Gait Analysis: 3D Motion Analysis and Stride Characteristics

Kristin, our gait lab technician, and Nancy are almost finished
putting the marker set on Jo. This will let the special
motion-capture cameras track her movements.

The 3-dimensional (3D) analysis performed by CGMA at The Children’s Hospital is comprised of several different tests, including kinematics, kinetics and stride characteristics. This 3D understanding of your child is a critical piece of the information that will enable the CGMA care team to more accurately assess abnormalities occurring throughout her movement.

3D Motion Kinematics

3D Motion Kinematics creates a 3-dimensional picture of how your child moves and walks. Small markers, similar to the electrodes used in the previous step, are used to help the cameras and computer software develop 3-dimensional joint motion data. These markers are different in that they are small reflective balls, similar to ping pong balls, that attach to your child’s skin with a small circular sticker. Markers are placed on specific bony landmarks of the pelvis and both lower extremities, and in some cases, the trunk and upper extremities.

Special cameras are located throughout the room and track these markers on your child as she walks across the room, capturing the data needed to create a 3-dimensional picture. This test is done as naturally as possible, barefoot with no assistive devices. As with the electrodes, they can cause some mild irritation when they are removed, but many patients say they just feel like removing a very small bandage or sticker.

Jo’s got the marker set on and she’s ready to walk
for the motion-capture cameras!

Your child’s data are then compared to graphs of normal gait to identify abnormal or unusual patterns of motion, as well as the magnitude of her variation from norm.

3D Motion Kinetics

In addition to the markers, we also measure the force your child gives off when walking. Motion kinetics describes the physical forces that produce joint motions during walking. Specifically, the foot/floor contact forces during the walking trial are measured directly by custom force platforms imbedded in the floor.

Stride Characteristics

Measurement of average walking velocity, cadence, stride length, gait cycle time, double limb support time and single limb support time are collectively referred to as Stride Characteristics. The CGMA staff compares your child’s stride characteristics to typically developing children’s to identify how your child’s needs may be different. They are all part of the complete analysis provided.

Step 5: Data Analysis and Recommendation