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Error message: The movement amplitude is insufficient.
These error messages can occur during Hip Joint Center calibration or Knee Joint Center Calibration when there is not enough range of motion.
Here are a few tips to proceed with the movement:
Increase Patient Movement
For the:
- Hip Joint Center calibration: Ask the patient to swing their leg in a larger circle, in front of and behind the trunk. Position the patient in a comfortable standing position where they can hold on. Ask the patient to stand tall, engage their abdominal muscles, and keep their pelvis stable while performing the movement.
- Knee Joint Center calibration: Ask the patient to increase their flexion-extension movement.
How to Help a Patient with Hip Range of Motion Limitation
Some patients have hip range of motion limitations, requiring a modification to the procedure. There are other possible alternatives to the HJC calibration circumduction:
- A leg swing: The patient performs a simple leg swing in a straight line forward and backward, then side to side, then forward and backward again, and so on.
- A foot slide: Keeping the foot near the treadmill surface, the patient slides their foot forward and then outward and backward in the shape of the letter D (for the right side), and repeats.
- Assist the patient manually: The Evaluator can hold the patient’s knee or proximal tibia in their hands, without blocking the view of the femoral tracker, and manually move the femur in a circular motion.
