What causes acromioclavicular sprain?

What causes acromioclavicular sprain?

The most common mechanism of injury to the acromioclavicular and coracoclavicular ligaments is a direct force applied to the superior aspect of the acromion, usually from a fall with the arm in an adducted position. This impact drives the acromion inferiorly, spraining the intra-articular acromioclavicular ligaments.

How can the acromioclavicular ligament be injured?

The AC joint is strong, but its location makes it vulnerable to injury from trauma. Injury to the ligaments (also called shoulder separation) can occur as a result of a fall, direct blow, or other trauma.

What is acromioclavicular sprain?

Acromioclavicular (AC) Joint Injury. An injury of the acromioclavicular joint targets the area where the shoulder blade (scapula) meets the collarbone (clavicle). The injury typically takes place in the form of a sprain, forcing the tendon apart by some type of blunt force trauma.

What does the acromioclavicular ligament do?

The acromioclavicular ligament serves to reinforce the joint capsule and serves as the primary restraint to posterior translation and posterior axial rotation at the AC joint.

What is are a common mechanism S of injury for an anterior dislocation of the shoulder?

Mechanism of injury — An anterior shoulder dislocation is usually caused by a blow to the abducted, externally rotated, and extended arm (eg, blocking a basketball shot). Less commonly, a blow to the posterior humerus or a fall on an outstretched arm may cause an anterior dislocation.

What is sprains and strains?

The difference between a sprain and a strain is that a sprain injures the bands of tissue that connect two bones together, while a strain involves an injury to a muscle or to the band of tissue that attaches a muscle to a bone.

What are 3 main ligaments that make up the acromioclavicular joint?

Acromioclavicular (AC) joint

Type Synovial plane joint; multiaxial
Ligaments Intrinsic: Superior acromioclavicular ligament, inferior acromioclavicular ligament Extrinsic: Coracoclavicular ligament (with conoid and trapezoid parts)
Innervation Lateral pectoral nerve, suprascapular nerve

What muscles attach to the acromioclavicular joint?


  • Pectoralis Major (Clavicular Head)
  • Sternocleidomastoid.
  • Deltoid.
  • Trapezius.

What is the most common direction to dislocate your shoulder?

The shoulder joint is the most frequently dislocated joint of the body. Because it moves in several directions, your shoulder can dislocate forward, backward or downward. The most common variety is a forward (anterior) dislocation.