Anatomy

Articulations

Shoulder Injury

Shoulder Dislocation Damage to the glenohumeral (GH) joint Considered a shoulder joint injury Often caused by a downward blow onto an arm that is abducted and externally rotated

Shoulder Injury

Shoulder Separation Damage to the acromioclavicular (AC) joint Considered a shoulder girdle injury Often caused by falling on an outstretched arm, forcing head of humerus upwards into the AC joint AC joint may be noticeably deformed

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Broken Wrist

Fractured distal radius Also called a Colles' fracture Extremely common Mechanism of injury is falling on a outstretched arm

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Avascular Necrosis

Function of the Patella

Mechanics of the Knee Knee Joint Structures Ligaments

Medial collateal Lateral collateral Anterior cruciate Posterior cruciate

Cartilages Medial meniscus Lateral meniscus

Knee Injury Unhappy Triad

Blow to the lateral aspect of knee with foot planted Medial knee joint “separates” Damaged structures:

Medial collateral ligament Medial meniscus Anterior cruciate ligament

Knee Joint Injury Q Angle

Quadriceps femoris line of pull runs from ASIS to center of patella Patellar ligament line of pull runs from center of patella to tibial tuberosity Q Angle is formed at the intersection of these two lines Greater Q Angles increase knee injury risk and poor patella tracking Generally, females have greater Q Angles

Joint Replacement

Sprained Ankle

Forced inversion damages ligaments on lateral ankle

Broken Ankle Forced eversion forces tarsals against fibula, breaking the bone above the lateral malleolus.

Sprained Ankle vs Broken Ankle

• Forced eversion pushes tarsals against fibula

• Results in broken fibula

• May also damage deltoid ligament on medial ankle

Broken Ankle