St Vincent’s Hospital Musculoskeletal Outpatient Physiotherapy Department provide rehabilitation treatments to their patients. They needed a method of consistently measuring human balance on one leg, over multiple physiotherapy sessions, as a means of assessing the patients’ response to their prescribed exercise program.

EnvisEng delivered a custom-built hardware and software analysis system to St Vincent’s Hospital, at a lower price point than any available  off-the-shelf force plate measurement system. The solution included an accurate “industrialised” Wii-fit style balance board, along with data acquisition equipment and bespoke software to meet the precise needs of St Vincent’s patient rehabilitation and treatment program.


The force plate itself was fabricated out of steel, with a square footprint of 750 x 750mm. Four load cells were located in the corners of the force plate. The top plate that the patient stands on was covered with a non-slip flooring laminate for safety and aesthetics.

The software application was written in LabVIEW, and has the following high-level features:

  • Multiple test modes:
    • Single leg balance
    • Repeated knee bends on one leg
    • Calf raise
    • Hop
  • Simple and Intuitive test procedure, with real-time balance plot and overall balance “score”
  • The balance “score” is calculated by the software and based on the overall width and height of the figure drawn by the movement of the centre of mass in the relative XY plane, over the duration of a test.
  • Patient-based data files to be recorded in a human-readable file format
  • Comparison mode for comparing current and past test results for a patient

The entire system was delivered to St Vincent’s hospital, at around half the price of available off-the-shelf force plate measurement systems, with the exact features, specifications and user interface required by the customer.

As the system is based on a modular data acquisition platform and custom-built software application, the customer has the option to expand the capabilities of the system as needed in the future. This may include more detailed analysis features, additional test modes, increased weight ratings… the possibilities are endless.

National Instruments Case Study