Biomedical subjects

Jeni R McNeal

Publications and source records attributed to Jeni R McNeal.

6 recordsLinked to original sources

PubMed2006

Stretching for performance enhancement.

Stretching exercises have been considered an essential component of physical training programs for decades. Cross-sectional studies have demonstrated that flexibility measures are related to performance in many sports, suggesting that using stretching to enhance flexibility may indirectly improve performance. However, observations by athletes and coaches have called into question the universal prescription of stretching for the purpose of enhancing sport performance, and this skepticism is being supported by a growing body of empirical data. Whereas the tissue responses and adaptations to stretching have been the most widely studied area of stretching research, comparatively little is understood regarding the neural influences on range of motion, which may have more applicability when the range of motion needs are related to skilled movements as in sport.

Biomechanical Phenomena↗

PubMed2006

Flexibility enhancement with vibration: Acute and long-term.

INTRODUCTION: The most popular method of stretching is static stretching. Vibration may provide a means of enhancing range of motion beyond that of static stretching alone. PURPOSE: This study sought to observe the effects of vibration on static stretching to determine whether vibration-aided static stretching could enhance range of motion acquisition more than static stretching alone in the forward split position. METHODS: Ten highly trained male volunteer gymnasts were randomly assigned to experimental (N = 5) and control (N = 5) groups. The test was a forward split with the rear knee flexed to prevent pelvic misalignment. Height of the anterior iliac spine of the pelvis was measured at the lowest split position. Athletes stretched forward and rearward legs to the point of discomfort for 10 s followed by 5 s of rest, repeated four times on each leg and split position (4 min total). The experimental group stretched with the device turned on; the control group stretched with the device turned off. A pretest was followed by an acute phase posttest, then a second posttest measurement was performed following 4 wk of treatment. Difference scores were analyzed. RESULTS: The acute phase showed dramatic increases in forward split flexibility for both legs (P < 0.05), whereas the long-term test showed a statistically significant increase in range of motion on the right rear leg split only (P < 0.05). Effect sizes indicated large effects in all cases. CONCLUSION: This study showed that vibration can be a promising means of increasing range of motion beyond that obtained with static stretching in highly trained male gymnasts.

Biomechanical Phenomena↗

PubMed2005

Anthropometric and physical abilities profiles: US National Skeleton Team.

The aim of this study was to characterize sprint ability, anthropometry, and lower extremity power in the US National Team Skeleton athletes. Fourteen athletes (male n = 7; mean +/- SD: height 1.794 +/- 0.063 m, body mass 81.2 +/- 3.7 kg, age 26.9 +/- 4.1 years; female n = 7; 1.642 +/- 0.055 m, 60.1 +/- 5.9 kg, 27.3 +/- 6.9 years) volunteered to participate. Sprinting ability was measured over multiple intervals using custom infrared timing gates in both an upright and a crouched sprint. The crouched sprint was performed while pushing a wheeled-simulated skeleton sled on rails on an outdoor skeleton and bobsleigh start track. Crouched skeleton sprint starts were able to achieve about 70% to 85% of the upright sprint times. The mean somatotype ratings for females were: 3.5-3.5-2.1, and males: 3.6-4.9-1.9. Lower extremity strength and power were measured via vertical jumps on a portable force platform using squat and countermovement jumps, and jumps with added mass. Jump height, power, rate offorce development and peak force were determined from force-time data. Lower extremity strength and power were strongly correlated with both upright and crouched sprint times. The results indicated that these athletes are strong sprinters with varying body structures, mostly mesomorphic, and that stronger and more powerful athletes tend to be better starters.

Adult↗

PubMed2005

Plaudits and pitfalls in studying elite athletes.

The study of elite athletes, because of their rarity, renders statistical power difficult to achieve, control groups difficult or impossible to find, and generalizability difficult to demonstrate. Alternative methods of analysis may be better suited to such study.

Humans↗

PubMed2004

Comparison of the Wingate and Bosco anaerobic tests.

The purpose of this study was to compare the Wingate cycling and Bosco repeated jumps anaerobic tests. Eleven men (21.36 +/- 1.6 years; 179.1 +/- 9.3 cm; 78.7 +/- 11.0 kg) and 9 women (21.89 +/- 3.66 years; 171.8 +/- 10.0 cm; 75.9 +/- 21.4 kg), all university athletes, volunteered to participate. Subjects performed each test in random order. The tests consisted of a 30-second Wingate test and a 60-second Bosco test. The Wingate test was conducted using a Monark cycle ergometer and the Bosco test was conducted on a force platform. Following the performance of each test, peak lactate concentrations were determined. Average and peak power values were statistically greater in men and on the Bosco test. Peak lactate values were statistically greater in men but did not differ based on test. Correlations between peak lactate concentrations between tests and lactate values with peak or average power were not statistically significant. The relationship between peak power between tests was statistically significant among men, but not women. The results of the study indicated that the Bosco and Wingate tests, which both measure anaerobic characteristics, appear to measure different aspects of anaerobic power and capacity. The Bosco test also may be inappropriate for athletes who are not well trained in jumping.

Adult↗

PubMed2002

A kinematic comparison of four abdominal training devices and a traditional abdominal crunch.

Abdominal exercises are often performed on roller or rocker mechanisms, which have been aggressively promoted through the television and print media. However, justifications are lacking as to why these devices are superior to traditional abdominal exercises such as crunches. This study sought to describe and compare the range of motion (ROM) of several joints during crunches performed on 4 different abdominal conditioning devices (2 roller and 2 pivot types) and a traditional crunch exercise. Ten men (29 +/- 5.87 years, 177.5 +/- 6.46 cm, 80.96 +/- 11.72 kg) and 10 women (33.4 +/- 10.16 years, 162.23 +/- 3.83 cm, 56.99 +/- 7.36 kg) subjects agreed to participate in the study. Subjects were videotaped in the sagittal plane (60 Hz) using standard kinematic methods. Reflective markers were placed on the right temple, auditory meatus, shoulder, hip, knee, ankle, heel, toe, and 2 sternum markers placed on a foam piece strapped to the subject's chest. The videotaped movements were automatically digitized (PEAK5 2-D) and the data smoothed using a Butterworth filter. Relative angular ROMs of the head (temple, auditory meatus, shoulder); neck (auditory meatus, shoulder, hip); trunk (near sternum, shoulder, hip); hip (shoulder, hip, knee); sternum/head (sternum near and sternum far with temple and auditory meatus); sternum/trunk (sternum near and sternum far with shoulder and hip); and a sum of 4 angles (head, neck, trunk, hip) were calculated. Sex by equipment repeated measures analyses of variance (ANOVAs) were calculated on the angles of the 5 exercises. When no main effect for sex was found, the data were collapsed across sex and a one-way ANOVA with repeated measures was calculated on the resulting data. Post hoc analyses of pairwise differences were calculated using Tukey's honestly significant difference statistic. Results showed that crunches performed with the abdominal devices resulted in less ROM in all angles measured when compared with a traditional crunch. The traditional crunch exercise was most closely simulated by the pivot-type devices. The results indicated that prescription of abdominal conditioning exercises via these devices results in training through smaller ROMs compared with a traditional crunch. The specific angle changes may require careful judgment as to appropriate application for exercisers with specific back and neck motion limitations.

Abdominal Muscles↗