Third biomechanical study of a novel tri-compartment offloader knee brace
Research Summary
Third biomechanical study of a novel tri-compartment offloader
Effect of a tri compartment offloader knee brace on knee moments and quadriceps activity during a chair rise and lower and stair descent in individuals with knee osteoarthritis.
Bishop, E.L., Kuntze, G., and Ronsky, J.L. (2020). Osteoarthritis and Cartilage. 28: S243-S244.
Presented at 2020 AOPA National Assembly
Key Findings
Improved Support During Key Actions
During chair rise and lower and stair descent, wearing a TCO resulted in significantly less quadriceps muscle effort and fewer internal knee extension moments (Fig. 2, 3).
Significantly Reduced Pain Scores
Patients wearing a TCO reported significantly lower pain scores compared to other bracing conditions (Fig. 4).
Replicates & Extends Previous Research
Corroborates PF and TF offloading capabilities of a TCO, which were demonstrated in previous studies.1– Budarick, A.R. et al. 2020. J. Biomech.Eng. 142.
– McGibbon, C.A. et al. 2020. Front. Bioeng. Biotech.
Research at the McCaig Institute for Bone and Joint Health (University of Calgary) was conducted to examine the biomechanical effects of the Spring Loaded Tri-compartment Offloader (TCO) in patients with multi-compartment knee OA. Adult patients between the ages of 45 and 75 with moderate to severe multi-compartmental knee OA were recruited to participate in the study. Following informed consent, participants were fitted with a TCO knee brace. After an acclimatization period, participants were asked to perform several activities of daily living while wearing the brace and while unbraced. Three-dimensional movement data and muscle activity data were collected from a state-of-the-art motion capture system and ground reaction forces were collected for the braced leg (Figure 1). Finally, participants were asked to report on their level of pain experienced while performing the movements without the brace and while wearing the brace.
Figure 1
A study participant wearing the Spring Loaded brace while climbing stairs during biomechanical data collection at the Clinical Movement Assessment Lab.
Results demonstrate that wearing the TCO lowers quadriceps muscle effort and internal knee extension moments during a chair rise and lower movement as well as a stair descent (Figure 2). These findings are important because both of these measures have been shown to contribute to patellofemoral (PF) and tibiofemoral (TF) joint offloading. The results therefore corroborate earlier research demonstrating the capacity of a TCO to produce PF and TF joint offloading.2– Budarick, A.R. et al. 2020. J. Biomech. Eng. 142.
– McGibbon, C.A. et al. 2020. Front. Bioeng. Biotech.
This study is the first to capture the effect of wearing the TCO on quadriceps muscle activity in knee OA patients and provides strong evidence supporting the proposed mechanism of offloading the knee joint. Participants reported lower levels of pain while wearing the Spring Loaded brace, suggesting that there is an immediate effect of the TCO on knee pain during these weight-bearing activities.
Figure 2
Knee extension moment for the chair rise and lower and stair descent in 3 brace conditions. Bars represent standard deviation and * represents significant difference between bracing conditions.
Figure 3
VM and VL muscle power for the chair rise and lower and stair descent in 3 brace conditions. Bars represent standard deviation and * represents a significant difference between bracing conditions.
Figure 4
Average reported pain scores (n=6) for OFF (white), LOW (grey) and HIGH (black). * represents a significant difference between bracing conditions.
Video: Research Overview
Dr. Emily Bishop presents study findings at the 2020 AOPA National Assembly
In this recorded session, Dr. Bishop discusses research findings on a Spring Loaded brace's assistive moment and effect on pain.
Collaborators

Dr. Emily L. Bishop
University of Calgary

Dr. Gregor Kuntze
University of Calgary

Dr. Janet L. Ronsky
University of Calgary
Partner Institutions

University of Calgary
Spring Loaded is currently collaborating with researchers at the University of Calgary to understand how the use of the Levitation knee brace influences user-reported outcomes such as pain, knee function, quality of life, physical activity levels and use of medication and other treatments. U of C researchers are also quantifying the potential of Spring Loaded bracing to offload the patellofemoral and tibiofemoral knee compartments.

Mitacs
Mitacs is a national, not-for-profit organization that has designed and delivered research and training programs in Canada for 20 years. Working with 70 universities, 6,000 companies, and both federal and provincial governments, Mitacs builds partnerships that support industrial and social innovation in Canada.