What Is the Subscapularis Muscle?

The subscapularis subscapularis, located in front of the scapula, is triangular. Starting from the subscapular fossa, the muscle bundles pass forward of the scapular joint and stop at the small humerus nodules. The role is to make the scapula joint introverted and internal rotation. The subscapularis muscle is suddenly injured due to sudden adduction and internal rotation of the upper limbs, or contracted repeatedly for a long period of time. Because there are no prominent symptoms, it is mostly unnoticed in the early stage. The continuous movement of the upper limbs stretches the injured area, which makes it difficult to repair, bleeding, exudation, mechanical adhesion, scarring and dysfunction. Shoulder adduction and internal rotation pain, the range of motion of the back of the affected limb is reduced.

The subscapularis subscapularis, located in front of the scapula, is triangular. Starting from the subscapular fossa, the muscle bundles pass forward of the scapular joint and stop at the small humerus nodules. The role is to make the scapula joint introverted and internal rotation. The subscapularis muscle is suddenly injured due to sudden adduction and internal rotation of the upper limbs, or contracted repeatedly for a long period of time. Because there are no prominent symptoms, it is mostly unnoticed in the early stage. The continuous movement of the upper limbs stretches the injured area, which makes it difficult to repair, bleeding, exudation, mechanical adhesion, scarring and dysfunction. Shoulder adduction and internal rotation pain, the range of motion of the back of the affected limb is reduced.

Chinese name

Subscapularis

Foreign name

subscapularis

First

disease

Article 2

Etiology and pathology

Article 3

Clinical manifestation

Architectural Study of Human Subscapularis Scapularis

The subscapularis muscle is located in the subscapular fossa and is triangular in shape. It is a multi-feathered muscle composed of multiple feathers. On the sagittal section of the muscle, there are 5-7 sheets or curved "C" key plates in the muscle. The 2 to 3 key plates above the muscle are longer and extend from the middle of the muscle abdomen to the abutment key. Near the end-end key, the key plate is bent and enlarged into a semi-circular shape, thickened and connected to the end-end key. The subscapular muscle fibers start from the bone surface of the subscapular fossa and the fascia on the surface of the subscapular muscle, facing each other, and stop at the above 5-7 boards, so the subscapularis muscle is composed of 5-7 double feathers. Its physiological cross-sectional area is 21.48 ± 6.4cm², which is larger than the physiological cross-sectional area of the deltoid muscle's middle subsection (20.52cm²). The role of the subscapular muscle is generally described in textbooks as adduction and internal rotation of the shoulder joint and as a descending arm muscle group in conjunction with deltoid muscle abduction. Basmiajan research shows that the subscapularis muscle plays an important role in the early abduction of the abdomen. The electromyographic activity of the subscapularis muscle peaks at 90 °, and the maximum activity of the deltoid muscle is between 90 ° and 180 °. Inman et al. Estimated that the muscle strength of the deltoid muscle was 8 times the limb weight at the 90 ° abduction position (assuming the limb weight was 9% of the body weight). The combined force of the subscapularis, small round muscle, and subanginosacral triceps is 9.6 times the weight of the limb, and the combined force is the largest when it is lifted up to 60 °. The physiological transverse cross-sectional area and maximum contractile tension of the subscapularis muscle are more reasonable than those in the central Asia of the deltoid muscle. The scapula key of the subscapularis is wide and thick, interwoven with the fibers of the anterior wall of the shoulder capsule, thereby enhancing the stability of the shoulder joint. In the movement of the shoulder joint, especially in rapid movement, the fat bone generates an accelerated centrifugal force at the shoulder joint. The subscapular muscle and muscle key sleeve muscles pull the fat bone by centrifugal contraction, so that the belly head is close to the glenoid. To prevent the displacement of fat bones, the subscapularis muscles in turn prevent the fat bones from dislocating forward. There are few reports on the morphology of the subscapularis muscle. Compared with the results of hin, the results of this study are larger in physiological cross-sectional area (26.3cm²). In addition to slightly different calculation formulas, it may also be affected by the height and weight of the race.

Anatomical characteristics and clinical significance of subscapular muscle

Objective: This article mainly studies the anatomical characteristics of the subscapularis muscle and its adjacent structures, and provides anatomical data and reference for the clinical treatment of subscapularis injury. Methods: Sixteen adult corpses without tissue lesions in the scapular region. Anatomically study the subscapularis muscle and its adjacent structures. Observe and measure the following data in a neutral position:

1. The distance from the highest point of the subscapularis at the humeral nodules to the coracoid process.

2. The distance from the upper edge of the subscapular muscle to the coracoid process.

3. The width of the subscapularis muscle at the humeral nodules.

4. Length of the subscapular tendon.

5. The width of the tendon of the subscapular muscle at 2.0 cm from the apex of the humerus nodules.

6. The thickness of the tendon at the subscapular muscle 2.0 cm from the apex of the humerus nodules.

7. The vertical distance between the junction of the subscapular muscle and the axillary nerve from the apex of the humerus nodules.

8. The vertical distance between the lower edge of the subscapularis muscle and the lower axillary nerve at 2.0 cm from the small tuberosity of the humerus.

9. The vertical distance from the axillary nerve into the four holes to the apex of the small tuberosity of the humerus.

10. Shoulder joint forward flexion at 90 o'clock, neutral position of forearm, 90 ° forearm pronation, 180 ° forearm adduction, adduction angle when the coracoid process is in contact with the subscapular muscle nodule stop. The measurement results were statistically analyzed using SPSS statistical software.

result:

1. The distance from the highest point of the subscapularis at the humeral nodule to the coracoid process is 2.500 ± 0.009cm.

2. The distance from the upper edge of the subscapular muscle to the coracoid process was 0.437 ± 0.008 cm.

3. The width of the subscapularis muscle at the humeral nodule nodal point is 3.188 ± 0.009cm.

4. The length of the subscapular tendon was 3.122 ± 0.008cm.

5. The width of the tendon of the subscapularis muscle 2.0 cm from the apex of the small tuberosity of the humerus is 3.822 ± 0.009 cm.

6. The thickness of the tendon at the scapula muscle 2.0 cm from the apex of the humerus nodules was 0.524 ± 0.008 cm.

7. The vertical distance between the junction of the subscapular muscle and the axillary nerve from the apex of the humerus nodules is 3.522 ± 0.008 cm.

8. The vertical distance between the lower edge of the subscapularis muscle and the lower axillary nerve at 2.0 cm from the small humerus nodule was 1.026 ± 0.008 cm.

9. The vertical distance from the axillary nerve into the four holes to the apex of the humerus nodules is 3.042 ± 0.008cm.

10. Shoulder joints bend forward 90 °, forearm neutral position, forearm pronation 90 °, and forearm pronation 180 °. When adducted, the adduction angles of the coracoid process and the small scapular nodules are in adduction. It is 44.506 soil 1.182 °, 50.013 soil 1.093 °, 54.292 ± 1.201 °, and the comparison between the three is P <0.05, which is statistically significant. Conclusion The study of the anatomical characteristics of the subscapularis muscle and its adjacent structures provides theoretical basis for the treatment of diseases related to the injury of the subscapularis muscle and the guidance of the shoulder joint activity.