Gerard Moras

Inter-rater reliability of muscle contractile property measurements using non-invasive tensiomyography

Tensiomyography (TMG) is a relatively novel technique to assess muscle mechanical response based on radial muscle belly displacement consecutive to a single electrical stimulus. Although intra-session reliability has been found to be good, inter-rater reliability and the influence of sensor repositioning and electrodes placement on TMG measurements is unknown. The purpose of this study was to analyze the inter-rater reliability of vastus medialis muscle contractile property measurements obtained with TMG as well as the effect of inter-electrode distance (IED). Five contractile parameters were analyzed from vastus medialis muscle belly displacement-time curves: maximal displacement (Dm), contraction time (Tc), sustain time (Ts), delay time (Td), and half-relaxation time (Tr). The inter-rater reliability and IED effect on these measurements were evaluated in 18 subjects. Intra-class correlation coefficients, standard errors of measurement, Bland and Altman systematic bias and random error as well as coefficient of variations were used as measures of reliability. Overall, a good to excellent inter-rater reliability was found for all contractile parameters, except Tr, which showed insufficient reliability. Alterations in IED significantly affected Dm with a trend for all the other parameters. The present results legitimate the use of TMG for the assessment of vastus medialis muscle contractile properties, particularly for Dm and Tc. It is recommended to avoid Tr quantification and IED modifications during multiple TMG measurements.

Six Weeks of Whole-Body Vibration Exercise Improves Pain and Fatigue in Women with Fibromyalgia

OBJECTIVE The aim of this study was to investigate the effectiveness of a 6-week traditional exercise program with supplementary whole-body vibration (WBV) in improving health status, physical functioning, and main symptoms of fibromyalgia (FM) in women with FM. METHODS Thirty-six (36) women with FM (mean +/- standard error of the mean age 55.97 +/- 1.55) were randomized into 3 treatment groups: exercise and vibration (EVG), exercise (EG), and control (CG). Exercise therapy, consisting of aerobic activities, stretching, and relaxation techniques, was performed twice a week (90 min/day). Following each exercise session, the EVG underwent a protocol with WBV, whereas the EG performed the same protocol without vibratory stimulus. The Fibromyalgia Impact Questionnaire (FIQ) was administered at baseline and 6 weeks following the initiation of the treatments. Estimates of pain, fatigue, stiffness, and depression were also reported using the visual analogue scale. RESULTS A significant 3 x 2 (group x time)-repeated measures analysis of variance interaction was found for pain (p = 0.018) and fatigue (p = 0.002) but not for FIQ (p = 0.069), stiffness (p = 0.142), or depression (p = 0.654). Pain and fatigue scores were significantly reduced from baseline in the EVG, but not in the EG or CG. In addition, the EVG showed significantly lower pain and fatigue scores at week 6 compared to the CG, whereas no significant differences were found between the EG and CG (p > 0.05). CONCLUSION Results suggest that a 6-week traditional exercise program with supplementary WBV safely reduces pain and fatigue, whereas exercise alone fails to induce improvements.

Effect of Acute and Chronic Whole-Body Vibration Exercise on Serum Insulin-Like Growth Factor–1 Levels in Women with Fibromyalgia

OBJECTIVE The purpose of this study was to investigate the effect of acute and chronic whole-body vibration exercise on serum insulin-like growth factor-1 (IGF-1) levels in women with fibromyalgia. METHODS A randomized controlled two-factor mixed experimental design was used. Twenty-four women with fibromyalgia (age +/- standard error of the mean, 54.95 +/- 2.03) were randomized into the vibration group or the control group. The vibration group underwent a protocol of static and dynamic tasks with whole-body vibration exercise twice a week for a total of six weeks, whereas the control group performed the same protocol without vibratory stimulus. Both groups continued their usual pharmacological treatment. Serum IGF-1 levels were determined using enzyme-linked immunosorbent assay (ELISA). To test the effects of long-term whole-body vibration exercise, serum IGF-1 measurements were taken at baseline and at weeks 1, 3, and 6 of the intervention. To test the short-term effects, at week 1, serum IGF-1 measurements were taken before and immediately following a session of whole-body vibration exercise. RESULTS Treatment adherence was 93% in the vibration group and 92% in the control group. None of the subjects dropped out of the study. There was an absence of change in IGF-1 at week 1 and week 6 of whole-body vibration exercise. CONCLUSION Results show no change in serum IGF-1 levels in women with fibromyalgia undergoing whole-body vibration exercise. Although high-intensity exercise and whole-body vibration exercise have been shown to increase serum IGF-1 in healthy individuals, the effectiveness of whole-body vibration exercise as a strategy to produce improvements in serum IGF-1 levels in women with fibromyalgia could not be demonstrated.

A Metronome for Controlling the Mean Velocity During the Bench Press Exercise

Moras, G, Rodríguez-Jiménez, S, Busquets, A, Tous-Fajardo, J, Pozzo, M, and Mújika I. A metronome for controlling the mean velocity during the bench press exercise. J Strength Cond Res 23(3): 926-931, 2009-Lifting velocity may have a great impact on strength training-induced adaptations. The purpose of this study was to validate a method including a metronome and a measurement tape as inexpensive tools for the estimation of mean lifting velocity during the bench press exercise. Fifteen subjects participated in this study. After determining their one repetition maximum (1RM) load, we estimated the maximum metronome rhythm (R) that each subject could maintain in the concentric phase for loads of 40 and 60% of 1RM. To estimate R, the 3 repetitions with highest concentric power, as measured by means of a linear encoder, were selected, and their average duration was calculated and converted to lifting rhythm in beats per minute (bpm) for each subject. The range of motion was measured using a regular tape and kept constant during all exercises. Subjects were instructed to begin with the barbell at arm lengths and lower it in correspondence with the metronome beep. They subsequently performed 5 repetitions at 3 different rhythms relative to R (50, 70, and 90% R) for each training load (40 and 60% of 1RM). A linear encoder was attached to the bar and used as a criterion to measure the vertical displacement over time. For each rhythm, the mean velocity was calculated with the metronome (time) and the reference distance and compared with that recorded by the linear encoder. The SEM for velocity between both testing methods ranged from 0.02 to 0.05 m·s−1 (coefficient of variation, 4.0-6.4%; Pearsons correlation, 0.8-0.95). The present results showed that the use of a metronome and a measurement tape may be a valid method to estimate the mean velocity of execution during the bench press exercise. This simple method could help coaches and athletes achieve their strength training goals, which are partly determined by lifting velocity.

Eccentric-Overload Training in Team-Sport Functional Performance: Constant Bilateral Vertical Versus Variable Unilateral Multidirectional Movements

PURPOSE To analyze the effects of 2 different eccentric-overload training (EOT) programs, using a rotational conical pulley, on functional performance in team-sport players. A traditional movement paradigm (ie, squat) including several sets of 1 bilateral and vertical movement was compared with a novel paradigm including a different exercise in each set of unilateral and multi-directional movements. METHODS Forty-eight amateur or semiprofessional team-sport players were randomly assigned to an EOT program including either the same bilateral vertical (CBV, n = 24) movement (squat) or different unilateral multidirectional (VUMD, n = 24) movements. Training programs consisted of 6 sets of 1 exercise (CBV) or 1 set of 6 exercises (VUMD) × 6-10 repetitions with 3 min of passive recovery between sets and exercises, biweekly for 8 wk. Functional-performance assessment included several change-of-direction (COD) tests, a 25-m linear-sprint test, unilateral multidirectional jumping tests (ie, lateral, horizontal, and vertical), and a bilateral vertical-jump test. RESULTS Within-group analysis showed substantial improvements in all tests in both groups, with VUMD showing more robust adaptations in pooled COD tests and lateral/horizontal jumping, whereas the opposite occurred in CBV respecting linear sprinting and vertical jumping. Between-groups analyses showed substantially better results in lateral jumps (ES = 0.21), left-leg horizontal jump (ES = 0.35), and 10-m COD with right leg (ES = 0.42) in VUMD than in CBV. In contrast, left-leg countermovement jump (ES = 0.26) was possibly better in CBV than in VUMD. CONCLUSIONS Eight weeks of EOT induced substantial improvements in functional-performance tests, although the force-vector application may play a key role to develop different and specific functional adaptations.

Heredabilidad de Laflexibilidad: un Estudio Hecho con Hermanos Gemelos

Abstract Flexibility (FL) defined as the scope of movement of one or several joints is a factor of sport performance, which is determinad by age, gender, training, anthropomorphic characteristics and genetic factors, of which very little has been studied. METHOD: To establish the relative importance of genetic and environmental infiuence on flexibility, we have studied the genetic component, using the Hereditability Index (Hl al a value of 1.0 indicates that 100% of the variation would be due to genetic variation) in 24 sportsmen spiit ihto 12 pairs of twin brothers (6 monozygoies and 6 dizygotes), who did not have any significant perinatal or environmental differences. Zygosity was determined by genetic analysis of the leukocyte human antigen system (LHA), especially the Class I and II loci, and other genetic variants. To calculate the FL, the subjects underwent an indirect flexometric test for the trigonometric calculation of the angie of aperture of the scapuiohumeral (FL, SHA) and coxofemoral joints (FL, CFA), the I atter broken down into the horizontal and sagittal fields, for active and forced passive movements and for both legs. RESULTS: We do not find significant differences in the age and anthropomorphic measurements between the two groups (MZ and DZ). The Hls which were statistically significant for F6,6, s (DZ MZ-1) over 4.2 and P

Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads.

The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg) were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P < 0.010) and peak force output differed between all loads for each condition (P < 0.045). Mean force outputs were greater in the concentric than in the eccentric phase under both conditions and with all loads (P < 0.001). There were no significant differences in peak force between concentric and eccentric phases at any load in either stable or unstable conditions. In conclusion, squatting with a rotational inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries.

Force production during squats performed with a rotational resistance device under stable versus unstable conditions.

[Purpose] Force production during a squat action on a rotational resistance device (RRD) under stable and unstable conditions. [Subjects and Methods] Twenty-one healthy males were asked to perform six sets of six repetitions of squats on an RRD on either stable or unstable surfaces. The stable and unstable sets were performed on different days. Muscular outputs were obtained from a linear encoder and a strain gauge fixed to a vest. [Results] Overall, the results showed no significant differences for any of the dependent variables across exercise modes. Forcemean outputs were higher in the concentric phase than in the eccentric phase for each condition, but there were no differences in velocity, time or displacement. The forcepeak was similar in the eccentric and concentric phases of movement under both stable and unstable conditions. There were no significant differences in forcemean between sets per condition or between conditions. [Conclusion] These results suggest that performing squats with a RRD achieves similar forcemean and forcepeak under stable and unstable conditions. The forcepeak produced is also similar in concentric and eccentric phases.

W5″ Test: A simple method for measuring mean power output in the bench press exercise

Abstract The aims of the present study were to assess the validity and reliability of a novel simple test [Five Seconds Power Test (W5″ Test)] for estimating the mean power output during the bench press exercise at different loads, and its sensitivity to detect training-induced changes. Thirty trained young men completed as many repetitions as possible in a time of ≈5 s at 25%, 45%, 65% and 85% of one-repetition maximum (1RM) in two test sessions separated by four days. The number of repetitions, linear displacement of the bar and time needed to complete the test were recorded by two independent testers, and a linear encoder was used as the criterion measure. For each load, the mean power output was calculated in the W5″ Test as mechanical work per time unit and compared with that obtained from the linear encoder. Subsequently, 20 additional subjects (10 training group vs. 10 control group) were assessed before and after completing a seven-week training programme designed to improve maximal power. Results showed that both assessment methods correlated highly in estimating mean power output at different loads (r range: 0.86–0.94; p < .01) and detecting training-induced changes (R2: 0.78). Good to excellent intra-tester (intraclass correlation coefficient (ICC) range: 0.81–0.97) and excellent inter-tester (ICC range: 0.96–0.99; coefficient of variation range: 2.4–4.1%) reliability was found for all loads. The W5″ Test was shown to be a valid, reliable and sensitive method for measuring mean power output during the bench press exercise in subjects who have previous resistance training experience.

Relación entre diferentes tests de salto en voleibol utilizando la plataforma de Bosco.

Resum Hem estudiat la relacio entre diferents tests de saIt utilitzats en el voleibol mitjancant la plataforma de Bosco. El grup avaluat esta integral per 25 jugadors de voleibol (9 nois i 16 noies) del Grup Especial de Tecnificacio Blume de Barcelona. Hem trobat diferencies significatives al passar els diferents tests especifics amb pilota i sense, aixi com entre els tests especifics i el CMJ de Bosco. Els resultats obtinguts ens fan pensar que cal establir criteris integradors que permetin interpretar la informado obtinguda al laboratori i a la pista per tal de trobar pautes utiis per l’entrenament.