Effect of low-load resistance combined with single-leg pressure training on the explosive strength of lower limb muscles in athletes

Introduction: In the game of cricket dynamic balance and the strength of lower limb muscles plays a major role while bowling or to control the bowling speed. Bowlers use different style of run ups to optimise their bowling speed. Therefore, for every athlete physical fitness plays essential role. Aim: To find the correlation between bowling speed and lower limb explosive power and dynamic balance in state and district level cricket bowlers. Materials and Methods: This cross-sectional study was conducted at Cricket Gurukul, Faridabad, Mahadev Desai Cricket Academy, Faridabad, Haryana and Indraprastha Cricket Academy, Punjabi Bagh, Delhi, India from January 2018 to January 2019. Total 98 male bowlers with age between 16-28 years, playing experience of at least 6 months in University/District level and playing frequency at least 5 days/weeks were included in the present study. Modified Star Excursion Balance Test (mSEBT) was used to measure the dynamic balance, broad jump test was used to measure lower limb explosive power and radar gun was used to measured bowling speed. Data was analysed in the Statistical Package for the Social Sciences (SPSS) software 2.0 version. Descriptive statistics was calculated. Pearson’s correlation coefficient was calculated. The p-value <0.05 was set as statistically significant. Results: Mean age was 19±3.1 years and Body mass index was 23.1±2.68 kg/m2 . Dynamic balance showed positive correlation with bowling speed (r=0.227, p<0.0001) and lower limb explosive power showed positive correlation (r=0.638, p<0.0001) with bowling speed in cricket bowlers. Conclusion: It was found that, the bowling speed of the cricket bowlers can improve majorly if the explosive power of the lower limb is improved whereas, there is less impact of dynamic balance on the bowling speed.

The main objective of this study was to investigate the relationship between agility and speed and the explosive power of the lower limbs in youth football players. A total of 45 male athletes (ages 12–14) participated in this study. Anthropometric measurements (body height, body weight, and waist circumference) were recorded, and participants completed a series of motor performance tests. These included field-based assessments such as the agility 10x5m test, the agility T-test, sprint tests (10m and 20m), and the standing long jump. Laboratory-based assessments included the Leonardo Mechanography platform for measuring maximal force during a two-legged jump (S2LJ), and isometric strength tests using a dynamometric chair to determine maximal torque in both lower limbs. Descriptive statistics and Pearson correlation analyses were used to examine the associations between agility and speed with explosive lower limb power. Results indicated significant correlations between agility tests and all explosive power measures, particularly between the agility T-test and both isometric torque and S2LJ force. Similarly, sprint performance (10m and 20m) showed strong inverse correlations with the standing long jump, S2LJ, and isometric torque, suggesting that greater explosive strength is associated with faster sprint times. These findings highlight the importance of developing lower limb explosive power in youth football training, as it contributes to improved agility and sprinting ability. Keywords: youth football, agility, speed, explosive power, standing long jump

IntroductionEnd stage liver disease (ESLD) negatively impacts muscle homeostasis with observed reductions in muscle mass (sarcopenia) and strength. The current recommended measures of muscle mass in ESLD are 3rd lumbar...

Lower limb ankle exoskeletons have been used to improve walking efficiency and assist the elderly and patients with motor dysfunction in daily activities or rehabilitation training, while the assistance patterns may influence the wearer's lower limb muscle activities and coordination patterns. In this paper, we aim to evaluate the effects of different ankle exoskeleton assistance patterns on wearer's lower limb muscle activities and coordination patterns. A tethered ankle exoskeleton with nine assistance patterns that combined with differenet actuation timing values and torque magnitude levels was used to assist human walking. Lower limb muscle surface electromyography signals were collected from 7 participants walking on a treadmill at a speed of 1.25 m/s. Results showed that the soleus muscle activities were significantly reduced during assisted walking. In one assistance pattern with peak time in 49% of stride and peak torque at 0.7 N·m/kg, the soleus muscle activity was decreased by (38.5 ± 10.8)%. Compared with actuation timing, the assistance torque magnitude had a more significant influence on soleus muscle activity. In all assistance patterns, the eight lower limb muscle activities could be decomposed to five basic muscle synergies. The muscle synergies changed little under assistance with appropriate actuation timing and torque magnitude. Besides, co-contraction indexs of soleus and tibialis anterior, rectus femoris and semitendinosus under exoskeleton assistance were higher than normal walking. Our results are expected to help to understand how healthy wearers adjust their neuromuscular control mechanisms to adapt to different exoskeleton assistance patterns, and provide reference to select appropriate assistance to improve walking efficiency.

Arm swing is an inherent aspect of human locomotion that enhances lower limb (LL) muscle activation, which may explain its benefits for stroke rehabilitation over fixed-arm approaches. This study analyzed how restricting arm movement affects LL muscle coordination by comparing treadmill walking with arms (WWA) and walking with no arms (WNA) through muscle synergy analysis. Surface electromyography was recorded from eight LL muscles in ten healthy participants. Significant differences were found in muscle activity envelopes at 50% of the gait cycle (GC) for the Gluteus Medius, 0% and 100% GC for the Vastus Lateralis and Semitendinosus, and 25% GC for the Semitendinosus, Gastrocnemius Medialis, and Soleus. The Rectus Femoris and Vastus Lateralis showed higher variability and activation in WNA compared to WWA. Synergy analysis revealed four muscle synergies, with a median global variance of 95%. While spatial components were similar, temporal differences emerged at 0% GC for Synergy 1, 5% and 90% GC for Synergy 2, and 95% GC for Synergy 3 (p < 0.05). Our results suggest that arm swing influences LL muscle activity and coordination during walking. Future studies will aim at understanding the effects of arm swing in stroke rehabilitation, which could help design more effective gait rehabilitation protocols including arm swing.

The physical capabilities underlying timed “Up and Go” test are time-dependent in community-dwelling older women

Bobath therapy is inferior to task-specific training and not superior to other interventions in improving lower limb activities after stroke: a systematic review.

BackgroundThere is currently no objective and accurate clinical assessment of reticular neuromuscular control in healthy subjects or patients with upper motor neuron injury. As a result, clinical dysfunctions of neuromuscular control could just be semi-quantified, efficacies and mechanisms of various therapies for neuromuscular control improving are difficult to verify.MethodsFourteen healthy participants were required to maintain standing balance in the kinetostatics model of Gusu Constraint Standing Training (GCST). A backward and upward constraint force was applied to their trunk at 0°, 20° and 25°, respectively. The multiplex recurrence network (MRN) was applied to analyze the surface electromyography signals of 16 muscles of bilateral lower limbs during the tests. Different levels of MRN network indices were utilized to assess reticular neuromuscular control.ResultsCompared with the 0° test, the MRN indices related to muscle coordination of bilateral lower limbs, of unilateral lower limb and of inter limbs showed significant increase when participants stood in 20° and 25° tests (P < 0.05). The indices related to muscle contribution of gluteal, anterior thigh and calf muscles significantly increased when participants stood in 20° and 25° tests (P < 0.05).ConclusionsThis study applied the dynamical network indices of MRN to analyze the changes of neuromuscular control of lower limbs of healthy participants in the kinetostatics model of GCST. Results showed that the overall coordination of lower limb muscles would be significantly enhanced during performing GCST, partly by the enhancement of neuromuscular control of single lower limb, and partly by the enhancement of joint control across lower limbs. In particular, the muscles in buttocks, anterior thighs and calves played a more important role in the overall coordination, and their involvement was significantly increased. The MRN could provide details of control at the bilateral lower limbs, unilateral lower limb, inter limbs, and single muscle levels, and has the potential to be a new tool for assessing the reticular neuromuscular control.Trial registration ChiCTR2100055090

Background: Elite referees make more than 1,400 changes of action and up to 500 changes of direction in a match, which places a high demand on the explosive power of lower limbs. Lower limb injuries are a common problem for soccer referees and have a negative impact on their performance in a match. The purpose of the study was to assess the explosive power and dynamic stability of soccer referees from the viewpoint of refereeing function. Methods: The research sample consisted of 26 soccer referees, including 13 head referees and 13 assistant referees. The following jump tests were administered to determine the referees’ lower limb explosive power: the countermovement jump test (CMJ), the countermovement jump test with free arms (CMJ FA), the squat jump (SJ), and a 10-second vertical jump test. The level of dynamic stability was diagnosed by the Y Balance test. Results: Compared to assistant referees, head referees reached higher levels of explosive power in all measured parameters but the differences were not statistically significant. For the level of dynamic stability, we observed significant differences in the composite score and % lower limb length in favor of the referees in the posteromedial and posterolateral directions for the left and right legs. Conclusions: The greatest differences were found in dynamic stability, specifically in the composite score and % lower limb length in the posteromedial and posterolateral direction. The differences may be caused by typical movement patterns associated with these two adjudicatory roles. We recommend the inclusion of compensatory exercises in the training of assistant referees.

Background: Explosive power, an essential component encompassing both speed and strength, plays a fundamental role in various physical activities, crucial for both competitive sports and general fitness. Objective This research presents an investigation into methodologies for enhancing lower limb explosive power in children aged 6–12 years. It also employs data-driven techniques in correlation analyses and modelling. Methods The study involved an 8-week experiment of training lower limb explosive power using squat jump, 15-metre sprint, hurdle hop, etc. The explosive power was measured using a TENDO device. Combined with correlation analysis and linear regression, predictive models of children's lower limb explosive power have been developed through a data-driven approach using a fuzzy rule-based system. Results Correlation analyses reveal significant associations between changes in explosive power and metrics such as vertical jump height and 30-meter sprint time. Regression analyses produce predictive equations tailored to gender-specific differences. The predictive models derived with the fuzzy rule-based system demonstrate good accuracy. Conclusions The proposed training programme effectively contributes to the enhancement of the lower limb power in children, while the advanced modelling techniques furnish precise prognostic tools, facilitating nuanced and targeted training interventions.

Disuse in older adults can critically decrease lower limb muscle power, leading to compromised mobility and overall quality of life. We studied how muscle power and its determinants (muscle mass, single muscle fibre properties and motor control) adapted to 2weeks of disuse and subsequent 2weeks of physical training in young and older people. Disuse decreased lower limb muscle power in both groups; however, different adaptations in single muscle fibre properties and co-contraction of leg muscles were observed between young and older individuals. Six physical training sessions performed after disuse promoted the recovery of muscle mass and power. However, they were not sufficient to restore muscle power to pre-disuse values in older individuals, suggesting that further countermeasures are required to counteract the disuse-induced loss of muscle power in older adults. Disuse-induced loss of muscle power can be detrimental in older individuals, seriously impairing functional capacity. In this study, we examined the changes in maximal explosive power (MEP) of lower limbs induced by a 14-day disuse (bed-rest, BR) and a subsequent 14-day retraining, to assess whether the impact of disuse was greater in older than in young men, and to analyse the causes of such adaptations. Sixteen older adults (Old: 55-65years) and seven Young (18-30years) individuals participated in this study. In a subgroup of eight Old subjects, countermeasures based on cognitive training and protein supplementation were applied. MEP was measured with an explosive ergometer, muscle mass was determined by magnetic resonance, motor control was studied by EMG, and single muscle fibres were analysed in vastus lateralis biopsy samples. MEP was ∼33% lower in Old than in Young individuals, and remained significantly lower (-19%) when normalized by muscle volume. BR significantly affected MEP in Old (-15%) but not in Young. Retraining tended to increase MEP; however, this intervention was not sufficient to restore pre-BR values in Old. Ankle co-contraction increased after BR in Old only, and remained elevated after retraining (+30%). Significant atrophy occurred in slow fibres in Old, and in fast fibres in Young. After retraining, the recovery of muscle fibre thickness was partial. The proposed countermeasures were not sufficient to affect muscle mass and power. The greater impact of disuse and smaller retraining-induced recovery observed in Old highlight the importance of designing suitable rehabilitation protocols for older individuals.

although low strength is a risk factor for falls, lower limb explosive power is more predictive of functional difficulties than strength. Power may be more predictive of a future fall than strength per se. to compare leg muscle strength and explosive power and asymmetry of leg strength and power of women aged 65 or over living at home, with and without a history of falls. a case controlled study of self-reported 'fallers' versus 'non-fallers'. twenty women, aged 65 or over, with a history of at least three falls in the previous year were age matched with 15 women with no history of falls in the previous year. lower limb explosive power, isometric strength of the quadriceps and hamstrings, isokinetic concentric strength (100 degrees/sec) of the quadriceps, hamstrings, ankle plantar- and dorsi-flexors and quadriceps eccentric strength (100 degrees/sec). Habitual physical activity was assessed using the self-completed Habitual Activity Profile Questionnaire. the women with a history of falls were less active but were not significantly weaker in any of the strength measurements, apart from ankle dorsiflexion adjusted for body weight. Both groups had significant asymmetry in all the leg muscles for both strength and power. Although both groups were asymmetrical in their lower limb power, the fallers demonstrated a significantly greater asymmetry. When the least powerful legs were compared, the women with a history of falls were 24% less powerful for their weight than those who did not fall (P=0.04). weakness and asymmetry is prevalent in women aged 65 and over, with and without a history of falls. Poor lower limb explosive power combined with asymmetry between limbs may be more predictive of future falls than more traditional measurements of strength in older women who live independently.

The high prevalence and increasing severity of osteoporosis have elevated it to a significant global public-health concern, imposing a substantial economic burden. Skeletal muscle strength and cardiorespiratory endurance serve as pivotal metrics in evaluating physical health. They play a vital role in mitigating the risks associated with bone density decline and the development of osteoporosis. This cross-sectional study was carried out among Chinese adults aged 30-60 years. Its aim is to investigate the associations between skeletal muscle strength, cardiorespiratory endurance, and bone density, thereby providing scientific evidence for formulating prevention and intervention strategies against osteoporosis. A handgrip dynamometer was employed to measure the subjects' grip strength, which served as an indicator for assessing their upper-limb muscle strength. Additionally, an isokinetic muscle-strength tester was utilized to determine the subjects' lower-limb isokinetic muscle strength, thereby evaluating the strength of their lower-limb muscles. The exercise cardiopulmonary testing system was utilized to directly measure the subjects' maximum oxygen uptake (VO₂ max) via a treadmill test. This crucial indicator was then employed to assess the subjects' cardiorespiratory fitness (CRF). Moreover, the QCT bone density analysis system was used to measure the thoracolumbar bone density of the subjects, and their bone density levels were evaluated based on the T value. A multiple stepwise linear regression model was utilized to further examine the associations between the independent variables grip strength, quadriceps muscle strength, and maximum oxygen uptake and the dependent variable, the bone density T value, stratified by gender. A series of factors potentially influencing the results were adjusted for, such as age, weight, body mass index (BMI), smoking and drinking habits, as well as vitamin D and calcium levels. In the final fully adjusted model, a significant positive correlation was detected between grip strength and the BMD T score (β = 0.03, p < 0.001). This correlation held significance in both women (β = 0.15, p < 0.001) and men (β = 0.07, p < 0.001). A significant correlation was observed between quadriceps muscle strength and the bone mineral density T score (β = 0.94, p < 0.001). Notably, this correlation was particularly pronounced in the female group, with a more significant relationship (β = 1.35, p < 0.001), whereas in the male group, the correlation was not significant (β = 0.42, p = 0.230). In addition, a significant correlation was identified between the maximum oxygen uptake and the bone density T value in the overall sample (β = 0.28, p = 0.009). Nevertheless, upon gender stratification, the correlation between the maximum oxygen uptake and bone density was not significant in women (p = 0.884), yet it was significant in men (β = 0.42, p = 0.009). In the 30-60 age group, a significant positive correlation was detected between skeletal muscle strength and bone density. Specifically, in women, lower limb muscle strength was more closely associated with bone density; however, this relationship was not significant in men. Moreover, the association between cardiorespiratory endurance and bone density varied by gender. It was not significant in women but demonstrated a significant positive correlation in the male group.

Background: Volleyball is known as sport that requires high physical fitness, including muscle power, agility and reaction; hence, body composition and anthropometric features play important roles in this field. The purpose of this study was to investigate the relationship between anthropometric and body composition indices with lower limb explosive power in female volleyball players. Material and method: This correlational study was conducted in which 16 semi-professional female volleyball players with an average age of 20.4 ± 1.34 years and BMI of 22.09 ± 3.42 kg/m2 voluntarily participated. All volleyball players had a history of participation in the Tehran province volleyball league. First, data were collected and recorded by demographic questionnaire. Then, the body composition (fat percentage, muscle mass, visceral fat) was measured and recorded in the 3-hours fasting condition by body analysis device (OMRUN Bf511). Finally, Sargent Vertical Jump Test was used to evaluate explosive power of the lower limb muscles. Results: Pearson correlation coefficient was used at the significant level p Conclusion: The results of this study show that resistance training along with volleyball specific power training can increase the muscle mass as well as it is at the same time.

Dai, J, Liang, X, Wang, H, Lin, W, Sun, J, Li, D, and Wang, N. The effect of elastic band variable resistance training on the explosive power of lower limbs in college basketball athletes. J Strength Cond Res 39(8): e1003–e1009, 2025—The aim of this study was to investigate the impact of elastic band variable resistance training (VRT) on the explosive power of college basketball players. This study hypothesizes that elastic band VRT is superior to traditional resistance training (RT) in enhancing the lower limb explosive power of college basketball athletes. A total of 28 college basketball players specializing in basketball were randomly assigned to either the VRT group ( n = 14) or the traditional RT group ( n = 14). A training intervention was conducted twice per week, for a total of 8 weeks. Testing included the countermovement jump with arm swing (CMJA), countermovement jump (CMJ), squat jump (SJ), reaction strength index (RSI), eccentric utilization rate (EUR), standing long jump (SLJ), 10-meter sprint, squat 1 repetition maximum (1RM), and squat index (SI). The analysis of variance revealed significant time main effects for both the VRT group and the RT group in CMJA ( p &lt; 0.001), CMJ ( p = 0.003), SJ ( p &lt; 0.001), RSI ( p = 0.014), SLJ ( p = 0.004), 10-meter sprint ( p &lt; 0.001), squat 1RM ( p &lt; 0.001), and SI ( p &lt; 0.001). However, the time main effect for the EUR index ( p = 0.841) was not significant. There were no significant group main effects for any of the measures ( p &gt; 0.05). The time × group interaction effect was significant for the SJ measure ( p = 0.026), while it was not significant for the other measures ( p &gt; 0.05). The effect of elastic band VRT on improving lower limb maximum strength is similar to that of traditional RT, but it is more effective in enhancing lower limb explosive power. Variable RT enhances the flexibility of RT regimens, resulting in more pronounced and enduring strength gains. When applying VRT, selecting the suitable intensity and techniques is crucial.