El ejercicio es medicina

En la mayor parte de las sociedades industrializadas, los cambios producidos como consecuencia del desarrollo han sido descritos en un informe de la Organización Mundial de la Salud (OMS)1 como favorecedores en la aparición de enfermedades crónicas o “enfermedades del desarrollo”. Estos cambios incluyen la transformación de los patrones de conducta alimentaria o de actividad física generando un estilo de vida sedentario. Actualmente la inactividad física es considerada no como uno de los principales, sino el mayor, de los problemas de salud pública del siglo XXI2, 3. Todos estos elementos tienen mayor relevancia en aquellas poblaciones que por sus especiales características (falta de recursos, enfermedad, discapacidad, etc.) son más sensibles a cualquiera de estos elementos perturbadores de salud, especialmente la inactividad física..

Masa muscular, fuerza isométrica y dinámica en las extremidades inferiores de niños y adolescentes con síndrome de Down

En general se ha observado que las personas con síndrome de Down (SD) tienen valores inferiores de fuerza muscular comparados con personas sin SD. También existe un déficit de masa muscular en los adultos con SD comparados con otros sin SD. Sin embargo, ningún estudio hasta la fecha había evaluado esta masa muscular en población pediátrica. Nuestro estudio pretende poner de manifiesto si también a edades tempranas existe un déficit de masa muscular y además relacionar ambos valores. Los niños y adolescentes con y sin SD (15±3 y 14±3 años respectivamente) de nuestro estudio obtuvieron valores similares de masa muscular ajustada por talla y estadio puberal, pero el grupo con SD obtuvo valores inferiores de fuerza (p<0.05). Además de esto, el grupo con SD ejerció menos kilogramos de fuerza por cada kilogramo de masa muscular. Alguna causa fisiológica o de transmisión podría explicar esta falta de fuerza ya que, al menos en esta franja de edad no existe un déficit de masa muscular. Deberían incentivarse los programas de entrenamiento específicos para este tipo de población para comprobar si es posible un incremento en su fuerza muscular.Generally it has been observed that population with Down syndrome (DS) has lower levels of muscular strength compared with others without DS. It is also known a deficit between muscular mass between adults with and without DS. However, there are no studies until the date which evaluated muscular mass in paediatric populations. Our study pretends to show whether also in earlier ages it does exist a deficit in the muscular mass and also to relate both values. Children and adolescents with and without DS (15±3 y 14±3 years respectively) from the study had similar values of muscular mass adjusted by height and puberal status, but DS group obtained lower values in all strength parameters. In addition, DS group also performed less kilograms of strength by kilogram of muscular mass. Some physiological or transmission impairment could explain this lack of strength as it known that there are not deficit in the muscular mass. Specific and adapted for this population training programs should be promoted to check whether an enhancement in their muscular strength is possible.Peer Reviewe

The finger flexors occlusion threshold in sport-climbers: an exploratory study on its indirect approximation

Blood flow partially determines specific climbing endurance (SCE) as it mediates oxygen bio-availability in the finger flexors. Blood flow is related to occlusion threshold (OT), which is defined as the contraction intensity at which intramuscular pressure exceeds perfusion blood pressure resulting in the cessation of local blood flow. The OT is represented as an inflection point on a force-time graph when isometric force is registered and applied through maximal and continuous tests. Endurance time (ET) to exhaustion is influenced by the relative isometric applied force and is different for each climber. The aim of this study was to explore whether an approximation of the finger flexors OT in sport climbers through records of ET to exhaustion at different isometric relative intensities was possible. We measured maximum finger hang ETs at 6 intensities ranging from 85% to 35% maximal force in 34 sport climbers of advanced and elite level. The values obtained were analysed by two different methods in an attempt to determine a change in the shape of the curve in the intensity-ET relationship graphs that approximated the OT for each climber. The results suggest that the finger flexors OT could be different among climbers, regardless of their strength and ability level. The presented methods do not accurately reflect the OT, but could indicate the intensity at which blood flow is restored in the active muscles. This is the first study to indirectly approximate the finger flexors OT in sport-climbers, a parameter that could be essential to assess SCE

Lack of impact moderating movement adaptation when soccer players perform game specific tasks on a third-generation artificial surface without a cushioning underlay

The objective of this study was to investigate how the inclusion of a cushioning underlay in a third-generation artificial turf (3G) affects player biomechanics during soccer-specific tasks. Twelve soccer players (9 males/3 females; 22.6 ± 2.3 y) participated in this study. Mechanical impact testing of each 3G surface; without (3G-NCU) and with cushioning underlay (3G-CU) were conducted. Impact force characteristics, joint kinematics and joint kinetics variables were calculated on each surface condition during a sprint 90° cut (90CUT), a sprint 180° cut (180CUT), a drop jump (DROP) and a sprint with quick deceleration (STOP). For all tasks, greater peak resultant force, peak knee extensor moment and peak ankle dorsi-flexion moment were found in 3G-NCU than 3G-CU (p < 0.05). During 90CUT and STOP, loading rates were higher in 3G-NCU than 3G-CU (p < 0.05). During 180CUT, higher hip, knee and ankle ranges of motion were found in 3G-NCU (p < 0.05). These findings showed that the inclusion of cushioning underlay in 3G reduces impact loading forces and lower limb joint loading in soccer players across game-specific tasks. Overall, players were not attempting to reduce higher lower limb impact loading associated with a lack of surface cushioning underlay

Presiones plantares, en estática bipodal, en niños/adolescentes con síndrome de Down

Objetivo: Determinar las presiones plantares en estática bipodal y la alineación de retropié y rodilla, en niños/adolescentes con Síndrome de Down (SD), comparando los datos con los de un grupo control (GC). Diseño. 32 sujetos con SD y 33 control. Se valoró la superficie plantar, presión media y máxima y su distribución porcentual en 9 zonas de la superficie plantar (plataforma”Footchecker”) en estática bipodal. Asimismo, se valoró la alineación del retropié en el plano frontal y la de la rodilla en los planos frontal y sagital. Resultados. En el grupo SD: superficie plantar mayor (p<0.0001); presión media menor (p<0.01); picos de presión menores en el retropié (zona interna p<0.0001) y mayores en parte interna del mediopié y del antepié (p<0.0001); participación menor del retropié, principalmente en parte interna (GC:23.09%; SD:15.87%; p<0.0001), y mayor de la parte interna del mediopié (GC:4%; SD10%; p<0.0001) y del antepié (GC:12%; SD:17%; p<0.0001). Conclusiones. El grupo SD presentó mayor desviación en valgo de talón y rodilla, tendencia al recurvatum de rodilla y aumento de la superficie de apoyo plantar, relacionado con el pie plano que suelen presentar estos sujetos. Además, presentó tendencia a menores presiones medias y modificación de la distribución porcentual de la carga, con menor participación del retropié y mayor de las zonas internas del mediopié y antepié; es decir, hubo un desplazamiento de la carga hacia la zona ántero-interna.Objective. To determine the plantar pressures in standing and the hindfoot and knee alignment, in children/adolescents with Down syndrome (DS). Material and Methods. The sample comprised two groups of 32 children / adolescents, one with DS and other without pathology (CG). We analyzed in standing she support surface, average and peak plantar pressures and their distribution (by means of a Footchecker platform), hindfoot alignment in the frontal plane and knee alignment in the frontal and sagital planes.Comparison between both groups was carried out. Results. The DS group showed: higher plantar surface (p<0.0001); lower average pressure (p<0.01); lower peak pressure in the hindfoot (internal zone p<0.0001) and a higher one in the internal zone of the midfoot and forefoot (p<0.0001); lower involvement of the hindfoot, specially in the internal part (CG:23.09%, DS:15.87%, p<0.0001) and a higher one of the internal part of the midfoot (CG:4%, DS:10%, p<0.0001) and forefoot (CG: 12%, DS: 17%, p <0.0001). Conclusions. The DS group presented higher valgus deviation of the hindfoot and knee, a tendency to a knee recurvatum and higher support surface, related to the flatfoot they usually had. On the other hand, they presented a tendency to lower average pressures and a variation in the porcentage distribution of load, with a lower involvement of the hindfoot and a higher one of the internal parts of the midfoot and forefoot: that’s to say, there was a load displacement towards the anterior and internal zone.Peer Reviewe

A new performance threshold in sport climbing: A change in how climbing trainers work?

Objectives: Previous research has shown that the finger flexor's occlusion threshold (OT) could be different among sport climbers when expressed as a percentage of their maximum finger force (OT%), and that there is no association between the OT% and the climberś ability level. The aim of the present study was to evaluate the possible association between the relative finger force applied at the OT% (rff-OT%) and climbing ability level. Equipment and methods: WWe approximated the finger flexor's OT of 34 sport climbers by finger hang endurance test analyses at different intensities between 35% and 85% of their individual maximum finger force on a previously individually adapted edge depth, and we valued their rff-OT% as the relative force they could perform at that intensity. Results: We found a high correlation between the rff-OT% and climbing ability in elite climbers. These findings suggest that having an OT at the highest possible percentage is critical, in addition to having a high relative finger force, as this would enable climbers to express relative force at a wider range of intensities with favorable metabolic conditions

Design and validity of a choice-modeling questionnaire to analyze the feasibility of implementing physical activity on prescription at primary health-care settings

Worldwide health policies are trying to implement physical activity on prescription (PAP) at healthcare settings. However, there is not a proper methodology to analyze PHC organizational staff factors. This study aims to validate two questionnaires to assess the self-perception of nurses and general practitioners to implement PAP at primary healthcare (PHC) settings. The designed choice-modeling Google-form questionnaire was sent to 11 expert nurses and 11 expert sports medicine physicians. Experts evaluated each question on a 1–5 points Likert-type scale according to their expertise. Aiken’s V coefficient values =0.75 were used to validate separately each question using the Visual Basic-6.0 software. A total of 10 sports medicine physicians and 10 nurses with 28.4 ± 5.1 y and 16.3 ± 11.8 y of PAP experience, respectively, validated the questionnaire. One expert in each group was not considered for offering 3 ± SD answers in =2 questions respect to the mean of the rest of experts. Final Aiken’s V coefficient values were 0.89 (0.77–1.00) for the nurses’ questionnaire and 0.84 (0.77–0.95) for the physicians’ one. The questionnaires designed to assess the PAP self-perception of PHC nurses and physicians were validated. This methodology could be used to analyze PHC organizational staff factors in order to achieve an efficient PAP implementation in other PHC contexts

Estimation of the second ventilatory threshold through ventricular repolarization profile analysis

Under the hypothesis that sympathetic control of ventricular repolarization may change once the second ventilatory threshold (VT2) has been reached, a novel methodology for non-invasive VT2 estimation based on the analysis of the T wave from the electrocardiogram (ECG) is proposed, and potential underlying physiological mechanisms are suggested. 25 volunteers (33.4 ± 5.2 years) underwent an incremental power cycle ergometer test (25 W/minute). During the test, respiratory gas exchange and multi-lead ECG were acquired. The former was employed to determine VT2, used here as a reference, whereas the latter was used to compute the temporal profiles of an index of ventricular repolarization instability (dT) and its low-frequency (LF) oscillations (LFdT). The sudden increases observed in dT and LFdT profiles above an established heart rate threshold were employed to derive VT2 estimates, referred to as VT2dT and VT2LFdT, respectively. Estimation errors of -4.7 ± 25.2 W were obtained when considering VT2dT. Errors were lower than the one-minute power increment of 25 W in 68% of the subjects and lower than 50 W in 89.5% of them. When using VT2LFdT, estimation error was of 15.3 ± 32.4 W. Most of the subjects shared common characteristic dT and LFdT profiles, which could be reflecting changes in the autonomic control of ventricular repolarization before and after reaching VT2. The analysis of ventricular repolarization dynamics during exercise allows non-invasive ECG-based estimation of VT2, possibly in relation to changes in the autonomic control of ventricular electrical activity when VT2 is reached