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This aims of this study were (I) to determine the velocity variable and regression model which best fit the load-velocity relationship during the free-weight prone bench pull exercise, (II) to compare the reliability of the velocity attained at each percentage of the one-repetition maximum (1RM) between different velocity variables and regression models, and (III) to compare the within- and between-subject variability of the velocity attained at each %1RM. Eighteen men (14 rowers and four weightlifters) performed an incremental test during the free-weight prone bench pull exercise in two different sessions. General and individual load-velocity relationships were modelled through three velocity variables (mean velocity [MV], mean propulsive velocity [MPV] and peak velocity [PV]) and two regression models (linear and second-order polynomial). The main findings revealed that (I) the general (Pearson's correlation coefficient [ r ] range = 0.964–0.973) and individual (median r = 0.986 for MV, 0.989 for MPV, and 0.984 for PV) load-velocity relationships were highly linear, (II) the reliability of the velocity attained at each %1RM did not meaningfully differ between the velocity variables (coefficient of variation [CV] range = 2.55–7.61% for MV, 2.84–7.72% for MPV and 3.50–6.03% for PV) neither between the regression models (CV range = 2.55–7.72% and 2.73–5.25% for the linear and polynomial regressions, respectively), and (III) the within-subject variability of the velocity attained at each %1RM was lower than the between-subject variability for the light-moderate loads. No meaningful differences between the within- and between-subject CVs were observed for the MV of the 1RM trial (6.02% vs . 6.60%; CV ratio = 1.10), while the within-subject CV was lower for PV (6.36% vs . 7.56%; CV ratio = 1.19). These results suggest that the individual load-MV relationship should be determined with a linear regression model to obtain the most accurate prescription of the relative load during the free-weight prone bench pull exercise.

AimTo determine the absolute and relative reliability of functional trunk tests, using a functional electromechanical dynamometer to evaluate the isokinetic strength of trunk flexors and to determine the most reliable assessment condition, in order to compare the absolute and relative reliability of mean force and peak force of trunk flexors and to determine which isokinetic condition of evaluation is best related to the maximum isometric.MethodsTest-retest of thirty-seven physically active male student volunteers who performed the different protocols, isometric contraction and the combination of three velocities (V1 = 015 m s−1 , V2 = 0.30 m  s−1, V3 = 0.45 m s−1) and two range of movement (R1 = 25% cm ; R2 = 50% cm) protocols.ResultsAll protocols to evaluate trunk flexors showed an absolute reliability provided a stable repeatability for isometric and dynamic protocols with a coefficient of variation (CV) being below 10% and a high or very high relative reliability (0.69 < intraclass correlation coefficient [ICC] > 0.86). The more reliable strength manifestation (CV = 6.82%) to evaluate the concentric contraction of trunk flexors was mean force, with 0.15 m  s−1 and short range of movement (V1R1) condition. The most reliable strength manifestation to evaluate the eccentric contraction of trunk flexors was peak force, with 0.15 m  s−1 and a large range of movement (V1R2; CV = 5.07%), and the most reliable way to evaluate isometric trunk flexors was by peak force (CV = 7.72%). The mean force of eccentric trunk flexor strength with 0.45 m  s−1 and short range of movement (V3R1) condition (r = 0.73) was best related to the maximum isometric contraction.ConclusionFunctional electromechanical dynamometry is a reliable evaluation system for assessment of trunk flexor strength.

The aims of the study were (i) to determine the reliability and concurrent validity of a functional electromechanical dynamometer (FEMD) to measure different isokinetic velocities, and (ii) to identify the real range of isokinetic velocity reached by FEMD for different prescribed velocities. Mean velocities were collected simultaneously with FEMD and a linear velocity transducer (LVT) in two sessions that were identical, consisting of 15 trials at five isokinetic velocities (0.40, 0.60, 0.80, 1.00, and 1.20 m·s−1) over a range of movement of 40 cm. The results obtained using each method were compared using Paired samples t-tests, Bland-Altman plots and the Pearson’s product–moment correlation coefficient, while the reliability was determined using the standard error of measurement and coefficient of variation (CV). The results indicate that the mean velocity values collected with FEMD and LVT were practically perfect correlations ( r > 0.99) with low random errors (<0.06 m·s−1), while mean velocity values were systematically higher for FEMD ( p < 0.05). FEMD provided a high or acceptable reliability for mean velocity (CV ≤ 0.24%), time to reach the isokinetic velocity (CV range = 1.68%–9.70%) and time spent at the isokinetic velocity (CV range = 0.53%–8.94%). These results suggest that FEMD offers valid and reliable measurements of mean velocity during a fixed linear movement, as well as a consistent duration of the isokinetic phase. FEMD could be an appropriate device to evaluate movement velocity during linear movements. More studies are needed to confirm the reliability and validity of FEMD to measure different velocity metrics during more complex functional exercises.

This study examined the differences in the bench press one-repetition maximum obtained by three different methods (direct method, lifts-to-failure method, and two-point method). Twenty young men were tested in four different sessions. A single grip width (close, medium, wide, or self-selected) was randomly used on each session. Each session consisted of an incremental loading test until reaching the one-repetition maximum, followed by a single set of lifts-to-failure against the 75% one-repetition maximum load. The last load lifted during the incremental loading test was considered the actual one-repetition maximum (direct method). The one-repetition maximum was also predicted using the Mayhew’s equation (lifts-to-failure method) and the individual load–velocity relationship modeled from two data points (two-point method). The actual one-repetition maximum was underestimated by the lifts-to-failure method (range: 1–2 kg) and overestimated by the two-point method (range: –3 to –1 kg), being these differences accentuated using closer grip widths. All predicted one-repetition maximums were practically perfectly correlated with the actual one-repetition maximum ( r ≥  0.95; standard error of the estimate ≤ 4 kg). The one-repetition maximum was higher using the medium grip width (83 ± 3 kg) compared to the close (80 ± 3 kg) and wide (79 ± 3 kg) grip widths ( P ≤  0.025), while no significant differences were observed between the medium and self-selected (81 ± 3 kg) grip widths ( P =  1.000). In conclusion, although both the Mayhew’s equation and the two-point method are able to predict the actual one-repetition maximum with an acceptable precision, the differences between the actual and predicted one-repetition maximums seem to increase when using close grip widths.

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 2 or more than 2 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.

This study aimed to compare the within-session reliability and magnitude of velocity variables recorded against a range of submaximal loads during the bench press (BP) exercise performed in a Smith machine using different grip widths. Sixteen physically active men (BP one-repetition maximum [1RM] relative to body mass = 1.01 ± 0.19 kg•kg −1 ) were randomly tested on 4 sessions using a close grip width (100% of biacromial width), medium grip width (150% of biacromial width), wide grip width (200% of biacromial width), and self-selected grip width (176 ± 17% of biacromial width). Mean velocity (MV), maximum velocity (Vmax), and vertical displacement were recorded with a linear velocity transducer against the 35%1RM, 55%1RM, and 75%1RM. The main findings revealed that (I) the self-selected was the only grip width with an acceptable reliability for all loads and velocity variables (CV ≤ 7.56%; ICC ≥ 0.82), (II) the medium grip width provided the highest reliability for MV (CV ratio ≥ 1.20), while a comparable reliability was observed for Vmax using the close, medium and self-selected grip widths (CV ratio ≤ 1.08), (III) the Vmax showed the highest reliability for all grip widths (CV ratio = 1.68), and (IV) the MV and vertical displacement of the barbell were generally higher for narrow grip widths (close and medium) compared to the wide and self-selected grip widths, while no significant differences between the grip widths were observed for Vmax (p > .05). Taken together, we recommend the assessment of Vmax using a self-selected grip width during the routine testing of BP performance against submaximal loads.

The purpose of this study was to investigate the acute effect of pre-activation with Variable Intra-Repetition Resistance and isometry on the overhead throwing velocity in handball players. Fourteen female handball players took part in the study (age: 21.2 ± 2.7 years, experience: 10.9 ± 3.5 years). For Post-Activation Potentiation, two pre-activation methods were used: (I) Variable Intra-Repetition Resistance: 1 x 5 maximum repetitions at an initial velocity of 0.6 m·s-1 and a final velocity of 0.9 m·s-1; (II) Isometry: 1 x 5 s of maximum voluntary isometric contraction. Both methods were "standing unilateral bench presses" with the dominant arm, using a functional electromechanical dynamometer. The variable analysed was the mean of the three overhead throws. Ball velocity was measured with a radar (Stalker ATS). The statistical analysis was performed using ANOVA with repeated measures. No significant differences were found for either method (variable resistance intra-repetition: p = 0.194, isometry: p = 0.596). Regarding the individual responses, the analysis showed that 86% of the sample increased throwing velocity with the variable resistance intra-repetition method, while 93% of the sample increased throwing velocity with the isometric method. Both the variable intra-repetition resistance and isometric methods show improvements in ball velocity in female handball players. However, the authors recommend checking individual responses, since the results obtained were influenced by the short rest interval between the pre-activation and the experimental sets.