Biomedical Physics & Technology

Comparison of three different pelvic circumferential compression devices: A biomechanical cadaver study (Article)

Knops, S.P. — 2011-02-02T00:00:00Z

Background: Pelvic circumferential compression devices are designed to stabilize the pelvic ring and reduce the volume of the pelvis following trauma. It is uncertain whether pelvic circumferential compression devices can be safely applied for all types of pelvic fractures because the effects of the devices on the reduction of fracture fragments are unknown. The aim of this study was to compare the effects of circumferential compression devices on the dynamic realignment and final reduction of the pelvic fractures as a measure of the quality of reduction. Methods: Three circumferential compression devices were evaluated: the Pelvic Binder, the SAM Sling, and the T-POD. In sixteen cadavers, four fracture types were generated according to the Tile classification system. Infrared retroreflective markers were fixed in the different fracture fragments of each pelvis. The circumferential compression device was applied sequentially in a randomized order with gradually increasing forces applied. Fracture fragment movement was studied with use of a three-dimensional infrared video system. Dynamic realignment and final reduction of the fracture fragments during closure of the circumferential compression devices were determined. A factorial repeated-measures analysis of variance with pairwise post hoc comparisons was performed to analyze the differences in pulling force between the circumferential compression devices. Results: In the partially stable and unstable (Tile type-B and C) pelvic fractures, all circumferential compression devices accomplished closure of the pelvic ring and consequently reduced the pelvic volume. No adverse fracture displacement (>5 mm) was observed in these fracture types. The required pulling force to attain complete reduction at the symphysis pubis varied substantially among the three different circumferential compression devices, with a mean (and standard error of the mean) of 43 ± 7 N for the T-POD, 60 ± 9 N for the Pelvic Binder, and 112 ± 10 N for the SAM Sling. Conclusions: The Pelvic Binder, SAM Sling, and T-POD provided sufficient reduction in partially stable and unstable (Tile type-B1 and C) pelvic fractures. No undesirable overreduction was noted. The pulling force that was needed to attain complete reduction of the fracture parts varied significantly among the three devices, with the T-POD requiring the lowest pulling force for fracture reduction. Clinical Relevance: The results of this biomechanical cadaver study suggest that circumferential compression devices can provide early, noninvasive circumferential compression in partially stable and unstable pelvic fractures for advantageous realignment and reduction of these fractures without overreduction. Clinical effectiveness of circumferential compression devices in patients with pelvic ring fractures remains to be determined. Copyright

Statistical analysis of structural brain connectivity (Article)

Boer, R. de — 2010-11-22T00:00:00Z

We present a framework for statistical analysis in large cohorts of structural brain connectivity, derived from diffusion weighted MRI. A brain network is defined between subcortical gray matter structures and a cortical parcellation obtained with FreeSurfer. Connectivity is established through minimum cost paths with an anisotropic local cost function and is quantified per connection. The connectivity network potentially encodes important information about brain structure, and can be analyzed using multivariate regression methods. The proposed framework can be used to study the relation between connectivity and e.g. brain function or neurodegenerative disease. As a proof of principle, we perform principal component regression in order to predict age and gender, based on the connectivity networks of 979 middle-aged and elderly subjects, in a 10-fold cross-validation. The results are compared to predictions based on fractional anisotropy and mean diffusivity averaged over the white matter and over the corpus callosum. Additionally, the predictions are performed based on the best predicting connection in the network. Principal component regression outperformed all other prediction models, demonstrating the age and gender information encoded in the connectivity network.

Cerebral Visual Impairment: Which perceptive visual dysfunctions can be expected in children with brain damage? A systematic review (Article)

Boot, F.H. — 2010-11-01T00:00:00Z

The current definition of Cerebral Visual Impairment (CVI) includes all visual dysfunctions caused by damage to, or malfunctioning of, the retrochiasmatic visual pathways in the absence of damage to the anterior visual pathways or any major ocular disease. CVI is diagnosed by exclusion and the existence of many different causes and symptoms make it an overall non-categorized group. To date, no discrimination is made within CVI based on types of perceptive visual dysfunctions. The aim of this review was to outline which perceptive visual dysfunctions are to be expected based on a number of etiologies of brain damage and brain development disorders with their onset in the pre-, peri- or postnatal period. For each period two etiologies were chosen as the main characteristic brain damage. For each etiology a main search was performed. The selection of the articles was based on the following criteria: age, etiology, imaging, central pathology and perceptive visual function test. The perceptive visual functions included for this review were object recognition, face recognition, visual memory, orientation, visual spatial perception, motion perception and simultaneous perception. Our search resulted in 11 key articles. A diversity of research history is performed for the selected etiologies and their relation to perceptive visual dysfunctions. Periventricular Leukomalacia (PVL) was most studied, whereas the main tested perceptive visual function was visual spatial perception. As a conclusion, the present status of research in the field of CVI does not allow to correlate between etiology, location and perceptive visual dysfunctions in children with brain damage or a brain development disorder. A limiting factor could be the small number of objective tests performed in children experiencing problems in visual processing. Based on recent insights in central visual information processing, we recommend an alternative approach for the definition of CVI that is based on functional visual processing, rather than anatomical landmarks. This could be of benefit in daily practice to diagnose CVI.

Effects on peripheral and central blood pressure of cocoa with natural or high-dose theobromine: A randomized, double-blind crossover trial (Article)

Bogaard, B. van den — 2010-11-01T00:00:00Z

Flavanol-rich cocoa products have been reported to lower blood pressure. It has been suggested that theobromine is partially responsible for this effect. We tested whether consumption of flavanol-rich cocoa drinks with natural or added theobromine could lower peripheral and central blood pressure. In a double-blind, placebo-controlled 3-period crossover trial we assigned 42 healthy individuals (age 62±4.5 years; 32 men) with office blood pressure of 130 to 159 mm Hg/85 to 99 mm Hg and low added cardiovascular risk to a random treatment sequence of dairy drinks containing placebo, flavanol-rich cocoa with natural dose consisting of 106 mg of theobromine, or theobromine-enriched flavanol-rich cocoa with 979 mg of theobromine. Treatment duration was 3 weeks with a 2-week washout. The primary outcome was the difference in 24-hour ambulatory systolic blood pressure between placebo and active treatment after 3 weeks. The difference in central systolic blood pressure between placebo and active treatment was a secondary outcome. Treatment with theobromine-enriched cocoa resulted in a mean±SE of 3.2±1.1 mm Hg higher 24-hour ambulatory systolic blood pressure compared with placebo (P<0.01). In contrast, 2 hours after theobromine-enriched cocoa, laboratory peripheral systolic blood pressure was not different from placebo, whereas central systolic blood pressure was 4.3±1.4 mm Hg lower (P=0.001). Natural dose theobromine cocoa did not significantly change either 24-hour ambulatory or central systolic blood pressure compared with placebo. In conclusion, theobromine-enriched cocoa significantly increased 24-hour ambulatory systolic blood pressure while lowering central systolic blood pressure.

Adverse effects of extra-articular corticosteroid injections: A systematic review (Article)

Brinks, A. — 2010-09-16T00:00:00Z

Background. To estimate the occurrence and type of adverse effects after application of an extra-articular (soft tissue) corticosteroid injection. Methods. A systematic review of the literature was made based on a PubMed and Embase search covering the period 1956 to January 2010. Case reports were included, as were prospective and retrospective studies that reported adverse events of corticosteroid injection. All clinical trials which used extra-articular corticosteroid injections were examined. We divided the reported adverse events into major (defined as those needing intervention or not disappearing) and minor ones (transient, not requiring intervention). Results. The search yielded 87 relevant studies:44 case reports, 37 prospective studies and 6 retrospective studies. The major adverse events included osteomyelitis and protothecosis; one fatal necrotizing fasciitis; cellulitis and ecchymosis; tendon ruptures; atrophy of the plantar fat was described after injecting a neuroma; and local skin effects appeared as atrophy, hypopigmentation or as skin defect. The minor adverse events effects ranged from skin rash to flushing and disturbed menstrual pattern. Increased pain or steroid flare after injection was reported in 19 studies. After extra-articular injection, the incidence of major adverse events ranged from 0-5.8% and that of minor adverse events from 0-81%. It was not feasible to pool the risk for adverse effects due to heterogeneity of study populations and difference in interventions and variance in reporting. Conclusion. In this literature review it was difficult to accurately quantify the incidence of adverse effects after extra-articular corticosteroid injection. The reported adverse events were relatively mild, although one fatal reaction was reported.

Kinematic evaluation of the finger's interphalangeal joints coupling mechanism-variability, flexion-extension differences, triggers, locking swanneck deformities, anthropometric correlations (Article)

Leijnse, J.N.A.L. — 2010-08-01T00:00:00Z

The human finger contains tendon/ligament mechanisms essential for proper control. One mechanism couples the movements of the interphalangeal joints when the (unloaded) finger is flexed with active deep flexor. This study's aim was to accurately determine in a large finger sample the kinematics and variability of the coupled interphalangeal joint motions, for potential clinical and finger model validation applications. The data could also be applied to humanoid robotic hands. Sixty-eight fingers were measured in seventeen hands in nine subjects. Fingers exhibited great joint mobility variability, with passive proximal interphalangeal hyperextension ranging from zero to almost fifty degrees. Increased measurement accuracy was obtained by using marker frames to amplify finger segment motions. Gravitational forces on the marker frames were not found to invalidate measurements. The recorded interphalangeal joint trajectories were highly consistent, demonstrating the underlying coupling mechanism. The increased accuracy and large sample size allowed for evaluation of detailed trajectory variability, systematic differences between flexion and extension trajectories, and three trigger types, distinct from flexor tendon triggers, involving initial flexion deficits in either proximal or distal interphalangeal joint. The experimental methods, data and analysis should advance insight into normal and pathological finger biomechanics (e.g., swanneck deformities), and could help improve clinical differential diagnostics of trigger finger causes. The marker frame measuring method may be useful to quantify interphalangeal joints trajectories in surgical/rehabilitative outcome studies. The data as a whole provide the most comprehensive collection of interphalangeal joint trajectories for clinical reference and model validation known to us to date.

Short and mid-term results of a comprehensive treatment program for longstanding adductor-related groin pain in athletes: A case series (Article)

Weir, A. — 2010-08-01T00:00:00Z

Objective: To evaluate short and mid-term results of active physical therapy in athletes with longstanding groin pain. Design: Case series. Setting: Primary care physical therapy practice. Participants: A total of 44 athletes suffering longstanding adductor-related groin pain. Intervention: A combination of passive (joint mobilization) and active (exercises) physical therapy interventions. Main outcome measurements: Return to (the same level of) sports, restriction in sports, and recurrence. Results: Directly after treatment, return to the same level and type of sport was successful in 38 athletes (86%), and without symptoms in 34 athletes (77%). At 6.5-51 months follow up, 10/38 (26%) of those that returned to sports had experienced a relapse; 22 (50%) athletes were able to participate in sports without any restrictions at the mid-term follow-up. Conclusions: For athletes with longstanding groin pain, short term results of physical therapy seem positive, whereas mid-term results are moderately positive. The risk for recurrence is high.

Response to the future of urodynamics: Non-invasive ultrasound videourodynamics (Letter To Editor)

Idzenga, T. — 2010-07-01T00:00:00Z

Assessment of visual orienting behaviour in young children using remote eye tracking: Methodology and reliability (Article)

Pel, J.J.M. — 2010-06-01T00:00:00Z

Human orienting behaviour requires a complex interaction between the visual and the oculomotor system. We present orienting gaze data measured in children using a remote eye tracking system. The aim of the study was to validate a data analysis method which did not require off-line correction of data gaps due to eye blinking or inadequate gaze tracking. In two sessions, blocks of short movies, amongst others cartoons, were shown to 35 children (2-9 years) for a test-retest analysis. The cartoons were subsequently shown in one of the monitor corners. Orienting eye movements were analysed on the basis of saccadic reaction time (SRT), reaction time to fixation (RTF) of cartoon and gaze fixation area (GFA) Differences were tested for significance using the Wilcoxon-signed ranks test and reliability was assessed using the intraclass correlation coefficient (ICC). SRT values could be calculated in ∼50% of gaze data and ranged between 150(30)ms (mean(SD)) and 390(190)ms (average SRTminand SRTmaxvalues of all subjects). RTF values could be derived in ∼90% of gaze data with an average RTFminof 210(30)ms and RTFmaxof 570(160)ms. Test-retest analysis showed a significant increase of GFA during the second session with ∼5% (P<0.05). The reliability of RTFminand GFA was best with an ICC of 0.84 and 0.80, respectively (P<0.0001). We conclude that remote eye tracking is well suited for quantification of timing and executing oculomotor fixations during orienting behaviour tasks. The presented method may be applied in young children with developmental disorders or brain damage.

The effect of experimental groin pain on abdominal muscle thickness (Article)

Jansen, J.A.C.G. — 2010-05-01T00:00:00Z

It is not clear whether abnormal abdominal muscle behavior in athletes with longstanding groin pain is a risk factor for groin pain or is caused by groin pain itself. Therefore, this study investigated whether anticipation of experimental groin pain influences abdominal muscle behavior. METHODS: In 14 healthy athletes, abdominal muscle thickness was measured using ultrasound under conditions of anticipated groin pain and acute groin pain. Groin pain was induced using superficial electrical skin stimulation. Tasks evaluated were isometric hip adduction and active straight leg raise (ASLR) left. RESULTS: The m. transversus abdominis and m. obliquus internus showed a significant decrease in thickness during "anticipation of pain" compared with "no pain" and "pain" during both hip adduction and ASLR (P values <0.04). For m. obliquus externus, a significant increase in thickness was found only during "pain" compared with "no pain" and "anticipation of pain" for ASLR (P<0.004). DISCUSSION: If ASLR or hip adduction is associated with anticipated groin pain, abdominal muscle behavior is different from a pain-free situation and from a painful situation. These results suggest that abnormal abdominal muscle behavior found in athletes with longstanding groin pain may be caused by a pain anticipatory motor strategy. This may have implications for rehabilitation.

Prevalence of double incontinence, risks and influence on quality of life in a general female population (Article)

Slieker-ten Hove, M.C.P. — 2010-04-01T00:00:00Z

Background: Urinary incontinence (UI) and anal incontinence (AI) are complaints with impact on quality of life (QOL). Few data are available on prevalence of double incontinence (DI) in the general female population. Objective: To determine prevalence of UI, AI, and DI, their associations with age, parity, and effects on QOL. Design, Setting, and Participants: Cross-sectional study on a general female population, aged 45-85 years. Measurements: Validated questionnaires measuring pelvic floor dysfunction and QOL. A short questionnaire was used for non-responders. Analyses were performed with Chi-square tests, ANOVA, and logistic regression. Results: Response rate was 62.7% (1,869/2,979); 59% of non-responders filled in the short questionnaire (620/1,051). No significant differences in stress urinary incontinence, vaginal bulging, solid stool incontinence and parity were found between responders and non-responders. DI with and without flatal incontinence were reported by 7.7% and 35.4%, respectively. Women with urge urinary incontinence (UUI) alone had an OR of 4.3 (95% CI 2.4-7.9) for liquid stool incontinence, 1.6 (95% CI 0.5-4.9) for solid stool incontinence and 2.4 for flatal incontinence (95% CI 1.5-3.8). Women with AI had an OR of 5.8 (95% CI 1.8-18.2) for UUI. Women with DIincluding flatus reported significantly poorer QOL. Limitation of the study was the lack of objective clinical validation of symptoms, which may have influenced the real prevalence data. Conclusions: Most important relation was found between UUI and liquid stool incontinence (OR 4.3). We recommend that clinicians take the history of patients with UUI or mixed urinary incontinence to exclude the co-existence of AI. Neurourol. Urodynam. 29:545-550, 2010.

Resting thickness of transversus abdominis is decreased in athletes with longstanding adduction-related groin pain (Article)

Jansen, J.A.C.G. — 2010-04-01T00:00:00Z

The purpose of the study was to compare thickness of the transversus abdominis (TA) and obliquus internus (OI) muscles between athletes with and without longstanding adduction-related groin pain (LAGP). Forty two athletes with LAGP and 23 controls were included. Thickness of TA and OI were measured with ultrasound imaging on the right side of the body during rest. Relative muscle thickness (compared to rest) was measured during the active straight leg raise (ASLR) left and right, and during isometric hip adduction. TA resting thickness was significantly smaller in injured subjects with left-sided (4.0 ± 0.82 mm; P < 0.001) or right-sided (4.3 ± 0.64 mm; P = 0.015) groin complaints compared with controls (4.9 ± 0.90 mm). No significant differences between patients and controls in TA or OI relative thickness during the ASLR and isometric hip adduction were found (all cases P ≥ 0.15). In conclusion, TA resting thickness is smaller in athletes with LAGP and may thus be a risk factor for (recurrent) groin injury. This may have implications for therapy and prevention of LAGP.

Pelvic floor muscle function in a general population of women with and without pelvic organ prolapse (Article)

Slieker-ten Hove, M.C.P. — 2010-03-01T00:00:00Z

Introduction and hypothesis: This study aims to examine the relationship between pelvic floor muscle function (PFMF) and pelvic organ prolapse (POP) in a general female population. Methods: Cross-sectional study on women aged 45-85 years. Validated questionnaires were used to assess pelvic floor muscle function. POP and PFMF were evaluated with vaginal examination. For statistical analysis chi-squared test for trend and analysis of variance were used. Results: Response rate to the questionnaire was 62.7% (1,869/2,979). No significant differences were found in muscle strength and endurance during voluntary muscle contraction between the POP stages. Women with POP stages I and II were significantly less able to achieve effective involuntary muscle contraction during coughing (38.3% and 37.7%) than women without POP (75.2%). Conclusion: Involuntary contraction of the PFM during coughing (that resulted in stabilization of the perineum) was significantly weaker in the women with POP stage I and II than in the women without POP.

Erratum: Prediction model and prognostic index to estimate clinically relevant pelvic organ prolapse in a general female population (International Urogynecology Journal and Pelvic Floor Dysfunction DOI: 10.1007/s00192-009-0903- 0) (Article)

Slieker-ten Hove, M.C.P. — 2010-03-01T00:00:00Z

Relation between subjective and objective scores on the active straight leg raising test (Article)

Mens, J.M.A. — 2010-02-01T00:00:00Z

DESIGN.: Cross sectional. Objective: To fill a gap in the validation of the active straight leg raising (ASLR) test concerning the relation between a patient's subjective score on the ASLR test and the objective measured force. Summary of Background Data: The ASLR test is used to classify patients presenting with pain in the low back and/or pelvic girdle. Although its reliability and validity have been demonstrated, some details are still lacking. Methods: The ASLR test was performed by 21 parous women with various ASLR scores. Subjective weakness was scored by the patient both with and without a pelvic belt; moreover the isometric forces of leg raising were measured. Results: The correlation coefficients between the subjective ASLR score and objective measured force at 0 and 20 cm elevation were -0.58 (P < 0.01) and -0.52 (P < 0.05), respectively, at the left side; and -0.45 (P < 0.05) and -0.63 (P < 0.01), respectively, at the right side. When measured with a pelvic belt the correlations were, respectively, -0.51 and -0.48 at the left side, and -0.47 and -0.50 at the right side (all P < 0.05). After applying a pelvic belt the mean subjective ASLR score decreased with 0.38 point at the left side and 0.48 point at the right side (both P < 0.05). With the belt, the measured force at 0 cm elevation increased by 11.6% (P < 0.001) at the left side and by 8.6% (P < 0.05) at the right side; at 20 cm elevation the changes in measured force were negligible. No significant correlation was found between the subjective and the objective changes elicited by the pelvic belt.Conclusion: The subjective scores on the ASLR test correlate well with the objective measured forces; this supports the reliability of the ASLR test. The subjective influence of a pelvic belt on the ASLR score could not be objectified.

Measurements of the Exerted Pressure by Pelvic Circumferential Compression Devices (Article)

Lieshout, E.M.M. van — 2010-01-01T00:00:00Z

Data on the efficacy and safety of non-invasive Pelvic Circumferential Compression Devices (PCCDs) is limited. Tissue damage may occur if a continuous pressure on the skin exceeding 9.3 kPa is sustained for more than two or three hours. The aim of this study was to gain insight into the pressure build-up at the interface, by measuring the PCCD-induced pressure when applying pulling forces to three different PCCDs (Pelvic Binder((R)) , SAM-Sling ((R)) and T-POD((R)) ) in a simplified model. The resulting exerted pressures were measured at four 'anatomical' locations (right, left, posterior and anterior) in a model using a pressure measurement system consisting of pressure cuffs. The exerted pressure varied substantially between the locations as well as between the PCCDs. Maximum pressures ranged from 18.9-23.3 kPa and from 19.2-27.5 kPa at the right location and left location, respectively. Pressures at the posterior location stayed below 18 kPa. At the anterior location pressures varied markedly between the different PCCDs. The circumferential compression by the different PCCDs showed high pressures measured at the four locations using a simplified model. Difference in design and functional characteristics of the PCCDs resulted in different pressure build-up at the four locations. When following the manufacturer's instructions, the exerted pressure of all three PCCDs tested exceeded the tissue damaging level (9.3 kPa). In case of prolonged use in a clinical situation this might put patients at risk for developing tissue damage.

No relation between pelvic belt tests and abdominal muscle thickness behavior in athletes with long-standing groin pain. measurements with ultrasound (Article)

Jansen, J.A.C.G. — 2010-01-01T00:00:00Z

Objective: To investigate whether abdominal muscle thickness in athletes with long-standing adduction-related groin pain (LAGP) differs between subgroups with a positive or no response to a pelvic belt. The response to a pelvic belt is defined positive in case of a decrease ≥1 on a Likert pain scale (0-10) during the squeeze test (SQT) or a decrease ≥1 on the active straight leg raise (ASLR) test score (0-10). DESIGN: Cross-sectional study. SETTING: Physical therapy practice. PATIENTS: Fifty athletes with LAGP. INDEPENDENT VARIABLES: Squeeze test and ASLR test. MAIN OUTCOME MEASURES: First, the effect of a pelvic belt on pain during the SQT and the ASLR test score was evaluated. Then, thickness of m. transversus abdominis (TA) and m. obliquus internus (OI) was measured using ultrasound during rest, ASLR left and right, and SQT. RESULTS: Of the 50 participants, 25 (50%) experienced a decrease in pain during the SQT when wearing a pelvic belt and 10 (20%) improved in ASLR performance with a pelvic belt. Thickness of TA and OI at rest (both cases P >.08) and relative thickness compared with rest during tasks (in all cases P >.12) revealed no significant difference when comparing the 2 subgroups based on the belt response during the SQT or ASLR. CONCLUSIONS: Using these methods, abdominal muscle thickness behavior in athletes with LAGP did not differ between the subgroups based on a positive or no response to a pelvic belt. However, the ultrasound method used may not have been sensitive enough to reveal differences between groups.

Pelvic floor muscle function in a general female population in relation with age and parity and the relation between voluntary and involuntary contractions of the pelvic floor musculature. (Article)

Slieker-ten Hove, M.C.P. — 2009-12-01T00:00:00Z

INTRODUCTION AND HYPOTHESIS: The objective of this study is to describe pelvic floor muscle function (PFMF) in relation to age and parity in a general female population and to test whether strength/endurance measurements represent all functions of the pelvic floor musculature. METHODS: A cross-sectional study was performed on 95% of the women aged 45-85 years from a small Dutch town. Validated questionnaires were used to obtain general information, and vaginal examination to test PFMF was performed on 649 women. Chi-square tests were used to analyse the relation between PFMF versus age and parity. Analysis of variance was used to compare muscle strength and endurance to the other PFMF items. RESULTS: Response rate to the questionnaire was 62.7% (1,869/2,979). PFM strength and endurance are not positively associated with the effective involuntary muscle contractions during coughing. CONCLUSIONS: Voluntary muscle contractions decreased with age, but there was no relation with parity. Muscle strength and endurance measurements alone are not sensitive enough to determine PFMF.

Pelvic floor muscle function in a general female population in relation with age and parity and the relation between voluntary and involuntary contractions of the pelvic floor musculature. (Article)

Slieker-ten Hove, M.C.P. — 2009-12-01T00:00:00Z

Platform accelerations of three different whole-body vibration devices and the transmission of vertical vibrations to the lower limbs (Article)

Pel, J.J.M. — 2009-10-01T00:00:00Z

Physical whole-body vibration (WBV) exercises become available at various levels of intensity. In a first series of measurements, we investigated 3-dimensional platform accelerations of three different WBV devices without and with three volunteers of different weight (62, 81 and 100 kg) in squat position (150° knee flexion). The devices tested were two professional devices, the PowerPlate and the Galileo-Fitness, and one home-use device, the PowerMaxx. In a second series of measurements, the transmission of vertical platform accelerations of each device to the lower limbs was tested in eight healthy volunteers in squat position (100° knee flexion). The first series showed that the platforms of two professional devices vibrated in an almost perfect vertical sine wave at frequencies between 25-50 and 5-40 Hz, respectively. The platform accelerations were slightly influenced by body weight. The PowerMaxx platform mainly vibrated in the horizontal plane at frequencies between 22 and 32 Hz, with minimal accelerations in the vertical direction. The weight of the volunteers reduced the platform accelerations in the horizontal plane but amplified those in the vertical direction about eight times. The vertical accelerations were highest in the Galileo (∼15 units of g) and the PowerPlate (∼8 units of g) and lowest in the PowerMaxx (∼2 units of g). The second series showed that the transmission of vertical accelerations at a common preset vibration frequency of 25 Hz were largest in the ankle and that transmission of acceleration reduced ∼10 times at the knee and hip. We conclude that large variation in 3-dimensional accelerations exist in commercially available devices. The results suggest that these differences in mechanical behaviour induce variations in transmissibility of vertical vibrations to the (lower) body.