Dynamic Handgrip Strength Endurance: A Reliable Measurement in Older Women

Background and Purpose: Dynamic handgrip strength endurance is essential for daily activities that require repetitive gripping movements for a sustained period. At this time, there is no information about the reliability of measurement of dynamic handgrip strength endurance in older individuals. Thus, the purpose of this study was to investigate the test-retest reliability of dynamic handgrip strength endurance in older women. Methods: A cross-sectional study was performed. Thirty older women aged 70.5 (3.6) years performed 2 assessment sessions (test and retest), separated by 3 days. During these sessions, the dynamic handgrip strength endurance was evaluated using a testing protocol consisted of 12 repeated maximal isometric contractions for 3 seconds, with a 5-second rest between contractions (repetitions). The maximal handgrip strength at each repetition (repeated maximal repetitions) was evaluated in both hands (preferred and nonpreferred hand) using an hydraulic dynamometer Jamar; while the percentage change (using the mean of the first and the last 3 repetitions as well as the mean of the first and the last 6 repetitions) and the fatigue index were calculated. Results: The test-retest reliability for the assessment of repeated maximal repetitions (intraclass correlation coefficient [ICC] = 0.82-0.95, standard error of measurement [SEM] = 0.76-1.22 kg, SEM 95% confidence interval [CI] = 0.53-1.69 kg, SEM% = 3.6-8.6) and of percentage change (ICC = 0.81-0.87, SEM = 3.26%-4.40%, SEM 95% CI = 2.23-6.33%, SEM% = 3.4-4.7) was found to be high, whereas fatigue index exhibited lower reliability (ICC = 0.69-0.84, SEM% = 10.9-11.8). Conclusion: A dynamic protocol of 12 repeated maximal repetitions may be used for the evaluation of dynamic handgrip strength endurance, using the repeated maximal repetitions and the percentage change as the most reliable indicators for the determination of muscle endurance. However, the assessment of fatigue index should be interpreted with more caution. © 2019 Journal of Geriatric Physical Therapy. All rights reserved

Reliability of Maximal Handgrip Strength Test in Pre-Pubertal and Pubertal Wrestlers

The purpose of this study was to evaluate the intersession and the intrasession reliability of maximal handgrip strength test in young wrestlers. Twenty-seven prepubertal (9.49 +/- 0.96yrs) and twenty-seven pubertal (14.60 +/- 0.50yrs) male wrestlers performed two assessment sessions separated by one day. Both assessments included a testing protocol consisted of three maximal isometric contractions, on both hands using a hydraulic dynamometer (Jamar). The intersession and intrasession reliability was high for both prepubertal and pubertal wrestlers (ICC = 0.87-0.99). The single trial as well as the best of two and three trials of handgrip strength were slightly less reliable (ICC = 0.87-0.94) than the mean of two and three trials in prepubertal (ICC = 0.95-0.97). The present results indicate that maximum handgrip strength can be measured reliably, using the Jamar dynamometer, in young wrestlers. A single trial as well as the two trials can be used as reliable, less-tiring and less time-consuming methods for the evaluation of handgrip strength than the three trials

Health-Promoting Effects of Serial vsIntegrated Combined Strength and Aerobic Training

Combined strength and aerobic training programs are widely used for improving markers of physical fitness and health. We compared the efficiency of a serial and an integrated combined training program on health and overall fitness in middle-aged females. 54 females (46.7±4.5yrs) were assigned to a serial (SCG) or an integrated (ICG) combined training group or to a control group (CG). The SCG and ICG performed a 3-month training combining aerobic dance and calisthenics. The 2 training programs differ in the sequence of aerobic and strength exercises. SCG performed the strength exercises prior to aerobic; in ICG, the aerobic and strength exercises were altered in a predetermined order. Body composition/circumferences, blood pressure, respiratory function, flexibility, balance, muscle strength/endurance, power and aerobic capacity were measured before and after training. SCG and ICG significantly increased muscle strength and endurance, power, aerobic capacity, flexibility, balance, fat-free mass and respiratory function (p<0.001-0.05), while significant reductions were observed for blood pressure, heart rate and body fat/circumferences (p<0.001-0.05). However, there were no significant differences between SCG and ICG after training. Serial and integrated combined training programs confer analogous adaptations and can be used interchangeably for counteracting the detrimental effects of sedentary lifestyle on indices of physical fitness and health

Can maximal handgrip strength and endurance be improved by an 8-week specialized strength training program in older women? A randomized controlled study [La force maximale et l'endurance de la poigne peuvent-elles être améliorées après un programme de musculation spécialisé de 8 semaines chez les femmes âgées? Une étude contrôlée randomisée]

Maximal handgrip strength and endurance are important indicators of upper limb function in older adults. Up to now, there is insufficient information regarding the efficacy of specialized strength training programs for improving handgrip strength. The purpose of this study was to investigate the effectiveness of an 8-week specialized handgrip strength training program on maximal handgrip strength and endurance in healthy older women. A randomized controlled trial was performed. Thirty-six healthy older women (>65 years) were randomly divided into a training group (TG) (n = 18) and a control group (CG) (n = 18). The TG participated in an 8-week specialized handgrip strength training program using rubber balls and hand grippers (2 training sessions/week, 10−15 min, 8–15 repetitions/set, 4–6 total sets/session). Prior to and after the completion of the program, maximal handgrip strength and dynamic endurance (indices: repeated maximal repetitions and percentage change in handgrip strength between first and last 6 repetitions) were assessed in both hands. Repeated measures MANOVA results indicated that maximal handgrip strength (+9.3%–10.4%) and strength values during repeated maximal repetitions (+14% to 27%) significantly increased in TG (p < 0.001), while the percentage change in handgrip strength between the first and last 6 repetitions decreased significantly (−6%) (p < 0.05), irrespective of the tested hand. The results of this study showed that an 8-week specialized handgrip strength training program can be used effectively by athletic trainers, physical and hand therapists to counteract the detrimental effects of the aging process on maximal handgrip strength and endurance in older adults. © 2020 SFC

Whole-body vibration training improves flexibility, strength profile of knee flexors, and hamstrings-to-quadriceps strength ratio in females

Objectives: Short-term whole-body vibration training (WBVT) has emerged as an exercise method for improving neuromuscular performance and has been proposed for injury prevention and rehabilitation. This study investigated the effects of a short-term (<= 2 months) WBVT program using a side-to-side vibration on: (i) strength profile of knee extensors (ME) and flexors (KF), (ii) "functional" hamstrings-to-quadriceps ratio (ECCKF/CONKE), (iii) flexibility and (iv) vertical jumping performance (VJ). Furthermore, we explored the retention of performance gains 21 days following WBVT. Design: Randomized-controlled trial. Methods: Twenty-six moderately active females (20.40 +/- 0.27 years) were assigned to a vibration (VG) or a control group (CG). The short-term WBVT program consisted of sixteen-sessions on a side-to-side vibration platform (frequency: 25 Hz, amplitude: 6 mm, 2 sets x 5 min). Isokinetic and isometric peak torque of KE and KF, ECCKF/CONKE, flexibility, and VJ were measured pre, 2 days post, and 21 days following the cessation of WBVT. Results: Post-training values of flexibility, isokinetic and isometric peak torques of KF and ECCKF/CONKE ratio were higher than pre-training values in VG (p < 0.05); however, they remained unchanged in CG. Post-training values were greater in VG vs. CG (p < 0.05). Twenty-one days following WBVT, post-training values were no longer significantly different than pre-training values. The short-term WBVT program had no effect on strength profile of KE and on VJ. Conclusions: A short-term side-to-side WBVT program improved flexibility, the strength profile of knee flexors, and the "functional" hamstrings-to-quadriceps ratio in moderately active females. Coaches and clinical practitioners should consider this type of training as an effective exercise mode for improving the strength asymmetry of reciprocal muscles at the knee joint. (C) 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved

Whole-body vibration and rehabilitation of chronic diseases: A review of the literature

The objectives of the study were to review the current literature and findings on the effects of whole-body vibration (WBV) as a training method on performance and its ability to aid in the rehabilitation of chronic diseases (neurological, musculoskeletal or metabolic conditions). Six electronic databases were searched. The combination of the search terminology used included WBV and several neurological, musculoskeletal and metabolic conditions. Twenty six papers were found to be relevant for this review and were included for critical evaluation with regards to sample characteristics, research intervention and methodology. Most studies were conducted on patients diagnosed with neurological conditions (n = 15) while less were performed on patients suffering from musculoskeletal (n = 7) or metabolic (n = 4) disorders. Comparisons were difficult to draw on because of the different pathologies and the differences in the methodology of each study. Some of the observed methodological flaws included limitations in relation to insufficient randomisation, lack of sample homogeneity (size, age variability) and poor blinding in most studies. No consensus could be reached as to whether WBV is more effective than other interventions or no intervention at all, while the additional effects that WBV may have in relation to other interventions could not be assumed. Nevertheless, chronic WBV training seems to only improve strength in neurological patients while balance and mobility improves only in patients suffering from musculoskeletal or metabolic but not from neurological conditions. Although WBV did not prove to be more effective compared to other training methods, it can be used, in some cases, as a less fatiguing and less time-consuming method to enhance physical capabilities. Future research should focus on the effectiveness of WBV in relation to no treatment at all, and to age

Does the number of trials affect the reliability of handgrip strength measurement in individuals with intellectual disabilities? [Le nombre d'essais peut-il affecter la fiabilité de la mesure de la force de poigne chez les personnes ayant une déficience intellectuelle ?]

The main objectives of this study were to examine which testing protocol (one/two/three trials) and method (best/average value) used for determining maximal handgrip strength is more reliable for individuals with intellectual disabilities (ID) and to compare the reliability and variability of maximal handgrip strength measurement between individuals with ID and healthy individuals. Twenty individuals with ID (18.7 ± 3.3 years) and 20 healthy individuals (18.5 ± 3.4 years) performed six separate sessions. During these sessions, the participants’ maximal handgrip strength was evaluated using three protocols with different number of trials (one/two/three). In individuals with ID, the protocols with one and two trials were less reliable (ICC = 0.78–0.95; SEM% = 9–21) than the protocol with three trials (ICC = 0.94–0.96; SEM% = 8–10) whereas in healthy individuals all protocols were equally reliable (ICC = 0.95–0.99; SEM% = 1.9–4.9). In individuals with ID, the mean of three trials (ICC = 0.96, SEM = 1.19–1.35 kg, SEM% = 8.2–8.7) had slightly higher reliability than the best of three trials (ICC = 0.94, SEM = 1.47–1.75 kg, SEM% = 9.2–10.1). Furthermore, the variability of maximal handgrip strength measurement was about twofold higher in individuals with ID (CV = 37–45%) vs. healthy individuals (CV = 21–23%). Maximal handgrip strength can be measured reliably in young individuals with ID using the mean of three trials as the most reliable approach for the determination of maximal handgrip strength. © 2020 SFC

Workplace exercise program in a hospital environment: an effective strategy for the promotion of employees physical and mental health. A randomized controlled study

Purpose: The demanding and exhausting working hours, as well as the bad and unsuitable working conditions that prevail in several hospitals, affect employees' physical and mental health. The purpose of this study was to examine the effectiveness of a daily 6-week supervised workplace exercise program on health indices, functional capacity, overall fitness, subjective vitality, and life satisfaction in health professionals. Methods: A randomized controlled study was used. 50 health professionals (40–55 years), working in a hospital environment, were divided into two groups: exercise (EG) and control group (CG). EG performed a 6-week supervised concurrent chair-based exercise program (stretching, strength, balance exercises, aerobic dance; 5 days/week, 30–40 min/day, 2 workouts/day lasted 15–20 min) in the hospital. Health indices (body composition, blood pressure, respiratory function), functional capacity (flexibility, balance), physical fitness (strength, cardiorespiratory fitness), subjective vitality, and life satisfaction were measured before and after the completion of the program. Additionally, after the completion of the program, EG participants’ enjoyment was assessed. Results: EG significantly increased (p < 0.001) lean body mass and respiratory function (range of mean increase 3.5–4.5%, depending on the variable), functional capacity (range of mean increase 18–40%, depending on the variable), lower and upper libs maximal strength (range of mean increase 10–25%, depending on the variable), subjective vitality (41.3%) and life satisfaction (21.5%); while significantly decreased (p < 0.001) heart rate during submaximal test (− 14%), body fat and blood pressure (range of mean decrease − 3.5% to − 5.5%, depending on the variable). In CG, all the above variables did not change. Furthermore, a great percentage of employees (95%) reported high levels of enjoyment. Conclusion: A workplace exercise program may be safely used for the promotion of employees' physical and mental health. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature

The efficacy of vertical vs. Horizontal plyometric training on speed, jumping performance and agility in soccer players

This study compared the efficacy of a vertical and horizontal plyometric training program on acceleration, speed, jumping performance, and agility in young soccer players during the in-season period. Thirty male soccer players (19.1±5.8 years) were assigned into a horizontal plyometric, a vertical plyometric, or a control group. The horizontal plyometric group and vertical plyometric group participated in an eight-week training program that was performed one day/week (in conjunction with conventional soccer training) and consisted of horizontal (for the horizontal plyometric group) or vertical plyometric exercises (for the vertical plyometric group). Acceleration (10-m sprint), speed (30-m sprint), agility, and jumping performance (horizontal and vertical) were assessed prior and after the completion of plyometric training programs. Agility, 30-m sprint performance, and vertical jumping performance (p<0.01) improved following the completion of training in both horizontal plyometric group and vertical plyometric group, whereas horizontal jumping performance improved only in horizontal plyometric group (p<0.01). There were no significant effects on acceleration for both horizontal plyometric group and vertical plyometric group. Furthermore, no differences were observed between groups in all performance parameters. In control group, acceleration, speed, agility, and jumping performance remained stable throughout the study. To sum up, horizontal or vertical plyometric training programs, consisting of one session/week, may be used by coaches and fitness professionals as effective exercise modalities for preserving or improving jumping performance, acceleration, speed, and agility in young soccer players during the in-season period. © The Author(s) 2016

The acute effects of different whole-body vibration amplitudes and frequencies on flexibility and vertical jumping performance

Frequency and amplitude determine the training load of whole-body vibration (WBV) exercise and thereby possible neuromuscular adaptations. We investigated the effects of amplitude and frequency of a single bout of WBV on flexibility and squat jump performance (SJ) and the time-course of these effects. In the amplitude study, twenty-five females performed three vibration protocols (VPs) for 6 min at frequency of 25 Hz and amplitudes of 4 mm, 6 mm, and 8 mm and one control protocol (CP). In the frequency study, eighteen females performed three VPs at 6 mm amplitude and frequencies of 15 Hz, 20 Hz, and 30Hz and one CP. Flexibility and SJ were measured before, immediately-post and 15 min recovery. All protocols were performed on a side-to-side alternating vibration plate. In the amplitude study, flexibility was improved (p < 0.01) immediately-post in VP4, VP6, VP8 (31.8 +/- 8.2, 31.9 +/- 7.6, 31.5 +/- 7.9, respectively) and at 15 min recovery (31.6 +/- 8.1, 31.5 +/- 7.9, 31.0 +/- 8.2, respectively) vs. pre-vibration (30.2 +/- 8.6, 30.3 +/- 8.1, 30.2 +/- 8.3, respectively), but remained unchanged in CP (30.6 +/- 8.3 immediately-post, 30.7 +/- 8.2 at 15 min vs. 30.4 +/- 8.2 pre-vibration). In the frequency study, flexibility was improved (p < 0.01) immediately-post in VP15, VP20, VP30 (31.5 +/- 5.2, 31.3 +/- 5, 31.7 +/- 5.3, respectively) and at 15 min recovery (31.3 +/- 5.4, 31.3 +/- 5.0, 31.3 +/- 5.3, respectively) vs. pre-vibration (30.6 +/- 5.4, 30.2 +/- 5.7, 30.3 +/- 5.9, respectively), but not in CP (30.7 +/- 5.1 immediately-post, 30.6 +/- 5 at 15 min vs. pre-vibration 30.5 +/- 5.7). There were no significant effects of amplitude or frequency on SJ. In conclusion, a single WBV bout using a side-to-side alternating vibration plate may increase flexibility which persists for at least 15 min, without altering jumping performance. These effects were observed irrespective of frequency and amplitude. (C) 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved