Pilot study on the use of SRT Zeptor®medical
in the post-operative rehabilitation of patients with knee prostheses
Vibration stimuli have been the subject of intensive research for years. Now that it has been recognized that these stimuli also have positive effects on the neuromuscular and neuroendocrine systems, research in the fitness and preventive fields is frequent and is increasingly being used in the medical and therapeutic environment.
In contrast to the sinusoidal two-dimensional vibration devices, the SRT Zeptor®medicaldevices have been in use for some time. They transmit three-dimensional oscillations in the sense of stochastic resonance vibrations (random frequency vibrations and harmonics) to the human body via two separate and independent foot plates. These devices operate in the low frequency range (1-12Hz).
As part of a pilot study conducted for the Master's Degree in Physical Therapy Sciences at the University of Applied Sciences SUPSI Landquart, the treatment effects of whole-body vibration in patients following surgical treatment of gonarthrosis (with total or unicondylar knee prosthesis) were to be investigated. The aim of the pilot study was to determine whether the use of the SRT Zeptor®medicalin functional follow-up treatment improves walking ability and gait safety compared to isolated functional follow-up treatment.
This could then provide an opportunity to increase the efficiency of follow-up treatment and discharge patients from postoperative rehabilitation in a better general condition. Therapy programs in conjunction with Zeptoring® could have a positive impact on postoperative rehabilitation due to their greater efficiency in stimulating nerve cells and muscles.
The 9 test subjects were randomly divided into 2 groups (ZEPTOR PLUS and KON). Both completed a predetermined program consisting of conventional physiotherapy with a home program. The ZEPTOR PLUS group completed their movement coordination program twice a week for 6 weeks on the SRT Zeptor®medicalinstead of on a hard surface like the KON group. All other therapy interventions were planned in the same way. At the time of the study, no further studies had been published on the follow-up treatment of knee prostheses with stochastic resonance therapy and the SRT Zeptor®medical.
During training with vibration stimuli, mechanical oscillating vibrations are first transmitted to the feet via floor plates and then further cranially. This means that the body is subjected to periodic changes in force, acceleration and deflection. The human body is a system whose components vibrate in response to a specific stimulus at a suitable frequency (natural frequency). Excessive or inadequate loads in terms of acceleration (rigid components) or frequencies (soft tissue) can lead to damage to structures and organs. When using whole-body vibration training, it is therefore important to consider the frequency, direction and duration of exposure as well as the average acceleration. In addition, the current load capacity of the entire body should be taken into account when planning the dosage. For this reason, the load caused by the stochastic vibrations primarily had to be investigated with regard to its damaging influence on the knee prostheses. To confirm the information provided by the manufacturer of the SRT Zeptor® medical regarding the intensity of the medical programs, the accelerations in all three axes were therefore measured using an MSR165 data logger and compared with the functional load during walking.
During the measurement, the data logger was fixed ventro-medially on the tibia using a non-elastic fixation band with Velcro fastener. The measurements of the intensities "strong", "moderate", "medium" and "light" planned for the studies were then carried out on the same person. A break was taken between each measurement to prevent excessive fatigue.
Measurement results and comparative values
The maximum axial load values for the knee prostheses program were in the region of +2.1 g. Minus the standard load of 1 g, this results in an additional load of approx. +1.1 g.
As a control value, measurements were taken during walking on the 6-minute walking test route, as the patients were all allowed and able to walk without a cane at the time of the ZEPTOR intervention. At a brisk pace, this resulted in additional load values of +1.4 g to +2.4 g. The maximum values are significantly higher, especially when starting, turning at the turning points and stopping, than with the strongest setting of the ZEPTOR.
Result regarding the possible use of the SRT Zeptor®medicalvibration plate
The measurements carried out with the MSR165 data logger as part of the pilot study thus showed that treatment with the SRT Zeptor®medicalvibration plate is also possible for patients who have undergone knee prosthesis surgery. The maximum accelerations for Zeptoring® were in the maximum range of 1.1 g, whereas for walking and turning they were three times the above range.
None of the test subjects in the group had to discontinue treatment with Zeptoring® or made negative comments. The test subjects never felt overwhelmed by the continuous slow increase in intensity. Of the 5 programs for knee prostheses tested and recommended by the manufacturer, the "light", "medium" and "moderate" programs were used and proved to be easy to use.
However, it should be noted that the maximum loads occur mainly in the middle phases and depend on the position. Increased heel loading triggers peaks!