Fischer et al. 2019 “Activating the somatosensory system enhances net quadriceps moment during gait”
Knee injuries and knee pain can lead to changes in walking patterns and weakness of the leg muscles, in particular the quadriceps muscle. In 2019, Fischer et al. published on the immediate effect of intermittent vibration stimulation applied to the skin around the knee via 2 bands that is timed to the walking cycle for improving quadriceps function during walking. In this study, participants with knee pain and prior injuries or disease (for example meniscus injury, osteoarthritis, or anterior cruciate ligament, ACL, injury) wore the device with vibration stimulation timed to the gait cycle, as well the same device without vibration. This research showed that the intermittent vibration increased quadriceps function during walking, measured in the gait laboratory by a parameter called the “knee flexion moment”, which is related to quadriceps muscle function, while just the compression without vibration did not. This study suggested that the vibration stimulus timed to the walking cycle can possibly restore quadriceps function in individuals with knee pain.
Fischer et al. 2020 Utilizing the somatosensory system via vibratory stimulation to mitigate knee pain during walking: Randomized clinical trial
Following this research, Fischer et al. published the longitudinal results of a controlled cross-over clinical study, in which the study participants with knee pain wore both an active treatment (the device with vibration stimulation timed to the gait cycle) as well as a passive treatment (off the shelf compressive knee bands without vibration) each for 4 weeks, with a 2-week period of washout (no treatment) between the 4-week treatments. The study participants were asked to wear the treatments for at least 1 hour per day during the active part of their day. This study demonstrated significant improvements in knee pain during walking and symptoms over the 4-week period for the active treatment (vibration stimulation timed to the gait cycle), while no significant improvements were found with the compressive off the shelf knee bands. For the active treatment, reductions in knee pain were also related to improvements in quadriceps function during walking, as measured in the gait laboratory by the “knee flexion moment” and knee flexion angle during walking. This work showed that knee pain during walking following knee injury or disease (e.g. osteoarthritis) can be improved by the use of intermittent vibration stimulation over a 4-week period.
Fischer et al. 2021 Intermittent vibrational stimulation enhances mobility during stair navigation in patients with knee pain
As part of the clinical study Fischer et al. published the longitudinal results of stair climbing. The researchers were interested in investigating the effects of vibrational stimulus synchronized to stair navigation, a more demanding task than walking, on muscle activity, knee motion, knee loading, and pain within this clinical trial. In this study, subjects were randomly assigned sequentially to both the active treatment with intermittent vibration and passive off the shelf compressive knee bands without vibration worn at the knee during motion for 4 weeks each with a 2-week washout period between treatments. The results showed that knee pain during stair navigation can be alleviated in subjects with knee pathologies by applying vibrational stimulation synchronized to motion. The stimulation appears to enhance muscle function (quadriceps) during stair ascent and control during stair descent. These results suggest the treatment with intermittent vibration stimulation could increase mobility and possibly benefit exercise therapy.