Search Results (11)

Conventional vibrational systems associated with proprioception are mostly equipped with a single standard frequency and amplitude. This feature often fails to show kinesthetic illusion on different subjects, as different individuals respond to different frequencies and amplitudes. Additionally, different muscle groups may also require the flexibility of frequencies and amplitudes. We developed a custom vibrational system that is equipped with flexible frequency and amplitude, adapted to a custom graphical user interface (GUI). Based on the user’s criteria, the proposed vibrational system enables a wide range of frequencies and amplitudes that can be swept under a single platform. In addition, the system uses small linear actuators that are wearable and attach to the subject without the need for restrictive straps. The vibrational system was used to model trunk proprioceptive impairment associated with low back pain. Low back pain is the leading cause of disability worldwide. It is mostly associated with impaired postural control of the trunk. For postural control, the somatosensory system transmits proprioceptive (position sense) information from the sensors in the skin, joints, muscles, and tendons. Proprioceptive studies on trunk muscles have been conducted where the application of vibration at a set amplitude and frequency across all participants resulted in altered proprioception and a kinesthetic illusion, but not in all individuals. To assess the feasibility of the system, we manipulated the trunk proprioception of five subjects, demonstrating that the vibrational system is capable of modulating trunk proprioception and the value of customizing parameters of the system to obtain maximal deficits from individual subjects. Full article

This study aimed to quantify the postures and muscle activity while parks and gardens workers operated ride-on mowers during a typical shift. Eight participants operated ride-on mowers in the same park but on different terrains (flat and undulating). Body postures and muscle activity were collected wirelessly and unobtrusively. Participants adopted a forward-flexed seated posture with the predominant movement being head rotation. Oscillatory movements (20–40° from neutral) of the thorax in all three planes of movement were noted in all participants. Low levels (<30% MVIC) of muscle activity were recorded in all muscles tested. These levels were elicited for most (>90%) of the recording time. Higher (>50% MVIC) activation levels were interspersed through the data, but these were not sustained. There was no difference in posture or muscle activity between the flat and undulating terrain. The forward-flexed posture combined with vibration can increase the risk of discomfort and injury in the low back while ride-on mowing. The low levels of muscle activity suggest participants did not actively brace for the occupational situation and task. The large inter-participant difference in posture attests to subjective variation to accommodate muscular stress, and this may not be optimal for injury mitigation. Full article

This study examined the impact of personalizing muscle vibration parameters on trunk control. We assessed how altered trunk extensor muscle (TEM) proprioception affects seated trunk control in healthy controls (HCs). To explore the link between altered TEM proprioception and impaired trunk control in chronic low back pain (cLBP), we performed equivalence testing between HCs undergoing TEM vibration and cLBP without vibration. Twenty HCs performed active joint reposition error (AJRE) testing to determine personalized vibration parameters. Each participant maintained balance on an unstable chair with eyes open and closed, with and without TEM vibration. We compared trunk control between HCs and twenty age- and sex-matched cLBP participants, using mean velocity and 95% confidence ellipse area of center-of-pressure changes to quantify trunk postural control. Equivalence was examined by comparing mean difference scores to minimal detectable change values and calculating between-group effect sizes. Personalized vibration parameters led to larger lumbopelvic repositioning errors (d = 0.89) than any single vibration frequency (d = 0.31–0.36). In healthy adults with no back pain, vision had large effects on postural control (η_p² = 0.604–0.842), but TEM vibration had no significant effects (p > 0.105) or interactions with vision (p > 0.423). Between-group effect sizes (d = 0.32–0.51) exceeded our threshold for performance equivalence (d < 0.2). Muscle vibration altered position sense during AJRE testing, and personalizing parameters amplified this effect. However, TEM vibration had minimal impact on seated trunk postural control in adults with no back pain and did not lead to performance degradation comparable to that in cLBP. Full article

(1) Background: The aim of this study was to investigate and compare the effect of sensorimotor training on transversus abdominis activation. (2) Methods: Seventy-five patients with chronic low back pain were randomly assigned to one of three groups (whole body vibration training using Galileo^®, coordination training using Posturomed^®, or physiotherapy (control)). Transversus abdominis activation was measured by using sonography pre- and post-intervention. Second, changes in clinical function tests and their correlation with the sonographic measurements were determined. (3) Results: All three groups showed an improvement in activation of the transversus abdominis post-intervention, with the Galileo^® demonstrating the largest improvement. There were no relevant (r > 0.5) correlations between activation of the transversus abdominis muscle and any clinical tests. (4) Conclusions: The present study provides evidence that sensorimotor training on the Galileo^® significantly improves the activation of the transversus abdominis muscle. Full article

Several studies agree that mechanical vibration can induce physiological changes at different levels, improving neuromuscular function through postural control strategies, muscle tuning mechanisms and tonic vibration reflexes. Whole-body vibration has also been reported to increase bone mineral density and muscle mass and strength, as well as to relieve pain and modulate proprioceptive function in patients with osteoarthritis or lower back pain. Furthermore, vibratory training was found to be an effective strategy for improving the physical performance of healthy athletes in terms of muscle strength, agility, flexibility, and vertical jump height. Notably, several benefits have also been observed at the brain level, proving to be an important factor in protecting and/or preventing the development of age-related cognitive disorders. Although research in this field is still debated, certain molecular mechanisms responsible for the response to whole-body vibration also appear to be involved in physiological adaptations to exercise, suggesting the possibility of using it as an alternative or reinforcing strategy to canonical training. Understanding these mechanisms is crucial for the development of whole body vibration protocols appropriately designed based on individual needs to optimize these effects. Therefore, we performed a narrative review of the literature, consulting the bibliographic databases MEDLINE and Google Scholar, to i) summarize the most recent scientific evidence on the effects of whole-body vibration and the molecular mechanisms proposed so far to provide a useful state of the art and ii) assess the potential of whole-body vibration as a form of passive training in place of or in association with exercise. Full article

Background: Chronic low back pain (CLBP) is one of the most common musculoskeletal disorders. Physical activity (PA) is often recommended as part of the management of CLBP, but to date, no one particular exercise has been shown to be superior. Vibrating exercise equipment (VEE) is widely available and used despite little scientific evidence to support its effectiveness in the prevention and treatment of musculoskeletal problems. The aim of this study was to evaluate the efficiency of using VEE compared with sham-VEE in women with CLBP. Methods: A randomized (1:1 randomization scheme) single-blinded sham-controlled intervention study was conducted. Through simple randomization, 92 women aged 49–80 years were assigned to one of two groups: VEE (the experimental group) and sham-VEE (the control group). The VEE and sham-VEE intervention consisted of aerobic exercises with specific handheld equipment. Both groups performed physical activity twice weekly for 10 weeks. The erector spinae muscles’ bioelectrical activity (using an eight-channel electromyograph MyoSystem 1400L), lumbar range of motion (Schober’s test) and pain intensity (visual analog scale) were measured in all participants at baseline and after 10 weeks. Results: There was a significant decrease in the bioelectrical activity of the erector spinae muscles during flexion movement (left: Me = 18.2 before; Me = 14.1 after; p = 0.045; right: Me = 15.4 before; Me = 12.6 after; p = 0.010), rest at maximum flexion (left: Me = 18.1 before; Me = 12.5 after; p = 0.038), extension movement (right: Me = 21.8 before; Me = 20.2 after; p = 0.031) and rest in a prone position (right: Me = 3.5 before; Me = 3.2 after; 0.049); an increase in lumbar range of motion (Me = 17.0 before; Me = 18.0 after; p = 0.0017) and a decrease in pain intensity (Me = 4.0 before; Me = 1.0 after; p = 0.001) following a program of PA in the VEE group. Conclusions: No significant changes were found in intergroup comparisons. The beneficial changes regarding decreased subjective pain sensation in the VEE and sham-VEE groups may be due to participation in systematic physical activity. However, PA with vibrating exercise equipment could be a prospective strategy for increasing lumbar range of motion and for decreasing pain and erector spinae muscle activity in people with CLBP. Full article

Operators of heavy equipment are often exposed to high levels of whole-body vibration (WBV), which has been associated with a variety of adverse health outcomes. Although anthropometric factors are known to impact vibration dose and risk of low back pain, studies have yet to investigate the influence of anthropometric factors on muscle activation during WBV exposure. This study quantified the relationships between muscle activation, vibration frequency, body mass, body mass index (BMI), and height both pre- and post-fatigue. Muscle activation of the external oblique (EO), internal oblique (IO), lumbar erector spinae (LE) and thoracic erector spinae (TE) were quantified using surface electromyography. Results indicate increased activation with increased mass, BMI, and frequency for the LE, TE, and IO, which may be a result of increased activation to stabilize the spine. Decreased muscle activation with increased height was seen in the TE, IO, and pre-fatigue EO, which could indicate higher risk for low back injury since height is associated with increased forces on the spine. This may contribute to the association between increased low back pain incidence and increased height. Results suggest that ISO 2631-1 health guidance should incorporate anthropometric factors, as these may influence muscle activation and back injury risk. Full article

Military foot marches account for 17–22% of Army musculoskeletal injuries (MSI), with low back pain (LBP) being a common complaint. Core-exercise and whole-body vibration (WBV) have been shown to decrease LBP in patients with chronic low back MSI. This study investigated if WBV and/or core-exercise influenced LBP or posture associated with a military ruck march. A randomized control trial with three groups: (1) WBV and core-exercise (WBVEx); (2) core-exercise alone (Ex); and (3) control evaluated the effects of core-exercise and WBV on LBP during/after a two 8 K foot marches with a 35 lb rucksack. The intervention groups completed three weeks of core-exercise training with/without WBV. Outcome measurements included visual analog scale (VAS), algometer, posture and electromyography (EMG). LBP, pressure threshold, and posture were elevated throughout the foot march regardless of group. LBP remained elevated for 48 h post foot march (p = 0.044). WBVEx and Ex did not have a significant effect on LBP. WBVEx and Ex both decreased muscle sensitivity and increased trunk flexion (p < 0.001) during the second foot march (FM2). The 8 K foot marches significantly increased LBP. Core-exercise training with/without WBV decreases low back muscle sensitivity. WBV and core-exercise increases trunk flexion which may help improve performance and may influence LBP. Full article

Whole body vibration has been proven to improve the health status of patients with fibromyalgia, providing an activation of the neuromuscular spindles, which are responsible for muscle contraction. The present study aimed to compare the effectiveness of two types of whole body vibrating platforms (vertical and rotational) during a 12-week training program. Sixty fibromyalgia patients (90% were women) were randomly assigned to one of the following groups: group A (n = 20), who performed the vibration training with a vertical platform; group B (n = 20), who did rotational platform training; or a control group C (n = 20), who did not do any training. Sensitivity measures (pressure pain and vibration thresholds), quality of life (Quality of Life Index), motor function tasks (Berg Scale, six-minute walking test, isometric back muscle strength), and static and dynamic balance (Romberg test and gait analysis) were assessed before, immediately after, and three months after the therapy program. Although both types of vibration appeared to have beneficial effects with respect to the control group, the training was more effective with the rotational than with vertical platform in some parameters, such as vibration thresholds (p < 0.001), motor function tasks (p < 0.001), mediolateral sway (p < 0.001), and gait speed (p < 0.05). Nevertheless, improvements disappeared in the follow-up in both types of vibration. Our study points out greater benefits with the use of rotational rather than vertical whole body vibration. The use of the rotational modality is recommended in the standard therapy program for patients with fibromyalgia. Due to the fact that the positive effects of both types of vibration disappeared during the follow-up, continuous or intermittent use is recommended. Full article

The purpose of this study was to investigate the functional decline in proprioceptors in patients with low back pain (LBP) by evaluating the entire range of response frequencies of proprioceptors. In previous studies, the function of proprioceptors was only evaluated by single frequency vibrations. However, because it is assumed that individual differences exist in response frequencies of proprioceptors, we developed a method using vibration with sweep frequency covering the entire range of response frequencies of proprioceptors. The center of pressure was determined in 35 elderly patients with non-specific LBP (NSLBP) and 28 elderly individuals with non-LBP (NLBP) during upright stances on a balance board without vision. Local vibratory stimulations to lower leg or trunk muscles were continuously varied between 27 and 272 Hz over 60 s to evaluate the proprioceptive predominance of a body location using the relative proprioceptive weighting ratio (RPW). Compared with the NLBP group, the NSLBP group exhibited a lower RPW value for the Vater-Pacini corpuscles. Thus, the NSLBP group relied more on the input of Vater-Pacini corpuscles in the trunk. A reduction in lower leg sensitivity at the Vater-Pacini corpuscles in the NSLBP group was observed. Full article

Rehabilitation and mobility training of post-stroke patients is crucial for their functional recovery. While traditional methods can still help patients, new rehabilitation and mobility training methods are necessary to facilitate better recovery at lower costs. In this work, our objective was to design and develop a rehabilitation training system targeting the functional recovery of post-stroke users with high efficiency. To accomplish this goal, we applied a bilateral training method, which proved to be effective in enhancing motor recovery using tactile feedback for the training. One participant with hemiparesis underwent six weeks of training. Two protocols, “contralateral arm matching” and “both arms moving together”, were carried out by the participant. Each of the protocols consisted of “shoulder abduction” and “shoulder flexion” at angles close to 30 and 60 degrees. The participant carried out 15 repetitions at each angle for each task. For example, in the “contralateral arm matching” protocol, the unaffected arm of the participant was set to an angle close to 30 degrees. He was then requested to keep the unaffected arm at the specified angle while trying to match the position with the affected arm. Whenever the two arms matched, a vibration was given on both brachialis muscles. For the “both arms moving together” protocol, the two arms were first set approximately to an angle of either 30 or 60 degrees. The participant was asked to return both arms to a relaxed position before moving both arms back to the remembered specified angle. The arm that was slower in moving to the specified angle received a vibration. We performed clinical assessments before, midway through, and after the training period using a Fugl-Meyer assessment (FMA), a Wolf motor function test (WMFT), and a proprioceptive assessment. For the assessments, two ipsilateral and contralateral arm matching tasks, each consisting of three movements (shoulder abduction, shoulder flexion, and elbow flexion), were used. Movements were performed at two angles, 30 and 60 degrees. For both tasks, the same procedure was used. For example, in the case of the ipsilateral arm matching task, an experimenter positioned the affected arm of the participant at 30 degrees of shoulder abduction. The participant was requested to keep the arm in that position for ~5 s before returning to a relaxed initial position. Then, after another ~5-s delay, the participant moved the affected arm back to the remembered position. An experimenter measured this shoulder abduction angle manually using a goniometer. The same procedure was repeated for the 60 degree angle and for the other two movements. We applied a low-cost Kinect to extract the participant’s body joint position data. Tactile feedback was given based on the arm position detected by the Kinect sensor. By using a Kinect sensor, we demonstrated the feasibility of the system for the training of a post-stroke user. The proposed system can further be employed for self-training of patients at home. The results of the FMA, WMFT, and goniometer angle measurements showed improvements in several tasks, suggesting a positive effect of the training system and its feasibility for further application for stroke survivors’ rehabilitation. Full article