groups, with each movement performed from a precisely defined starting position - the test position. The strength and functional capabilities of the muscles being tested are judged by the nature of the test movement and the resistance that is overcome.
The basic principles of MMT - assessment by the degree of impairment (6-degree scale), the use of gravity and manual resistance as criteria have been preserved to this day. At the same time, MMT was supplemented by tests that included new muscle groups, adequate to the initial positions and more precise test movements. All this provided the opportunity to determine with considerable accuracy the degree of weakening or complete loss of strength of a given muscle or muscle group, as well as to differentiate the slightest substitution movements.
The main provisions applied in MMT:
- initial position of the patient during testing (test position);
- test movement;
- the heaviness of the body part moved by the muscles being examined;
- manual resistance applied by the physician;
- muscle strength assessment.
A. The initial position (test position) is selected in such a way as to ensure conditions for isolated performance of the movement being tested. In order to correctly assess the condition of the muscles being tested, it is necessary to fix one of their attachment sites (always proximal). This can be done using several methods. First of all, the test position itself and the weight of the body are sometimes sufficient to stabilize the segments that are the proximal attachment site of the muscle being tested (e.g., during hip flexion). Another method of stabilization is additional fixation of the proximal parts of the body with the doctor's hand (e.g., during hip abduction, knee extension). The third method of additional stabilization used in testing shoulder and hip joint rotation is the so-called counterpressure. With its help, the tested segment is maintained in the correct position, allowing axial rotation, fixing a possible violation of the initial position due to the application of manual resistance.
B. Test movement is the work of the muscles under study, in which they act on a certain segment of the limb, in a strictly defined direction and amplitude of movement. For example, the volume of test movement for single-joint muscles is usually the full range of movement of the joint they act on. When testing, it should be borne in mind that the inability to perform the required movement in full may be associated not only with muscle weakness, but also with mechanical defects, such as shortening of the ligaments of the antagonist muscles, with fibrosis of the capsule, with incongruence of the articular surfaces, etc. That is why, before starting testing, the doctor must check by passive movement whether the joint is free.
B. The heaviness of the body part moved by the tested muscles (gravity). Depending on the initial position of the patient, the test movement can be directed vertically upwards, against gravity, i.e. be antigravity. Accordingly, the position is called antigravity. In this case, the tested muscles must develop a force exceeding the heaviness of the moved segment in order for the movement to occur.
The ability of the tested muscles to perform antigravity movement in full is considered to be one of the main criteria in assessing MMT - a satisfactory degree (3 points) indicates a functional threshold, an occupied middle position between the loss of muscle function and a normal muscle layer. At the same time, the gravity factor cannot be decisive in determining the degree of muscle strength, for example, the face (facial expressions are important here, since there are no joints and amplitude of movement), pronators and supinators of the forearm.
D. Manual resistance, which the examiner provides during testing, is another basic criterion for assessing muscle strength. As a rule, the place of resistance is the distal part of the segment that is moved by the muscle being tested (for example, when testing knee flexion - the distal part of the tibia). This allows the examiner to use the longest possible lever arm and thus use less force to overcome the muscles being tested.
There are three methods of applying manual resistance:
- continuous uniform resistance throughout the entire test movement; it cannot be used in cases of stiffness, joint contractures, pain syndrome, etc.;
- "overcoming" test. The patient makes a test movement, resisting the initial light and gradually increasing manual resistance from the doctor. Subsequently, the resistance increases to the degree that allows the strength of the muscles being tested to be overcome, to be overcome. It is the resistance necessary for overcoming that is the criterion of muscle strength;
- isometric test. The patient attempts to perform a test movement, resisting adequate, recorded resistance from the doctor. The resistance should be slightly greater than the strength of the muscles being tested, so that the latter will be in an isometric contraction.
D. Muscle strength is assessed according to 6 degrees.
For muscle groups where gravity is the primary testing criterion, the assessment is carried out as follows.
- Grade 5, normal (N), defines the strength of the corresponding normal muscle. It can perform a full range of motion, resisting gravity and maximum manual resistance.
- Grade 4, good (G). The muscle is able to perform a full range of motion against gravity and moderate manual resistance. Corresponds to approximately 75% of the strength of a normal muscle.
- Grade 3, fair (F). The muscle can perform a full range of motion against gravity (no additional resistance is used). Corresponds to approximately 50% of the strength of a normal muscle.
- Grade 2, weak, poor (P). The muscle is able to perform a full range of motion, but with gravity eliminated. Cannot overcome the force of gravity of the body part being tested. Corresponds to approximately 25-30% of the strength of a normal muscle.
- Grade 1, traces of movement, twitching, trace (T). When attempting to make a movement, there is a visible and palpable contraction of the muscle, but not enough force to make any movement of the tested segment. Corresponds to approximately 5-10% of the strength of a normal muscle.
- Grade 0, nula (Nu): When attempting to move the muscle, there is no visible palpable contraction.
Degrees 5, 4 and 3 are also called functional.
For muscle groups where gravity is not a determining factor in the assessment, grades 5 and 4 are characterized by the amount of manual resistance provided by the physician. Grade 3 expresses the performance of a full range of motion, and grade 2 - an incomplete range.
In the case of facial muscles, especially where there are no joints and, accordingly, no range of motion, the only criterion is the specific facial expression of the muscle being tested. Since objective assessment is difficult, a reduced assessment scheme was proposed: normal, satisfactory, traces, and zero.
It should not be forgotten that the assessment in MMT is relative and, most importantly, functional. It does not allow direct comparison of the level of absolutely preserved muscle strength of two different muscle groups, for example, the upper and lower extremities or the muscles of different patients.
Myofascial pain syndrome. It is known that skeletal muscles make up more than 40% of the human body weight. Most researchers, based on the Basel Anatomical Nomenclature, identify 696 muscles, of which 347 are paired and 2 are unpaired. Myofascial trigger points (TP) can form in any of these muscles, from which pain and other symptoms are usually transmitted to distant parts of the body.
Normally, muscles do not contain TT, they do not have compactions, they are not painful upon palpation, do not give convulsive reactions and do not reflect pain when squeezed.
A myofascial trigger point is an area of increased irritability (usually within tense bundles of skeletal muscles or in the muscle fascia). It is painful when compressed and can reflect pain, increased sensitivity and vegetative manifestations in its characteristic zones. There are active and latent TPs:
- active TTs cause pain;
- Latent TTs can persist for many years after damage to the musculoskeletal system, periodically causing acute attacks of pain even with minor overstretching, overload or hypothermia of the muscle.
Myofascial pain referred from a particular muscle has a distribution zone (pattern) specific to that muscle:
- spontaneous pain is rarely localized in the TT responsible for it - the pain is dull and prolonged;
- pain reflected from myofascial TP is non-segmental in nature: it is not distributed in accordance with familiar neurological zones or with zones of pain irradiation from visceral organs.
The intensity and prevalence of the referred pain pattern depend on the degree of irritability of the TP, and not on the volume of the muscle;
TTs are directly activated when:
- acute overload;
- physical fatigue;
- direct damage;
- cooling the muscle;
TTs are indirectly activated by:
- other trigger points;
- visceral diseases (diseases of internal organs);
- articular arthritis, arthrosis;
- emotional disorders;
Secondary TPs are apparently formed in an adjacent or synergistic muscle that is constantly overloaded because it is in a state of “protective” spasm, which allows reducing the load on the hypersensitive contracted and weakened muscle containing the primary TPs.
Myofascial TPs cause rigidity and weakness in the affected muscles.
Examination of the patient:
- in the presence of active TP in the muscle, its active or passive stretching causes increased pain;
- movements associated with stretching the affected muscle are limited; when trying to increase the amplitude of this movement, severe pain occurs;
- the pain intensifies when the contracting muscle overcomes a measured resistance (for example, the doctor’s hand).
When palpating the affected muscle:
- the tension of muscle fibers located in the immediate vicinity of the TT is revealed;
- TT is felt as a clearly defined area with acute pain, which is less pronounced even a few millimeters from the border of this point;
- pressing a finger on an active TT usually causes a “jump symptom”;
- Moderate continuous pressure on a fairly irritable TP causes or increases pain in the area of referred pain.
Palpation technique:
- pincer palpation - the belly of the muscle is grasped between the thumb and other fingers, squeezed and then the fibers are "rolled" between the fingers in order to identify tight bands; after identifying the band, it is palpated along its entire length in order to determine the point of maximum pain, i.e. TT;
- deep sliding palpation - moving the skin across the muscle fibers with the fingertip. This movement allows changes in the underlying tissues to be determined. The doctor moves the skin to one side of the palpated fibers with the fingertip and then makes a sliding movement across these fibers, creating a skin fold on the other side of the fibers. Any compacted structure (tight cord) in the muscle during this type of palpation is felt as "something rotating under the fingers";
- pinching palpation - the fingertip is placed against the tense cord at a right angle to its direction and is sharply lowered into the tissue, then the finger is quickly raised and the cord is "hooked". The finger movements are the same as when plucking a guitar string. This type of palpation is the most effective for provoking a local convulsive response.
ATTENTION! In order to weed out a tight cord, the muscle must be stretched to 2/3 of its normal extension. The palpated cord is felt as a tight cord among normally relaxed fibers;
- zigzag palpation - the doctor alternately moves the fingertip to one side and then to the other across the muscle fibers, moving it along the muscle.
ATTENTION! Zigzag palpation reveals a tight cord that includes the TT, deep palpation along these fibers reveals the localization of the TT itself in the form of a nodule.