In forward support phase, the trunk is virtually erect with less than how many degrees forward lean?

In forward support phase, the trunk is virtually erect with less than how many degrees forward lean?

• A. Less than 5 degrees
• B. 10 degrees
• C. 15 degrees
• D. 20 degrees

Answer: (A)

During the forward support phase, the body aims to minimize horizontal braking by keeping the torso almost vertical. A tiny forward lean—less than about 5 degrees—helps keep the ground reaction force aligned with the body's center of mass, so the leg can land under the hip and drive forward rather than slow the body down. If the trunk leans more (10, 15, or 20 degrees), the line of force moves ahead of the hips, increasing braking and complicating the switch to propulsion. So the best description is a trunk that remains virtually erect with less than 5 degrees of forward lean.

During the forward support phase, the body aims to minimize horizontal braking by keeping the torso almost vertical. A tiny forward lean—less than about 5 degrees—helps keep the ground reaction force aligned with the body's center of mass, so the leg can land under the hip and drive forward rather than slow the body down. If the trunk leans more (10, 15, or 20 degrees), the line of force moves ahead of the hips, increasing braking and complicating the switch to propulsion. So the best description is a trunk that remains virtually erect with less than 5 degrees of forward lean.