Vertical jumping ability is an important fundamental skill for many athletic activities. The present work is focused on developing an understanding of the role of various movement strategies on vertical jump performance. The overall objective of this study was to determine if higher hip than knee joint contribution was more effective in enhancing vertical jump height. Additionally, the study explored possible links between the muscle activity and mechanical outputs, and to develop understanding of the role of the lumbar spine and hip. Twenty male university varsity athletes performed ten repetitions of three jumping strategies: preferred, hip dominant and knee dominant. Kinematics, kinetics and muscle activity of the lower limb and trunk were collected. The main observation was that the vertical jump height was positively associated with higher hip than knee work done. However, the within-subject comparisons between the trained hip and knee dominant tasks did not provide additional support for the importance of the hip. Higher hip work appeared associated with greater biceps femoris than gluteus maximus activity. The knee work increased with higher activity of the vastus lateralis and rectus femoris. Finally, higher trunk muscle activity and tighter coupling were associated with the vertical jump height and the max force. This study provides some evidence that encouraging hip dominance together with higher spine stiffness may improve two-foot vertical jump performance. This work has potential implications for training protocols that may be used to improve vertical jump performance.

Determining if an athlete, who has had Anterior Cruciate Ligament (ACL) surgery, is ready to return to sport is a difficult clinical decision, partially due to the lack of standardized evaluation protocols. Since there is a risk of re-injury post-surgery, medical teams need to be cautious. However, athletes who are perceived to be ready to return to sport do not necessarily do so. Some leave sport altogether while others return to a lower competition level. As psychological thoughts and emotions are relevant to athletes’ injury experiences, a psychological component, such as sport confidence, needs to be thoughtfully considered during the return to sport process. Our objectives were to develop the relationship between drop vertical jump (DVJ) performance and physical attributes in young healthy adults and to then apply this relationship to ACL participants. Another objective was to see if the relationship is improved by including confidence (determined from a survey). It was hypothesized that including confidence will predict the ACL participants’ DVJ performance more precisely. Thirty-five participants were in the control group with thirteen participants in the ACL group. All were recreationally active and all had the following anthropometric and performance measurements recorded: height, weight, calf and thigh girth, knee angle, leg dominance, percent body fat, skeletal muscle mass, anaerobic power, balance, and drop vertical jump height. The ACL group also completed a confidence survey. Regression analyses were performed. The results showed that anaerobic power and relative skeletal muscle mass were significant predictors of DVJ performance; however, DVJ performance could not be predicted precisely. The analysis was also carried out by gender. No significant predictors for male’s DVJ performance were found while the significant predictors for female’s DVJ performance were weight, power and knee extension angle. Once again, DVJ performance could not be precisely predicted. On the other hand, results showed that power could be more precisely predicted by body weight than could DVJ performance. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2009-08-19 16:08:52.13

Made available in DSpace on 2014-06-11T19:28:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-01-26Bitstream added on 2014-06-13T19:26:51Z : No. of bitstreams: 1 pereira_sstc_me_guara.pdf: 3610434 bytes, checksum: da234218018e1309611898e259e36014 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As atividades realizadas em meio aquático sofrem interferência das propriedades físicas peculiares ao mesmo. O salto vertical é uma habilidade esportiva muito utilizada em programas de reabilitação, principalmente em trabalhos de pliometria. O objetivo deste estudo foi pesquisar as forças envolvidas no salto vertical praticado em ambiente aquático e terrestre e as interdependências entre as variáveis cinéticas e cinemáticas dos mesmos. Para tal foi utilizada uma amostra composta por dez sujeitos, todos do sexo feminino, com idade média de 11,6 ± 1,35, praticantes de ginástica rítmica. Os sujeitos realizaram uma série de três saltos com contra movimento, consecutivos, sobre plataforma de força no solo, repetindo o mesmo procedimento dentro d’água. Para realização do experimento foi utilizada a técnica de cinemetria para mensuração de ângulo de flexão de joelhos e altura do salto e uma plataforma de força para mensuração das forças de reação vertical do solo. Os resultados foram analisados através da correlação de Pearson, com nível de significância de 5%. Através dos resultados obtidos observou-se que no salto executado em ambiente aquático a altura atingida, velocidade média e tempo de vôo foram maiores e a força de impacto em membros inferiores reduzida, comparados com os resultados obtidos no solo. As correlações foram evidentes entre altura do salto e velocidade de saída, em ambos ambientes. O presente trabalho deve servir como base para a elaboração de programas de treinamento envolvendo o salto, em meio aquático e terrestre, como em atividades de pliometria. Novas pesquisas devem ser realizadas, utilizando uma população praticante de modalidade esportiva que tenha o salto vertical como ação primordial para o bom desempenho na execução da mesma. / The activities carried out in the aquatic environment suffer interference from physical properties peculiar to it. The vertical jump is a sporting skill widely used in rehabilitation programs, especially in studies of plyometric. The aim of this study was to investigate the forces involved in the vertical jump practiced in aquatic and terrestrial environment and the interdependence of the kinetic and kinematic variables of the same. For this purpose we used a sample consisting of ten subjects, all female, with an average age of 11.6 ± 1.35, practicing rhythmic gymnastics. The subjects performed a series of three consecutive counter movement jumps on force platform on the ground, repeating the same procedure in the water. To conduct the experiment was used the technique of kinemetry measuring the angle of the knees push-up and height of the jump and a platform for measuring the strength of the forces of ground vertical reaction. The results were analyzed by the Pearson’s correlation, with a significance level of 5%. The results obtained showed that the jump in running time to reach the aquatic environment, average speed and time of flight were higher and the force of impact on lower limbs, compared with the results in the ground. This work should serve as basis for the development of training programs involving the jump in water and ground, as in activities of plyometric. New research should be carried out using a method of population practicing sports that has the vertical jump as a primary action for the good performance in implementing the same.

O objetivo do estudo foi investigar o construto da tarefa de múltiplas acelerações a partir de parâmetros biomecânicos de saltos verticais. 19 jogadoras da seleção brasileira adulta de basquetebol feminino realizaram o teste de múltiplas acelerações (teste T), salto vertical com contramovimento (SV) e salto vertical com contramovimento precedido de corrida (SVcorrida). Os parâmetros biomecânicos do SV foram, tempo de fase concêntrica (Tcon), pico de força de propulsão (PFP), tempo decorrido entre início da fase concêntrica e o pico de força de propulsão (TPFP), taxa de desenvolvimento de força (TDF) e impulso (I); para SVcorrida, velocidade média de aproximação (Velmédia), tempo total do movimento (Ttotal), pico de força passiva (PFPa), tempo decorrido entre início da fase de apoio e pico de força passiva (TPFPa), pico de força de propulsão (PFP), tempo decorrido entre início da fase de apoio e pico de força de propulsão (TPFPp), Load Rate (LR) e taxa de desenvolvimento de força (TDF). Para análise dos dados, inicialmente, recorreu-se a análise de componentes principais, revelando que 61,3% da variância total do SV foi explicada pelo componente predominantemente temporal (Tcon, TPFP e PFP) e 20,7% pelo componente predominantemente cinético (I e TDF); para SVcorrida, 58,7% da variância total foi explicada pelo componente predominantemente temporal (Ttotal, TPFPa, TPFPp, LR e TDF), 15,4% pelo componente predominantemente cinético (PFPa e PFP) e 12,8% pelo componente velocidade (Velmédia). Adicionalmente, foram reveladas correlações significantes de 0,55 (Tcon), -0,54 (Velmédia) e -0,49 (PFP) com o teste T, evidenciando um construto determinado pela capacidade de se gerar elevada força na fase concêntrica, reduzir o tempo de fase concêntrica e se aproximar do ponto de mudança de direção com elevada velocidade. / The main aim of the study was to investigate the multiple-acceleration task construct from vertical jumps biomechanics parameters. Nineteen female basketball players from Brazilian national team performed the multiple-acceleration test (T test), countermovement jump (VJ) and countermovement jump preceded by run (VJr). The VJ biomechanics parameters observed were: concentric phase duration (CPD), propulsion peak force (PPF), time to reach propulsion peak force (TPPF), rate of force development (RFD) and impulse (I); for VJr the parameters were mean velocity (MV), movement total duration (MTD), passive peak force (PaPF), time to reach passive peak force (TPaPF), propulsion peak force (PPF), time to reach propulsion peak force (TPpPF), load rate (LR) and rate of force development (RFD). Data were first analyzed by principal component analysis. The results showed that 61.3% of VJ variance could be explained by time factor (CPD, TPPF and PPF), and 20.7% by kinetic factor (I and RFD). To VJr, 58.7% of total variance could be explained by time factor (MTD, TPaPF, TPpPF, LR, RFD) and 15.4% by kinetic factor (PPF and PaPF) and 12.8% by velocity factor (MV). Furthermore, significant correlations were found between T test with CPD, MV and PPF (0.55, -0.54 and -0.49, respectively), revealing a T test construct related to the ability of generating high level of force in concentric phase, diminishing time of concentric phase, and to reach the change direction point with greatest possible speed.

The purpose of this study was to compare changes in static and countermovement jump variables across a competitive season of collegiate soccer to estimated training load and subjective measures of fatigue. Monitoring data from 21 male collegiate soccer players were retrospectively examined. Nine vertical jump sessions occurred across the season in addition to daily training load assessment and daily mood-state assessment. Group average changes from the first testing session were calculated and compared to the group average training load for the 7 days preceding each vertical jump testing session for static and countermovement jump height and allometrically scaled peak power. Statistical analysis demonstrated strong relationships between changes in vertical jump height for both conditions, allometrically scaled peak power for static jumps, and estimated training load. The results indicate changes in static jump height and allometrically scaled peak power may be more useful athlete fatigue monitoring tools than countermovement jump variables.

Marklyft är en övning som effektivt tränar bland annat höftextensorer, som är en av de viktigaste muskelgrupperna för att utföra ett vertikalhopp. Trots detta har inga studier gjorts på korrelationen mellan marklyft och vertikalhopp, däremot finns flertalet studier gjorda på korrelation mellan knäböj och vertikalhopp. Syftet med denna studie var att undersöka eventuella samband mellan marklyft - vertikalhopp, vertikalhopp - BMI (Body Mass Index) och marklyft - BMI hos friska fysioterapeutstudenter (n = 15) på Uppsala Universitet. Detta för att undersöka om marklyft skulle kunna användas som alternativ träning för att förbättra personers vertikalhopp. Vertikalhopp mättes med elektronisk hoppmatta och marklyft med 1RM-test. BMI räknas ut med deltagarnas längd och vikt. Variablerna sammanställdes och sambandet räknades ut via Pearsons korrelationskoefficient. Resultaten visade ingen korrelation mellan vertikalhopp och marklyft (p = 0,773, r = 0,083) och en svag negativ korrelation för BMI och vertikalhopp (p = 0,514, r = -0,188). En mycket stark positiv korrelation mellan BMI och marklyft (p = 0,013, r = 0,721) påträffades, där de med högre BMI lyfte mer i marklyft. Slutsatsen av studien resulterar i att marklyft inte borde rekommenderas som en alternativ övning för att förbättra vertikalhoppsförmågan. Dock behövs fler studier med bland annat fler deltagare för att vidare undersöka eventuella kliniska tillämpningar. / Deadlift is an exercise that proves to effectively train the hip extensors amongst other muscle groups, which is one of the most important muscle groups for performing a vertical jump. Despite this connection, no studies have been made on the correlation between deadlifts and vertical jumps, contrary to the numerous studies made regarding the correlation between squat and vertical jump. The purpose of this study was to examine the possible correlation between deadlifts, vertical jumps as well as BMI (Body Mass Index) amongst healthy physiotherapy students (n=15) at Uppsala University. This to assess the use of deadlift as an alternative training method to improve a person’s vertical jump ability. Vertical jumps were measured with an electronic jump mat and deadlifts were measured with 1RM-test. BMI was calculated using the person’s height and weight. The variables were then compiled and calculated using Pearson's correlation coefficient. The results presented no correlation between vertical jumps and deadlifts (p = 0,773, r = 0,083), and a weak negative correlation between BMI and vertical jumps (p = 0,514, r = -0,188). A very strong positive correlation between BMI and deadlifts (p = 0,013, r = 0,721) was detected, whereas participants with higher BMI lifted more in deadlift. The conclusion of this study dictates that deadlift should not be recommended as an alternative exercise to improve vertical jump ability. However, more studies with larger populations are needed to scrutinize clinical applications.

This study examined and compared static, countermovement, and rebound-type drop jumps from the upper and lower extremities among USA Junior National Team male gymnasts. Twenty-one gymnasts performed two repetitions each of upper (UE) and lower extremity (LE) static (SJ), countermovement (CMJ), and drop (DJ) jumps on a force platform. Average measures of maximum jump height (MXHT), peak force (PF), rate of force development (RFD), and peak power (PP) were calculated for analysis. In addition, sample-specific allometric scaling was used to scale PF and PP. Four 2x3 repeated measures ANOVAs were calculated for analyses. Statistically significant main effects were observed for UE vs LE for MXHT, PF, RFD, and PP (all p < 0.001). Statistically significant main effects for jump-type were also observed: MXHT, PF, RFD, and PP (all p < 0.001). Finally, statistically significant extremities x jump-type interaction effects were obtained for MXHT, PF, RFD, and PP (all p < 0.001). These gymnasts showed better performances in CJs relative to SJs, but performances were unexpectedly poorer in the DJs. Despite using rebound-type jumps in tumbling and vaulting with UE and LE, the DJs did not appear to capture the athletes’ stretch-shortening cycle skill or may reflect poor stretch-shortening cycle skill.

The purpose of this investigation was to examine the relationships between measures ofmaximal isometric force (peak force [PF]), rate of force development (RFD), vertical jump performance (VJ) and 1-repetition maximum (1RM) strength in recreationally trained men. The subjects in this study were 26 men ([mean ± SD]: age 22± 1 years; height 175 ± 7 cm; mass 90 ± 10 kg). They were tested for PF using the isometric midthigh pull exercise. The 1RM for the squat and bench press exercise were determined as a measure of dynamic strength. Explosive strength was measured as RFD from the isometric force-time curve. Correlations between the variables were calculated using Pearson product moment correlation coefficient. There was a nearly perfect correlation between measures of PF and 1RM squat (r = 0.97, p < 0.05) and 1RM bench press (r = 0.99, p < 0.05). The correlations were very strong between VJ and PF (r = 0.72, p < 0.05) and 1RM bench press (r = 0.70, p < 0.05). There were also strong correlations between VJ and 1RM squat (r = 0.69, p < 0.05). There were no significant correlations with RFD. The results showed that isometric maximum strength determined during the isometric midthigh pull test correlated well with 1RM and VJ testing. However, RFD measured during the same test did not appear to correlate as well with other measures. The isometric midthigh pull provides an efficient method for assessing strength in recreationally trained individuals. Practioners wishing to obtain performance data related to maximum strength may wish to consider isometric testing as a less time intensive method of testing.

The primary objective of this study was to analyze the relationship between testosterone levels and vertical jumping performance in elite men and women athletes. The secondary objective was to verify whether testosterone levels and vertical jumping performance were different in men and women athletes and if those measurements were different between different athletic groups. Seventy (22 women and 48 men) elite athletes in track and field (sprinters), handball, volleyball, and soccer competing at national and international levels participated in the study. After 10 hours of fasting and 1 day of rest, blood samples were drawn from the antecubital vein for determining testosterone levels. Vertical jumping tests consisted of countermovement jumps conducted on a resistive platform connected to a digital timer. Resting testosterone levels in women were 9.5% of those of the men (respectively 0.62 ± 0.06 ng·ml-1 and 6.49 ± 0.37 ng·ml-1; p < 0.001). Countermovement jump performance was significantly different between women and men athletes, with women's jumping ability 86.3% of that of men (p < 0.001). A significant positive relationship was identified between testosterone levels and vertical jump performance when all data where considered (r = 0.61, p < 0.001, n = 70).

The purposes of this dissertation were to examine common athlete training and monitoring practices in men’s collegiate soccer and to report the programming strategies and monitoring outcomes for an NCAA Division I men’s collegiate soccer team whose coaching and sport science staff collaborated on a daily basis. The following are the major findings of the dissertation: Study 1 – Coaches from all divisions of play responded to a custom survey. A majority of coaches developed an in-season training plan that varied both daily and weekly volume and intensity. One-third of the coaches performed no athlete monitoring, and a number of coaches performed purely subjective monitoring of training load and fatigue. Common athlete monitoring tools included sport performance, self-report questionnaires, and physical performance tests. Most coaches believed their athletes did not change or improved in all aspects of performance, while injuries were a mix of new and recurrent. Study 2 – Statistical differences in training load were found between each phase of the season, and training load variation was found with respect to the number of days before a match. Phasic training loads were highest during the pre-season and non-conference portions of the season and decreased significantly during conference play and the post-season. The daily training load values reflected the player groups’ match involvement and therefore led to different loading strategies between the groups. Study 3 – No statistically significant decreases in squat jump height occurred across the season, although a moderate practical decline occurred following the pre-season. The correlation between training load and squat jump height were statistically non-significant, while the cross-correlation was significant. The athlete monitoring program was successful in managing the athletes’ neuromuscular fatigue across the season as evidenced by the maintenance of squat jump height and positive relationship between training load and changes in squat jump height. Coach education on the importance of athlete training load and fatigue monitoring is imperative. Collaboration between coaching and sport science staffs in conjunction with an athlete monitoring program can ensure variation in training load and can help manage athlete fatigue across a competitive season.