Question

Describe the joints and motions involved in taking a step forward if a person is initially standing still. Assume the person holds his foot at the same angle throughout the motion.

Short answer

As the foot comes off the ground in the step, the hip joint is going to move the femur in a protracted motion and the knee will flex the shin toward the thigh. As the foot lands, the knee extends the leg and the hip retracts the femur.

Step-by-step solution

Step 1. Introduction

• The point at which two or more bones meet is called a joint, or articulation. Joints are responsible for movement, such as the movement of limbs, and stability, such as the stability found in the bones of the skull.

Step 2. Explanation

• Taking a step would require bending the knee (modified hinge joint) and moving the leg in the hip (ball and socket joint) since the motion of the foot is excluded.
• As the foot comes off the ground in the step, the hip joint is going to move the femur in a protracted motion and the knee will flex the shin toward the thigh.
• As the foot lands, the knee extends the leg and the hip retracts the femur.