Which muscles create more rigidity in the spine?

• A. Spinal multifidus
• B. Spinal erectors: iliocostalis, longissismus, spinalis
• C. Latissimus dorsi
• D. External obliques

Answer: (A)

Deep spinal stability comes primarily from the spinal multifidus, a deep segmental stabilizer that spans across small sections of the spine. Its fibers attach close to each vertebra, allowing it to lock down each segment and resist fine, localized movements as you lift or brace. This segmental rigidity helps maintain a neutral spine under load and during rapid or heavy movements. The spinal erector group, while important for overall extension and posture, provides broad, gross back stiffness rather than precise, segment-by-segment stabilization. The latissimus dorsi and external obliques contribute to movement and overall trunk stability in different ways, but they are not the primary sources of spinal rigidity.