Research Outputs
Reliability of a standing isokinetic shoulder rotators strength test using a functional electromechanical dynamometer: effects of velocity
Background. The evaluation of the force in internal rotation (IR) and external rotation (ER) of the shoulder is commonly used to diagnose possible pathologies or disorders in the glenohumeral joint and to assess patient’s status and progression over time. Currently, there is new technology of multiple joint isokinetic dynamometry that allows to evaluate the strength in the human being. The main purpose of this study was to determine the absolute and relative reliability of concentric and eccentric internal and external shoulder rotators with a functional electromechanical dynamometer (FEMD). Methods. Thirty-two male individuals (21.46 ± 2.1 years) were examined of concentric and eccentric strength of shoulder internal and external rotation with a FEMD at velocities of 0.3 m s−1 and 0.6 m s−1 . Relative reliability was determined by intraclass correlation coefficients (ICC). Absolute reliability was quantified by standard error of measurement (SEM) and coefficient of variation (CV). Systematic differences across velocities testing circumstances, were analyzed with dependent t tests or repeated measures analysis of variance in case of two or more than two conditions, respectively. Results. Reliability was high to excellent for IR and ER on concentric and eccentric strength measurements, regardless of velocity used (ICC: 0.81–0.98, CV: 5.12–8.27% SEM: 4.06–15.04N). Concentric outcomes were more reliable than eccentric due to the possible familiarization of the population with the different stimuli. Conclusion. All procedures examined showed high to excellent reliability for clinical use. However, a velocity of 0.60 m s−1 should be recommended for asymptomatic male patients because it demands less time for evaluation and patients find it more comfortable.
The addition of very light loads into the routine testing of the bench press increases the reliability of the force–velocity relationship
Background: The aim of this study was to examine whether the addition of very light loads for modeling the force–velocity (F–V) relationship during the bench press (BP) exercise can confirm its experimental linearity as well as to increase the reliability and concurrent validity of the F–V relationship parameters (maximum force (F0), maximum velocity (V0), F–V slope, and maximum power (Pmax)). Method: The F–V relationship of 19 healthy men were determined using three different methods: (I) 6-loads free method: six loads performed during the traditional free-weight BP exercise (≈ 1–8–29–39–49–59 kg), (II) 4-loads free method: four loads performed during the traditional free-weight BP exercise (≈ 29–39–49–59 kg), and (III) 4-loads Smith method: four loads performed during the ballistic bench press throw exercise in a Smith machine (≈ 29–39–49–59 kg). Results: The linearity of the F–V relationship was very high and comparable for the three F–V methods (p = 0.204; median Pearson’s correlation coefficient (r) = 0.99). The three methods were ranked from the most to the least reliable as follows: 6-loads free (coefficient of variation (CV) range = 3.6–6.7%) > 4-loads Smith (CV range = 4.6–12.4%) > 4-loads free (CV range = 3.8–14.5%). The higher reliability of the 6-loads free method was especially pronounced for F–V slope (CVratio ≥ 1.85) and V0 (CVratio ≥ 1.49) parameters, while the lowest difference in reliability was observed for F0 (CVratio ≤ 1.27). The 6-loads free and 4-loads free methods showed a very high concurrent validity respect to the 4-loads Smith method for F0 and Pmax (r ≥ 0.89), a moderate validity for the F–V slope (r = 0.66–0.82), and a low validity for V0 (r ≤ 0.37). Discussion: The routine testing of the F–V relationship of upper-body muscles through the BP exercise should include trials with very light loading conditions to enhance the reliability of the F–V relationship.
Efecto de los juegos reducidos en la composición corporal y la condición física aeróbica en un grupo de adolescentes escolares
The regular practice of physical activity contributes to weight control and improves maximal oxygen uptake (VO2max), socialization and quality of life. Aim: To determine the effect of moderate-to-vigorous physical activity on body composition and VO2max in a group of overweight school-age males. Material and Methods: We studied fifty-five overweight males aged 15.6 ± 0.7 years. Participants were divided in two groups (experimental and control groups). The intervention in the experimental group was the practice of small-sided games during 60 minutes, two days per week and during 11 weeks. At baseline and the end of the intervention, body composition was measured using bioimpedance and VO2max was calculated using the Course Navette test. Results: A 7% reduction in the percentage of body fat and a 9% increase in VO2max were observed in the experimental group (p < 0.01). No changes were recorded in the control group. Conclusions: Eleven weeks of small-sided exercises performed twice per week increased VO2max and reduced fat mass in overweight adolescents.
Reliability and validity of different methods of estimating the one-repetition maximum during the free-weight prone bench pull exercise
This study examined the reliability and validity of three methods of estimating the one-repetition maximum (1RM) during the free-weight prone bench pull exercise. Twenty-six men (22 rowers and four weightlifters) performed an incremental loading test until reaching their 1RM, followed by a set of repetitions-to-failure. Eighteen participants were re-tested to conduct the reliability analysis. The 1RM was estimated through the lifts-to-failure equations proposed by Lombardi and O'Connor, general load-velocity (L-V) relationships proposed by Sánchez-Medina and Loturco and the individual L-V relationships modelled using four (multiple-point method) or only two loads (two-point method). The direct method provided the highest reliability (coefficient of variation [CV] = 2.45% and intraclass correlation coefficient [ICC] = 0.97), followed by the Lombardi's equation (CV = 3.44% and ICC = 0.94), and no meaningful differences were observed between the remaining methods (CV range = 4.95-6.89% and ICC range = 0.81-0.91). The lifts-to-failure equations overestimated the 1RM (3.43-4.08%), the general L-V relationship proposed by Sánchez-Medina underestimated the 1RM (-3.77%), and no significant differences were observed for the remaining prediction methods (-0.40-0.86%). The individual L-V relationship could be recommended as the most accurate method for predicting the 1RM during the free-weight prone bench pull exercise.
Evaluation of tactical performance in invasion team sports: A systematic review
The objectives of this revision were to identify game indicators, the references for evaluating tactical efficiency, and the types of data analysis used in invasion team sports for the analysis of tactical performance. A search of the principal electronic databases was carried out, the procedure was adjusted to the PRISMA-P 2015 protocol, and 62 non-experimental published articles were obtained from the years 2000–2016. The results showed the complimentary use of diverse types of indicators and the frequent elaboration of instruments ad hoc. The individual technical-tactical actions were widely used. The record of standardised team actions was scarce. The research lines with a sequential data record for their temporary analysis were significant. The transitory or final score and the results of game sequences were the most used references of performance. The big data tools of analysis, web analysis, and the detection of temporal patterns or the application of polar coordinates were emerging methods of analysis.