Gait analysis is a medical technology used to measure how a person walks. It helps clinicians understand movement problems that may not be obvious by eye alone. By recording body motion, foot forces, and timing, a gait lab can reveal patterns linked to injury, neurological conditions, joint disease, or recovery after surgery.
This matters because better measurements can lead to better treatment decisions.
Key Facts
- Walking speed = distance walked / time taken
- Stride length is the distance between two successive contacts of the same foot.
- Cadence = number of steps / minute
- Ground reaction force is the force the floor exerts back on the foot during contact.
- Joint angle data show how the hip, knee, and ankle move through the gait cycle.
- A gait cycle runs from one foot strike to the next foot strike of the same foot.
Vocabulary
- Gait analysis
- Gait analysis is the measurement and study of how a person walks.
- Motion capture
- Motion capture uses cameras and markers or sensors to track body movement in three dimensions.
- Force plate
- A force plate is a floor sensor that measures forces from the foot during standing or walking.
- Cadence
- Cadence is the number of steps a person takes per minute.
- Gait cycle
- The gait cycle is one complete walking pattern from one foot contact to the next contact of the same foot.
Common Mistakes to Avoid
- Confusing step length with stride length: step length is from one foot to the other, while stride length is from one foot back to the same foot.
- Ignoring walking speed: many gait measurements change when a patient walks faster or slower, so speed must be recorded or controlled.
- Treating one trial as enough data: a single walk may be affected by balance, attention, or sensor error, so clinicians usually compare multiple trials.
- Reading force plate data as body weight only: the force changes during movement and includes braking, pushing, and vertical loading forces.
Practice Questions
- 1 A patient walks 10 m in 8 s during a gait test. What is the patient's walking speed in m/s?
- 2 A patient takes 90 steps in 60 s. What is the patient's cadence in steps per minute?
- 3 A gait lab finds that a patient has a shorter stance time on the right leg than on the left leg. Explain what this might suggest and why a clinician would compare it with force plate and motion-capture data.