M.S. - Kinesiology and Leisure Science

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Age and sex differences in simulated collision avoidance driving
(University of Hawaii at Manoa, 2006) Ryan, Ann Marie
The ability to avoid collisions is essential for survival. Diminished avoidance abilities among older adults and those under age 12 may account for the disproportionately high number of older individuals and children involved in pedestrian-vehicle collisions (Choueiri, E. M, Choueiri, G. M, Choueiri, B. M., 1993); (Kingma, J., 1994); (Mathey, F.J.,1983). The growing number of traffic-related fatalities underscores the need to attain a better understanding of collision avoidance response skill changes across the life span and the need to develop systems for screening and assessing individual collision avoidance skills. The primary objective of the parent research was to develop a battery of tests and to examine the relationships between sensory, attention, cognition and motor skills with collision avoidance ability. The degree of skill exhibited by an individual in avoiding automobile collisions in the simulator is expected to be a useful indicator of his/her ability to perform other related complex vehicle-maneuvering tasks such as those required for automobile operation. The purpose of this thesis project was to develop a simulated collision avoidance testing (SCAT) apparatus and procedure and conduct a pilot study to examine the SCAT system sensitivity to age and sex differences of the vehicle operator, particularly with respect to intra-task manipulations of visibility, event uncertainty, and type of evasive maneuver. One hundred and six healthy functional volunteers served as participants. These volunteers have 19 (6-19 years) participants in the young group; 43 (20-59 years) participants in the adult group, and 44 (60-74+ years) participants in the senior group. Five sets of tasks were performed: (1) Simulated Collision Avoidance Task with overall measures including crash frequency and crash severity;(2) Sensory Integrity tests (vision, hearing, and health questionnaires); (3) Information Processing Tasks including reaction time and movement time tests; (4)Tasks of Everyday Attention and Cognition (TEAC): Visual Elevator Test (attention switching), Trails B Test (visual search), Telephone Directory Search Test (visual search), and Telephone Number Dialing Test (short-term memory); and (5) Movement Control Tasks: Grip Strength Test (strength), Balance Test (balance), Gross Motor (Fitts Tapping Test), Needle Threading Test (fine motor skill), Bow Tying Test (fine motor skill), and Tweezer Transfer Test (fine motor skill). The total time per test session was 90-120 minutes. Only the simulator results are presented in this thesis. Overall results for the SCAT showed significant differences in crash frequency ratio and crash severity as a function of age, sex, uncertainty and maneuver. Visibility was only marginally significant. The effects of age depended on level of task such that the senior group had a significantly higher crash frequency and severity than the other age groups for uncertain scenarios, while differences between other age groups were not significantly different There was an interaction of sex and maneuver in crash severity such that males performed worse than females. Females varied very little across maneuvers while males had progressively more fatal crashes from left to right to stop maneuvers. The stop maneuver had a significantly greater crash frequency than the left or right maneuvers. The right and stop maneuvers had a higher crash severity than the left maneuver for uncertain scenarios. Beneficial outcomes of this research for Hawaii and the nation may include improved medical screening and assessment batteries to aid licensing agencies, rehabilitation facilities, physicians, driver education specialists, law enforcement officers, families of unfit drivers, and all drivers on the road in identifying drivers who, for whatever reason, are unfit to drive without assistance. This research helps identify when collision avoidance abilities (and cognitive and motor function) reach maximal development, when they begin to decline, and the possibility of compensatory measures for recognized deficiencies. These findings are especially relevant to the identification of older persons at risk of auto accidents. Given the sensitivity to age and/or disability demonstrated by SCAT, these tasks may hold potential for screening candidates for driver's license renewal and for impaired driver rehabilitation in virtual reality ... risk free to the real world traffic. SCAT may comprise useful test battery elements for testing and predicting collision avoidance ability of potential drivers and for assessing an individual's fitness to drive thereby reducing traffic fatalities and extending the number of years of safe driving for motorists.
The relationship between social environment and walking levels in older women in Hawaiʻi
(University of Hawaii at Manoa, 2008) Nagira, Megumi
The purpose of this study was to examine the relationship between physical activity levels and perceptions of the environment by elderly women in Hawaii. Participants (n=l44) were surveyed to explore what elderly women do for physical activity, how much activity they perform in a week, if their background affects their physical activity and if their perception of the physical environment affects their level of activity. Results indicated that walking was the most frequent exercise to be reported with 61 % of the participants meeting the CDC's recommendation. Walking for transport was associated with distance to the community centers, means of transportation, and geographic barriers. Other findings include walking for leisure was associated with residential density while leisure time physical activity was related to living situation. Gardening was related to lack of parking and cul-de-sacs. Age was related to less activity-friendly environments, less education, and living situation.
The relationship between heart rate variability, self-perception, exercise, mood, and sleep indicies in collegiate women's track and field during a competitive season
(University of Hawaii at Manoa, 2008) Leonhardt, Lorita P.A
This research examined in-season changes in physiological and psychological measures, and related them to training over time (4-months) in women's track and field during a competitive collegiate season. Fifteen female athletes between the ages of 18 and 24 years old participated. Each participant completed the Exercise Orientation Questionnaire (EOQ), where four questions were derived from the Self-Loathing Subsca1e (SLSS) questionnaire, the Epworth Sleepiness Scale (ESS) Questionnaire, the Profile of Mood States (POMS) Standard Form Questionnaire, and heart rate variability (HRV) testing protocols during each of their four testing sessions. Testing sessions included the application of a tilt table to measure the LFIHF ratio in female track and field athletes. A developmental and quasi-experimental research design with repeated measures was employed in this study. Data collection of the LFIHF ratio occurred across three plains (0 degrees, 70 degrees, and 0 degrees). The test results revealed that there were no significant differences in the following: (1) LFIHF ratio over the four trials due to the high amount of in-season training that they received over a period of 4-months; (2) comparison to the POMS and SLSS questionnaires as a covariate; and (3) comparing the ESS questionnaire as a covariate. In conclusion, the physiological stress from the tilt table testing did not seem to affect the participant's ability to adapt to physiological stress over the four trials, however, it can be noted that when using the ESS questionnaire as a covariate, data appear to be approaching significance.
Validation of the human activity profile in the HIV-Positive population using indirect calorimetry
(University of Hawaii at Manoa, 2008) Barnett, Alexis T.
Objective(s): To determine if the HAP is a valid measure of physical activity level for the HIV-Positive population. Design: Validation using VO2max as the "gold standard" to compare HAP scores resulting from the Maximal Activity Score (MAS) and the Adjusted Activity Score (AAS). Setting: Clinical laboratory Participants: Twenty-six HN-positive participants (23 male, 3 female; age 45.96±9.28 years) receiving HAART. Intervention: Participants completed the HAP and the exercise test on the same day. Maximal oxygen uptake was determined using standard indirect calorimetry techniques. Responses to the HAP resulted in two scores: the maximal activity score (MAS: maximal activity that is still being performed) and the adjusted activity score (AAS: MAS minus the number of activities that the subject can no longer perform). Correlations between AAS, MAS and VO2 max were generated. Main Outcome: MAS, AAS, and VO2max values. VO2max values were assessed using indirect Calorimetry. Results: Mean VO2max was 37.73 ± 6.95 ml O2kg-lmin-l. The mean MAS and AAS scores were 86.5 ± 7.6 and 75.7 ± 19.2, respectively. The VO2max was poorly correlated with MAS and AAS at p =0.31 and p =0.32, respectively. The poor correlations were likely due to the fact that the mean VO2max of the subjects in the present study exceeded 10 METS, the design limitations of the HAP. Conclusions: Based on the validation criteria used in the present study, the HAP is not a valid indicator of physical activity capacity for HIV -positive patients on HAART. Further study is needed to find a more accurate instrument to estimate physical activity capacity for this population.
Anaerobic capacity via a maximal run test
(University of Hawaii at Manoa, 2007) Keen, Shannon A.K
Quantifying anaerobic power in runners while running is problematic compared to the determination of aerobic capacity. Aerobic capacity is the maximal amount of oxygen consumed during maximal exertion and is assessed primarily by open circuit indirect calorimetry yielding data such as VO2 max, ventilation, and heart rate (Crouter et al., 2001; Nioka et al., 1998). Anaerobic capacity is the maximum amount of adenosine triphosphate (ATP) generated through anaerobic energy systems (Green et al., 1993). Measurements of the contributions of these energy systems during activity can determine the metabolic requirements for exercise performance and the design of sport specific training regimens. Training results in increased A TP production,• which results in more efficient aerobic and anaerobic work for longer periods of time with less muscular fatigue (Nevill et al., 1989; Stathis et al., 1994; Thorstensson et al., 1976; Thorstensson et al., 1975). Quantification of anaerobic capacity requires exhaustive exercise performed at an optimal resistance resulting in a suitable duration (Green et al., 1993; Vandewalle et al., 1987). This type of high intensity activity results in an increase in blood lactate concentrations (Nummela, Alberts et al., 1996; Nummela, Mero et al., 1996). Peak blood lactate concentrations occur approximately seven minutes post exercise (Fujitsuka et al., 1982). Because of the relationship between peak blood lactate accumulation and anaerobic capacity, blood lactate concentration has been reported to be a reliable indication of anaerobic power in both laboratory and field settings. (Fujitsuka et al., 1982; Gratas-Delamarche et al., 1994; Green et al., 1993; Lacour et al., 1990; Ohkuwa et al., 1984; Vandewalle et al., 1987). Anaerobic testing can be divided into two categories: laboratory testing and field testing. Field tests include shuttle runs, sprints, and vertical jumps. Laboratory testing consists of cycle ergometer and treadmill tests. Field tests such as the vertical jump and Margaria-Kalamen stair climb test have been criticized due to the limited duration and low intensity (Vandewalle et al., 1987). However, sprints of various distances ranging from 100 - 400m have been shown to be good predictors of anaerobic capacity (Patton et al., 1987; Scott et al., 1991; Shaver, 1975). Distances over 400m are more directly related to aerobic capacity rather than anaerobic capacity (Shaver, 1975). Blood lactate values correlate with mean velocity for may runners (Ohkuwa et al., 1984), and for females (Lacour et al., 1990) in distances under 40Om. Laboratory sprint tests on treadmills measure anaerobic capacity and protocols such as peak power obtained in the Maximal Anaerobic Running Test (MART) have been found to correlate moderately with .the Wingate Anaerobic Test (r = 0.52) (Nummela, Alberts et al., 1996). Treadmill sprint tests determine anaerobic capacity by run time to exhaustion or by incremental increases in speed until subject cannot keep up with specified intensity for designated time period (Falk et al., 1996; Nummela, Alberts et al., 1996). The use of a treadmill for sprint tests allows the researcher easy control over factors such as speed and incline; however, controversy arises due to the inability to run at maximum speed, difficulty finding an optimal stride, and failure to attain maximal energy requirement (Frishberg, 1983; Schnabel et al., 1983). The Wingate Anaerobic Test (WAnT) is a highly regarded measurement of anaerobic capacity and power. Measurements of peak power, absolute power, relative power and anaerobic fatigue have become the standard for measurement of anaerobic capacity. (Falk et al., 1996; Green et al., 1993; Murphy, 1986; Nummela, Alberts. et al., 1996; Sands et al., 2004; Weinstein et al., 1998) The WAnT has been accepted as an anaerobic test because of its intensity and duration characteristics as well as its simple and inexpensive protocol. The WAnT elicits high concentrations of blood lactate (Inbar, 1996) which has been found to be significantly correlated with mean power for females (r = 0.48 - 0.72) (Gratas-Delamarche et al., 1994; Weinstein et al., 1998). A disadvantage of the WAnT and other cycle ergometer tests is how the data are interpreted for trained individuals who are untrained in cycling. Results from a non-weight bearing anaerobic test are not easily transferable to the playing field where the athlete has to account for his/her own body weight (Sands et al., 2004) and should not be used as a predictor of performance in sport due to specificity of skills (Beckenholdt et al., 1983). Consequently, non-weight bearing cycle ergometer test results may not be indicative of sprint performance (Baker and Davies, 2002) or other weight bearing activities. A 200m sprint was found to correlate with the WAnT for peak power and mean power when related to body size (r = -0.54 and -0.82) (Patton et al., 1987). A 200m sprint takes approximately 25- 35 seconds, when completed as a maximum effort sprint (Hautier, 1994; Patton et al., 1987; Shaver, 1975). World record times for the 200m sprint are 19.32 sec. for males and 21.34 sec for females (Morrison, 2006). This distance provides a duration similar to that of the Wingate protocol; therefore, utilization of the 200m sprint might be an alternative to the WAnT. Thus, a 200m-field test may be a better indication of anaerobic capacity for athletes that have to complete swift bouts of anaerobic running in their sport. The Hawaii Anaerobic Run Test (HART) was introduced in a pilot study completed in the University of Hawaii performance lab. This test utilized a 200m sprint to determine anaerobic capacity in sprinters. The pilot study showed the HART to be a valid and reliable test of anaerobic performance (Smith, unpublished Master's Thesis, 2005). The purpose of this study was two-fold: determine the sensitivity of the HART for runners and cyclists when compared to the WAnT and to determine the relationship between velocity and momentum obtained in the HART test with power values obtained in the WAnT. The hypotheses of this study were: (1) there would be no differences between blood lactate accumulation for runners and cyclists regardless of test; and (2) there would be no differences between runners and cyclists in velocity and momentum collected during the HART or power values collected during the WAnT.
Determination of anaerobic performance via maximal sprint field test
(University of Hawaii at Manoa, 2007) Harmon, Andrea S.
The purpose of this study was to compare the specificity of the WAnT and a recently developed 200 meter sprint, Hawaii Anaerobic Run Test (HART). by evaluating the performance of seventy seven male and female runners and cyclists and untrained males and females on both tests. The HART protocol consisted of a five minute warm up followed by a 200 meter sprint on a track. The WAnT was performed in the laboratory using a cycle ergometer to perform a 30 second sprint against a weighted flywheel. Finger prick blood lactate samples were taken seven minutes after completion of each test. Pearson product moment correlation coefficients were generated comparing power data from the WAnT with velocities and momentums from the HART. Strong correlations were found between peak and mean momentum and power (r=O.82. r=O.78. respectively). Data from this study suggest that the HART is a valid field test for evaluating anaerobic power during running.
Glenohumeral peak torques and strength ratios relationship with injury in adolescent female volleyball athletes
(University of Hawaii at Manoa, 2007) Freemyer, Brett G.
Context: Research of adolescent volleyball athletes' isokinetic strength is nonexistent. Objective: 1"0 evaluate the relationship between shoulder injuries, anthropometric characteristics, and shoulder internal and external rotation strength. Design: Multivariate analysis of variance and covariance design with two conditions: (1) skill level and (2) previous shoulder injury. Setting: Human Performance and Athletic Training Labs at the University of Hawai'i, Manoa. Subjects: 38 adolescent club volleyball athletes, 10-15 years of age (mean 13.02 +1- 1.60). Main Outcome Measures: Concentric and eccentric peak torque of the shoulder internal and external rotators on a Biodex System 3 Dynamometer at 60°s-1 Results: Older and more skilled athletes had significantly higher peak torque measurements in concentric and eccentric internal/external rotation compared with the athletes of the younger and lesser skill levels. No differences existed between the healthy and injured subjects in terms of peak torque produced. Strength ratios were not different across skill levels, however injured subjects produced significantly lower eccentric internal rotation/concentric external rotation (p ~ 0.02) than healthy subjects. Conclusions: Differences in the internal and external shoulder rotator strength ratios appear to be related to injury prevalence more than absolute strength. Shoulder dysfunction related to strength ratio deficits may also exist in adolescent volleyball athletes.
Reliability of hand held stopwatches during H.A.R.T. field testing
(University of Hawaii at Manoa, 2007) Lundquist, Kelly M.
The purpose of this study was to assess the reliability of split times obtained by band held stopwatches (HHS) compared to electronic timing (ET) during a 200-m sprint. Twenty-six timers were given instruction and practice until good agreement was achieved between ET and HHS. Two HHS timing methods were compared with ET: single-split timers (SST) and multiple-split timers (MST). Trained runners (8 males, 10 females) participated in this study. A repeated measures ANOVA was used to determine the validity. Reliability was analyzed using Intraclass Correlation models. No differences were found between the five MST (p = 0.092). An ICC of 0.92 indicated high reliability. ET resulted in significantly faster times than MST or SST (F = 4.73,p = 0.009). High ICC values (ICC model (2, 3) = 0.96 and 0.99) indicated that the two HHS methods were reliable. It was concluded that ET should be the method of choice.
Effect of intermittent hypoxic exposure on heart rate variability in endurance trained athletes using autoregressive spectral analysis
(University of Hawaii at Manoa, 2006) Martin, Vanessa R.
Context: Spectral analysis of beat-to-beat fluctuations in heart rate (Heart Rate Variability (HRV)) provides an efficient, non-invasive assessment of autonomic function and cardiovascular adaptations. Changes in HRV may result from a number of different physiological factors including training level and acclimation to altitude. Objective: To investigate the effects of intermittent hypoxic exposure (IHE) via CVACTM chamber on HRV in endurance trained athletes using autoregressive (AR) spectral analysis. Methods: Thirteen endurance trained subjects (four females; age 30.3 ± 8.9 years, nine males; age 30.1 ± 9.2 years) underwent an intermittent hypoxic conditioning protocol that involved increased exposure to altitude each week over eight weeks. Heart rate variability measures were taken in both supine and tilt positions pre and post altitude exposure to evaluate the acute effects, changes in acute effects over time, and chronic effects. Results: No significant differences were found in HRV using the AR spectral analysis (p>0.01). No negative effects of IHE on HRV were found. Conclusions: Intermittent hypoxic exposure delivered via CVACTM had no effect on HRV in endurance trained athletes when analyzed by the AR spectral analysis.
Identifying disparities in physical activity and body mass index in an understudied group of adolescents
(University of Hawaii at Manoa, 2006) Combs, Jan M.
Purpose: The objectives of this study were to provide descriptive data on body mass index (BMI) and pedometer-determined physical activity in a sample of Pacific Islander (PI) adolescents. Methods: A multiethnic sample of adolescents, a total of 171 (78 boys and 93 girls), in grades seven and eight, wore sealed pedometers for 6-8 weekdays. The ethnic composition of the sample was 64% PI (Native Hawaiian, Part Native Hawaiian, and Samoan) and 36% Non-Pacific Islander (Filipino, Black, Japanese, Portuguese, White, American Indian, Hispanic, Chinese, Indo-Chinese, and other). BMI was determined from height and weight. Participants were classified as normal, at-risk, or overweight using CDC BMI-for- age growth charts to obtain percentile ranking. Greater than or equal to the 95th percentile of BMI for each age and sex group was used to classify overweight participants. Results: The total sample (N= 171) accumulated 10,663 ± 4,200 steps/day. Boys (12,360 ± 4,271) accumulated approximately 3,000 more steps/day than girls (9,241 ± 3,583) (p=.001) and 8th grade (11,623 ±4,280) accumulated approximately 1,800 more steps/day than 7th grade (9,800 ±3,953) (p=.01). PI (IO,649±4,377) and Non-PI (IO,689±3,89S) accumulated similar steps/day. No significant differences were found on BMI between sex and grades. There were also no significant ethnic differences in BMI, however, 33.4% of the PI adolescents were classified as overweight compared to 23% of the Non-PI adolescents. Conclusion: Boys and girls were less active than U.S. counterparts, with the exception of 8th grade boys. The overweight prevalence among PI adolescents (33%) was more than double the national average (15%). Clearly, interventions are needed to reduce the prevalence of overweight in this population.
Comparison of the BodyGem, Harris Benedict prediction equation, and a metabolic cart on resting energy expenditure
(University of Hawaii at Manoa, 2006) Go, Kurt C.L.
The purpose of this study was to compare measurements of resting energy expenditure (REE) via indirect calorimetry using the BodyGem with measurements from a metabolic cart and the Harris-Benedict equation. Participants were 25 women (12) and men (13) aged 21-39 years who were tested on one occasion. Results indicated mean REE (kcal•day-I) for the metabolic cart, BodyGem, and Harris-Benedict equation were 1,321. 7, 1,280.5, and 1,609.7 kcal•d-1, respectively. Pearson correlation coefficients (r) were significant ranging from r=0.64 to r=0.98 for weight, height, and body mass index compared to REE measurements. There was a significant difference in mean REE between the metabolic cart and Harris-Benedict equation, but no significant difference between the BodyGem and the metabolic cart. Therefore, it was concluded that the BodyGem provided an accurate method to measure REE and the Harris-Benedict equation should not be used if other methods are available.
A descriptive study of body mass index and pedometer-determined physical activity of Guamnanian adolescents
(University of Hawaii at Manoa, 2006) Calvo, Frank D.
The purpose of the study is to examine physical activity and Body Mass Index (BMI) in Guamanian adolescents. Methods: A total of 192 adolescents, (105 Chamorro, 45 Filipino, & 42 Other) ethnicity in grades 6-8 wore sealed pedometers for 8 consecutive days. Height and weight measures was used to measure determine. Results: Boys (8537 ± 2698) accumulated approximately 1,200 (14%) more than girls (7369 ± 2343)(P<.01). No ethnic and grade main effect found in PA. Results indicated overweight status by sex. There were no significant differences found in BMI sex, grade, and ethnicity. Interaction (p < .01) main effect for boys normal weight group (9018 ± 2930) accumulated approximately 1,100 (12%) more steps/day than at-risk/overweight BMI group. In contrast, girls at-risk/overweight group (7826 ± 2617) accumulated approximately 700 (9%) more steps per day than normal weight group. Conclusion: Guamanian adolescents accumulated approximately 2,000-5,000 steps/day than the U.S. counterparts. The overweight prevalence of Guamanian adolescents (25%) was higher than the national average (15%). Further, interventions are needed to reduce the prevalence of overweight in Guamanian adolescents.
A descriptive study of physical activity and body mass index in Palauan adolescents
(University of Hawaii at Manoa, 2006) Calvo, Stephanie Ngirchoimei
Background: The purpose of the study was to examine physical activity and body mass index in Palauan adolescents using pedometers and BMI measurements. Methods: A total of 131 (63 females, 68 males; ages 10-14) middle school aged children from two accredited private schools participated in the study. The ethnicity group sample was 112 Palauans (85.5%), 11 Filipinos (8.4%), 7 Asians (5.3%) and 1 other (.8%). Participant's steps/day (eight days of monitoring) and height and weight measurements were obtained to determine Body Mass Index. Results: Boys (10800 ± 3167) accumulated approximately 2,800 (14%) more steps/day than girls (8000 ± 2967) (p<.01). No significant differences were found for the grade main effect and sex by grade interaction. There were no significant differences found in BMI between sexes, grades, and sex by grade interaction. Although there were no significant sex differences in BMI, approximately 29% of the boys were classified as overweight compared to 22% of the girls. It is evident that overweight disparities exist between Palauan boys and girls. Girls in the lean/healthy group acquired approximately 940 more steps/day (13%) than girls in the at-risk/overweight group. However, boys in the lean/healthy group accumulated 1400 steps/day (11 %) lesser than boys in the at-risk group. Conclusions: Palauan adolescents mean steps/day was 1900 (17%) lower when compared to national youth. We found a large disparity in overweight between boys and girls. In this study, 26% of the participants were overweight, which was 42% higher than the national average (15%).
Sprint biomechanics of female National Collegiate Athletic Association division track and field athlete
(University of Hawaii at Manoa, 2006) Tamura, Kaori
Sprinting success is achieved by a fast start such that maximal horizontal velocity can be achieved and maintained (Johnson and Buckley, 2000; Mann and Herman, 1985). Sprint velocity can be defined as the product of stride rate and stride length. Consequently, velocity can be increased by increasing stride rate or stride length or both; however, both factors are interdependent and individual morphologic and physiologic characteristics may influence the individual's motor abilities and utilization of the energy system (Coh et. al., 2001). It has been reported that world class sprinters demonstrate increases in stride length and stride rate, landing angle, thigh acceleration, trunk inclination, and decreases in components such as thigh angle and ground contact time (Kunz and Kaufmann, 1981). However, it is the ratio between the contact time and the flight time that is the most crucial factor in the kinematic structure of the sprinting stride. Successful sprinters demonstrated shorter contact phases and longer flight phases than less successful sprinters (Coh et. al., 2001). Reaction time, technique, electromyographic (EMG) activity, force production, neural factors, and musculoskeletal structures are other biomechanical factors that can influence sprint performance (Mero et. al., 1992). Hypothetically, successful sprinters must have the ability to exert large ground-reaction forces (GRF) in shorter time periods than a less successful sprinters (Alexander, 1989; Kunz and Kaufmann, 1981; Weyand et. al., 2000). Ground reaction forces are only achievable when the body is instantaneously in contact with the surface of the ground (contact phase). The contact phase can be divided into braking and propulsion phases according to the vertical movement of whole body center of gravity (CG) or the negative and positive horizontal reaction forces during foot contact (Luhtanen & Komi, 1978). The braking phase starts from initial foot contact to the lowest position of CG, during which the extensor muscles of the stance leg work eccentrically (Luhtanen & Komi, 1978; Miller, 1983). The velocity of the CG decreases following initial foot impact then the velocity increases during the subsequent propulsion phase (Cavanagh, 1980). It has been reported that the angle between the horizontal running surface and the line from CG to initial foot contact point (landing angle) can affect contact times and CG velocity during the braking phase. In order to minimize decreases in velocity during the braking phase it is crucial to keep the CG close to the point of initial foot contact at touchdown resulting in large landing angles. (Deshon & Nelson, 1964; Kunz & Kaufman, 1981) Payne (1983) reported that the type of foot contact influenced the braking force. He found that running with no heel contact demonstrated the absence of the first vertical force peak and smoother force/time patterns. This type of foot contact was mainly seen in 400 to 800 m specialists and should be considered mechanically more efficient than foot contacts causing high impact forces where the CG was behind the contact foot (Payne, 1983). Nett (1964) studied type of foot contact during sprinting and reported that running speed influenced ground contact. He reported that initial foot contact occurred on the lateral aspect of the 5th metatarsophalangeal joint, high on the ball of the foot. As the running speed decreased, the contact point shifted to a more posterior position, or toward the heel. This can be seen in the 400 m run, where the initial foot contact point shifts back toward the heel and foot plant is somewhat flatter. In distances greater than 1500 m, the initial foot contact occurs on the lateral edge of the longitudinal arch between the heel and the head of 5th metatarsal. Nett further noted that during the load-phase of the contact foot, the heel strikes the ground, even in the case of sprinters; especially when the sprinters are fatigued (1964). Conversely, Mann (1980) and Novacheck (1998) reported that the heel of sprinters did not or "may not" touch the ground throughout the sprint, and that initial ground contact was dependent on gait speed. Consequently, as speed increased initial contact changed from the hind-foot to the forefoot. This issue remains unclear because only five studies have involved examination of type of foot contact during sprinting and its effect on the biomechanics of sprint performance (Nett, 1964; Mann. 1980; Payne, 1983; Novacheck, 1995; Novacheck, 1998) Differences between levels of elite sprinters have been observed biomechanically (Alexander, 1989; Kunz & Kaufman, 1981; Luhtanen & Komi, 1978; Mann, 1981; Mann and Herman, 1985). However, present kinematic research generally does not extend to the influence of type of foot contact during the ground contact phase of the sprint gait cycle. Although two main biomechanical factors - stride length and stride rate - have been widely accepted by researchers as key factors in sprint performance, foot contact type during the contact phase is unclear and controversial. Therefore, the purpose of this research study was to investigate type of foot contact during the contact phase and its effect on the biomechanics of the 200 m sprint.
Overweight and non-overweight: adolescent attitudes toward physical activity
(University of Hawaii at Manoa, 2006) Taeu, Melissa M.
The purpose of this study was to investigate the attitudes overweight and non-overweight adolescents have towards physical activity as measured by the Children's Attitudes toward Physical Activity (CATPA) Inventory (Schutz & Smoll, Carre, & Mosher, 1985). Participants' (N=133) height and weight were measured and used to calculate their Body Mass Index (BMI). BMI was used to place participants into two groups, at-risk of overweight/overweight and non-overweight. Findings resulted in significant gender differences in the vertigo (F (1, 130) = 4.897, P = 0.029) and aesthetic (F (I, 130) = 5.970, P = .000) dimensions. These results suggested that boys had more positive attitudes towards the thrill and risk involved in physical activity whereas girls possessed more positive attitudes toward the beauty of movement in physical activity. Significant differences were also found between the at-risk of overweight/overweight and non-overweight groups in the social continuation (P = 0.016) and health and fitness enjoyment dimensions (P = .008). These results suggested that at-risk of overweight/overweight adolescents did not have favorable attitudes toward activities for their social nature or for the health benefits.
Effect of intermittent hypoxic exposure delivered via cyclic variation in altitude conditioning chamber on heart rate variability in aerobic athletes
(University of Hawaii at Manoa, 2006) McGrady, B. Kyle
In recent years, a focus of cardiovascular research has been heart rate variability (HRV). Heart rate variability has been defined as the beat-to-beat fluctuations in heart rate over time. In clinical studies, a low HRV has been related to increased risk of sudden cardiac death (Guzzetti et at., 2005). Analysis of HRV has been considered an effective, non-invasive method of assessing the circulatory system control~ as well as enabling a distinction between the sympathetic and parasympathetic components of the autonomic nervous system (Zuzewicz et at., 1999). Heart rate variability relies on a balance between the sympathetic and parasympathetic function, a\1owing for adjustments to heart rate when placed in changing environments. Because of the known changes that take place with acclimatization to altitude, athletes and scientists have had an interest in using attitude exposure to influence performance. Unfortunately, living at altitude is unrea1istic for most of the world's population, thus the use of attitude chambers have been tested for acclimati7mon to attitude. Altitude chambers a\1ow for short-term exposure to altitude on a regular basis, often referred to as Intermittent Hypoxic Exposure (IHE), and have been shown to elicit acclimatization responses (Ricart et at., 2000). According to a review by Levine (1997), nm is further classified into two subcategories, depending on the exposure time. One category, the "live-low train-high" method, receives exposure during exercise which enhances the training stimulus. The other category, the "live-high, train-low" method, receives exposure during rest which elicits the acclimatization effect. It has been reported that living and training at altitude has not been found very effective in improving performance at sea level (Wilber, 2001). Recently, however, Fulco et al. (2000) showed that living at high altitudes and training at lower altitudes (sea level) may result in the most beneficial combination to bring about the physiological changes to improve subsequent sea level performance in well-trained, competitive runners. It has been demonstrated and documented that changes in control of the autonomic nervous system occur due to altitude exposure; specifically, there is a sympathetic response, and subsequent a parasympathetic withdrawal, which is seen using spectral analysis of HRV (Zuzewicz et al., 1999; Roche et al., 2002). Hansen and Sander (2003), using direct measures of sympathetic activity, reported increased sympathetic activity at altitude versus sea level, and also reported increase sympathetic activity remained elevated 3-4 months after acclimation to altitude. Farinelli, et al. (1994) further investigated the changes due to altitude exposure and identified a desensitization of the heart to the sympathetic system because of the high sympathetic tone. When tested at altitude, acclimatized subjects, being unable to obtain an adequate sympathetic response, must call on a greater reduction in parasympathetic activity to compensate. Rodriguez, et al. (2000), reported that erythropoiesis was effectively stimulated after a relatively short exposure at rest, in a hypobaric chamber (90 minutes per day for 3 weeks at 5,500M); however, there is no indication of the amount of exposure needed to initiate changes in HRV. If IHE has a beneficial effect on HRV, then IHE may be a viable therapy for populations such as cardiac patients. To our knowledge, the effect of short-term intermittent cyclic hypoxic exposure on HRV has not been investigated. The purpose of this study is two-fold: 1) to investigate the acute effects of altitude acclimatization using the Cyclic Variation in Altitude Conditioning (CVACTM) chamber (described in detail below) on autonomic control of the heart during supine rest and a head-up tilt at sea level, and 2) to investigate the chronic effects of altitude acclimatization on HRV at sea level. It was hypothesized that: 1) there would be no significant differences in HRV variables at sea level immediately before or after cyclic nm (acute changes), and 2) there would be no significant differences in HRV variables at sea level due to nm throughout the 10 weeks of testing (chronic changes).
A feasibility study of cardiovascular risk factors in undergraduate female students at the University of Hawaiʻi at Manoa
(University of Hawaii at Manoa, 2006) Rote, Cindy
Every thirty-five seconds an American will die of cardiovascular disease (CVD), making it the leading cause of death in the United States since 1900 (American Heart Association [AHA],2006). In 2003, the American Heart Association (AHA) reported that 483,842 women and 432,245 men died of CVD in the United States. For the past twenty-two years, the number of CVD deaths for women bas exceeded those of males (AHA, 2004). With an aging US population, the number of women who will be affected by CVD will probably continue to exceed that of males. The primary means to decrease the incidence of CVD is to prevent the progression of the disease by modifying cardiovascular risk factors (CVRF). Modifiable CVRF include: high blood pressure, high blood cholesterol, cigarette smoking, obesity, physical inactivity, and diabetes mellitus. The AHA and federal programs such as the National Institute ofHea1th are making efforts to increase research in CVD in women to decrease the current health disparity between men and women (Wenger, 2004). In the past, most CVD research focused on white middle-aged males (Wenger, 2004). However, women and other minority groups have higher CVD mortality rates than Caucasians. African-Americans and Hispanics have been shown to have higher CVD rates than Caucasians (AHA, 2006). While Native Hawaiians have cardiovascular mortality rates that are almost five-times higher than combined national figures for all races (Contreras, 1999), and heart disease is the leading cause of death in Asian Americans and Pacific Islanders (AAPI) (Contreras, 1999). Native Hawaiian females have mortality rates above rates of all males in Hawai'i, except native Hawaiians and Caucasians (Hawai'i State Health Planning & Development Agency, 2001). Yet, only 0.2 percent of Federal health related grants have gone towards research in AAPI (Gosh 2003); therefore, further research on AAPI seems warranted. As of July 2004, the AAPI population was approximately 15 million and was estimated to grow to 41 million by the year 2050 (US Census, 2006 & 2001). Although Asian Americans and Pacific Islanders are the fastest growing race groups in the United States (US Census, 2001), cardiovascular disease data and research for AAPI are lacking (Ghosh, 2003). Accurate cardiovascular disease baselines for AAPI currently do not exist and are needed to further facilitate CVD research on AAPI women (Ghosh, 2003; Ro, 2002;Contreras, 1999). Asian Americans and Pacific Islanders make up 51% of Hawai'i's population, and Hawai'i has the largest concentration of AAPI in the United States (U.S. Census State & County Quick Facts, 2000). There is growing recognition that certain CVRF for CVD can be identified in young people many years before the onset of symptoms of CVD (Ford, et al., 2004). Serum cholesterol levels measured in a group of young males, mean age 22, showed a strong graded relationship with CVD later in life (Klag et al., 1993). This raises the possibility that CVRFs can be identified, modified, and the disease either prevented or delayed for both males and females. Reports of increasing rates of CVRF in young Americans was of concern, but was mostly based upon large studies which have fundamentally different populations than the ethnic mixture in Hawai'i. In most large epidemiological studies involving CVD, obesity and adiposity were commonly assessed with using body mass index (BMI) (kg/m2 ) or waist to hip ratio (WHR). Although easily calculated, the use of BMI or WHR may be misleading, as they only provide gross estimates of body composition. The use of anthropometric equations developed to estimate body composition could potentially give a better picture of the relationship between obesity and CVRFs. However, these methods tend to be population specific and most of the equations were developed for populations that are ethnically very different than those found in Hawaii. Asians have been shown to have a lower BMI and higher percentage of body fat than whites of the same stature and weight (Deurenburg et al., 2002; Wang, 1994). Polynesians with a BMI of approximately 25 kglm2 have a lower percentage of body fat than Europeans at the same BMI levels (Swinburg,1999). Therefore, using the BMI or WHR to study the relationship between obesity and CVRFs may not be suitable for the AAPI population. By comparing various body composition techniques with CVRFs it may be possible to obtain a clearer picture of the relationship between adiposity and CVRFs. There is a lack of data concerning the CVRFs in young women and specifically AAPI women. The University of Hawai'i at Manoa (UHM) was an optimal location to study CVRF in young AAPI women. There were 14,251 undergraduates enrolled at UHM, of which approximately 32% were AAPI females (UHM, 2005). The purpose of this pilot study was three-fold: 1) to create a CVRF profile for young AAPI women at the UHM; 2) to describe differences in CVRF among different ethnic groups within the undergraduate female population at the UHM; and 3) to evaluate body mass index (BMI), waist circumference (WC). waist to hip ratio (WHR), dual-energy x-ray absorptiometry (DEXA), skinfold (SKF), bioelectrical impedance (BIA) and an estimate of aerobic physical fitness as a means to better predict CVRF among the different ethic groups sampled. It was hypothesized that: I) ethnic difference would exist for CVRF. and 2) body composition measurements would account for a greater portion of the variance for selected CVRF than BMI.
Effect of intermittent hypoxic exposure delivered via cyclic variation in altitude conditioning chamber on anaerobic physical performance in well-trained athletes
(University of Hawaii at Manoa, 2006) Oba, Yukiya
Competitive endurance athletes often participate in altitude training in an effort to improve sea-level performance (Clark, Aughey, Gore, and Hahn, 2004). Traditional altitude training involves living and training continuously at high altitude, which was hypothesized to improve sea-level aerobic performance by stimulating the training intensity and the oxygen carrying capacity of the cell (Eckardt, Boutellier, Kurtz, Schopen, Koller, and Bauer, 1989; Mizuno, Bro-Rasmussen, Mygind, Schibye, Rasmussen, and Saltin, 1990). However, chronic continuous exposure to high altitude has been shown to compromise training intensity (Rusko 1996), thus the negative effects may offset the beneficial effects of altitude training (Levine and Stray-Gundersen, 1997). Moreover, access to high altitude exposure on a regular basis is limited and expensive (Levine, 2002). Intermittent hypoxic exposure (IHE) is defined as the discontinuous exposure to hypoxia, in an attempt to reproduce the adaptative effects of altitude without sustaining the reverse impact of chronic hypoxia (Levine, 2002). According to a review of the literature by Levine (2002), IHE can be further divided into two subcategories: 1) hypoxic exposure during exercise, where the main goal is to enhance the training stimulus (e.g., "live-low, train-high" methodology), or 2) hypoxic exposure at rest where the primary goal is to elicit the acclimatization effect (e.g., "live-high, train-low" methodology). Intermittent hypoxic exposure protocols have been administered at sea level with the use of nitrogen houses, hypoxic tents, or hypobaric chambers (Wilber, 2000). Study results indicate that IHE during exercise (Casas, Casas, Pages, Rama, Richard, Ventura, Ibanez, Rodriguez, and Viscor, 2000) or at rest (Rodriguez, Ventura, Casas, Casas, Pages, Rama, Richart, Palacios, and Viscor, 2000; Katayama, Sato, Matsuo, Ishida, Iwasaki, and Miyamura, 2004) can enhance aerobic performance without eliciting the negative effects seen in traditional altitude training. Intermittent hypoxic exposure has also been proven to stimulate, 'anaerobic' adaptation to altitude training as noted by increases in 100 m sprint swim times and muscle-buffering capacity (Martino, Myers, and Bishop, 1995). Intermittent hypoxic exposure while training physically has been shown to improve Wingate anaerobic test (WAnT) results of elite triathletes (Meeuwsen, Ingrid, Hendriksen, and Holewijn, 2000). However, conflicting results have been reported with this regimen after moderate- to high-intensity training under hypoxic conditions (Truijen, Toussaint, Dow, and Levine, 2003; Morton and Cable, 2005) as the improvement in performance may be attributed to the effects of the training regimen. Results of recent studies have revealed significant improvements in anaerobic performance following passive (rest) IHE (Nummela and Rusko. 2000; Gore, Hahn, Aughey, Martin, Ashnden, Clark, Granham, Roberts, Slater, and McKenna, 2001; Roberts, Clark, Townsend, Anderson, Gore and Hahn, 2001; Beidleman, Mum, Fulco, Cymerman, Ditzler, Stulz, Staab, Robinson, Skirinar, Lewis, and Sawka, 2003). However. performance improvement criteria were determined by 400 m sprint time (Nummela and Rusko et al., 2000), and four-minute all-out cycling performance, variables which were part of the sea level weekly training regimen (Nummela and Rusko et al., 2000). In the aforementioned studies, the "live-high, train-low" protocol involved "living" at high altitude for long periods of time (range = 8 to 16.5 hours daily). Rodriguez, et al. (2000), reported that erythropoiesis was effectively stimulated after relatively short exposures at rest, in a hypobaric chamber (90 minutes per day three weeks at 5,500 m). To our knowledge, the effect of short-term intermittent cyclic hypoxic exposure on anaerobic performance has not been investigated. The purpose of this study was to investigate the effects of intermittent cyclic hypoxic exposure at rest on 30-second maximal anaerobic performance variables. We hypothesized that: there would be no significant difference in anaerobic performances before and after cyclic THE delivered via the Cyclic Variation in Altitude Conditioning (CVAC) chamber.
Creatine phosphokinase levels in HIV-seropositive individuals after a single bout of isokinetic resistance exercise
(University of Hawaii at Manoa, 2006) Heeter, Andrea
Context: Human Immunodeficiency Virus (HIV) is a life long immunosuppressive disease that leads to aerobic and anaerobic deconditioning, and diminished capacity to function independently in society, Acquired Immunodeficiency Syndrome (AIDS), the risk of AIDS wasting, and death. Normal elevations of creatine phosphokinase (CK) in HIV-Seropositive individuals, even at rest, are not consistently associated with varied symptoms of the disease; however it is the most reliable muscle damage quantifier. Additionally, investigation of an acute high-intensity resistance exercise bout on HIV -Seropositive individuals is limited and may be detrimental to HIV-Seropositive individuals by suddenly activating the immune system, thereby increasing HIV replication Objective: To investigate the effects of a single bout of high-intensity concentric resistance exercise and CK in the HIV -Seropositive population. Design: Data were analyzed using analysis of variance (ANOVA) for peak torque (PT) knee flexion and extension, body mass index (BMI), and percent body fat, 2 x 5 repeated measures ANOV A for CK levels, and 2 x 3 repeated measures ANOV A for number of repetitions to 50% fatigue per set. Setting: AIDS clinic and University athletic training lab Participants: 13 HIV -Seropositive participants (two females and eleven males; age = 44.5 ± 8.5 years, 8MI = 25.2 ± 3.7) and six HIV-negative participants (one female and five males; age = 40.5 ± 4.0 years, 8MI = 30.7 ± 2.5). Intervention(s): Participants performed three sets of isokinetic knee flexion and extension to 50% fatigue on the 8iodex 3 systems. Main Outcome Measure(s): Serum CK levels pre-test and post-exercise at 24, 48, 96, and 168 hours. Peak Torque knee flexion and extension, number of repetitions to fatigue, 8MI, and percent body fat were measured pre-exercise. Results: No differences were revealed in CK levels regardless of group (P = 0.09) and no interactions between groups and CK collection times (P = 0.66). No difference in PT flexion or extension for the HIV-Seropositive (54.2 ± 22.2 and 95.4 ± 37.8 respectively) and the HIV-Negative (124.7 ± 41.9, P = 0.15 and 70.2 ± 19.4, P = 0.15) groups. Percent body fat and 8MI were significantly lower in the HIV-Seropositive group (25.2 ± 3.7, P = 0.01; 25.4 ± 7.8, P = 0.02) than the HIV-Negative group (30.7 ± 2.7; 34.4 ± 4.7). Conclusions: A single acute bout of anaerobic concentric resistance exercise did not sufficiently cause a significant increase in CK levels in HIV -Seropositive individuals.
Can microcurrent electrical neuromuscular stimulation decrease symptoms associated with delayed onset muscle soreness?
(University of Hawaii at Manoa, 2005) Wolff, Toby
Traumatic injury typically presents with the five cardinal signs of inflammation 'secondary to the release of histamine and norepinephrine. These chemical mediators increase capillary permeability, allowing exudate high in proteins and leukocytes, and phagocytic cells to destroy, and marginize damaged tissue. Injured tissues are electropositive but become electrical negative in the early stages of the healing process. These processes are dependent on membrane' permeability and active transport across the cell membrane (prentice, 1999; Starkey, 1999) Active transport theoretically increases with microcurrent electrical neuromuscular stimulation (MENS) thereby re-establishing the body's natural electrical balance resulting in adenosine triphosphate (ATP) replenishment and providing the metabolic energy necessary for healing to occur (Starkey). The biophysical efficacy of MENS (<500 µA) is based on the theory that currents less than 500 µA increase ATP levels while currents greater than µA decrease ATP levels. Currents less than 500 µA create a proton imbalance forcing them across the mitochondrial membrane, as they move from anode to cathode, causing an increase in the production of ATP (Baily, 2003; Starkey, 1999). Successful treatment of fracture and wounds using MENS is well documented (Assimacopoulos, 1968; Carley & Wainapel, 1985; Feedar et al., 1991; Gault & Gatens, 1976; Gentzkow et al., 1991; Mulder, 1991; Wolcott et al., 1969; Wood et al., 1993) These studies involved placing the cathode directly over the fracture site or ulcer in wound healing (Brighton et al., 1981; Connolly et al., 1997; DC Paterson et al., 1982). Conversely, MENS treatment of delayed onset muscle soreness (DOMS) is inconclusive, controversial, anecdotal and limited(Allen et al., 1999; Bonacci & Higbie, 1997; Lambert et al., 2001; Weber et al., 1994) Delayed onset muscle soreness is a soft tissue injury characterized by the disruption of the cell membrane and active transport system resulting in decreased ATP production and streaming of the Z-lines in type IIB muscle fibers (Friden, 1984; Newham et al., 1983), All but one (Lambert et al., 2001) of the aforementioned studies involved treatment with alternating polarity (Bonacci & Higbie, 1997; Denegar et al" 1992; Weber et al., 1994) or didn't specify (Allen et al., 1999) over the injury site during the treatment period, Conversely, Lambert was the only investigator who placed the cathode (negative) over the injury site, AdditionaI1y~ Lambert and Bonacci utilized extended treatment periods (96 continuous hours, 8 continuous hours, respectively), Therefore the purpose of this study was to examine the effect of MENS treatment protocols typically used in athletic training clinical practices with specific attention to polarity, The hypothesis for this study was that there will be no difference among MENS treatments relative to pain, edema, and range of motion and muscle strength associated with DOMS,

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