Lapaluun

Lapaluun is the Finnish term for the scapula, also known as the shoulder blade. It is a large, flat, triangular bone that forms the posterior part of the shoulder girdle and serves as a site for muscle attachment and as a lever for arm movements. The scapula rests on the upper posterior thorax, overlying ribs 2 through 7, and connects to the clavicle at the acromioclavicular joint and to the humerus at the glenohumeral joint. The sternum does not directly contact the scapula.

Anatomy and surfaces: the scapula has a broad, concave anterior (costal) surface and a posterior surface that features the spine of the scapula, which extends laterally as the acromion. The coracoid process projects anteriorly, and the glenoid cavity (glenoid fossa) sits laterally to form the socket for the humeral head. The bone has three borders (medial, lateral, superior) and three angles. The supraspinous and infraspinous fossae fill the posterior surface above and below the spine.

Muscle attachments and function: the scapula provides attachment for many muscles, including the rotator cuff (supraspinatus, infraspinatus, teres minor, subscapularis), serratus anterior along the medial border, trapezius, rhomboids, and pectoralis minor on the coracoid. It acts as a movable base for the upper limb, enabling comfortable positioning of the glenoid for humeral motion and coordinating shoulder girdle movement through scapulohumeral rhythm.

Nerve and vascular supply: the scapula receives blood from branches such as the circumflex scapular and suprascapular arteries, and its innervation comes from nerves including the long thoracic nerve and the suprascapular nerve, among others.

Clinical relevance: scapular fractures are uncommon due to protection by the rib cage but may indicate high-energy trauma. Scapular dyskinesis or winging can result from nerve injury or muscle weakness and may affect shoulder function; imaging (X-ray, CT, MRI) is used to evaluate morphology and soft-tissue status.