When does the erector spinae first become active during gait?

When does the erector spinae first become active during gait?

• A. Mid-swing only
• B. Toe off only
• C. Just prior to heel contact to about 20% of the gait cycle
• D. 80-100% only

Answer: (C)

The erector spinae help stabilize the trunk in anticipation of and during the initial ground contact of the gait cycle. They fire just before heel contact to prepare the spine for the transient forward momentum and ground reaction forces, a crucial anticipatory action that keeps the trunk upright as the foot lands. This activation continues into the early stance phase (about the first 20% of the cycle) to maintain spinal extension and control as the body accepts weight. After this early window, their primary role isn’t needed in the same way, and the pattern shifts to other stabilizers. So, the best description is that they activate just before heel contact and continue through roughly 20% of the gait cycle, aligning with the need for trunk stability right at weight acceptance.

The erector spinae help stabilize the trunk in anticipation of and during the initial ground contact of the gait cycle. They fire just before heel contact to prepare the spine for the transient forward momentum and ground reaction forces, a crucial anticipatory action that keeps the trunk upright as the foot lands. This activation continues into the early stance phase (about the first 20% of the cycle) to maintain spinal extension and control as the body accepts weight. After this early window, their primary role isn’t needed in the same way, and the pattern shifts to other stabilizers.

So, the best description is that they activate just before heel contact and continue through roughly 20% of the gait cycle, aligning with the need for trunk stability right at weight acceptance.