Knee Connect: Physiotherapy Exercise Performance With Visual Feedback After Total Knee Arthroplasty

The research team will recruit 10 post-op total knee replacement patients who are enrolled in the Knee Class at Sunnybrook Holland Orthopaedic and Arthritic Centre to perform five exercises over two sessions. Each patient will complete five tasks.

• Quarter squats
• Standing hip flexion
• Standing knee flexion
• Sitting knee extension
• Sitting knee flexion

The first three exercises will be performed with and without visual feedback. During standing hip flexion, standing knee flexion and quarter squat exercises, patients will first perform a set of each exercise following an instruction brochure. Patients will then repeat these exercises with the Knee Connect visual feedback system. The KneeConnect will be worn during the entire session, and will record the patient's knee angle and velocity regardless of visual feedback condition.

For the next two exercises, sitting knee extension and sitting knee flexion, patients will perform the first set of exercises (3 repetitions) with visual feedback of their leg position in space but without seeing an end target. The Knee Connect will measure the knee angle during these tests. For the subsequent set, the Knee Connect system will present a visual target for the patient to achieve. This target will be 5 degrees above the patient's maximum terminal knee angle recorded without motivational targets. A third set will be completed with the knee angle target set 10 degrees above the patient's maximum. A caveat to the target modification for seated knee extensions is that target changes to hyperextension, will result in a full extension target.

After each participant has completed the exercises with the KneeConnect system they will be asked to complete a short survey. The survey has been designed to assess the KneeConnect's usefulness and how much participants liked using the system.

After the data collection has been completed each day, the data will be transferred from the smartphone to a secure computer. These files will then be extracted to measure:

• Knee angle during each exercise
• Knee angular velocity during each exercise

A Leven's test will be used on all of the data to assess the equality of variance in each group. Each pair of data will be compared using a paired t-test to test the difference between with/without visual feedback and with/without motivational targets.

Inclusion criteria

• Be enrolled in the "Knee Class" postoperative physiotherapy
• Be able to provide informed consent
• 3-6 weeks post-operative from primary total knee replacement surgery

Exclusion criteria

• Revision total knee arthroplasty
• Neuromuscular disorder
• Knee Stiffness (knee flexion of <90 degrees during previous Knee Class session)
• Hip Stiffness (hip flexion of <90 degrees)