Introduktion: Smartphoneapplikationen My Jump2 har bedömts att ha större tillgänglighet och inte vara beroende av labbutrustning vid vertikala hopptester. I jämförelse med kraftplatta (golden standard) har applikationen visat sig valid och reliabel. My Jump2 har uppvisat mycket bra- perfekt korrelation mot övrig kraftutrustning. Jämförelse mellan My Jump2 och kliniska tester är ännu inte beprövat på detta område. Syfte: Syftet med denna kliniska studie var att analysera samband och korrelationer mellan värden från My Jump2 och kliniska tester gällande funktionell bedömning av underbenets muskulatur. Därför jämfördes värden hos aktiva, icke skadade män och kvinnor. Metod: Totalt 26st kvinnor och män testades vid ett indivduellt testtilfälle i gymmiljö. 3rep MAX, lunge-test, antal tåhävningar och bäst av tre drop jump analyserades på dominanta benet. Pearsons korrelation användes för att undersöka samband mellan My Jump2 och kliniska tester och ANCOVA för att undersöka skillnader mellan deltagare. Resultat: Huvudfynden var att MyJump2 uppvisade två signifikanta korrelationssamband för männen och ett för kvinnorna vid jämförelse med kliniska tester. Signifikanta skillnader gällande RSI-värde med hänsyn till muskelstyrka 3rep MAX (95% CI; 0,01-0,19, p = 0,03) fanns mellan könen. Ingen signifikant skillnad i stiffness med hänsyn till ROM (95% CI; -0,11- 0,55, p = 0,18) justerat mot kön (95% CI; -0,78-2,03, p = 0,37) återfanns. Konklusion: Resultaten indikerar på att vidare forskning är nödvändig. Endast få signifikanta korrelationssamband återfanns mellan värden från My Jump2 och kliniska tester. My Jump2 visar signifikanta nivåer för RSI-värdet med hänsyn till muskelstyrka och kön. Studien kan inte bekräfta förväntade samband mellan My Jump2 och kliniska tester för underbenet. / Introduction: The smartphoneapplication My Jump2 has been assessed in rescent research for its validity and reliability. In comparison to golden standard devices, My Jump2 shows great- perfect correlation measuring jump height. Eventhough former results indicate usability of the smarthphoneapplication, further research is needed in order to evaluate clinical usefulness in a more expanded population. Aim: The aim of this study was to analyse the relationship and correlations between measured values from My Jump2 and clinical testing of lower extremity performance. This in an active and recreational population, both male and female. Method: A total of 26 males and females were tested individually in a gym-location. 3rep MAX, lunge-test, heel-rises to exhaustion and best of three drop jumps were analysed on the dominat leg. Pearsons correlation was used to evaluate the relationship between My Jump2 and clinical tests and ANCOVA to analyse diffrences within the testgroup. Results: Analysis showed two significant correlations between functional values for the men and one for women when comparing My Jump2 and clinical tests. A significant difference in RSI-value was found between the covariate (sex) (95% CI; 0,01-0,19, p = 0,03) considering 3rep MAX (factor). No significant difference was found in stiffness between the covariate (sex) considering ROM (factor). Conclusion: This study indicates that further research is needed. Analysis shows few significant correlations between My Jump2 and clinical tests. My Jump2 results shows significant values regarding RSI-values considering sex and musclestrenght. This study can not confirm the relationship and correlations between measured values from My Jump2 and clinical testing of lower extremity performance.

The purpose of this dissertation was to explore the interrelationships of several important fitness characteristics in Division 1 athletes. Sport performance magnitude is the summation of an individual athlete’s technical, psychological, and fitness characteristics. Athletes who excel in any or all characteristics perform better in their chosen sports. General fitness characteristics that are important to almost all sports include strength, power, vertical jump height, shortdistance sprinting ability, muscularity, and body fat percentage. These variables have been shown in previous research to independently affect athletic performance outcomes, but their relationships to one another are less clear. Eighty Division I athletes from 4 sports were examined in a variety of fitness characteristics as part of a continuous athlete monitoring program. Data on strength, power, vertical jump height, short-distance sprinting speed, muscularity, and body fat percentage were collected and analyzed. Analysis revealed several important relationships. Firstly, strength is highly related to muscularity, with lean body mass as one of the most important determinants of strength. Secondly, athletes who can produce high relative (scaled per body mass) forces and powers tend to be considerably higher jumpers and much faster sprinters. Lastly, leaner athletes out-perform less lean athletes in almost every metric, especially relative strength and power, vertical jumping ability, and sprinting ability.

Purpose: To determine if jumping-performance changes during a peaking phase differed among returners and new players on a female collegiate volleyball team and to determine which variables best explained the variation in performance changes. Methods: Fourteen volleyball players were divided into 2 groups—returners (n = 7) and new players (n = 7)—who completed a 5-wk peaking phase prior to conference championships. Players were tested at baseline before the preseason on measures of the vastus lateralis cross-sectional area using ultrasonography, estimated back-squat 1-repetition maximum, countermovement jump height (JH), and relative peak power on a force platform. Jumping performance, rating of perceived exertion training load, and sets played were recorded weekly during the peaking phase. Results: There were moderate to very large (P < .01, Glass Δ = 1.74) and trivial to very large (P = .07, Δ = 1.09) differences in JH and relative peak power changes in favor of returners over new players, respectively, during the peaking phase. Irrespective of group, 7 of 14 players achieved peak JH 2 wk after the initial overreach. The number of sets played (r = .78, P < .01) and the athlete’s preseason relative 1-repetition maximum (r = .54, P = .05) were the strongest correlates of JH changes during the peaking phase. Conclusions: Returners achieved greater improvements in jumping performance during the peaking phase compared with new players, which may be explained by the returners’ greater relative maximal strength, time spent competing, and training experience. Thus, volleyball and strength coaches should consider these factors when prescribing training during a peaking phase to ensure their players are prepared for important competitions.

Monitoring tests are commonly used to assess weightlifter’s preparedness for competition. Although various monitoring tests have been used, it is not clear which test is the strongest indicator of weightlifting performance. Therefore, the purpose of this study was to (1) determine the relationships between vertical jump, isometric mid-thigh pull (IMTP) and weightlifting performance; and (2) compare vertical jumps to IMTP as monitoring tests of weightlifting performance in a large cohort of male and female weightlifters. Methods: Fifty-two competitive weightlifters (31 males, 21 females) participated in squat and countermovement jump testing (SJ, CMJ), and IMTP testing performed on force plates. All laboratory testing data was correlated to a recent competition where the athletes had attempted to peak. Results: Squat jump height (SJH) was the strongest correlate for men and women with the Sinclair Total (r = 0.686, p ≤ 0.01; r = 0.487, p ≤ 0.05, respectively) compared to countermovement jump height (r = 0.642, p ≤ 0.01; r = 0.413, p = 0.063), IMTP peak force allometrically scaled to body mass (r = 0.542, p ≤ 0.01; r = −0.044, p = 0.851) and rate of force development at 200 ms (r = 0.066, p = 0.723; r = 0.086, p = 0.711), respectively. Further, SJH was a stronger correlate of relative weightlifting performance compared to IMTP peak force in females (p = 0.042), but not male weightlifters (p = 0.191). Conclusions: Although CMJ and IMTP are still considered strong indicators of weightlifting performance, SJH appears to be the most indicative measure of weightlifting performance across a wide-range of performance levels. Thus, SJH can be used as a reliable measure to monitor weightlifting performance in male and female weightlifters.

Abstract available in the Medicine & Science in Sports & Exercise

To assess acute performance-related effects of foam rolling, this study investigated the immediate effects of a standard foam rolling protocol on explosive strength of the plantarflexors and alpha motor neuron excitability in the soleus. Explosive strength was measured via vertical jump height (JUMP) and the Reactive Strength Index (RSI) obtained from a single leg drop jump. Alpha motor neuron excitability was measured by H reflex amplitude as H wave to M wave ratio (HM) obtained from the soleus muscle. JUMP and RSI measures were analyzed from nineteen subjects (12 male, 7 female) HM data were analyzed from 15 subjects (9 male, 6 female). Subjects attended one day of practice and instruction for the single leg drop jump and one day for data collection. One leg was randomly assigned to be the test leg (FL) and the other as the control (NL). The reported dominant leg and gender were also recorded for each subject. Subjects performed two single leg drop jumps per leg from a box height of 30 cm and then 10 soleus H reflexes were obtained. The intervention, which followed standard professional guidelines, consisted of 2.5 minutes of foam rolling for the FL and rest for the NL, followed by a 5 minute warm up on a cycle ergometer. The best jump and the average HM ratio were chosen for analysis. For each variable a post/pre ratio was calculated for statistical analysis. A 2x2x2 factor ANOVA with repeated measures on both factors was used for each variable. Analysis revealed no statistically significant differences for any of the variables, either as main effects or any of the interaction effects. Subjects trended towards a slightly larger post-intervention decrease in JUMP and RSI for the FL than the NL but this was not significant. It was concluded that a 2.5 minute intervention of foam rolling had no acute effect on explosive strength of the plantarflexors or alpha motor neuron excitability of the soleus. / text