The scapula is the most mobile bone of the human skeleton, from which a multitude of muscles and ligaments originate. Therefore, it is all the more critical when the scapula is afflicted by injury or disease and the body is consequently subjected to severe stresses that should be treated immediately.
What is the scapula?
Schematic diagram showing the anatomy of the shoulder. Click to enlarge. The scapula, which is also known as the shoulder blade in technical language, represents a significant bone of the human skeleton. Thereby, the scapula is found in a flat, triangular shape in the organism, connecting the upper arms and the trunk, and at the same time forming the posterior part of the human shoulder girdle. The main function of the shoulder blade, besides the mobility of the upper arms, is also their suspension as well as attachment to the human torso. In addition, the shoulder blades are also the starting and attachment points of numerous muscles and ligaments. Extreme stress or accidents can cause diseases of these muscles or other injuries in the area of the scapula, which inhibit mobility and therefore need immediate attention.
Anatomy and structure
A scapula is a flat bone in a triangular shape that is present on both the left and right sides of the human torso. Together, these two scapulae join to form what is known as the shoulder girdle of the human skeleton. This shoulder girdle is connected to the sternum via the clavicles. Furthermore, the scapula is subdivided on its back side by the so-called spina scapulae, which represents a bony ledge and ends on the front side in the so-called acromion. Together with the clavicle, this forms the acromioclavicular joint, which is also known as the acromioclavicular joint, or AC joint for short. Under the acromion ends another process, the coracoid, which is an origin of numerous muscles and ligaments that stabilize the acromioclavicular joint. Thus, the scapula is composed of a large number of muscles and tendons that are responsible for the movement of the arm. Another component at the side of the scapula is the glenoid cavity, also known as the glenoid. The humeral head is also located in the glenoid cavity, which is present once on each side. Furthermore, each scapula is composed of an upper glenoid fossa, a shoulder glenoid fossa located in the center above, and the lower glenoid fossa. In addition, a joint surface for the upper arm is attached in between each.
Functions and tasks
As an important component of the human skeleton, the scapula is considered to have a variety of functions. Among these, it is primarily responsible for attaching the upper arm. Likewise, numerous muscles and ligaments arise from the scapula, which are important for central movement processes. However, the scapula plays a particularly important role in the suspension and mobility of the arm. For example, the scapula rotates inward with arm movements when they extend beyond the horizontal. In addition, the shoulder blade is an attachment point of the rotator cuff, which comprises a muscle group that is of great importance for many movement sequences. For this reason, the shoulder joint is often dubbed the most mobile joint in the human body.
Diseases and complaints
Serious accidents or falls can cause injuries to the shoulder blade. This can result in a fracture of the scapula, which, however, rarely requires surgical treatment. In particularly severe accidents, however, there may be simultaneous damage to the scapula and clavicle. In this case, the resulting instability of the shoulder suspension requires surgical intervention. More common than fractures, however, are diseases affecting the muscles attached to the scapula. Diseases such as impingement syndrome, in which the sliding space of the tendons is restricted, are particularly common. A rotator cuff rupture, in which a tendon of the shoulder joint is torn, is also often present. In addition to limited arm mobility, the symptoms include a lack of strength on the part of the patient.In addition, paralysis of the serratus anterior muscle may occur, which is manifested by protrusion of the scapula, also known in medicine by the technical term scapulta alata.
