What to Expect for Your Child’s Gait or Sports Analysis

When you arrive at the center, you’ll check in for your child’s appointment and fill out a few forms.  Our physical therapist — who stays with your child throughout their entire visit — will start with the physical exam to collect a variety of information, including:

• Height and weight
• Measurements such as leg length, knee and ankle widths, others
• Strength and range of motion at hips, knees and ankles
• Muscle selectivity and spasticity
• Foot position when standing still
• Balance when sitting and standing
• Sensation and skin condition

We analyze this information, as well as prior medical history, and add it to the motion data we collect during the rest of your child’s analysis.

During this step, your child’s physical therapist will take them to the lab and ask them to walk the distance of the room several times. This can also include running and other movements, if possible. This is challenging for some kids, but we work with your child to make sure they are as comfortable as possible throughout the appointment.

We’ll record video of your child’s session for our movement analysis specialists to review. This recording allows our team to observe your child walking at normal speed, slow motion and frame by frame.

The 3D analysis we perform includes several calculations, including kinematics, kinetics and stride characteristics (specifically for gait). These tests allow us to create a computer-generated model of your child’s skeleton to more accurately assess their movement challenges.

For gait analysis, the physical therapist will ask your child to walk a line the length of the room. At first, your child will complete this barefoot and, if possible, without orthotics or assistive devices. This helps us capture their most natural walking form. Then, if your child has an assistive device, the therapist will ask them to walk with it.

For a sports analysis, your child will perform squatting, jumping and running movements that may mimic how they perform in their sport.

Motion capture cameras around the room will record your child’s movements in 3D from a 360-degree view.

What is motion capture?

This is when your child gets to put on the "robot suit." It’s an interesting exercise where they perform again for the cameras, only this time they get to dress up.

Motion capture is the same technology used to make some of your child’s favorite animated movie characters and video games. It records movement using special cameras and computer programs. This provides us a more complete picture of your child’s movement.

3D motion kinematics: A picture of movement

Our 3D motion capture system creates a 3D picture of how your child moves and walks. We place small markers on different bony parts of the body. These markers are reflective balls — like small ping pong balls — that stick to your child’s skin. We typically place markers on the pelvis and legs but we may include the midsection and arms if necessary.

Cameras throughout the room track these markers on your child as they walk, squat or jump, capturing the data needed to create a 3D picture. We do this test   as naturally as possible  — barefoot for gait analysis and in athletic shoes for sports.  Removing the markers is similar to removing a small bandage or sticker.

For a gait analysis, we compare your child’s walking pattern to other children. This helps us identify certain patterns of motion and measure how different those patterns are.

3D motion kinetics: Measuring the force of moving

In addition to motion kinematics, we also study motion kinetics, or the physical force that produces joint movement when walking. Custom force platforms embedded into the floor measure the force of a foot landing.

Stride characteristics: Measuring how your child walks in a gait analysis

Stride is a cycle from the first contact of one foot with the ground to the next time the same foot contacts the ground. During this part of the analysis, we measure your child’s stride characteristics, like average walking speed, cadence, stride length, symmetry and more. Our staff compares your child’s measures to other children to identify potential health issues.

Isokinetic dynamometer: Measuring your child’s strength in a sports analysis

Isokinetic means constant speed. Our isokinetic dynamometer machine measures how hard your child’s muscles work as they move or how much force their muscles can generate. Your child will complete several repetitions of motion at different speeds while the machine measures how much force their muscles produce. This allows us to look for muscle strength weaknesses and imbalances. This test is only part of a sports analysis.

Plantar pressures: A picture of your footprint in a gait analysis

Plantar pressure measurements show us what parts of the feet are in contact with the ground and how weight is distributed as your child steps from one foot to the other. A special black mat embedded into the floor records the foot pressure distribution when a foot meets it. This data looks like a rainbow map of your child’s feet.

As your child is walking, we also collect data on how their muscles are working. We use dynamic electromyography for this, which shows when different muscles activate during movement.

What to expect from dynamic electromyography

We attach small sensors called surface electrodes to the parts of your child’s body that need evaluation, typically the front and back of the thigh muscles, hamstrings, shin and calf muscle. These sensors wirelessly send information to the computer. We’ll ask your child to walk or perform other activities while we measure the firing of each individual muscle.

The surface electrodes attach to the skin like stickers. They do not bother most kids and are easy to remove after the test. Our staff is specially trained to make sure this is done as easily and quickly as possible.

Dynamic electromyography with fine-wire electrodes

Sometimes we need more information than the basic dynamic electromyography test can provide. For deep muscles that we can’t measure from the surface, your therapist might use a fine-wire electrode, which is a different type of sensor than the surface electrode.

Fine-wire electrodes are tiny wires that we insert through the skin directly into the muscles that need further evaluation. While this is an invasive technique that may be briefly painful when we insert the needle, most children find it only mildly irritating with few aftereffects. This technique provides valuable information about the cause of movement problems, especially in kids with specific types of foot abnormalities.

Fine-wire electromyography is not part of a typical visit, and we only use it if we can’t accurately assess a muscle with a surface electrode.