Jump Power Research Articles

Effects Of Different Intensity And Duration Of Warm-up On Hemodynamics, Jump Power, And Flexibility.

PURPOSE: Tabata protocol (TP), usually consisting of eight to nine bouts of 20-sec of maximal exercise with 10-sec rest, is time-efficient intervention with both aerobic and anaerobic benefits. This study investigated the effectiveness of different variations of TP as a warm-up procedure. METHODS: Twenty-five healthy subjects (13 females and 12 males) participated in this study. Participants performed 6 randomized exercise sessions separated by at least 48 hours. The exercise sessions involved 3-min (TP3-20:10; TP3-30:10), 5-min (TP5-20:10; TP5-30:10) or 8-min (TP8-20:10; TP8-30:10) consecutive bodyweight squats of either 20-sec workout with 10-sec rest (20:10) or 30-sec workout with 10-sec rest (30:10). Heart rate (HR), blood pressure (BP), thigh skin surface temperature (TT), vertical jump performance (VJ), and flexibility (F) were measured before and after execution of the protocols. Countermovement jump was used to measure VJ and sit-and-reach test was used for measuring F. RESULTS: Two-way ANOVA demonstrated significant condition∗time interaction (p<0.01) and time main effect (p<0.01) for F. Significant condition∗time interaction (p<0.01) and condition (p<0.01) and time main effects (p<0.01) were observed for HR. There were significant main effects for time with the post-test demonstrating higher values than the pre-test values for both SBP and DBP (p<0.01). Significant time main effect (p<0.01) was also noted for TT indicating reduction in TT following exercise bouts. CONCLUSIONS: The findings are suggestive of a decrease in F following a higher duration of exercise (TP8-20:10 and TP8-30:10). This may be ascribed to greater accumulation of metabolites (lactic acid, ammonia, and hydrogen ion) in the working muscles, which may alter Type III and IV afferent neural activity to increase pain perception. Local tissue acidosis also stimulates bradykinin release, which may contribute to the transmission of nociceptive signals from skeletal muscle. Additionally, higher duration of exercise may increase cortisol level that decreases the pain threshold level. Therefore, the decreases in flexibility may be explained by one or a combination of metabolic, hormonal, and neurobiological changes stimulating the brain to inhibit the muscular response.

The Examination of Relationships Between Lower Extremity Muscle Strength, Vertical Jump and Anaerobic Power Parameters in Female Football Players

The Examination of Relationships Between Lower Extremity Muscle Strength, Vertical Jump and Anaerobic Power Parameters in Female Football Players

Associations between novel jump test measures, grip strength, and physical performance: the Osteoporotic Fractures in Men (MrOS) Study.

Weight-bearing jump tests measure lower extremity muscle power, velocity, and force, and may be more strongly related to physical performance than grip strength. However, these relationships are not well described in older adults. Participants were 1242 older men (mean age 84 ± 4years) in the Osteoporotic Fractures in Men (MrOS) Study. Jump peak power (Watts/kg body weight), force (Newton/kg body weight) at peak power, and velocity (m/s) at peak power were measured by jump tests on a force plate. Grip strength (kg/kg body weight) was assessed by hand-held dynamometry. Physical performance included 400m walk time (s), 6m usual gait speed (m/s), and 5-repeated chair stands speed (#/s). In adjusted Pearson correlations, power/kg and velocity moderately correlated with all performance measures (range r = 0.41-0.51; all p < 0.001), while correlations for force/kg and grip strength/kg were weaker (range r = 0.20-0.33; all p < 0.001). Grip strength/kg moderately correlated with power/kg (r = 0.44; p < 0.001) but not velocity or force/kg. In adjusted linear regression with standardized βs, 1 SD lower power/kg was associated with worse: 400m walk time (β = 0.47), gait speed (β = 0.42), and chair stands speed (β = 0.43) (all p < 0.05). Associations with velocity were similar (400m walk time: β = 0.42; gait speed: β = 0.38; chair stands speed: β = 0.37; all p < 0.05). Force/kg and grip strength/kg were more weakly associated with performance (range β = 0.18-0.28; all p < 0.05). Jump power and velocity had stronger associations with physical performance than jump force or grip strength. This suggests lower extremity power and velocity may be more strongly related to physical performance than lower extremity force or upper extremity strength in older men.

Sex Differences in Muscle-Bone Interactions in Chinese Men and Women

Muscle-bone interactions are important for bone health as mechanical forces from muscular contraction place large stresses on bone. Little is known about sex differences in bone and muscle characteristics in Asians. PURPOSE: To examine sex differences in bone characteristics, grip strength, and lower body strength and power in Chinese adults (n=53). METHODS: Chinese males (n=28) and females (n=25) had body composition and aBMD (total body, lumbar spine, dual femur) assessed by DXA, and bone geometry (4%, 38%, 66%) of the non-dominant tibia measured by pQCT. Leg strength (two-leg press) and power (jump mat) and maximal grip strength (handgrip dynamometer) were measured. RESULTS: There were no sex differences in physical activity or calcium intake. After adjusting for height and weight, males had significantly greater leg press 1RM, grip strength, jump height, jump time, lumbar spine aBMD, 4% total BMC, 4% total area, and 4% bone strength index (BSI) (p<0.05) than females. In males, leg 1RM was positively correlated with total body aBMD (r= 0.427), and left femoral neck aBMD (r=0.445), and jump power was positively correlated with total body aBMD (r=0.580) and all hip aBMD variables (r=.487 to 0.646) (all p< 0.05). Females generally had stronger correlations between muscle and bone variables: leg 1RM (all p<0.05) and jump power (all p<0.003) were positively related to all aBMD variables (r=0.432 to 0.819). Jump power and BSI were positively correlated (r=0.378, p=0.048) in males, whereas jump power and leg 1RM showed moderate to strong correlations with 4% total BMC, total area, and total BSI (r=0.460 to 0.836, p<0.05) in females. CONCLUSION: Based on our findings, Chinese males had greater bone size, bone strength, and muscle strength than females; however, females exhibited more and stronger relationships between muscle and bone variables than males.Table 1: Sex Differences in Muscle and Bone variables (unadjusted Means ± SD)

Age-related Differences in Vertical Jump Power and Muscle Size and Quality of the Vastus Lateralis

Age-related Differences in Vertical Jump Power and Muscle Size and Quality of the Vastus Lateralis

Do muscular strength and jump power tests reflect the effectiveness of training programs for basketball athletes?

Abstract Aims: Muscular strength (MS) and jump power (JP) tests are used to assess athletic ability and measure the effectiveness of training programs. However, their use in various sport modalities needs to be investigated further. This study aimed to explore the changes in MS and JP during three different moments of a macrocycle training session and verify the validity of the tests used to predict the effectiveness of basketball training programs. Methods: During macrocycle training (three different moments), sixteen basketball players were evaluated for MS (measured using isokinetic dynamometry at the speed of 60°/s) during concentric contraction of knee flexor and extensor muscles and JP, using countermovement vertical jump (CMVJ) on a force platform. Results: Peak torque and maximal work values for knee extension and flexion showed no differences, during the three moments analyzed. Additionally, no changes were observed for CMVJ. Conclusions: Our results suggest that the effectiveness of basketball training programs does not seem to be related to the performance achieved by athletes on the tests used. Moreover, the lack of changes in MS and JP values during the macrocycle could be related to the training structure used; volume, intensity, density and workload specificity.

Combination of DXA and BIS body composition measurements is highly correlated with physical function-an approach to improve muscle mass assessment.

Fluid volume estimates may help predict functional status and thereby improve sarcopenia diagnosis. Bioimpedance-derived fluid volume, combined with DXA, improves identification of jump power over traditional measures. DXA-measured lean mass should be corrected for fluid distribution in older populations; this may be a surrogate of muscle quality. Sarcopenia, the age-related loss of muscle mass and function, negatively impacts functional status, quality of life, and mortality. We aimed to determine if bioimpedance spectroscopy (BIS)-derived estimates of body water compartments can be used in conjunction with dual-energy X-ray absorptiometry (DXA) measures to aid in the prediction of functional status and thereby, ultimately, improve the diagnosis of sarcopenia. Participants (≥ 70years) had physical and muscle function tests, DXA, and BIS performed. Using a BMI correction method, intracellular water (ICWc), extracellular water (ECWc), and ECWc to ICWc (E/Ic) ratio was estimated from standard BIS measures. Jump power was assessed using jump mechanography. The traditional measure used to diagnose sarcopenia, DXA-derived appendicular lean mass (ALM) corrected for height (ALM/ht2), was the least predictive measure explaining jump power variability (r2 = 0.31, p < 0.0001). The best measure for explaining jump power was a novel variable combining DXA ALM and BIS-derived E/Ic ratio (ALM/(E/Ic); r2 = 0.70, p < 0.0001). ALM/(E/Ic) and ICWc had the highest correlation with jump power and grip strength, specifically jump power (r = 0.84 and r = 0.80, respectively; p < 0.0001). The creation of a novel variable (ALM/(E/Ic)) improved the ability of DXA to predict jump power in an older population. ALM/(E/Ic) substantially outperformed traditional lean mass measures of sarcopenia and could well be an improved diagnostic approach to predict functional status. DXA-measured ALM should be corrected for fluid distribution, i.e., ALM/(E/Ic); this correction may be considered a surrogate of muscle quality.

Medial Post Foot Orthotic Influences Knee Valgus Angle Excursions During a Vertical Jump Task

Medial posting is a common therapeutic midsole foot orthotic that is used to control excessive pronation movement, and creating a more supinated position of the foot. Consequently, these altered biomechanics may also create more favorable movements at other joints, such as the knee. Knee valgus angle has been identified as a risk factor for lower extremity joint injury, and medial posting may reduce excessive valgus during dynamic tasks, therefore decreasing the risk of injury. PURPOSE: Investigate if medial post orthotics influence knee valgus and performance outcomes during a vertical jump. METHODS: Thirty healthy participants volunteered (18m/12f; age 24.8 ± 3.1y; height 173.94 ± 8.72cm; mass 73.7 ± 13.2kg). Six maximal vertical jump trials were recorded using electromagnetic 3D biomechanical and force plate assessment. Three trials were performed with bilateral medial posting orthotics, and three without, with the order randomized. Max vertical jump height, jump power, and total valgus range of motion (excursion) during the take-off phase were extracted for each limb and averaged across the three trials for analysis. Paired samples t-tests were performed to assess differences in outcomes between orthotic conditions. Alpha level was set a priori at P ≤ 0.05. RESULTS: There were no differences in vertical jump height between the orthotic (46.9 ± 9.0cm) and no orthotic conditions (46.1 ± 8.6cm, t = -0.58, p = 0.56). Jump power also was the same between the orthotic (1219.4 ± 520.9) and no orthotic conditions (1243.5 ± 456.5W, t = 0.35, p = 0.72). Both the left (orthotic: 15.2 ± 7.4o; no orthotic: 18.3 ± 10.5o; t = 2.46, p = 0.02) and right (orthotic: 17.9 ± 8.6o; no orthotic: 19.9 ± 12.4o; t = 1.96, p = 0.05) limbs demonstrated significantly less knee valgus excursion when using the orthotic. CONCLUSIONS: The medial post orthotic was successful at reducing knee valgus excursion angles during a maximal vertical jump, while also maintaining vertical jump performance, measured via vertical jump height and power. Although medial posting is a common orthotic to correct excessive pronation at the foot, it may also have therapeutic efficacy at knee joint injury prevention during dynamic tasks.

Low peak jump power is associated with elevated odds of dysmobility syndrome in community-dwelling elderly individuals: the Korean Urban Rural Elderly (KURE) study.

Dysmobility syndrome was proposed to encompass the risks affecting musculoskeletal outcomes. Jump power measurement is a safe, reproducible high-intensity test for physical function in elderly. However, the relationship between jump power and dysmobility syndrome remains unknown. A total of 1369 subjects (mean 71.6years; women, 66%) were analyzed from a community-based cohort. Dysmobility syndrome was defined as the presence of ≥ 3 factors among falls in the preceding year, low lean mass, high fat mass, osteoporosis, low grip strength, and low timed get-up-and-go (TUG) performance. Subjects were grouped into tertiles of jump power relative to weight based on sex-stratified cutoffs (32.4 and 27.6W/kg in men; 23.9 and 19.9W/kg in women) or into the failed-to-jump group. The prevalence of dysmobility syndrome was 20% overall, increasing from the highest (T1) to lowest (T3) jump power tertile (1, 11, 15% in men; 11, 16, 39% in women) and the failed-to-jump group (39% in men; 48% in women). Low jump power or failed-to-jump was associated with elevated odds of dysmobility syndrome (T3 vs. T1, adjusted odds ratio [aOR] 4.35, p < 0.001; failed-to-jump vs. T1, aOR 7.60, p < 0.001) and its components including falls, low lean mass, high fat mass, and poor TUG performance but not osteoporosis after adjustment for covariates. Jump power modestly discriminated dysmobility syndrome (area under the curve [AUC], 0.71, p < 0.001), which improved discriminatory performance when added to conventional risk factors (AUC, from 0.75 to 0.79, p < 0.001). Low peak jump power was associated with elevated odds of dysmobility syndrome and its components, independent of age and comorbidities.

Predicting Knee and Thigh Injury Risk Using Scaled Vertical Jump and Standing Long Jump Power

Predicting Knee and Thigh Injury Risk Using Scaled Vertical Jump and Standing Long Jump Power

Comparisons Between Jump Power, Swing Velocity, and Hitting Measures in Collegiate Baseball and Softball Athletes

Successful performance in baseball and softball requires the ability to perform multiple skills efficiently. The skills most critical to the game include fielding, throwing, and hitting and each have components of strength, agility, and muscular power. PURPOSE: To evaluate the relationships and differences between maximal leg power and swing velocity in collegiate baseball and softball players. METHODS: Thirty-four subjects (20.4±1.3yrs, 176.8±9.8cm, and 77.7±13.9kg) were assessed for vertical jump power and swing velocity using a force plate and visual 3D technology, respectively. Mean differences were calculated by independent t-tests and relationships between parameters of interest were calculated using Pearson Correlation coefficients. Statistical significance was set at 0.05. RESULTS: Baseball (n=17) and softball (n=17) player mean age, height (cm), and weight (kg) were 20.7±1.2yrs, 184.8±4.1cm, 88.3±9.8kg and 20.1±1.4yrs, 168.9±6.7cm, 67.0±8.0kg, respectively. Vertical jump power and swing velocity means were 1528.3±169.7W, 38.6±1.4m/s and 1045.4±121W, 29.8±1.8m/s, respectively. Baseball players were significantly taller (p≤0.01) and heavier (p≤0.01) than softball players. They also generated significantly more jump power (p≤0.01) and achieved higher swing velocities (p≤0.01) but no differences were revealed for hitting measures. Vertical jump power tests revealed moderate to strong relationships for baseball players (r=.58-.96, p<0.05) between height, weight, swing velocity, batting average, and slugging percentage for baseball but only height and weight for softball players. Swing velocity revealed poor to moderate relationships for both groups (r=-.28-.51) for batting average, slugging percentage, and home runs. CONCLUSION: Statistical evaluation revealed moderate to strong relationships between vertical jump power and anthropometric measures for both groups. Furthermore, baseball players display moderate to strong relationships between vertical jump power, swing velocity, batting average, and slugging percentage. In conclusion, evaluating and predicting performance from physiological variables remains a challenge, however, maximal leg power could serve as a moderate indicator of performance in baseball athletes.

Acute Effect of Biomechanical Muscle Stimulation on the Counter-Movement Vertical Jump Power and Velocity in Division I Football Players

Jacobson, BH, Monaghan, TP, Sellers, JH, Conchola, EC, Pope, ZK, and Glass, RG. Acute effect of biomechanical muscle stimulation on the counter-movement vertical jump power and velocity in division I football players. J Strength Cond Res 31(5): 1259-1264, 2017-Research regarding whole body vibration (WBV) largely supports such training augmentation in attempts to increase muscle strength and power. However, localized biomechanical vibration has not received the same attention. The purpose of this study was to assess peak and average power before and after acute vibration of selected lower-body sites in division I athletes. Twenty-one subjects were randomly assigned to 1 of 2 conditions using a cross-over design. Pretest consisted of a counter-movement vertical jump (VJ) followed by either localized vibration (30 Hz) to 4 selected lower-body areas or 4 minutes of moderately low-resistance stationary cycling (70 rpm). Vibration consisted of 1 minute bouts at each lower-leg site for a total of 4 minutes followed by an immediate post-test VJ. Repeated measures analysis of variance yielded no significant differences (p > 0.05) in either peak power or peak velocity. Similarly, no significant differences were found for average power and velocity between conditions. It should be noted that, while not significant, the vibration condition demonstrated an increase in peak power and velocity while the bike condition registered slight decreases. Comparing each of the post-VJ repetitions (1, 2, and 3) the vibration condition experienced significantly greater peak power and velocity from VJ 1 to VJ 3 compared with the bike condition which demonstrated no significant differences among the post-test VJs. These results yielded similar, although not statistically significant outcomes to previous studies using WBV. However, the novelty of selected site biomechanical vibration merits further investigation with respect to frequency, magnitude, and duration of vibration.

Age-related Differences in Maximal and Rapid Hamstrings to Quadriceps Strength Capacities and Vertical Jump Power

Age-related Differences in Maximal and Rapid Hamstrings to Quadriceps Strength Capacities and Vertical Jump Power

Lower Jump Power Rather Than Muscle Mass Itself is Associated with Vertebral Fracture in Community-Dwelling Elderly Korean Women.

Sarcopenia is considered to be a risk factor for osteoporotic fracture, which is a major health problem in elderly women. In this study, we aimed to investigate the association of sarcopenia, with regard to muscle mass and function, with prevalent vertebral fracture in community-dwelling elderly women. We recruited 1281 women aged 64 to 87 years from the Korean Urban Rural Elderly cohort study. Muscle mass and function were measured using bioimpedance analysis and jumping mechanography. Skeletal muscle index (SMI) and jump power were used as an indicator of muscle mass and function, respectively. Among the participants, we observed 282 (18.9%) vertebral fractures and 564 (44.0%) osteoporosis. Although age, body mass index, and prevalence of osteoporosis increased as both SMI and jump power decreased, prevalence of vertebral fracture increased only when jump power decreased. In univariate analysis, compared with the highest quartile of jump power, the lowest quartile had a significant odds ratio of 2.80 (95% CI 1.79-4.36) for vertebral fracture. This association between jump power and vertebral fracture remained significant, with an odds ratio of 3.04 (95% CI 1.77-5.23), even after adjusting for other risk factors including age, bone mineral density, previous fracture, and cognitive function. In contrast, there was no association between SMI and vertebral fracture. Based on our results, low jump power, but not SMI, is associated with vertebral fracture in community-dwelling elderly Korean women. This finding suggests that jump power may have a more important role than muscle mass itself for osteoporotic fracture.

Peak Vertical Jump Power as a Marker of Bone Health in Children.

The objective of this investigation was to evaluate the accuracy of peak vertical jump power (VJP) to identify children with bone mineral density (BMD) below average, defined as BMD measured by DXA and adjusted for body height at the whole body less head≤- 1.0 standard deviation (SD). The sample included 114 boys and girls aged 8.5±0.4 years old. VJP was estimated from a countermovement jump performed on a contact mat using the measured flight time to calculate the height of rise of the center of gravity. Logistic regression analysis revealed that the odds ratio of having BMD≤1.0 SD decreased 1.2% per watt of power and the probability of BMD below average was 75.6% higher in boys than in girls with the same peak power jump. Receiver operating characteristic analysis showed that the best trade-off between sensitivity and specificity to identify children with BMD<- 1.0 SD was 635 watts in boys (sensitivity=63.3%; specificity=69.2%; AUC=0.816, 95% CI: 0.681-0.95; p<0.001) and 515 watts in girls (sensitivity=75.0%; specificity=77.0%; AUC=0.849, 95% CI: 0.698-0.999; p=0.002). These cut-off values correspond to a vertical jump of 19.9 cm and 20.5 cm in 8-year-old boys and girls, respectively. The VJP showed a reasonable sensitivity and specificity as well good discriminant ability to identify children with BMD below average.

Effects of Whole-Body Vibration on Muscular Performance in Young Women

Whole-body vibration (WBV) induced mechanical oscillations have been shown to affect the musculoskeletal system. WBV platforms are categorized as side-alternating or synchronous. Few studies have compared acute muscular responses to different frequencies or types of platforms in women. PURPOSE: To compare the acute effects of Power Plate (PP) (synchronous) and Vibraflex (VF) (side-alternating) WBV devices on muscular performance in recreationally active women, 20-30 years. METHODS: Female subjects (n=12) performed 5 protocols in random order separated by 48 hour washout periods: 1) Control (no vibration); 2) VF 18 Hz; 3) VF 21 Hz; 4) PP 30 Hz; and 5) PP 50 Hz. Subjects stood barefoot on the platform for 5, 1 min bouts separated by 1 min rest. Immediately after vibration, vertical jump power and leg press 1RM were assessed. RESULTS: There were significant condition effects for jump velocity, jump power, and leg press strength for the VF (p<0.05). The 18 Hz frequency elicited significantly greater jump velocity and jump power compared to the 21 Hz. However, 21 Hz resulted in significantly greater leg press 1RM compared to control and 18 Hz (p<0.05). None of the PP conditions were significantly different from the control. Analysis of the difference scores from control determined that there was a significant frequency main effect (p=0.50) for jump power, which increased after the low frequency protocols and decreased after the high frequency protocols. CONCLUSION: These results suggest that for the VF, the 18 Hz frequency was more effective for improving jump power than 21 Hz, but 21 Hz was more effective for increasing leg press strength.Table 1: Jump Power and Strength Measures (Mean SD) (n=12)

Vertical Jump and Standing Long Jump Power to Determine Lower Extremity Imbalance and Injury Risk

Vertical Jump and Standing Long Jump Power to Determine Lower Extremity Imbalance and Injury Risk

Peak Jump Power Reflects the Degree of Ambulatory Ability in Patients with Mitochondrial and Other Rare Diseases.

Metabolic diseases that lead to neuromuscular, bone, and joint involvement can reduce ambulation and quality of life. Using jumping mechanography, we developed a novel assessment, peak jump power (PJP), and related this to ambulatory ability in patients either having a known or suspected underlying rare disease. From adults and children, we recruited 88 healthy controls and 115 patients (61 with mitochondrial disease and 54 with another diagnosis). Patients were categorized as having no complaints of weakness or ambulation (ambulatory competent; AC), weakness but able to ambulate without aids (ambulatory weakness; AW), or not able to ambulate without aids such as a walker, cane, or wheelchair (ambulatory assistance; AA). Subjects were asked to perform five successive jumps from a squat position. Instantaneous power (W; watts) was calculated and the highest result was divided by the body mass (kg) to calculate PJP (W/kg). Between healthy controls and AC patients, there was no difference in mean PJP (20.5 ± 7.0W/kg vs. 19.0 ± 7.4W/kg, p = 0.601; mean ± SD). Progressively lower results were found in patients with AW with a mean PJP of 11.7 ± 5.1W/kg (p < 0.001 versus AC) and further those with AA with a mean PJP of 5.8 ± 3.2W/kg (p < 0.001 versus AW). A subgroup analysis of subjects showed that those who did not use ambulatory aids all had a PJP above 10W/kg. Using this threshold, the receiver operating characteristic curve (ROC) analysis showed PJP to be highly sensitive evaluation of ambulatory ability (sensitivity 95.8%, specificity 52.1%).

Jump power reflects the degree of disability in neuromuscular disease

Jump power reflects the degree of disability in neuromuscular disease

Instrument Assisted Soft Tissue Mobilization Increases Vertical Jump Power in Athletes with Ankle Joint Injury

Instrument Assisted Soft Tissue Mobilization Increases Vertical Jump Power in Athletes with Ankle Joint Injury