Effect of 6-weeks WBVT on the behaviour of the lower limb muscle fibres during vertical jumping.

The purpose of the current study was to examine the effect of 6 weeks of whole body vibration training (WBVT) on body composition, muscle activity of the gastrocnemius and vastus lateralis, gastrocnemius muscle architecture (static and dynamic) and ground reaction forces (performance jump) during the take-off phase of a countermovement jump in young healthy adult males. A total of 33 men (23.31 ± 5.62 years) were randomly assigned to a whole body vibration group (experimental group, EGWBVT: n = 17; 22.11 ± 4.97 years) or a control group (CG: n = 16; 24.5 ± 6.27 years). The total duration of the intervention phase (WBVT) was 6 weeks with a frequency of 3 sessions per week. Statistically significant differences were observed (P ≤ 0.05) between pre- and post-test in the power peak (Δ 1.91 W · kg-1; P = 0.001), take-off velocity (0.1 cm · s-1; P = 0.002) and jump height (Δ 0.4 cm; P = 0.002) for EGWBVT. There were no statistically significant differences in any of the body composition and muscle architecture variables. Moreover, no significant differences were found between EGWBVT and CG nor changes in muscle activity during take-off phase of the gastrocnemius and vastus lateralis pre- versus post-training. This study suggests that a 6-week WBVT programme with increasing intensity improves jump performance but does not alter muscle activity nor muscle architecture in healthy young men.

Effects of Synchronous Whole Body Vibration Training on a Soft, Unstable Surface in Athletes with Chronic Ankle Instability.

The aim of this study was to evaluate the effects of a 6-week WBV training program, performed on a soft, unstable surface, on peak torque, reaction time and the electrical activity of ankle muscles in recreational athletes with chronic ankle instability (CAI). 50 recreational athletes with self-reported unilateral CAI were randomly assigned to a vibration group (VIB), non-vibration group (N-VIB) or control group. The VIB and N-VIB groups performed unilateral balance training on the unstable ankle on a BOSU® Balance Trainer 3 times weekly for 6 weeks. The VIB group trained on a vibration platform, and the N-VIB group trained on the floor. Muscle reaction times and electrical activity of the peroneus brevis (PB), peroneus longus (PL) and tibialis anterior (TA) muscles were assessed in response to sudden inversion, isokinetic peak torque and isokinetic strength ratios of the ankle evertor muscles. After 6 weeks of training, a significant improvement was shown in reaction times of the PB (Pre=60.99±9.17 ms, Post1=54.90±6.99 ms, p=0.003), PL (Pre=61.20±10.72 ms, Post1=55.21±9.04 ms, p=0.007) and TA (Pre=65.31±11.78 ms, Post1=59.07±9.99 ms, p=0.007) muscles in the VIB group, whereas no significant changes were found in the N-VIB group or the control group. There were no significant changes in electrical activity, peak torque and eccentric-concentric ratio for any of the groups after training. In conclusion, a 6-week WBV training program on a soft, unstable surface improves the reaction times of the PB, PL and TA muscles in recreational athletes with CAI. Trial registration: ClinicalTrials.gov NCT02794194.

Analysis of Performance Losses and Degradation Mechanism in Porous La2-X NiTiO6-δ:YSZ Electrodes.

The electrode performance and degradation of 1:1 La2-xNiTiO6-δ:YSZ composites (x = 0, 0.2) has been investigated to evaluate their potential use as SOFC cathode materials by combining electrochemical impedance spectroscopy in symmetrical cell configuration under ambient air at 1173 K, XRD, electron microscopy and image processing studies. The polarisation resistance values increase notably, i.e., 0.035 and 0.058 Ωcm2 h-1 for x = 0 and 0.2 samples, respectively, after 300 h under these demanding conditions. Comparing the XRD patterns of the initial samples and after long-term exposure to high temperature, the perovskite structure is retained, although La2Zr2O7 and NiO appear as secondary phases accompanied by peak broadening, suggesting amorphization or reduction of the crystalline domains. SEM and TEM studies confirm the ex-solution of NiO with time in both phases and also prove these phases are prone to disorder. From these results, degradation in La2-xNiTiO6-δ:YSZ electrodes is due to the formation of La2Zr2O7 at the electrode-electrolyte interface and the ex-solution of NiO, which in turn results in the progressive structural amorphization of La18NiTiO6-δ phases. Both secondary phases constitute a non-conductive physical barrier that would hinder the ionic diffusion at the La2-xNiTiO6-δ:YSZ interface and oxygen access to surface active area.

Synthetic open cell foams versus a healthy human vertebra: Anisotropy, fluid flow and µ-CT structural studies.

Commercial synthetic open-cell foams are an alternative to human cadaveric bone to simulate in vitro different scenarios of bone infiltration properties. Unfortunately, these artificial foams do not reproduce the anisotropic microstructure of natural bone and, consequently, their suitability in these studies is highly questionable. In order to achieve scaffolds that successfully mimic human bone, microstructural studies of both natural porous media and current synthetic approaches are necessary at different length scales. In this line, the present research was conducted to improve the understanding of local anisotropy in natural vertebral bone and synthetic bone-like porous foams. To attain this objective, small volumes of interest within these materials were reconstructed via micro-computed tomography. The anisotropy of the microstructures was analysed by means of both their main local histomorphometric features and the behaviour of an internal flow computed via computational fluid dynamics. The results showed that the information obtained from each of the micro-volumes of interest could be scaled up to understand not only the macroscopic averaged isotropic and/or anisotropic behaviour of the samples studied, but also to improve the design of macroscopic porous implants better fitting specific local histomorphometric scenarios. The results also clarify the discrepancies in the permeability obtained in the different micro-volumes of interest analysed. STATEMENT OF SIGNIFICANCE: A deep insight comparative study between the porous microstructure of healthy vertebral bone and that of synthetic bone-like open-cell rigid foams used in in vitro permeability studies of bone cement has been performed. The results obtained are of fundamental relevance to computational studies because, in order to achieve convergence values, the computation process should be limited to small computation domains or micro-volumes of interest. This makes the results specific spatial dependent and for this reason computation studies cannot directly capture the macroscopic average behaviour of an anisotropic porous structure such as the one observed in natural bones. The results derived from this study are also important because we have been able to show that the specific spatial information contained in only one healthy vertebra is enough to capture, from a geometric point of view, the same information of "specific surface area vs. porosity" - in other words, the same basic law - that can also be found in other human bones for different patients, even at different biological ages. This is an important finding that, despite the efforts made and the controversies formulated by other authors, should be studied more thoroughly with other bone species and tissues (healthy and/or diseased). Moreover, our results should help to understand that, with the extensive capabilities of current 3D printing technologies, there is an enormous potential in the design of biomimetic porous bone-like scaffolds for bone tissue engineering applications.

Topical ketoprofen TDS patch versus diclofenac gel: efficacy and tolerability in benign sport related soft-tissue injuries.

OBJECTIVE: To compare the ketoprofen TDS patch with diclofenac gel in the treatment of traumatic acute pain in benign sport-related soft-tissue injuries. DESIGN: 7-14 treatment days, prospective, randomised, open study. PATIENTS: Outpatients aged 18-70 years diagnosed for painful benign sport-related soft-tissue injury (sprains, strains and contusions within the prior 48 h), randomised to either ketoprofen patch 100 mg once daily (n = 114) or diclofenac gel 2-4 g three times daily (n = 109). INTERVENTION: 7-14 days of topical non-steroidal anti-inflammatory drugs treatment to assess the pain intensity changes (daily activities and spontaneous at rest) in a daily diary (100-mm Visual Analogue Scale (VAS)). MAIN OUTCOME MEASUREMENT: Pain intensity (VAS). RESULTS: The ketoprofen patch was not inferior to diclofenac gel in reducing the baseline pain during daily activities (difference of -1.17 mm in favour of ketoprofen patch, 95% CI (-5.86 to 3.52), reducing to the baseline VAS 79%. Ketoprofen patch presented also a higher cure rate (64%) than diclofenac gel (46%) at day 7 (p = 0.004). Patient opinions about the treatment comfort (pharmaceutical shape, application and dosage) were also statistically higher for the ketoprofen patch (>80% of the patients rated as good or excellent the patch removal and skin adherence). CONCLUSION: Ketoprofen patches are effective and safe pain relievers for the treatment of sports injury pain with advantages compared with diclofenac gel.

Gender variability in electromyographic activity, in vivo behaviour of the human gastrocnemius and mechanical capacity during the take-off phase of a countermovement jump.

PURPOSE: The purpose of this study was to analyse gender differences in neuromuscular behaviour of the gastrocnemius and vastus lateralis during the take-off phase of a countermovement jump (CMJ), using direct measures (ground reaction forces, muscle activity and dynamic ultrasound). METHODS: Sixty-four young adults (aged 18-25 years) participated voluntarily in this study, 35 men and 29 women. The firing of the trigger allowed obtainment of data collection vertical ground reaction forces (GRF), surface electromyography activity (sEMG) and dynamic ultrasound gastrocnemius of both legs. RESULTS: Statistically significant gender differences were observed in the jump performance, which appear to be based on differences in muscle architecture and the electrical activation of the gastrocnemius muscles and vastus lateralis. So while men developed greater peak power, velocity take-offs and jump heights, jump kinetics compared to women, women also required a higher electrical activity to develop lower power values. Additionally, the men had higher values pennation angles and muscle thickness than women. CONCLUSION: Men show higher performance of the jump test than women, due to significant statistical differences in the values of muscle architecture (pennation angle and thickness muscle), lower Neural Efficiency Index and a higher amount of sEMG activity per second during the take-off phase of a CMJ.

Variabilidad del peso en mujeres con cáncer de mama (IIIB) después de tratamiento / Weight change in women after treatment with breast cancer (IIIB)

Resumen Introducción: se ha descrito ampliamente el efecto del sobrepeso y la obesidad en pacientes con cáncer de mama. A pesar de que se reconocen diferencias étnicas de dichas asociaciones, aún es insuficiente la información en población latinoamericana. Metodología: estudio longitudinal tipo cohorte retrospectiva, con muestreo no probabilístico. El objetivo principal fue describir el comportamiento del peso de mujeres con cáncer de mama, localmente avanzado del subtipo luminal A después de tratamiento oncológico multimodal. Resultados: la edad promedio al diagnóstico de cáncer fue de 52 años. El tiempo promedio de seguimiento de 2.3 años en los cuales hubo una tasa de recurrencia de 12.1%. La mayoría de las pacientes presentaron sobrepeso/obesidad (67.56%) con una variación promedio de -0.17 Kg al final del seguimiento. Las pacientes con metástasis presentaron una pérdida mayor de peso que su contraparte sin recurrencia (-5.06 Kg, p<0.05). Conclusiones: el sobrepeso y obesidad son una característica muy prevalente en pacientes con cáncer de mama luminal A en estadio localmente avanzado. No hubo evidencia concluyente de aumento de riesgo de metástasis o muerte asociado a exceso de peso en esta población. Al contrario la pérdida de peso fue una característica estadísticamente significativa de pacientes que presentaron recurrencia a distancia durante el seguimiento, sin poderse definir como un factor causal.(Acta Med Colomb 2020; 45. DOI:https://doi.org/10.36104/amc.2020.1563).

Abstract Introduction: the effect of overweight and obesity in patients with breast cancer has been widely described. Despite the recognition of ethnic differences in these associations, information is still lacking for the Latin American population. Methods: a retrospective, longitudinal cohort study with non-probabilistic sampling. The main objective was to describe how weight behaved after multimodal cancer treatment in women with locally advanced luminal A subtype breast cancer. Results: the average age at cancer diagnosis was 52 years. The average follow-up time was 2.3 years, during which there was a 12.1% rate of recurrence. Most patients were overweight/obese (67.56%), with an average variation of -0.17 kg at the end of follow up. Patients with metastasis had a greater weight loss than those without recurrence (-5.06 kg, p<0.05). Conclusions: overweight and obesity are a prevalent characteristic of locally advanced luminal A breast cancer patients. There was no conclusive evidence of increased risk of metastasis or death related to excess weight in this population. To the contrary, weight loss was a statistically significant characteristic of patients with distal recurrence during follow up, although it was not established as a causal factor.(Acta Med Colomb 2020; 45. DOI:https://doi.org/10.36104/amc.2020.1563).

Weight change in women with breast cancer (IIIB) after treatment

Introduction: the effect of overweight and obesity in patients with breast cancer has been widely described. Despite the recognition of ethnic differences in these associations, information is still lacking for the Latin American population. Methods: a retrospective, longitudinal cohort study with non-probabilistic sampling. The main objective was to describe how weight behaved after multimodal cancer treatment in women with locally advanced luminal A subtype breast cancer. Results: the average age at cancer diagnosis was 52 years. The average follow-up time was 2.3 years, during which there was a 12.1% rate of recurrence. Most patients were overweight/obese (67.56%), with an average variation of -0.17 kg at the end of follow up. Patients with metastasis had a greater weight loss than those without recurrence (-5.06 kg, p<0.05). Conclusions: overweight and obesity are a prevalent characteristic of locally advanced luminal A breast cancer patients. There was no conclusive evidence of increased risk of metastasis or death related to excess weight in this population. To the contrary, weight loss was a statistically significant characteristic of patients with distal recurrence during follow up, although it was not established as a causal factor.

Introducción: se ha descrito ampliamente el efecto del sobrepeso y la obesidad en pacientes con cáncer de mama. A pesar de que se reconocen diferencias étnicas de dichas asociaciones, aún es insuficiente la información en población latinoamericana. Metodología: estudio longitudinal tipo cohorte retrospectiva, con muestreo no probabilístico. El objetivo principal fue describir el comportamiento del peso de mujeres con cáncer de mama, localmente avanzado del subtipo luminal A después de tratamiento oncológico multimodal. Resultados: la edad promedio al diagnóstico de cáncer fue de 52 años. El tiempo promedio de seguimiento de 2.3 años en los cuales hubo una tasa de recurrencia de 12.1%. La mayoría de las pacientes presentaron sobrepeso/obesidad (67.56%) con una variación promedio de -0.17 Kg al final del seguimiento. Las pacientes con metástasis presentaron una pérdida mayor de peso que su contraparte sin recurrencia (-5.06 Kg, p<0.05). Conclusiones: el sobrepeso y obesidad son una característica muy prevalente en pacientes con cáncer de mama luminal A en estadio localmente avanzado. No hubo evidencia concluyente de aumento de riesgo de metástasis o muerte asociado a exceso de peso en esta población. Al contrario la pérdida de peso fue una característica estadísticamente significativa de pacientes que presentaron recurrencia a distancia durante el seguimiento, sin poderse definir como un factor causal.(Acta Med Colomb 2020; 45. DOI:https://doi.org/10.36104/amc.2020.1563).