Visual criteria for musculoskeletal statics and dynamics

Visual diagnostics is one of the methods used to identify visible criteria of musculoskeletal disorders, their severity, variability under the influence of irrational physical activity during physical education and sports, as well as therapeutic measures (during the recovery period).

Each time, when solving certain problems, the doctor compares the athlete's statics and dynamics with the normative model. This not only facilitates the diagnosis of musculoskeletal disorders (MSD), but also allows for the shortest possible time to offer an optimal rehabilitation program.

Optimal statics is such a spatial arrangement of the elements of the musculoskeletal system, in which the balance of the musculoskeletal system in a vertical position of a person is maintained with minimal energy expenditure of postural (shortened) muscles.

Optimal statics includes an optimal static stereotype consisting of a regional postural balance of the muscles of the trunk and limbs. The postural balance of the muscles of the region in turn consists of the postural balance of the antagonist muscles, optimal statics of the articular-ligamentous apparatus.

The spine and limbs are divided into regions according to the differences in static and dynamic tasks they perform.

A region is a set of vertebral motor segments (VMS) or bones (for limbs) that perform the same static and dynamic functions. The boundaries of regions are the attachments of the main postural and phasic muscles.

To assess the optimality of statics, vertical lines (perpendicular to the support) are used: through the general center of gravity (general median plumb line) and the center of gravity of the spine and limb regions (regional median plumb line); horizontal lines through the bone landmarks of the regions and through the transverse processes of the vertebrae. Their relative positions between themselves and the support plane are assessed sequentially in three planes:

• frontal (rear and front view);
• sagittal (side view) and
• horizontal (top view).

For example, the criterion of optimal statics in the frontal plane as a whole is a plumb line dropped from the middle of the distance between the occipital tubercles, passes through the middle of the distance between the patient's feet. The criterion of postural balance of the muscles of the cervical region is a plumb line dropped from the middle of the distance between the occipital tubercles, passes through the body C7 _. The criterion of postural balance of the muscles of the lower limb as a whole is a plumb line dropped from the angle of the scapula, passes through the calcaneal tubercle of the calcaneus.

Horizontal lines passing through the boundaries of the spine and limb regions are normally parallel to each other and to the plane of support. For example, the upper boundary of the cervical region is a line passing through the lower edges of the auricles or the lower edges of the occipital bone. The lower boundary coincides with the upper boundary of the thoracic region - a line connecting the upper boundaries of the acromioclavicular joints.

Suboptimal statics is an asymmetrical mutual arrangement of the articular elements of the musculoskeletal system, accompanied by an increase in the gravitational load on the postural muscles, in which the body is in a state of “stopped fall” and/or movement stopped at a certain stage.

Visual criteria for suboptimal statics:

• displacement of the projection of the general center of gravity relative to the median plumb line (forward, backward, to the sides) relative to the middle of the distance between the feet;
• violation of parallelism between horizontal lines passing through the boundaries of regions.

Regional postural muscle imbalance is a violation of the tone-strength balance of shortened and relaxed muscles of the region, which results in an asymmetrical mutual arrangement of the constituent elements of the region and a distortion of their gravitational load.

Visual criteria for regional postural muscle imbalance:

• displacement of the projection of the regional median plumb line relative to the location of the projection of the general median plumb line;
• violation of the parallelism of horizontal lines drawn across the boundaries of the region;
• change in the curvature of the spine (lordosis, kyphosis): its increase, smoothing, deformation, appearance of curvature in the frontal or horizontal plane. For example, a combination of hyperlordosis of the upper cervical region and kyphosis of the middle and lower cervical regions, a combination of hyperlordosis in the thoracolumbar junction with kyphosis in the lumbar region, or the formation of lordosis in the middle thoracic region.

The pathobiomechanics of postural and physical muscles is presented in the form of basic forms - shortening and relaxation of the muscle.

The main forms of postural muscle imbalance are:

A hypertonic, shortened muscle, accompanied by a decrease in its excitability threshold while maintaining the neuromotor apparatus. Its visual signs:

• convergence of attachment sites;
• enlargement and deformation of the muscle contours in the area of its location;

A hypotonic, relaxed muscle, accompanied by an increase in its excitability threshold while maintaining the neuromotor apparatus. Its visual signs:

• removal of attachment sites;
• flattening (smoothing) of the muscle contours in the area where it is located.

A dynamic stereotype is a complex motor act consisting of an evolutionarily developed sequence and parallelism of the inclusion of simple motor patterns of the joints of the spine and limbs. For example, walking, running, breathing, lifting weights, etc.

Pattern (model, drawing) is a temporary spatial relationship of excitatory and inhibitory processes, manifested in the qualitative and quantitative characteristics of the statics and dynamics of a person. A typical motor pattern is a motor act of the spine and/or limbs region, arising as a result of an evolutionarily developed pattern of sequential or parallel activation of 5 main muscle groups corresponding to the types of contraction (agonists, synergists, neutralizers, fixators, antagonists). Visual criteria of a typical motor pattern:

• making a movement in a specific direction;
• smooth movement while maintaining constant speed;
• the shortest trajectory and sufficient volume of movement.

A non-optimal dynamic stereotype is a violation of the parallelism and sequence of switching on motor patterns, switching off one pattern and replacing it with another.

Visual criteria for a suboptimal dynamic stereotype:

• the appearance of additional compensatory synkinesias in adjacent or distant regions of the spine and limbs.

Atypical motor pattern is a violation of the evolutionarily developed sequence and type of switching on and off of the main muscle groups.

Visual criteria for an atypical motor pattern:

• the appearance of additional movements;
• change in traffic volume;
• distortion of the trajectory and speed of movement.

In patients during an exacerbation, the following stages of change in the motor stereotype can be conditionally distinguished: generalized, polyregional, regional, intraregional, local.

• The generalized stage of changes in the motor stereotype (MS) is characterized by the spine functioning as a single biokinematic link. At this stage, movements are mainly possible in the craniovertebral MSS, hip and ankle joints (without movements in the knee joints), the deformations of the musculoskeletal system are located in one plane. This becomes possible due to changes in the relationship between the pelvis and lower limbs. Such a system is unstable: the static component is predominant over the statokinematic one.
• The polyregional stage of DS changes is characterized by the appearance of new links in the biokinematic chain "spine - limbs". Movements are observed in the mid-thoracic spine, as well as in the area of the knee joints. The spine is divided into two biokinematic links (upper - as part of the cervical and upper thoracic sections and lower - lower thoracic, lumbar and sacral).

In such situations, it is highly undesirable to carry out mobilization techniques and active physical exercises to restore the full range of motion in the affected spine. This leads to a disruption of the developing DS, which will contribute to an increase in the load on the affected PDS. In addition, such a situation can lead to a new exacerbation.

• The stage of regional changes in the DS is characterized by the appearance of movements in new areas of the musculoskeletal system. Due to this, new pairs of links in the biokinematic chain of the spine arise - it is divided into five biokinematic links (cervical - upper thoracic - lower thoracic - lumbar - sacral). In this case, additional deformations occur in those planes in which there were no curvatures yet. All this contributes to the formation of a stable new posture.
• The intraregional stage of changes in the DS is characterized by the appearance of movements in the PDSs located within the regions. For the cervical spine, these are transitional PDSs: the upper cervical level into the mid-cervical and the mid-cervical into the lower cervical; for the thoracic spine, the appearance of movements in one of the upper thoracic PDSs and in one of the lower ones, and in the lumbar spine, at the places of transition of the upper into the lower lumbar level.
• The local stage of changes in the spinal ligament is characterized by the presence of a complete “block” in the affected spinal ligament and a simultaneous combination of hypermobility with hypomobility in different planes in all unaffected spinal ligaments.