Effect of Increasing Cadence on Knee Joint Load in Patients with Medial Compartment Knee Osteoarthritis: A Pilot Observational Study

Slow gait speed is a common phenomenon in patients with knee osteoarthritis (KOA), which is deemed to reduce the joint load but leads to a series of related problems. It is still necessary to further study how to maintain or increase walking speed without significantly increasing the knee joint load. In this study, we investigated the effect of increasing cadence to improve walking speed on knee joint load in patients with unilateral medial compartment KOA. Eleven moderate (Kellgren-Lawrence grade=2-3) patients with unilateral medial KOA were recruited. All the participants were indicated to walk along a 5-meter walkway with normal walk (NW) and fast walk (FW). NW: self-select walking speed, FW: mostly increasing cadence to fast walk. Three to five minutes walk training before every kind of walking tests to ensure that they were familiar with the procedure and the difference of walking speed of every trial in each test was less than 10%. Every test was repeated for 5 times. The gait analysis system that composed with 15 optical cameras and 2 AMTI force plates was used to collect the kinematics and kinetics parameters of NW and FW, and observed the effects of improved walking speed mainly by increasing step rate on the affected knee. Compared with NW (58.078 +/- 4.588), the knee range of motion(ROM) of FW (57.493 +/- 5.120) had no significant change (p=0.684). Ankle ROM of FW (19.371 +/- 10.274) was significantly lower than NW (24.556 +/- 6.544) (p=0.043). There were significant differences in the first peak of knee adduction moment (peak1_KAM) and the first and second peak of flexion moment (Peak1 &peak2_KFM) between NW and FW (p<0.05), while there was no significant difference in KAM impulse (p=0.306). For patients with medial KOA, rapid walking with increased cadence may significantly increase KAM peaks and the first peak of KFM, but it will not affect the overall KAM impulse.it can be further explored that the effect of increase cadence with different patterns on the lower extremity joint load in patients with medial KOA, and the possibility of increasing cadence as a modified gait program can be developed.