Which joint position most accurately represents a loose-packed position?

• A. Hip placed in 0° of abduction
• B. Glenohumeral joint placed in 15° of abduction
• C. Tibiofemoral joint placed in 25° of flexion
• D. Humeroulnar joint placed in 30° of flexion

Answer: (C)

Loose-packed position is the joint configuration where the joint surfaces are least congruent and the capsule is most lax, creating maximum joint space and allowing the greatest amount of accessory movement. For the knee, the open-packed (loose-packed) position occurs at about 25 degrees of knee flexion, when the tibiofemoral surfaces are not pressed tightly together and the surrounding ligaments are relatively slack. This makes 25 degrees of knee flexion the best choice for a loose-packed position among the options.

The other joints listed have different commonly accepted open-packed positions: the hip is typically open-packed around 30 degrees of flexion with 30 degrees of abduction and slight lateral rotation, not with zero abduction; the glenohumeral joint’s loose-packed position is about 55 degrees of abduction and 30 degrees of horizontal adduction, not 15 degrees of abduction; the humero-ulnar joint is generally open-packed near about 70 degrees of elbow flexion, not 30 degrees.