What does form closure refer to in pelvic stability?

What does form closure refer to in pelvic stability?

• A. Stability of the pelvic ring provided by bones and ligaments.
• B. Stability provided by muscle strength and function.
• C. Stability provided by nerves and fascia.
• D. Stability provided by cartilage and synovial fluid.

Answer: (A)

Form closure is the passive stability provided by the pelvic ring’s architecture—the bones and ligaments that form a closed, load‑bearing ring. This structural arrangement of the sacrum, ilia, pubic bones, and their supporting ligaments creates a stiff framework that resists motion under weight even without muscle contraction. In other words, the stability comes from the anatomy itself, not from active muscle forces. Other contributors to pelvic stability fall under different mechanisms: force closure is stability produced by muscle strength and coordinated action, nerves and fascia relate to control and tensioning of tissues, and cartilage with synovial fluid mainly supports joint surfaces rather than establishing the ring’s passive stability.

Form closure is the passive stability provided by the pelvic ring’s architecture—the bones and ligaments that form a closed, load‑bearing ring. This structural arrangement of the sacrum, ilia, pubic bones, and their supporting ligaments creates a stiff framework that resists motion under weight even without muscle contraction. In other words, the stability comes from the anatomy itself, not from active muscle forces. Other contributors to pelvic stability fall under different mechanisms: force closure is stability produced by muscle strength and coordinated action, nerves and fascia relate to control and tensioning of tissues, and cartilage with synovial fluid mainly supports joint surfaces rather than establishing the ring’s passive stability.