General and Sports Anatomy - L.V. Kapilevich, K.V. Davletyarova 2008

Dynamic Morphology
General Dynamic Morphology

Dynamic Morphology is the science that studies the anatomical basis of body movements and postures, provides an anatomical Analysis of the function of both passive and active components of The Musculoskeletal System, and assesses the condition of all body parts.

1. General dynamic morphology – kinesiology – studies The Structure of the Organism in relation to performed movements.

2. Special Dynamic Morphology studies body structure in relation to athletic requirements.

3. The boundary field with biomechanics studies the positions of centers of gravity and volume, and the conditions of equilibrium.

Outline of the anatomical analysis of body postures and movements.

1. Description of the morphology of a posture or movement.

2. Characterization from the perspective of the laws of mechanics (forces).

3. Characterization of Muscle Function.

4. State of regulatory and supporting systems.

5. The impact of movements (exercises) on the organism (the latter has evolved into a separate branch – sports morphology).

I. Description of body postures and movements.

Carried out visually or based on photo and video data. The following are assessed:

1. Symmetry of posture;

2. presence and type of support;

3. relative positioning of body parts.

At this stage, movement phases are distinguished and characterized.

II. Characterization from the perspective of the laws of mechanics.

The following are considered:

1. acting forces;

2. position of the center of gravity;

3. position of the center of volume;

4. magnitude of the body's specific gravity;

5. area of support;

6. type of equilibrium;

7. conditions for maintaining equilibrium.

Operating forces during movement:

1. External forces – applied to The Human Body from the outside (Figure 20):

✵ Gravity. Equal to body mass applied to the common center of gravity (CCG) and directed vertically downwards.

✵ Support reaction force – the counter-action of the supporting surface under pressure. Applied at the point of support; in an upright position, it is equal to gravity and acts in the opposite direction, while in other cases, it is directed at an angle to the supporting surface. It can be resolved into two components: vertical (normal pressure force, where 'normal' in mathematics means perpendicular) – directed upward parallel to gravity; horizontal (friction force) – perpendicular to gravity.

✵ Environmental resistance force. Acts during motion (friction against air or Water) and depends on the frontal surface area, medium viscosity, and velocity. The frontal surface area can be reduced, for example, by changing a cyclist's riding position.

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Figure 20. External forces acting on the human body.

2. Internal forces (arising from the interaction of body parts):

✵ Passive: elastic recoil of soft Tissues; bone resistance force; molecular cohesion force of synovial fluid in the joints.

✵ Active: Muscle contraction force. Its magnitude depends on the Anatomical and physiological cross-sectional areas of the muscle, the angle of pull, and the lever arm.

Any force can act as either a propulsive or braking force. Gravity is propulsive during a fall, braking during a jump, and neutral when perpendicular.

Center of gravity of the body (CCG)

CCG is the point of application of the resultant of all gravitational forces acting on its component parts (body segments). Every part of the body has its own center of gravity.

The CCG serves as an indicator of body mass distribution. The higher the CCG, the greater the mass of the upper body (as seen in gymnasts). Track and field athletes have a lower CCG than gymnasts because their lower limb Muscles are more developed. It constantly shifts due to breathing and Blood Circulation, tracing a sphere 5–10 mm in diameter.

Methods of Determination:

Using first- or second-class levers (Figures 21 and 22), the CCG is approximately symmetrical along the anteroposterior and transverse axes, while along the vertical axis, it is located slightly above the midpoint of the body.

Figure 21. METHOD OF DETERMINING the CCG using the first-class lever principle.

Figure 22. Method of determining the CCG using the second-class lever principle.

Ivanitsky proposed the following index:

(Distance from CCG to the plantar surface / body height) * 1000

It is most commonly around 555–565, corresponding to the 1st–5th sacral vertebrae.

It is higher in men than in women (men: 572, women: 559).

It depends on body build and constitution.

In children: newborn - 5th-6th thoracic vertebra, 2 years - 1st lumbar vertebra; by 16-18 years of age, it descends downwards and backwards.

Center of Volume (CV)

The CV is the point of application of all water pressure forces acting on the body's surface.

It is of particular importance in swimming: if the COM coincides with the CV, the body remains motionless in the water; otherwise, a rotational moment arises.

The water displacement method is used to determine the CV.

Typically, the CV is 2-6 cm higher than the COM; during inhalation, it is even higher.

Specific gravity (density) of the body.

It equals the mass per unit volume. The average is 1.044. It increases with Muscle Development and decreases with fat accumulation. It is lower in women than in men. It increases with age: up to 17 years in men and up to 13 years in women, after which it slightly decreases.

Support area

It is determined by the supporting surfaces and the space between them (Figure 23). The larger the support area, the greater the stability.

Figure 23. Support area in the standing position.

With feet apart, the support area is larger than when together; on two legs, it is larger than on one; on skis, it is larger than on ice skates.

Types of equilibrium

They are determined by The ratio of the support to THE POSITION OF the COM. If the COM is above the support, the equilibrium is unstable (standing). If the COM is below the support, it is stable (hanging).

Conditions for maintaining equilibrium.

Equilibrium is maintained if the vertical line of the COM passes within the support area. The degree of stability depends on the height of the COM and the size of the support area. The lower the COM and the larger the support area, the greater the stability.

III. Function of the Locomotor Apparatus.

1. position or movement of individual links in the joints;

2. state and nature of work of individual muscle groups.

IV. State of the regulatory systems.

Assessment of the condition includes:

1. determining the shape of the chest;

2. condition of the intercostal muscles;

3. position and excursion of the Diaphragm;

4. State of the Abdominal muscles.

V. Determination of the effect of body positions or movements on the organism.

Takes into account METABOLISM/18.html">The Influence of exercise on the Skeletal System, joint mobility, muscle development, posture, FOOT condition, etc.

Morphokinesiological analysis of the upper extremity

MAIN TYPES OF movements:

1. Bringing an object closer to the torso. The muscles work with a superior support. In the elbow joint – flexion; shoulder – extension and adduction; wrist – flexion or extension and abduction. Muscles: flexors of the forearm and wrist, extensors and adductors of the shoulder. Joint stress is reduced.

2. Pushing an object away from the torso. Superior support, shoulder joint – flexion, elbow – extension, radiocarpal – flexion, shoulder girdle – upward and forward. Muscles: flexors of the shoulder, extensors of the forearm, flexors of the wrist and fingers. In the joints – increased pressure of the bones against each other.

3. Striking and punching. Various movements are possible; the most typical is a straight punch (boxing) – similar to variant 2. Striking surface – the heads of the Metacarpal bones and the dorsal surface of the 1st Phalanges.

4. Swinging movements. The straightened arm is moved backward (wind-up), which increases the preliminary stretching of the muscles. Movement involves adduction of the shoulder and forward movement of the shoulder girdle, with the corresponding muscles engaged.

5. Support on the hands (handstand, support on parallel bars). The upper extremity is fixed in an extended position; tone is increased in the extensors of the forearm and the flexors of the fingers and wrist. Bones are compressed along their longitudinal axes; The Role of the muscles is joint fixation and protection against hyperextension. When hanging on parallel bars or a horizontal bar, the muscles merely protect the joints from stretching.

6. Approach and withdrawal of the torso relative to the hand (pull-ups on a horizontal bar, push-ups). During both upward and downward movement, the exact same muscles are used, simply: – against gravity – overcoming work, – with gravity – yielding work. During pull-ups, the forearm flexors, and the shoulder extensors and adductors are active. In a push-up – the triceps brachii and shoulder flexors.

7. Locomotor movements (performed during swimming). The arm acts as a lever, with water serving as a movable fulcrum. During walking, running, and jumping, the arms perform auxiliary locotions that alter the body's momentum.

Points of support: 1) proximal (more frequent, superior), 2) distal (less frequent – hang, push-up, inferior).

Morphokinesiological analysis of the lower extremity

1. Support function. Performed in a standing position supported by one or both legs. The leg is extended at the knee and hip joints, and in a neutral position at the ankle. Accordingly, the extensors of the thigh and leg are active, along with the leg muscles – the flexors and extensors of the foot. The axes of the three main joints lie in different planes, the transverse axes are not parallel, and the longitudinal axes of the thigh and leg form an angle of 170⁰, which impedes simultaneous flexion in the joints, thereby reducing the load on the muscles.

2. Shock-absorbing function. Reduces impact during walking and running due to the presence of the foot arch, ligaments, and foot flexor muscles (which make the arch steeper). The longitudinal arch is supported by the leg muscles, and the transverse arch by the intrinsic Muscles of the foot. During landings (jumps), the shock-absorbing function is performed by all joints – they are partially bent, and upon impact, the extensors of the thigh and leg and the flexors of the ankle reflexively contract, meaning they perform yielding work, which allows for subsequent movement in the joints. When landing on the heel (long jump), the shock-absorbing role of the foot is not utilized at all; this function is performed by the other segments of the extremity (artificial shock absorbers, such as sand, are used).

3. Locomotor function. Pushing off from supporting surfaces (usually stationary) ensures the Displacement of the entire body in space. This involves plantar flexion of the foot, extension at the knee joint, extension at the hip joint, and pelvic movement.

4. Strikes. The distal end of the leg moves freely. The joints operate sequentially: extension at the hip joint, extension at the knee joint, extension at the ankle joint.

5. Moving the torso away from the point of support. Extension at the Hip and knee joints, flexion at the ankle. When lifting a heavy load, the foot may be fixed, in which case the latter movement does not occur.

6. Support function during a hang on the toes or with bent legs. Support on the dorsal surface of the foot or the posterior surface of the lower leg. The body rests on the dorsal surface of the forefoot or the posterior surface of the upper calf. On the toes – strong tension of the foot extensors (which are weaker than the flexors). Hanging with bent legs – the Posterior muscle group of the thigh and lower leg (since the lower leg is fixed, the gastrocnemius muscle flexes the thigh).

7. Pushing the body away from the water. Depends on the stroke style: breaststroke – abduction + flexion, adduction + extension (hip – knee); crawl – flexion – extension at the hip joint.

Displacement of Internal Organs in various body positions

Research method: contrast radiography.

Heart.

During an arched hang, handstand, or bridge, the blood flow to The Heart changes.

During a front leaning rest, a cross support, or a support with arms to the sides on rings, intrathoracic pressure increases.

In a front leaning rest, the heart shifts toward the HEAD by 1.5–2 cm; during a hang on rings, it shifts by 6 cm in beginners and 3.4 cm in trained gymnasts. In a handstand or an arched hang, the heart assumes a horizontal position and shifts toward the head by 6–8 cm during a handstand and by 3.5–3.6 cm during a hang. The dimensions of the heart also change. When the body is positioned upside down, the heart works harder (strict load dosing is required).

Diaphragm.

In untrained individuals, during a handstand or an arched hang, its muscular part shifts significantly (more so on the right dome), which impairs breathing and disrupts blood circulation.

Stomach.

Its usual position is oblique or vertical, which is normally highly variable. During an arched hang and a handstand, it assumes a horizontal position and shifts toward the head by 7 cm (hang) and 19 cm (handstand).

Large Intestine.

The transverse colon shifts toward the head by 20 cm, the flexures by 11–12 cm, and the cecum by 11 cm. The convexity is directed toward the head rather than the feet.

Liver and Gallbladder.

These organs are fixed and shift only slightly.

Kidneys.

They shift vertically by 10–14 cm.