Master of Science

thesisIntra-abdominal pressure (IAP) is the pressure within the abdominal cavity. IAP is routinely studied in the field of urogynecology to comprehend its relation to pelvic floor disorders. In contrast to the potential negative role of high IAP on the pelvic floor, IAP is important for various forms of human performance. Given the disparate thoughts on IAP and its impact on pelvic floor health and sport and exercise performance, better understanding the IAP response in women without pelvic floor disorders during physical activity is warranted. In brief, the purpose of the study was to describe IAP responses during a variety of exercises and physical activities in women without a history of pelvic floor disorders. Our primary aim is to calculate the percentage of maximal for a select group of the activities detailed in a previous study, using the IAP during seated ValSalva (VM) as the maximal capacity. A secondary aim is to characterize the relationship between the relative term of percent of maximal for each activity, and maximal IAP. We hypothesize that there will be an inverse relationship between percentage of maximal for each activity and maximal IAP. In total, the data of 55 women were included in the analysis. Women were aged 20-54 (M 30.38 ± SD 9.43 yrs) and had BMI values between 17.7-28.9 (M 22.4 ± SD 2.63 kg/m2). Participants completed a 1-hour exercise protocol in a human performance laboratory. Pearson r correlation results indicate that all relative values (% maximal of seated VM) were significantly and negatively correlated at (p < 0.001) with seated VM IAP, except for seated shoulder press with 6.9 kg (p 0.023) and 9.1 kg (p 0.557). Our findings support the contention that the IAP response to individual, submaximal activities exhibits a similar relationship to maximal capacity as that observed in well-established measures of fitness, such as muscular strength and oxygen consumption. It is imperative that coaches understand the relationship between IAP and higher intensity efforts during training. With this knowledge, strength and conditioning specialists may adjust training practices in order to limit the likelihood of precipitating pelvic floor symptoms in women

A Comparison of Morphological, Jump, and Sprint Kinematic Asymmetries in Division I Track and Field Athletes

International Journal of Exercise Science 16(1): 1306-1319, 2023. Inter-limb asymmetries are the difference in performance in one limb with respect to the other. Running events in track and field are considered symmetrical while jumping and throwing events are considered asymmetrical. It is unknown if competing in these different events result in differences in inter-limb asymmetries, thus, this study compared the magnitude of jump, sprint, and morphological asymmetries in track and field athletes who compete in symmetrical and asymmetrical events. Forty-six Division I track and field athletes performed a series of vertical jumps (VJ) and broad jumps (BJ) with force platforms measuring peak force of each limb, and 30-meter fly sprints with kinematics (step length (SL), flight time (FT), and contact time (CT)) recorded during the sprints. Additionally, thirty-eight of these subjects underwent body composition analysis via dual x-ray absorptiometry to determine morphological asymmetries. Asymmetries were calculated using the symmetry index and the asymmetry measures were compared between sprinters, distance runners, throwers, and jumpers utilizing a one-way analysis of variance or Kruskal-Wallis tests with post-hoc comparisons as necessary. There were no differences in VJ, BJ, and sprint kinematic asymmetries found between groups but there were differences in leg fat mass asymmetries (H(3)=8.259, p=0.041, eta2= 0.101) as well as arm lean mass (H(3)=9.404, p=0.024, eta2=0.152), fat mass (H(3)=17.822,

Associations Between Jump Performance and Asymmetries with 30-m Sprint Completion Time

Asymmetries of the lower body during jumping have been examined as a method to predict risk for injury and guide training program development. Studies have primarily focused on how these asymmetries affect jump performance, but none have examined this in Division I track athletes nor how these are related to sprint performance. PURPOSE: To examine the relationship between jump performance and asymmetries of the vertical and broad jumps with 30-m sprint completion times. METHODS: Twenty-five Division I Track and Field athletes (12 sprinters and 13 non-sprinters) (height = 177.21 ± 10.43 cm; weight = 78.67 ± 24.15 kg) participated in this study. These subjects performed two trials of both the vertical jump (VJ) with their hands on their hips while standing on force platforms. Subjects also performed two trials of the broad jump (BJ) while standing on force platforms and the distance of the BJ was measured using a 100-m tape measure. Following the jump tests, subjects performed two trials of 30-m sprints in which time was recorded using timing gates and the trial with the shortest completion time was used for analysis. Force data from the VJ was used to determine jump height and inter-limb asymmetries and the trial with the greatest jump height was used for analysis. Force data from the BJ was used to determine inter-limb asymmetries from each trial and the trial with the greatest jump distance was used for analysis. Asymmetries were calculated with the symmetry index equation [(high value-low value)/total*100]. Spearman rank correlations were then conducted to determine if the jump performance and asymmetries were associated with sprint completion times. Significance was set at an alpha level of 0.05. RESULTS: Spearman rank correlations determined that both the VJ and BJ were negatively associated with 30-m sprint completion time (rs= -0.644 p=0.001 and rs=-0.563 p=0.003, respectively). Additionally, both the VJ height and BJ distance were positively correlated (rs=0.643 p=0.001). The VJ and BJ asymmetries were not significantly correlated with 30-m sprint performance (p\u3e0.05) nor were they correlated with either the VJ height or BJ distance. CONCLUSION: The findings of study indicate that coaches may want to monitor jump performance as it is related to sprint performance. On the other hand, the asymmetries measured were not associated with jump or sprint performance and this may be due to the sample as they were highly trained individuals with low levels of asymmetries during both jumps

Association Between Single-Leg Agility and Single-Leg Vertical Jumping Performance in Active Adults

The vertical jump is crucial in sports and indicates lower body explosiveness. Additionally, vertical jumping requires landing bilaterally or unilaterally. PURPOSE: To determine any differences in unilateral vertical jump performance when landing unilaterally or bilaterally. METHODS: Thirty recreationally trained individuals (age = 23.5 ± 2.2 years) performed three trials of vertical jumps under four different conditions in random order (unilateral-left vertical jump with bilateral landing, unilateral-right vertical jump with bilateral landing, unilateral-left vertical jump with ipsilateral landing, and unilateral-right vertical jump with ipsilateral landing). Kinetic data (peak force, relative peak force, peak power, and relative peak power) was obtained from all jumps at 1000 Hz sampling rate. The average score between trials for the vertical jump were used for statistical analysis in SPSS 25. Independent T-tests were used to find differences in vertical jump measures depending on landing condition with p-value at 0.05. RESULTS: No significant differences between limbs in jump height (Right = 0.08 cm ± 0.04; Left cm = 0.11 ± 0.05), peak force (Right = 473.3 N ± 135.6; Left = 600.1 N ± 182.6), relative peak force (Right = 6.8 N*kg ± 2.6; Left = 7.8 N*kg ± 1.9), peak power (Right = 1505.4 W ± 524.5; Left = 1934.9 W ± 771.9), and relative peak power (Right = 21.3 W*kg ± 7.2; Left = 25.5 W*kg ± 5.8) during unilateral vertical jumps between the landing conditions (p \u3e 0.05). CONCLUSION: It appears that landing conditions do not affect unilateral jump performance in recreationally trained athletes

The Relationship between Squat Jump Performance and Sprint Profile in Collegiate Track and Field Athletes

The squat jump (SJ) necessitates the inter-play of various biomechanical components for better jump performance. Good sprint performance requires the inter-play of many of the same biomechanical components. Researchers have previously examined how the speed, force, velocity, and power interact during sprinting, but have yet to examine how these measures are associated with SJ performance measures. PURPOSE: Examine the relationship between squat jump performance measures and the sprint profile measurements of collegiate track and field athletes. METHODS: Twenty-five athletes (18 males and 7 females) completed two squat jump trials with a linear encoder attached to a 45 lbs. bar placed on the athlete’s upper back. Measures of interest during the concentric phase of the SJ included jump height, maximum force, maximum velocity, maximum power, and rate of force development. Athletes then completed two 30-meter acceleration sprints. The MySprint mobile application was used to acquire the athlete’s sprint profile and to assess maximal theoretical horizontal force, maximal theoretical velocity, optimal velocity, maximal theoretical power, maximal speed, maximal ratio of force, force-velocity slope, and decrease in ratio of force. The best trial was used for statistical analysis. Pearson’s or Spearman’s correlation coefficients were conducted between SJ measures and sprint profile measures. RESULTS: There was a positive correlation between SJ height and maximal speed (r = 0.402; p = 0.042). Maximal power during the SJ was positively correlated with maximal speed (r = 0.476; p = 0.014); optimal velocity (r = 0.469; p = 0.018); maximal theoretical power (r = 0.462; p = 0.018); maximal theoretical velocity (r = 0.452; p = 0.021); theoretical horizontal force (r = 0.431; p = 0.028); and maximal ratio force (r = 0.428; p = 0.029). Maximal velocity during the SJ was correlated with maximal speed (r = 0.519; p = 0.007); maximal theoretical velocity (r = 0.499; p = 0.010); optimal velocity (r = 0.486; p = 0.014); and maximal theoretical power (r = 0.484; p = 0.012). No other correlations were significant. CONCLUSION: Maximal velocity and power during the concentric phase of the SJ are moderately to strongly correlated with maximal sprinting speed, velocity, and power. SJ height is positively correlated with maximum sprint speed. There is a lack of significant correlations between other measures of the SJ and sprint profile measures. SJ power and velocity are correlated with sprint performance, therefore power and velocity improved through plyometric SJ training may be transferable to achieve better sprint performance

The Effects of Three Post-Activation Potentiation Methods on Muscular Activation of Knee Extensors: A Pilot Study

Post-Activation Potentiation (PAP) is a phenomenon that involves a maximal voluntary contraction that potentiates a subsequent dynamic muscular contraction. Manual Resistance Training has been used to alternative resistance training methods. However, the application of MRT on PAP methods on muscular activation has not been yet studied. PURPOSE: To assess the feasibility of three different methods of eliciting PAP in combination with three different resting time periods between the maximal voluntary contraction and the subsequent dynamic activity METHODS: Four subjects (1 male and 3 females; mean ± SD; age = 21.7 ± .5 years) participated in this randomized crossover pilot design. Subjects performed a general warm-up and dynamic stretching followed by a knee extension maximal voluntary contraction (MVC) test at 90º flexion. Subjects were then randomly placed into three conditions: Traditional PAP (T-PAP), Constant Manual Resistance Training PAP (CMRT-PAP), and Practical Manual Resistance Training PAP (PMRT-PAP). PAP was induced through 4-maximal knee extension contractions. The T-PAP condition used an isokinetic machine at 60 deg/sec; for CMRT condition a custom built device was used to replicate the isokinetic machine through manual resistance provided by a partner; for PMRT-PAP manual resistance was applied by a partner through resisting the shank directly. Following each of the PAP protocols, dynamic muscular contraction was tested on the isokinetic machine using 4 repetitions of the knee extension at 180 deg/sec. Electromyography was used to assess muscular activation of the Vastus Lateralis (VL) and Vastus Medialis; electrodes for the VL were placed at mid-distance between the greater trochanter and the lateral condyle of the femur, whereas the electrode for the VM was placed at 20% of the distance between the anterior iliac crest and patellar tendon. Data were analyzed using the MyoMuscle Noraxon software; data were processed using a band pass: low pass at 10 Hz and high pass at 450 Hz. Raw data were smoothed by root mean squared and rectified by half-wave rectification. Data were then normalized to MVC values for further comparison. RESULTS: On average – in comparison to MVC values – during the T-PAP condition subjects increased muscular activation by 164% and 160% on the VL and VM sites, respectively. Similarly, subjects during the CMRT and PMRT increased muscular activation of the VL by 166% and 128%, respectively, and, VM by 158% and 115% respectively. CONCLUSION: T-PAP, CMRT-PAP, and PMRT-PAP methods appear to be feasible methods to potentiate muscle activation of the VL and VM during dynamic knee extension. Furthermore, these findings indicate that PAP may be elicited by non-traditional resistance training approaches such as Manual Resistance Training

Manual Resistance Training as an Alternative Post-Activation Potentiation Method: A Pilot Study

Post-activation potentiation (PAP) can be defined as an acute effect of improved muscular performance as a result of their contractile history. PAP is typically induced through weight resistance exercises. Manual Resistance Training (MRT) is a form of accommodating resistance, but it’s feasibility as an alternative method to elicit PAP is not known. PURPOSE: 1) To assess if potentiation can be achieved through the use of MRT, and 2) to compare the effectiveness of MRT applications of eliciting PAP to that accomplished through an isokinetic dynamometer. METHODS: Six (2 males and 4 females) young adults (mean ± SD; age = 21.6 ± 1.0 years, weight = 49.8 ± 4.1 kg, BMI = 24.2 ± 3.4, BF (%) = 25.8 ± 4.1 %) were recruited. Subjects participated in a Maximal Voluntary Contraction (MVC) baseline testing using a 5-sec isometric knee extension test at a 90-degree angle. Following the MVC test, subjects were randomly placed into one of three conditions: Baseline PAP (PAP), Constant Manual Resistance Training (CMRT), and Practical Manual Resistance Training (PMRT). For the PAP condition, subjects performed all knee extensions on a Biodex isokinetic dynamometer. The subjects performed 4-repetitions of knee extensions at 60 deg/sec, then performed 4-repetitions at 180 deg/sec. During the CMRT condition, subjects performed 4-repetitions of knee extensions on a custom-made device that allowed the application of constant resistance controlled by a partner, followed by 4-repetitions on the isokinetic dynamometer at 180 deg/sec. During PMRT condition, subjects performed 4-repetitions of knee extensions with the research assistant applying force on the distal portion of the shank, followed by isokinetic knee extensions at 180 deg/sec. Peak force from the 4-rep isokinetic leg extensions done at 180 deg/sec was used for analysis. Data was analyzed on SPSS 23 IBM. Data normality was assessed using a Shapiro-Wilk test. Data appeared to be non-normally distributed, therefore, a non-parametric Friedman test was used to assess differences between conditions. RESULTS: The Friedman test revealed no differences between the PAP (115.93 ± 46.72 Nm), CMRT (108.4 ± 47.0 Nm), and PMRT (113.98 ± 50.7 Nm) groups (p = 0.241). CONCLUSION: A traditional PAP, CMRT and PRMT methods might be viable methods to induce similar PAP effects on peak torque during knee extension. CMRT and PMRT might represent alternative methods to induce PAP that can be used in practical and sport settings in where no equipment might be available

Scores for the Modified Functional Movement Screen in Active Older Adults

The modified Functional Movement ScreenTM (mFMS), an adapted form of the traditional FMS for older adults, consists of a battery of tests aiming at identifying areas of movement deficiency. Prompt identification of movement deficiency can help exercise practitioners create a tailored program to improve these limitations. PURPOSE: To establish normative values for the mFMS in healthy active older adults. METHODS: There were 141 individuals (56 males and 85 females; mean age ± SD: age 69.51 ± 7.41 years) who participated in the study. Participants performed an 8-10 minute warm-up at a self-selected pace on a treadmill or stationary bike then completed some dynamic stretches. Following the warm-up protocol, the mFMS screening test was administrated, including the deep squat (DS), shoulder mobility screen (SM), lower body motor control screen (LB-MCS), active straight leg raise (ASLR), shoulder and ankle clearing tests. Due to the range of the mFMS scoring criteria (0-3) for screens and (pass/fail) for the clearing tests, all screens (DS, SM, LB-MCS, ASLR) and clearing tests (shoulder and ankle) were analyzed as categorical and not continuous variables. Consequently, percent counts were reported for each variable. RESULTS: The DS, which requires extensive mobility and motor control, presented a challenge for many subjects: only 17.0% of older adults were able to achieve a perfect score during the DS test. The majority of older adults (95%) did not report any pain during the ankle clearing tests. Similarly, a large proportion of older adults did not report any pain during the shoulder clearing tests (95.7% for the right and 96.3% for the left). More than half of the older adult subjects (53.9%) were able to pass both the right and left LB-MCS. A greater percentage of subjects (41.1%) were able to achieve a perfect score on the right SM compared to (26.2%) for the left. Lastly, the majority of subjects completed the ASLR with a perfect score, 68.8% and 68.1% for the right and left legs, respectively. CONCLUSION: This study highlights areas of mobility, stability, and movement proficiency that seem to be of concern across the active older adult population. Mobility among inactive, physically frail or untrained older adults may display lower scores and therefore screening should be approached with caution. Additionally, exercise practitioners working with active older adults may use values reported in this study as a reference point for comparison

Changes in vertical jump performance and body composition before and after COVID-19 lockdown

This study aimed to determine the effects of a 16-week COVID-19 lockdown on body composition and vertical jump performance. Thirteen martial artists participated in this study. Participants were tested at: 1) pre-lockdown (pre), 2) post-lockdown (post), 3) two-weeks-post-lockdown (post+2), and 4) four-weeks-post-lockdown (post+4). Repeated-measures-ANOVAs were conducted with post-hoc analyses. Differences were observed in vertical jump height (VJH) (10.33%), peak velocity (PV) (3.10%), reactive-strength-index-modified (RSImod) (13.8%), and peak-propulsive-power (PPP) (6.00%) from pre-to-post. There as an increase from post-to-post+2 in VJ (13.06%), PV (4.12%), RSImod (14.0%), and PPP (4.66%). There was an increase from post to post+2 in VJH (10.8%), PV (3.1%), RSImod (14.0%), and PPP (3.0%). Fat mass (FM) and BF% increased from pre to post (13% and 11%, respectively) and decreased from post to post+4 (8% and 11%, respectively); fat-free mass (FFM) decreased from pre-to-post (11%) and decreased from post-to-post+4 (8%). There were moderate associations (rmc = 0.42-0.47) between FFM and VJH, FMM and PPP, FFM and PV, BF% and PV, and FM and PV. While the lockdown resulted in a significant decrease in vertical jump performance and increases in BF and FM, participant’s performance returned to pre-lockdown levels after only 2-4 weeks of post-lockdown training by decreasing BF, FM, and increasing FFM

Physical fitness in older adults: Is there a relationship with the modified Functional Movement Screen™?

© 2020 Elsevier Ltd Introduction: The modified Functional Movement Screen™ (mFMS) has been used to screen for mobility, stability, motor control, and balance in older adults, yet, its relationship to measures of physical fitness is not fully understood. The purpose of this study was to determine the association between mFMS scores and measures of physical fitness in older adults. A secondary aim was to determine physical fitness differences depending on mFMS Lower Body Motor Control Screen scores. Methods: One hundred and eight older adults completed this cross-sectional study. Measurements of physical fitness included: Handgrip Strength (HG), Back-Leg Strength Dynamometer (BLS), 8 foot Up and Go (8UG), Vertical Jump (VJ), Medicine Ball Throw (MBT), Chair Stand (CST), Arm Curl (AC), and 6-Minute Walk test (6 MW). The mFMS consisted of four screens: Shoulder Mobility Screen (SMS), Deep Squat (DS), Active Straight Leg Raise (ASLR), and a Lower Body Motor Control Screen (LB-MCS). Spearman\u27s R correlations determined associations between physical fitness tests and mFMS scores (DS, SMS, ASLR). Independent t-tests or Mann Whitney U tests determined whether individuals who passed the LB-MCS displayed higher physical fitness scores. Results: The DS was significantly correlated with all fitness measures (p \u3c 0.05). Higher DS scores were associated with better HG (r = 0.31), BLS (r = 0.49), VJ height (r = 0.54), MBT (r = 0.41), CST (r = 0.57), AC (r = 0.30), 6 MW (r = 0.50), and 8UG (r = −0.61) performance. Individuals who passed the LB-MCS displayed superior BLS, 8UG test, and 6 MW test performance (p \u3c 0.05). Discussion & conclusion: Higher DS scores are associated with higher physical fitness scores. Individuals who passed the LB-MCS displayed better physical fitness scores. Practitioners may desire to use the mFMS to measure physical fitness in older adults