Swimming Start Research Articles

Ability Of Competitive Swimmers To Modify Start Depth Is Not Dependent Upon Age

PURPOSE: There is a distinct paucity of research relating to safety concerns in competitive swimming starts. The purpose of this study was to expand upon the existing literature by examining the ability of competitive swimmers of different ages to modify on request the maximum head depth achieved during a competitive swimming start. METHODS: Fourteen swimmers aged 10 years and under (age = 7.9 ± 1.3 years, height = 1.29 ± 0.10 m, mass = 30.94 ± 6.6 kg), ten 11-12 year old swimmers (age = 11.3 ± 0.5, height = 1.48 ± 0.06 m, mass = 42.9 ± 6.1 kg), and eighteen 13-14 year old swimmers (age = 13.5 ± 0.5, height = 1.62 ±.06 m, mass = 54.0 ± 6.3 kg) were filmed underwater during execution of two competitive starts. All subjects were members of a USA Swimming sanctioned swim club. Swimmers completed one start and a subsequent freestyle sprint without instruction. Prior to the second start the swimmers were asked to make the start as shallow as possible while still completing the sprint. For each start, the maximum depth of the center of the head was determined using 2D DLT analysis. RESULTS: A two-way mixed design ANOVA for maximum depth of the center of the head yielded no interaction between instruction and age group, but significant main effects for both instruction (F1,39 = 16.6; p < 0.01) and age group (F2,39 = 5.4; p = 0.08). As there was no significant interaction between instruction and age group, the 10&U, 11-12, and 13-14 groups were combined in an analysis of the ability to modify depth. When instructed to dive shallowly, the maximum head depth decreased significantly (p<0.01) from 0.56 ± 0.03 m to 0.45 ± 0.02 m. Similarly, the uninstructed and instructed groups were combined in an analysis of the age groups. The maximum head depth was significantly greater (p =.006) for 13-14 year olds (.58 ±.03 m) than for 10&U swimmers (.42 ±.04), but neither group was different with respect to maximum head depth from 11-12 year olds. CONCLUSIONS: Swimmers 14 years of age and younger possess the ability to modify competitive start depth on command. However, from a safety perspective, it is important to note that not all swimmers successfully modified their competitive start depth. Supported by a grant from USA Swimming

The Anti-fatigue Effects of the Low-Molecular-Weight Fraction of Bonito Extract in Mice

Bonito extract (BE), a hot-water extract of bonito muscle, has traditionally been considered as a folk remedy for fatigue. In this study we investigated the effects of BE on physical fatigue. BE was divided into, high, mid, and low-molecular-weight fractions (LMF), to explore the effectiveness of BE compounds. The swimming times to exhaustion of mice administered 0.86 g/kg BE and those administered 0.86 g/kg LMF were significantly longer than those of the vehicle-treated mice in a forced swimming model, indicating that BE possesses an anti-fatigue effect and that the LMF contributes to this effect. The LMF was also confirmed to aid the recovery of locomotor activity after physical fatigue in a forced walking model. We also examined respiratory gas levels and found that oxygen consumption and lipid oxidation were significantly greater in the group administered LMF than in the vehicle group, indicating that LMF promotes the utilization of fatty acids as an energy source. To elucidate why the mice administered LMF showed an anti-fatigue effect, we evaluated metabolic variables during exercise. The concentrations of nonesterified fatty acids and ketone bodies were higher, whereas serum and muscle lactic acid levels were lower in the mice administered LMF than in those in the vehicle group after the start of swimming. When the results were taken as a group they indicated that the effect of BE administration on improving endurance capacity was mediated, at least partly, by an increased utilization of lipids as a source of energy during exercise.

The Times They Are A-Changing

Sometimes, when I find myself unable to articulate the essence of a period in time, I turn to the lyrics of one of the great musical talents of the past century. During the tumultuous 1960s, Bob Dylan wrote “If your time to you; Is worth savin; Then you better start swimming; Or you'll sink like a stone; For the times they are a-changin.” Little did he know that less than two years later, he would be pressured into a fundamentally radical change that would alter the course of his professional life and the music industry as he knew it. It was a change of technology—the switch from acoustic guitar to the irresistible twang of an electric guitar.Much like the technological and cultural changes that Dylan and others wrote about, the clinical engineering world is transitioning right in front of our noses. Advancements in medical technology and the recent demand for an increasing knowledge of IT systems design and analysis very closely resembles the uncertainty and conflict surrounding the introduction of electrical guitars into the folk/rock music scene of Dylan's time. Moreover, like Dylan we are presented with a choice that will impact our careers and our field. Do we, as clinical engineers, stand firm in our familiar and established scope of work and responsibilities or do we have an obligation to shift our priorities as the technology changes around us?While I will not pretend to know the one right answer, I will make the observation that as the line between CE and IT becomes increasingly ambiguous, it is all the more necessary that we continue to justify the importance and critical impact of the work we do. To do this, of course, we need to recognize that the demand for our services and the required knowledge base is a-changing. The language of CE is changing right before us and many will soon find themselves unable to “talk the talk” if we do not expand our knowledge base immediately.There is good news! As Rick Schrenker notes, there are countless resources available that will translate the evolving language for clinical engineers at all levels. If we plan to stay ahead of the curve, it is important that we schedule time in our busy days to learn about new technologies and techniques by studying textbooks and articles published by IEEE, FDA, AAMI, and related organizations. These institutions are devoted to providing CEs with guidance and information about the latest advancements in the field. They will not only keep us abreast to new and exciting news in the medical technology industry, but they will also guide us through evolving CE challenges like music notes on a page. If CE intends to remain a critical establishment in the clinical arena, it is imperative that we take the time to learn.When Bob Dylan first appeared at the Newport Folk Festival in 1965 with his electric guitar in hand, the change was not well accepted by all. Many fervent lovers of the acoustic folk traditions refused to accept his new sound and booed and sneered during his performances. Standing by his standards and artistic expectations, however, Dylan took a chance and did what he felt was the best move for his career. He later went on to further develop his folk style and his poetically eccentric lyrics but with his newly adopted sounds, eventually producing some of his life's greatest works. Like Dylan, the clinical engineering arena needs to stand firm in maintaining the same level of standards and objectives, but accomplish them using a different sound, no matter how many sentimentalists resist the change. If we plan to embrace the electric guitar, we must learn to play it before we can take the stage.

수영과 핀수영 스타트 동작의 운동학적 비교

수영과 핀수영의 스타트 동작의 운동학적 변인들을 3차원 영상분석법으로 비교분석하였다. 수영 스타트에서는 상지는 후상방으로 몸통은 전상방으로 이동했다가 전하방으로 하강하는 양상을 보인 반면 핀수영 스타트에서는 모든 분절이 전하방으로 이동하는 양상을 보였다. 수영 스타트에서 신체중심은 멀리 전방으로 수평 이동하다가 하방으로 급격히 이동하는 반면 핀수영 스타트에서의 중심은 짧은 시간에 전하방으로 가깝게 이동하는 것으로 나타났다. 입수 시 수영의 중심은 수직 속도가 핀수영의 중심은 수평속도가 높게 나타났다. 수영과 핀수영 모두 상지의 속도가 하지보다 더 신체중심의 속도에 영향을 미치는 것으로 나타났다. 핀수영 스타트에서 고관절은 점프 전에 굴곡을 하는 반면 수영에서는 점프 후 공중에서 2번 굴곡을 하는 것으로 나타났다. 핀수영의 슬관절 굴곡 신전운동이 수영보다 더 급격한 것으로 나타났다. The kinematic variables for swimming and fin-swimming start motions were analyzed and compared using 3-dimensional cinematography. For the swimming start, the arm segment moved towards the upper rear and trunk towards the upper front followed by a descent towards the lower front, while the fin-swimming start motion showed movement towards the lower front for all segments. The total body center of gravity for the swimming start showed horizontal movement far to the front followed by a rapid descent while the fin-swimming start showed close movement towards the lower front in a short period of time. Upon entering the water, the center of gravity for swimming showed high vertical velocities while fin swimming had high horizontal velocities. For both swimming and fin swimming, the upper extremity velocity had more influence on the total center of gravity velocity than the lower extremities. Flexion of the hip joint was observed before the jump for the fin swimming start while the swimming start showed two flexions in mid-air succeeding the jump. The flexion and extension movements at the knee joint during the fin-swimming start motion were shown to be larger and more rapid than those of fin-swimming.

Swimming behaviour of Schistosoma mansoni cercariae: responses to irradiance changes and skin attractants

The swimming behaviour of many cercarial species is governed by sensitive responses to light and dark stimuli. We studied the effect of irradiance changes on swimming behaviour of Schistosoma mansoni cercariae and found only insignificant responses. Decreasing light intensity results in a weak tendency of the cercariae to start swimming movements, and increasing light intensity tends to inhibit the start of swimming. These responses seem not suitable to increase the transmission success. Whether the cercariae show chemo-orientation towards human skin was studied by video-tracking their swimming movements around agar containing human-skin-surface extracts and when immersed into skin extracts. They showed no directed chemotactic orientation, as they did not correct their swimming paths in direction towards the skin-extract substrates, also not when shifting between forward and backward swimming. However, the cercariae shifted more between backward and forward swimming and therewith increased their rate of change of direction. This response may support an accumulation around the skin substrates and could guide the cercariae towards the host's skin surface when they are already in close proximity to it.

Kinematics of fast start swimming in a pelagic fish, the mackerel Scomber scombrus

Kinematics of fast start swimming in a pelagic fish, the mackerel Scomber scombrus

Choral Conducting: Philosophy and Practice, and: A Handbook for Beginning Choral Educators (review)

Reviewed by: Choral Conducting: Philosophy and Practice, and: A Handbook for Beginning Choral Educators Mary Rose Adkins Choral Conducting: Philosophy and Practice. By Colin Durrant. New York: Routledge, 2003. [204 p. ISBN 0-415-94357-4. (pbk.) $24.95.] Photographs, illustrations, bibliography, index. A Handbook for Beginning Choral Educators. By Walter Lamble. Bloomington: Indiana University Press, 2004. [ix, 145 p. ISBN 0-253-34434-4. $39.95.] Appendices. In his two-part book, Choral Conducting: Philosophy and Practice, Colin Durrant presents his philosophy and approach to choral conducting by citing numerous studies and books on the subject. By dividing the book into two sections titled "Philosophy" and "Practice," the author provides a logical sequence for the reader. In the first section, consisting of six chapters, Durrant cites several philosophers that he has found relevant to conducting and singing. After a thorough examination of the concepts, the second section of the book, consisting of five chapters, provides suggestions for putting these ideas into practice. Durrant does not focus on a particular type of choir or age of singer; rather he suggests that these concepts are applicable to all types of choral groups. In chapter 1, Durrant explains the purpose of the book as a support for courses in conducting, but not as a how-to text that isolates theory from people. He states that "conductors help us to connect the creations of composers to our own lives" (p. 7). Durrant introduces the idea that learning to swim and learning to sing have common elements. He encourages the reader to "start swimming with effective and efficient strokes" (p. 10) by reading the text in its entirety to facilitate reflection and consideration. Chapter 2, "Human Learning and Behavior," begins with a look at the brain and its potential. Durrant emphasizes that the brain does not exist without the body; thus the term "bodymind" is introduced as the basis for the holistic approach to conducting that is prevalent throughout the book. This chapter also presents conditions for learning, comparing human-compatible and human-antagonistic approaches. The common negative approach of spotting only the mistakes in the singing as a sign of the conductor's ability is an example that most choral conductors can understand. Durrant believes that the activity of singing should be pleasant and non-threatening, and it is the responsibility of the conductor or teacher to create that environment. Chapter 3 attempts to answer the question "Why do people sing?" (p. 36). Research studies cited in the chapter indicate that the social benefits and the bonding with a group are as important to the singer as the actual experience of singing. Therefore, in chapter 4 Durrant expands on the idea that the role of the conductor is to connect. This chapter provides an historical perspective on conducting to show that personality and behavioral traits have influenced the evolution of conducting into what it is today. The last two chapters of the philosophical section of the book bring all the theories to a conclusion with the author's own model for an effective choral conductor. Durrant's model includes philosophical principles, musical-technical skills, and interpersonal skills. An extensive chart defines the skills and abilities required for each category. The second section of the book covers the practical aspects of conducting, such as rehearsing, conducting gestures, and the development and health of the voice in all ages. In chapter 7, Durrant offers his own eight-part model of effective choir rehearsing and conducting, while chapter 8 includes a description of conducting gestures with photographs and journal entries by Durrant's own students on their observations of the conducting styles of various conductors. In chapter 9 Durrant cites research on the changing voice, both male and female, including range charts and characteristics of the voices. He also includes the aging voice in this chapter, and his understanding of this group is insightful and shows [End Page 1023] compassion and kindness. In chapter 10, Durrant presents course outlines for both initial and advanced conducting courses. The last chapter, appropriately titled "Last Movement," returns to the swimming metaphor introduced in chapter 1. Durrant summarizes his personal belief that conductors influence the musical and emotional lives of...

Maximum Hand, Head, Knee, And Toe Depths During The Competitive Swimming Start Differ With Race Distance

Maximum Hand, Head, Knee, And Toe Depths During The Competitive Swimming Start Differ With Race Distance

Maximum Hand, Head, Knee, And Toe Depths During The Competitive Swimming Start Differ With Race Distance

Maximum Hand, Head, Knee, And Toe Depths During The Competitive Swimming Start Differ With Race Distance

Physical Space for Virtual Services and Collections

Physical Space for Virtual Services and Collections Lynn Silipigni Connaway (bio) When discussing the information environment and how information is used, they cannot be better described than by the words of Bob Dylan in the song, "The Times They Are A-Changin": If your time to you is worth savin' Then you better start swimmin' Or you'll sink like a stone For the times they are a-changin'. As librarians, we need to understand better how people are acquiring and using information—"start swimming," or we may "sink like a stone." Users from the Alexandrian Library in 331 BC would easily recognize that they were in today's modern library. The physical attributes of the collection would be different, but they would know they were in a library. What happens to the library as place when the collection becomes increasingly electronic? New libraries continue to be built—to house the libraries' physical collections, provide access to electronicmaterials, and serve as a physical place where people come to read and to study. Fifteen years ago new libraries were being built to accommodate public access terminals. It was rare to see a user with a portable computer. Now that libraries and campuses are wired, the user is becoming unwired. What is the future of the library as a physical space? In 2003, Grant Gross reported that five billion gigabytes of data were generated in 2002, equaling 800 megabytes per person or enough data to fill 500,000 Library of Congresses. Of these data, 92 percent were stored magnetically on hard drives. Between [End Page 127] 1999 and 2002 the amount of magnetically stored data increased 80 percent, and the amount of physically stored data increased 43 percent. Yet, Americans consume 11,916 sheets of paper a year, and Europeans consume 7,280 sheets of paper a year.1 The notion of the "paperless society" has not materialized. Indeed, content that is accessed electronically is often printed for use. Therefore, in order to provide services and resources, including physical space, it is necessary to understand what types of information are being used, how that information is being used, and by whom. Information Use and Physical Space Studies One of the user communities that has embraced electronic information delivery most enthusiastically is the health science information community. Several recent studies of health information use may provide a clue where other disciplines are headed in terms of user needs, which will have an impact on planning for library space. An online survey of 2,000 adults aged 18 or older was conducted by the Pew Internet and American Life Project to determine whether and how they use the Internet to gather health and medical information. The report indicates that80 percent of adult Internet users (93 million Americans) searched for at least one of 16 health topics online. This is an 18 percent increase from a previously conducted study by Pew. The study reports, "Looking for health or medical information is one of the most popular activities online, after using e-mail (93 percent of adult users), and researching a product or service (83 percent)."2 Those seeking online health information believe that their health information and services improve; and their relationships with their doctors change, because of their newly gained knowledge of the subjects. Online groups and e-mail provide a support network for those who seek consumer health information.3 In the academic world, Brinley Franklin and Terry Plum examined the usage of networked electronic services in four health sciences libraries during a six-year period. In these libraries there are more than five remote users for each in-library user among the faculty, staff, and research fellow groups. Grant-funded research "accounted for approximately 32 percent of the networked electronic services activity at the health sciences libraries and 16 percent at the main campus libraries."4 For researchers with grant-funded projects, networked electronic services appeared to be used more from on-campus than from inside the library.5 In a recent Pew Internet and American Life study, Deborah Fallows reported, "Most Internet users still default to the traditional offline ways of communicating, transacting affairs, getting information, and entertaining themselves. ... The Internet...

Expression of a Reflex Biting/Snapping Response to Amino Acids Prior to First Exogenous Feeding in Salmonid Alevins

VALENTINČIČ, T., C. F. LAMB AND J. CAPRIO. Expression of a reflex biting/snapping response to amino acids prior to first exogenous feeding in salmonid alevins. PHYSIOL BEHAV 67(4) 567–572, 1999.—Five days prior to first exogenous feeding, amino acid stimuli released reflexive biting/snapping behavior in alevins of both rainbow trout ( Oncorhynchus mykiss) and brook trout ( Salvelinus fontinalis). The biting/snapping responses of salmonid larvae, which obtain nutrients solely from their yolk sacs, were videotaped during presentations of amino acids that are potent olfactory and taste stimuli to adult rainbow trout. The tested salmonid alevins possessed developed eyes and olfactory and taste organs several days prior to the start of spontaneous swimming and exogenous feeding. Five days prior to the first occurrence of complex feeding behavior, l-proline and l-alanine, which released swimming, turning, and biting/snapping (exaggerated biting) behaviors in adult rainbow trout, triggered reflexive biting/snapping behavior in the alevins of rainbow and brook trout, but did not induce swimming. In contrast, l-proline released vigorous swimming, but not biting/snapping activity in alevins of the European freshwater huchen ( Hucho huncho), another salmonid species. Unlike in adult rainbow trout where visual and olfactory stimuli control all the successive behavior patterns of feeding behavior, taste stimuli released in alevins of rainbow and brook trout the early biting/snapping reflex independently from the complex feeding behavior. The independent biting/snapping reflex of rainbow and brook trout alevins ceased at the onset of spontaneous swimming activity several hours prior to the first exogenous feeding.

A Multidisciplinary Investigation of the Relation of State Sport Confidence with Preference and Velocity of Swimming Starts

This study investigated the relations of state sport confidence with preference of swimming start, i.e., pike or flat, and vertical velocity for male and female NCAA Division I swimmers. Ten male and 10 female swimmers who had a minimum of five years competitive swimming experience participated. Men generated greater vertical velocity on both the pike and flat starts. Analyses of variance indicated a relationship foc gender with the most confident swimming start and vertical velocity for the pike and flat starts. In addition, a significant interaction between gender, preferred swimming start, and most confident swimming start was found. Discriminant function analysis using gender as the grouping variable and the dependent variables of vertical velocity and state sport confidence indicated that gender was an indicator of swimmers' performance and state sport confidence on the pike and flat starts.

Central circuitry in the jellyfish Aglantha. I: The relay system

1. The relay system is an interneuronal pathway in the margin of the jellyfish Aglantha digitale. It excites a second interneuronal pathway, the carrier system, and is itself excited by pacemaker neurones concerned with slow swimming. It also excites a slow conduction pathway in the tentacles causing graded, tonic contractions of all the tentacles during slow swimming. 2. The pacemakers, the carrier system and the relay system all contribute to the production of excitatory postsynaptic potentials (EPSPs) in a giant axon that runs in the outer nerve ring (ring giant axon). These EPSPs may cause the latter to spike during slow swimming. If it does so, it will fire tentacle giant axons, producing twitch contractions of the tentacles. Such contractions probably help to contract the tentacles rapidly at the start of slow swimming. This is an unusual case of a giant axon that normally mediates escape behaviour being appropriated for use during a non-escape activity. 3. The relay system can conduct impulses on its own but their conduction velocity is greatly increased when preceded by either pacemaker or ring giant spikes. This phenomenon, termed the 'piggyback effect', may be due to extracellular field effects rather than to actions mediated by chemical or electrical synapses. 4. Recordings from the epithelial cells that ensheath the ring giant and outer nerve ring neurones show miniature synaptic potentials and other events that seem to reflect events in the nervous system, but no functions can be assigned to them. 5. There is no obvious counterpart to the relay system in medusae lacking escape circuitry.

Effects of site of tactile stimulation on the escape swimming responses of hatchling Xenopus laevis embryos

Hatchling Xenopus laevis embryos usually swim when the skin is touched with a fine hair. Less common are small, local V‐flexions and more general C‐flexions. Simple flexions or the initial flexion at the start of swimming occur predominantly on the opposite side to the stimulus to direct the animal away from the stimulus. Strokes to the midline lead to random sidedness of responses.The reliability of the sidedness of flexions and the first flexions of swimming decreases the more rostrally the stimuli are given. The range of directions of swimming paths are larger with more rostral stimuli so responses to head stimuli are unpredictable in direction.In animals immobilized in α‐bungarotoxin, strokes to the skin produce electrically recorded motor output which corresponds to: V‐flexions, C‐flexions and swimming. Fictive activity generally starts on the side opposite to the stimulus. The fictive responses suggest that the three basic behaviour patterns observed can be generated entirely within the central nervous system without any sensory feedback.We discuss possible mechanisms for the generation of ‘protean’ responses to head stimulation which are unpredictable in direction.

Changes in cardiac rhythm in man during underwater submersion and swimming studied by ECG telemetry.

A previously reported method for electrocardiographic (ECG) telemetry in water using frequency-modulated current was improved to obtain more stable ECGs. The ECGs of seven healthy men were monitored using the improved method during and after whole-body submersion or underwater swimming. Bradycardia and arrhythmias were observed during the submersion, and transient tachycardia was detected after the start of underwater swimming, followed by bradycardia with arrhythmias. Three different types of arrhythmias were observed: sinus arrhythmia (SA), supraventricular extrasystole (SE) and ventricular extrasystole (VE). SA and SE tended to develop during the latter half of the period of submersion or underwater swimming, and especially after the restart of breathing. VEs were detected in only one subject during submersion, whereas they occurred in most subjects during and after underwater swimming. Individual variations were found in development of arrhythmias, one subject showing no arrhythmia. Bradycardia, SA and SE could depend on vagal suppression in underwater conditions, and VE may be related to the effect of muscular movement on cardiac function in addition to vagal inhibition.

Surfactant homeostasis in the rat lung during swimming exercise.

Swimming rats for up to 2 h in water at 34 +/- 1 degree C increased the rate of breathing by 60% and tidal volume by 200-300%. In each case we infused 20 muCi X kg-1 [methyl-3H]choline chloride, via a caudal vein, 3 h prior to the end of swimming. Maximum specific activity of tissue phospholipid (PL) and alveolar PL (PLalv) occurred in 1 and 12 h, respectively. Total PLalv, specific activity of PLalv and the percentage of total PL released (%A/T) increased within 10 min of start of swimming and were sustained for at least 2 h of swimming [PLalv in mg X g dry lung-1: 5 s swim, 7.3 +/- 0.96 (mean +/- SD; n = 15 rats); 1-h swim, 10.1 +/- 1.1 (n = 23 rats)]. After a 1-h swim, PLalv returned to control within 4 h. Pretreatment with propranolol hydrochloride (10 mg X kg-1) (P), atropine methyl nitrate (3 mg X kg-1) (A), indomethacin (15 mg X kg-1), and cyproheptadine (1 mg X kg-1) did not alter the increase in PLalv with swimming, however, both P and A reduced the increase in specific activity of PLalv and %A/T. We suggest that the exercise releases surfactant from two pools: a readily released pool that responds to direct distortion of the alveolar type II cell and a pool that is under sympathetic nervous control.