bluuebunny/crossref_metadata_2025 huggingface dataset:
Determining Daily Physical Activity Levels of Youth with Developmental Disabilities: Days of Monitoring Required?
Authors: Kim So-Yeun , Yun Joonkoo
Published: August 2016

This study examined sources of variability in physical activity (PA) of youth with developmental disabilities (DD), and determined the optimal number of days required for monitoring PA. Sixteen youth with DD wore two pedometers and two accelerometers for 9 days, including 5 weekdays (W) and 2 weekends (WK). A two-facet in fully crossed two-way ANOVAs were employed to estimate sources of variability across W, WK, and W and WK combined (WWK) for each device. Primary sources of variability were the person and the person by day interaction for both devices. Using a pedometer, four, six, and eight days of measurements were required to determine typical PA levels of the participants during W, WK, and WWK, respectively. Using one accelerometer, four days of measurements were estimated across all days.
Accuracy of Pedometer Steps and Time for Youth with Intellectual Disabilities during Dynamic Movements
Authors: Pitetti Kenneth H. , Beets Michael W. , Flaming Judy
Published: August 2016

Pedometer accuracy for steps and activity time during dynamic movement for youth with intellectual disabilities (ID) were examined. Twenty-four youth with ID (13 girls, 13.1 ± 3.2 yrs; 11 boys, 14.7 ± 2.7 yrs) were videotaped during adapted physical education class while wearing a Walk4Life 2505 pedometer in five locations around the waist. Researchers viewed each videotape and recorded observed steps and activity time. Observed findings were compared with pedometer recorded steps and time. On average, pedometer registered steps were underestimated by approximately 14% ± 16.5%, whereas pedometer registered time was overestimated by approximately 8.7% ± 21.8%. The findings indicate that the accuracy of pedometers may be compromised during dynamic movement for youth with ID.
Short Term Auditory Pacing Changes Dual Motor Task Coordination in Children With and Without Dyslexia
Authors: Getchell Nancy , Mackenzie Samuel J. , Marmon Adam R.
Published: August 2016

This study examined the effect of short-term auditory pacing practice on dual motor task performance in children with and without dyslexia. Groups included dyslexic with Movement Assessment Battery for Children (MABC) scores > 15th percentile (D_HIGH, n = 18; mean age 9.89 ± 2.0 years), dyslexic with MABC ≤ 15th percentile (D_LOW, n = 15; mean age 10.43 ± 1.8 years), and typically developing (TD, n = 18; mean age 10.64 ± 1.8 years). Participants clapped and walked simultaneously for 3 pretest trials, completed 16 trials with auditory pacing, and 3 posttest trials without pacing. D_LOW differed significantly from D_HIGH and TD in mean relative phase (MRP) of the clap relative to the step, and variability (VRP) of the MRP. Significant differences also existed between pretest blocks and all other blocks in MRP. The results suggest that a short-term auditory pacing may be effective in improving MRP in all children. Further, there may be subtypes of dyslexia wherein children have more profound coordination difficulties and may preferentially change dual motor task performance with auditory pacing.
Challenging Situations When Teaching Children With Autism Spectrum Disorders in General Physical Education
Authors: Obrusnikova Iva , Dillon Suzanna R.
Published: August 2016

As the first step of an instrument development, teaching challenges that occur when students with autism spectrum disorders are educated in general physical education were elicited using Goldfried and D’Zurilla’s (1969) behavioral-analytic model. Data were collected from a convenience sample of 43 certified physical educators (29 women and 14 men) using a demographic questionnaire and an elicitation questionnaire. Participants listed 225 teaching challenges, 46% related to cooperative, 31% to competitive, and 24% to individualistic learning situations. Teaching challenges were categorized into nine themes: inattentive and hyperactive behaviors, social impairment, emotional regulation difficulties, difficulties understanding and performing tasks, narrow focus and inflexible adherence to routines and structure, isolation by classmates, negative effects on classmates’ learning, and need for support.
Creating Evidence-Based Research in Adapted Physical Activity
Authors: Reid Greg , Bouffard Marcel , MacDonald Catherine
Published: August 2016

Professional practice guided by the best research evidence is a usually referred to as evidence-based practice. The aim of the present paper is to describe five fundamental beliefs of adapted physical activity practices that should be considered in an 8-step research model to create evidence-based research in adapted physical activity. The five beliefs are individualization, critical thinking, self-determination, program effectiveness, and multifactor complexity. The research model includes conceptualize the problem, conduct research on the process of the problem, conceptualize and specify the intervention, evaluate intervention outcomes, evaluate intervention processes, determine person-by-treatment interactions, determine context-dependent limitations, and investigate factors related to intervention adoption maintenance. The eight steps are explained with reference to two research programs that used a randomized control group design.
Obesity Levels in Institutionalized Mentally Retarded Adults
Authors: Kelly Luke E. , Rimmer James H. , Ness Richard A.
Published: August 2016

The purpose of this investigation was to determine the percent body fat of 553 institutionalized mentally retarded adults, ages 18 to 40 yrs, from the Denton State School in Texas. The subjects included 343 males and 210 females. Their percent body fat was estimated with generalized regression equations. Body density for males was measured by the sum of three skinfolds, two girths, and age. Body density for females was measured by the sum of three skinfolds and age. The results from this study revealed that 45.2% of the males and 50.5% of the females were obese. The percent body fat of the female subjects was significantly greater than that of the male subjects. A post hoc analysis revealed that profoundly mentally retarded subjects had significantly lower percent body fat than those subjects functioning at the severe and mild levels. These findings indicate a serious need for more investigation of the caloric intake and expenditure of this population in an institutional environment.
The Relationship of Motor Skills and Social Communicative Skills in School-Aged Children With Autism Spectrum Disorder
Authors: MacDonald Megan , Lord Catherine , Ulrich Dale A.
Published: August 2016

Motor skill deficits are present and persist in school-aged children with autism spectrum disorder (ASD; Staples & Reid, 2010). Yet the focus of intervention is on core impairments, which are part of the diagnostic criteria for ASD, deficits in social communication skills. The purpose of this study is to determine whether the functional motor skills, of 6- to 15-year-old children with high-functioning ASD, predict success in standardized social communicative skills. It is hypothesized that children with better motor skills will have better social communicative skills. A total of 35 children with ASD between the ages of 6–15 years participated in this study. The univariate GLM (general linear model) tested the relationship of motor skills on social communicative skills holding constant age, IQ, ethnicity, gender, and clinical ASD diagnosis. Object-control motor skills significantly predicted calibrated ASD severity (p < .05). Children with weaker motor skills have greater social communicative skill deficits. How this relationship exists behaviorally, needs to be explored further.
The Effects of Therapeutic Horseback Riding on Balance
Authors: Biery Martha J. , Kauffman Nancy
Published: August 2016

This study sought to determine the effects of therapeutic horseback riding on the balance of eight individuals with mental retardation. The subjects were initially tested on four standing balance items and six quadruped balance items. Next, 6 months passed with no intervention. The intention of this time lapse was to use the subjects as their own control. After this delay, the subjects were tested again using the same procedure as in the initial testing. They were then involved in a 6-month therapeutic riding program designed to provide vestibular stimulation in a variety of ways, with the horse’s movement as a base. A third identical testing session occurred at the end of the therapeutic riding program. The results of the study showed that significant improvement was seen on standing and quadruped balance after the therapeutic riding program. It is concluded that if programming goals for individuals with mental retardation include improved balance, then therapeutic riding may be beneficial to those goals.
The Spinal Injured Athlete
Authors: Wells Christine L. , Hooker Steven P.
Published: August 2016

Physiological variables identified as important factors in athletic performance are discussed in relation to the spinal cord injured (SCI) athlete. These include body composition, pulmonary function, cardiorespiratory efficiency, muscular strength and endurance, and anaerobic power. SCI athletes are less fat and have a larger lean body mass than nonathletes, and male SCI are less fat than female SCI. Static lung volumes are usually below normal values in SCI subjects, but athletic SCI subjects tend to have higher values than sedentary SCI. Sedentary SCI subjects have lower aerobic power (O2max) than the general able-bodied (AB) sedentary population on tests of arm cranking or wheelchair ergometry. Low-lesion paraplegics generally achieve O2max values comparable to AB subjects. O2max is inversely related to level of injury, that is, the higher the SCI, the lower the O2max. However, elite SCI athletes are capable of achieving very high levels of O2max during arm exercise. SCI subjects respond well to strength and muscular endurance training. Paraplegic subjects achieve higher anaerobic power scores than quadriplegic subjects. Increases in O2max occur at about the same magnitude as in AB subjects. The required intensity level appears to be about 70–80% of maximal heart rate reserve.
Fractionated Reaction Times and Movement Times of Down Syndrome and Other Adults with Mental Retardation
Authors: Davis Walter E. , Sparrow William A. , Ward Terry
Published: August 2016

A fractionation technique was employed to determine the locus of reaction time delay in Down syndrome (DS) and other adult subjects with mental retardation (MH). Twenty-three subjects (8 nondisabled, 8 MH, and 7 DS) responded to a light, sound, and combination light/sound signal. Dependent measures of premotor time, motor time, total reaction time, and movement time were obtained during a 20° elbow extension movement and were analyzed separately. As expected, both MH and DS subjects were slower and more variable in their responses than the subjects without disabilities. In turn, DS subjects were significantly slower but not more variable than the MH subjects. There were no significant differences between the DS and MH subjects on movement times. Evidence for both a specific (premotor) and a generalized (both premotor and motor) locus of delay was found. Some difference in signal effect was also found for the DS subjects.
Effects of Reinforcement Based Exercise on Fitness and Work Productivity in Adults with Mental Retardation
Authors: Croce Ronald , Horvat Michael
Published: August 2016

The present study evaluated the effects of a reinforcement based aerobic and resistance exercise program on three obese men with mental retardation and below average fitness levels. A multiple-baseline-across-subjects design was employed to evaluate treatment effectiveness and retention of treatment effects on five dependent measures: body weight, percent body fat (body composition), oxygen consumption (predicted max V̇O2 in ml/kg/min), composite isometric strength (in kg of force), and work productivity (pieces of work completed). Subjects improved during treatment from their baseline scores on cardiovascular fitness, strength, and work productivity measurements (p<.05); however, retention of gains made during treatment were inconsistent and the data that indicated subjects’ scores were regressing back toward baseline measurements. There were no significant differences for body weight and percent body fat measurements for treatment and retention phases (p>.05). Results indicated that adults with mental retardation respond to a progressive exercise program in much the same manner as their nonretarded peers and that such an exercise program can facilitate job performance.
The Responsibilities of Olympic Sponsors? BP and the London 2012 Olympic Games
Authors: Chard Chris , Mallen Cheryl , Bradish Cheri L.
Published: August 2016

In 2008, the London Organising Committee of the Olympic Games (LOCOG) announced that they had signed a $58 million (US) sponsorship agreement with British Petroleum (BP), an oil company with well-known environmental concerns and offenses. The current case is set in July 2010 amidst BP’s most recent, and largest, environmental incident. The purpose of this case is to answer a key question: What action (if any) should LOCOG take with respect to its partnership with BP given the Gulf Coast oil spill? Additionally, students are challenged to form opinions regarding the environmental and social responsibilities of an Olympic sponsor, and to develop a strategic plan and policies for Olympic partners related to their environmental and social actions in the future.
Cryotherapy Effects, Part 1: Comparison of Skin Temperatures and Patient-Reported Sensations for Different Modes of Administration
Authors: Love Hailey N. , Pritchard Kimberly A. , Hart Joseph M. , Saliba Susan A.
Published: August 2016

Context:

Alterations in skin sensations may be responsible for pain reduction provided by cryotherapy, but the exact physiological mechanism is unknown.

Objective:

To investigate perceptions of skin sensations associated with different modes of cryotherapy administration and skin temperature at the point of perceived numbness.

Design:

Repeated measures.

Participants:

30 healthy subjects (12 Male, 18 Female, Age = 21.1±1.9 years).

Interventions:

Crushed ice bag, ice massage, and cold water immersion.

Main Outcome Measures:

Perceptions of sensations during each mode of cryotherapy administration were derived from a Modified McGill Pain Questionnaire. Skin temperature was recorded when numbness was reported for each treatment.

Results:

Participants experienced sensations that included cold, tight, tingling, stinging, and numb. Ice massage sensations transitioned rapidly from cold to numb, whereas cold water immersion and ice bag treatments produced altered sensations for longer duration. Ice massage decreased skin temperature significantly more than the other two modes of cryotherapy administration.

Conclusions:

Ice massage may be the best mode of cryotherapy administration for achievement of anaesthesia as rapidly as possible, whereas cold water immersion and ice bag application may be better for attainment of pain reduction associated with noxious stimulation of skin receptors.
Navicular Drop Before and After Fatigue of the Ankle Invertor Muscles
Authors: Gardin Fredrick Anthony , Middlemas David , Williams Jennifer L. , Leigh Steven , Horn Rob R.
Published: August 2016

Context:

Navicular drop is widely believed to be an indicator of elevated susceptibility to pronation-related injuries, which may be increased by fatigue in the muscles that dynamically support the medial longitudinal arch.

Objective:

The purpose of this study was to evaluate navicular drop before and after fatigue of the ankle invertor muscles among individuals with different foot types.

Participants:

20 male and 16 female recreationally active, college-age volunteers (20.03 ± 1.48 years of age).

Methods:

Navicular drop was measured before and after inducing fatigue in the ankle invertor muscles. Participants’ foot types were classified as high-arch, neutral, or low-arch.

Results:

There was no interaction between foot type and trial, and no main effect for trial. A main effect for foot type was significant (p = .001). Intra-class correlation coefficients for prefatigue and postfatigue measurements indicated good internal consistency.

Conclusion:

Our fndings failed to provide any evidence to support the existence of a relationship between ankle invertor muscle fatigue and static measurements of change in navicular height from a sitting to standing position.
Biomechanical Analysis of Olympic Javelin Throwers
Authors: Komi Paavo V. , Mero Antti
Published: August 2016

A two-dimensional film analysis was performed on five men and six women finalists in the javelin throw of the Los Angeles Olympic Games of 1984. In addition to the great interindividual variation in the measured kinematic and kinetic parameters, the results indicated that in men the winner had the highest release velocity of javelin (29.12 m × s−1), and that a significant (p < .01) relationship could be obtained between the release velocity and throwing distance. Despite great variation in throwing distance in women (55.88 m - 69.56 m) the release velocities were in relatively small range (20.73 m × s−1 - 23.62 m × s−1). High impact loading was specific to the last foot contact on the ground. It was characterized by a short duration (0.032 s) and high velocity knee flexion (12.66 ± 2.11 and 12.27 ± 3.81 rad × s−1, respectively, for men and women). The respective knee extension velocities averaged 5.80 ± 2.00 and 7.60 + 5.17 rad × s−1. Despite the fact that a small number of analyzed world-class throws revealed only some biomechanical differences between good and poorer performance, the results can be used to identify some new criteria for successful performance in javelin throw.
Techniques Used in the Transition from Approach to Takeoff in the Long Jump
Authors: Hay James G. , Miller John A.
Published: August 2016

The purposes of this study were (a) to describe the techniques used by elite female athletes during the transition from approach to takeoff in the long jump and (b) to determine which characteristics were significantly related to the officially recorded distance of the jump. The subjects were the 12 finalists in the Women's Long Jump at the 1984 Olympic Games. A motion-picture camera placed with its optical axis at right angles to the runway was used to record the performances of the subjects. Means and standard deviations of the variables identified in a theoretical model and correlations between these variables and the distance of the jump were computed. Significant correlations revealed that the less the downward velocity at touchdown at the end of the third-last stride, and the less this velocity is changed by the vertical forces transmitted via the supporting foot, and the shorter the duration of the next flight phase, the greater the distance of the jump.
Effects of Supramaximal Velocity on Biomechanical Variables in Sprinting
Authors: Mero Antti , Komi Paavo V.
Published: August 2016

The effects of running at supramaximal velocity on biomechanical variables were studied in 13 male and 9 female sprinters. Cinematographical analysis was employed to investigate the biomechanics of the running technique. In supramaximal running the velocity increased by 8.5%, stride rate by 1.7%, and stride length by 6.8% over that of the normal maximal running. The elite male sprinters increased their stride rate significantly but did not increase their stride length. The major biomechanical differences between supramaximal and maximal running occurred during the contact phase. In supramaximal running the inclination of the ground shank at the beginning of eccentric phase was more "braking" and the angle of the ground knee was greater. During the ground contact phase, the maximal horizontal velocity of the swinging thigh was faster. The duration of the contact phase was shorter and the flight phase was longer in the supramaximal run as compared to the maximal run. It was concluded that in supramaximal effort it is possible to run at a higher stride rate than in maximal running. Data suggest that supramaximal sprinting can be beneficial in preparing for competition and as an additional stimulus for the neuromuscular system during training. This may result in adaptation of the neuromuscular system to a higher performance level.
Greg Louganis’ Springboard Takeoff: II. Linear and Angular Momentum Considerations
Authors: Miller Doris I. , Munro Carolyn F.
Published: August 2016

A linear and angular momentum analysis was conducted on Greg Louganis' forward and reverse 3-m springboard takeoffs performed during National Sports Festival V in Colorado Springs, and differences among dives were examined. At initial contact with the board, his horizontal velocity approximated 0.5 m/s across all dives analyzed. In the forward 3.5 somersaults pike, the horizontal velocity subsequently increased in magnitude until the latter half of recoil. By contrast, in the forward and reverse dives and reverse 2.5 somersaults, horizontal velocity displayed an initial reduction followed by an increase to the final value of 0.8 to 1.2 m/s. His vertical velocities at touchdown (−4.3 to −4.5 m/s) increased to 5.0 to 6.0 m/s during the takeoff, with the final upward velocity being related to the type of dive performed. At initial contact, Louganis’ total body angular momentum with respect to his center of gravity was negligible. By the end of the takeoff, it had increased to 18 kg-m-m/s for the forward dive straight and was three and four times that magnitude for his reverse 2.5 and forward 3.5 somersaults pike, respectively. Between 80 and 90% of the total angular momentum at the end of the takeoff was due to the segment remote contributions. The importance of the upper extremities in developing somersaulting angular momentum was shown by the fact that they were responsible for between 30 and 43% of the final angular momentum in all but the forward dive straight.
Push-Off Force in Speed Skating
Authors: de Koning Jos J. , de Boer Ruud W. , de Groot Gert , Schenau Gerrit Jan van Ingen
Published: August 2016

In speed skating, performance is related to the product of the amount of work per stroke and the stroke frequency. Work per stroke is dependent on the component of the push-off force in the direction perpendicular to the gliding direction of the skate. The push-off force at different velocities was measured in three trained speed skaters. The results showed that the peak push-off force and mean force do not change at different velocities, and that the stroke time was decreased at higher velocities. It can be concluded that these speed skaters regulate their velocity not by changing the push-off force but by changing their stroke time. The shape of push-off–time curves is dependent on push-off technique and differs during straight lane and curve skating.
Critical Examination of Ground Reaction Force in the Running Forward Somersault
Authors: Miller Doris I. , Nissinen Mauno A.
Published: August 2016

Ground reaction forces (GRF) elicited by nine male gymnasts during a running forward somersault were examined to investigate their characteristics in relation to the performance. Support averaged 135 ms with braking GRF dominating in the antero-posterior direction. Vertically, impact averaging 13.6 body weights (BW) was recorded followed by a second peak of 6.1 BW. The relative minimum in vertical GRF and lowest body position coincided temporally at 23% of support time; maximum knee flexion and minimum distance between the center of gravity (CG) and the support point occurred at 36 and 37%, respectively; and the second vertical GRF peak and maximum dorsiflexion were registered at 44%. The results suggested that, while vertical touchdown and last contact velocities of the CG could be approximated from GRF, eccentric ankle and knee extensor contraction continues beyond the relative minimum in the vertical GRF curve and is more closely related to the period before the CG reaches its minimum distance from the support point.
The Effects of Track Turns on Lower Extremity Function
Authors: Hamill Joseph , Murphy Michael , Sussman Donald
Published: August 2016

The mechanics of moving along a curved path suggest that runners must change their body positions and thus adjust their lower extremity function as they accomplish a track turn. The purpose of the present study was to investigate the changes in the kinetics and kinematics of the lower extremity as runners proceed around the turn of a 400-m track (radius 31.5 m). Five skilled runners served as subjects in the study and were required to perform 10 trials in three conditions, running at 6.31 m/s plus or minus 5% (4:15 min/mile pace). The right and left limbs on a track turn and the right limb on the straightaway were evaluated using ground reaction force data and kinematic data from high-speed film. Statistical analysis of the 18 ground reaction force variables and 4 kinematic variables suggested that the right and left limbs at the midpoint of the track turn were asymmetrical and that most of the differences occurred in the first portion of the footfall Significant differences were found in the touchdown angle, maximum pronation angle, all mediolateral variables, and in the vertical variables describing the collision phase of the footfall (p < .05). The data suggest that the etiologies of injuries to the right and left lower extremity differ, with right foot injuries being of the impact type and left leg injuries being of the overpronation type.
Mechanical Energetics of World Class Cross-Country Skiing
Authors: Norman Robert W. , Komi Paavo V.
Published: August 2016

The purpose of this study was to determine whether world class skiers were alike in their mechanical power outputs (normalized for body mass and velocity and called mechanical cost, MTC) and body segment energy transfers when skiing in competition on level and uphill terrain using the diagonal technique. Eleven competitors were analyzed from film taken during a 15-km World Championship race on a level (1.6°) and uphill (9.0°) section of the course. Metabolic rates were estimated from assumptions concerning the efficiencies of positive and negative work and calculations, from the film, of the mechanical power produced by the skiers. The results showed that skiing on the slope was 2.2 times more demanding mechanically than skiing on a level track (MTC of 4.0 vs. 1.8 J • kg−1 • m−1, respectively). Skiers who had high MTC had low energy transfers (r = −0.9). Even in this presumably homogeneous group of elite skiers there were large individual differences in MTC and other mechanical variables, suggesting technique problems for some. Furthermore, on flat terrain the estimated metabolic rate was only about 76% of an MV02 of 80 ml • kg−1 • min−1. This suggests that speed, using the diagonal stride, may be limited by constraints on body segment utilization and not by the physiological energy delivery system of these highly trained athletes.
Influence of Heel Flare and Midsole Construction on Pronation Supination and Impact Forces for Heel-Toe Running
Authors: Nigg Benno M. , Bahlsen H. Alexander
Published: August 2016

The purpose of this study was to determine the influence of lateral heel flare on pronation, external impact forces, and takeoff supination for different midsole constructions. Data were collected using force platforms and high-speed film cameras. Fourteen male subjects participated in the study, running heel-toe at a speed of 4 m/s. The analysis of kinetic and kinematic variables showed that changes in lateral heel flare of 16°, 0°, and a rounded heel can be used to influence initial pronation during heel-toe running. It could be shown that changes in lateral heel flare do not have a relevant influence on changes in total and/or maximal pronation. Changes in lateral heel flare do have an effect on vertical impact force peaks if the midsole is relatively hard but not if the midsole is relatively soft. Based on the present study, a running shoe with a relatively hard midsole material and a neutral flare would have low initial pronation values and low vertical impact force peaks.
Evaluation of Rearfoot Asymmetries in Running with Worn and New Running Shoes
Authors: Vagenas George , Hoshizaki Blaine
Published: August 2016

The purpose of this study was to identify the kinematic characteristics of bilateral rearfoot asymmetry during heel–toe running under two experimental conditions: worn (broken-in) running shoes and new (standardized) running shoes. High-speed cinematography (150 fps) was used to film the lower limbs of four male runners in the frontal plane while running on a treadmill at their training pace. Six successive footfalls were analyzed for each subject and selected kinematical variables of the rearfoot function were calculated. Significant asymmetries were found in lower leg angle and Achilles tendon angle at touchdown and at maximum pronation. Total pronation and rearfoot angle were almost symmetric. The angular displacement graphs for the shank and foot revealed a distinct overall asymmetry between the lower limbs in both conditions. The mean values of the kinematical asymmetries were appreciably higher in the new shoe condition. It is proposed that the degree of these asymmetries is subject to changes due to injury, personal running style, and stability of the running shoe. Trends of bilateral dominance specific to rearfoot control in running were identified.
Running Injuries and Shoe Construction: Some Possible Relationships
Authors: Stacoff Alex , Denoth Jachen , Kaelin Xaver , Stuessi Edgar
Published: August 2016

Shock attenuation of the impact peak and overpronation are both considered important in running shoe design. A number of investigations indicate that both of these factors are related to various running injuries. These indications are mostly empirical or based on statistics and often show a lack of arguments to relate external measurements to internal loading of joints or muscles. The purpose of this paper is to present some relationships between impact peak, pronation, and forces at the subtalar joint and on muscles (which are in tension in pronation) during touchdown in rearfoot running. The calculations show that the material properties of the shoe sole (altered from Shore A20 to A50) largely influence the rearfoot movements during touchdown (increase in pronation velocity from 7 to 25 rad/s) and increase to some extent the muscle forces on the medial side (600 to 850 N) of the subtalar joint. In comparison, the impact peak (1550 to 1600 N) and the ankle joint forces (2500 to 2700 N) change very little. Hence, running shoe design should be focused more on the control of the rearfoot movement during touchdown and less on pure shock attenuation.
Evaluating the Approach in the Horizontal Jumps
Authors: Hay James G. , Koh Timothy J.
Published: August 2016

The purpose of this study was to develop measures of a long or triple jumper’s ability to use programming and visual control strategies during the approach to the takeoff. Five such measures were developed. The performances of the competitors in the men’s and women’s horizontal jumps at the 1987 Big Ten Conference Championships were filmed to obtain the required data. Percentiles were computed for each of the five measures and these were used, in conjunction with a performance profile, to evaluate the ability of an athlete to use the two strategies.
Mechanical Power Output and Estimated Metabolic Rates of Nordic Skiers During Olympic Competition
Authors: Norman Robert , Ounpuu Sylvia , Fraser Margo , Mitchell Ronald
Published: August 2016

This paper explores whether there may be useful information in estimates of metabolic rates obtained from biomechanical calculations of mechanical power output. Thirteen men were analyzed as they passed a camera on each of three laps on an 11.8° uphill in the 30-km classical technique Olympic Nordic ski event. A 15-segment model was constructed; velocity, stride length, stride rate, mechanical power output, and from this latter measure an estimate of oxygen consumption, were obtained. The average lap velocity was 5.65 m•s−1 (20 km•hr−1), the film site velocity was 2.58 m•s−1, and the correlation between them was 0.75. There were no significant differences from lap to lap in any variable, nor were there dramatic differences between the skiers in the top 14 compared with those finishing in 35th place or slower in stride length or stride rate. However, the faster skiers had estimated VO2 from 80 to 112 ml•kg−1 • min−1 on most laps while the slower skiers had values from 53 to 77. If a VO2 estimated from biomechanical data can ultimately be shown to be accurate, a rather useful tool may have been identified for coaches, athletes, and sport scientists that can be used during competition in endurance events.
A Biomechanical Approach to Alpine Ski Binding Design
Authors: Wunderly Glenn S. , Hull Maury L.
Published: August 2016

A new approach to ski binding design is advanced. It begins with a release locus derived from injury mechanics research and knowledge of the expected loading conditions and then incorporates these into the final binding design. A mechanical ski binding designed by following the new approach is presented. This binding offers a number of performance features not found in commercially available designs. One feature is the ability to eliminate the axial force supported by the tibial shaft from affecting release in forward bending. A second feature is the binding’s ability to release according to virtually any preprogrammed locus of the combination of moments in both bending and torsion. A third feature is a release mechanism that is insensitive to the common frictional forces that affect the release consistency of conventional heel/toe bindings. In addition to these features, the binding offers a variety of operational conveniences. The presentation of the binding not only describes the design details but also evaluates the release performance (i.e., locus and consistency) based upon laboratory tests under quasistatic loading.
The Effect of Pedal Platform Height on Cycling Biomechanics
Authors: Hull Maury L. , Gonzalez Hiroko K.
Published: August 2016

Using a five-bar linkage model of the leg/bicycle system in conjunction with experimental kinematic and pedal force data, the inverse dynamics problem is solved to yield the intersegmental moments. Among the input data that affect the problem solution is the height of the pedal platform. This variable is isolated and its effects on the total joint moments are studied as it assumes values over a ±4-cm range. Platform height variation affects the total joint moment peak values by up to 13%. Relying on a cost function derived from the hip and knee moments, it is found that the platform height that minimizes the cost function is +2 cm. The sensitivity of the cost function to the platform height variable is low; over the variable range the cost function increases 2% above the minimum. These results hold for a pedaling rate of 90 rpm. As pedaling rate is varied above and below 90 rpm, the sensitivity of the cost function increases. The platform heights that minimize the cost function are the lower and upper limits for 60 and 120 rpm, respectively. Thus the platform height variable interacts with pedaling rate, requiring a compromise in platform height adjustment. The compromise height depends on the individual’s preferred pedaling rate range.
Measurement of Push-Off Force and Ice Friction during Speed Skating
Authors: Jobse Hans , Schuurhof Ruud , Cserep Ferenc , Schreurs A. Wim , de Koning Jos J.
Published: August 2016

Portable equipment for active measurements of push-off force and ice friction was developed. The equipment consists of a pair of skates with three measuring elements between the shoe and the skate blade to register force in both fore/aft and normal direction. A portable computer samples the friction force and normal force signals during one or more strokes, calculates the mean coefficient of ice friction, and stores the sampled data in memory. The push-off force and ice friction force were measured. The peak push-off forces reach values of up to 140% of body weight. The magnitude of the coefficient of ice friction varies, depending on the weather conditions and preparatory method, generally between 0.003 and 0.007 when skating the straightaway. During the skating of the curves the coefficient of ice friction is 35% higher, most likely due to the different skating technique in the curves.
A Dual Piezoelectric Element Force Pedal for Kinetic Analysis of Cycling
Authors: Broker Jeffrey P. , Gregor Robert J.
Published: August 2016

In light of substantial interest in the measurement of rider-induced loads, a new bicycle pedal instrumentation system is presented. The system employs dual piezoelectric transducers and permits the measurement of three components of a uniaxial load, moments about the pedal’s vertical axis, and the point of application of the applied load. Force and moment patterns derived from pedal output agree with previously reported data. Unique to this design, however, is the determination of center of pressure—and these data indicate that the applied load location varies during the pedaling cycle, with a significant effect on the calculated pedal moment.
Intrasubject Variability of Upper Extremity Angular Kinematics in the Tennis Forehand Drive
Authors: Knudson Duane V.
Published: August 2016

The intra subject variability of the angular kinematics of the wrist and elbow joints in the tennis forehand drive were studied. Two varsity tennis players were filmed as they performed flat forehand drives. The DLT method of 3-D reconstruction was used to measure the angular motion of the upper extremity for eight strokes to assess the intra subject variability of selected kinematic variables. Curves were synchronized to impact and averaged. Wrist and elbow angular position data were quite consistent, with curve coefficients of variation (CV) less than 5.9%. The consistent angular positions during the forward stroke did not result from highly consistent patterns of angular velocities or accelerations. For both the wrist and elbow joints, intra subject variability increased for the angular velocity (CV = 90.6%) and angular acceleration (CV = 129.5%) curves. Biomechanical studies comparing derivatives or kinetic variables across subjects may have to be interpreted with reference to intra subject variability.
The Pedaling Technique of Elite Endurance Cyclists: Changes with Increasing Workload at Constant Cadence
Authors: Kautz Steven A. , Feltner Michael E. , Coyle Edward F. , Baylor Ann M.
Published: August 2016

A pedal dynamometer recorded changes in pedaling technique (normal and tangential components of the applied force, crank orientation, and pedal orientation) of 14 elite male 40-km time trialists who rode at constant cadence as the workload increased from similar to an easy training ride to similar to a 40-km competition. There were two techniques for adapting to increased workload. Seven subjects showed no changes in pedal orientation, and predominantly increased the vertical component of the applied force during the downstroke as the workload increased. In addition to increasing the vertical component during the downstroke, the other subjects also increased the toe up rotation of the pedal throughout the downstroke and increased the horizontal component between 0° and 90°. A second finding was that negative torque about the bottom bracket during the upstroke usually became positive (propulsive) torque at the high workload. However, while torque during the upstroke did reduce the total positive work required during the downstroke, it did not contribute significantly to the external work done because 98.6% and 96.3 % of the total work done at the low and high workloads, respectively, was done during the downstroke.
Body Segment and Release Parameter Contributions to New-Rules Javelin Throwing
Authors: Whiting William C. , Gregor Robert J. , Halushka Marie
Published: August 2016

Eight male javelin throwers were filmed while throwing new-rules javelins during competition at five meets over a 2-year period. Body segment kinematics and javelin release parameters were assessed relative to their contribution to throwing performance. The data suggest that successful throws, as judged by distance thrown, are characterized by higher release speeds, longer last-step lengths, less flexion of the front-leg knee during the final plant phase, and an orderly progression of peak speeds at the hip, shoulder, and elbow from the onset of double leg support until release. Individual variability in performance was associated with differences measured between several throwing variables. Limitations inherent to two-dimensional analysis were identified that highlighted the need for three-dimensional investigation of the javelin throw.
A Multivariable Analysis of Lower Extremity Kinematic Asymmetry in Running
Authors: Vagenas George , Hoshizaki Blaine
Published: August 2016

This study investigated the phenomenon of kinematic asymmetry of the lower limbs in distance runners. The subjects, 29 male distance runners, were recorded by high-speed filming while running on a motor driven treadmill under two experimental conditions (with running shoes and barefoot). Twelve selected kinematic variables were subjected to multivariate statistical analysis. It was demonstrated that the lower limbs of distance runners possess a multifaceted kinematic asymmetry for touchdown and foot contact as well as for the entire phase of foot support of the running stride. Significant kinematic asymmetries were found in the lower leg angle, rearfoot angle, mediolateral velocity of the foot, and in some temporal variables. Contemporary running shoes seem to significantly change the degree of rearfoot control asymmetry observed in normal barefoot running. The findings of the present study confirm previous data suggesting that the phenomenon of kinematic asymmetry in runners is warranted.
The Technique of Elite Flatwater Kayak Paddlers Using the Wing Paddle
Authors: Kendal Selina J. , Sanders Ross H.
Published: August 2016

The technique of elite New Zealand kayak paddlers using the Norwegian wing paddle was analyzed to identify factors leading to success. Five male New Zealand kayak paddlers were filmed with two high-speed cinematographic cameras. Paths of the blade tip and joint centers were determined from film data. Velocities ranged from 4.63 to 5.38 m/s. Stroke frequency ranged from l .93 to 2.26 cycles/s. Results indicated that the more successful paddlers, based on previous competitive performances, had similar movement patterns and blade paths and that these differed from those of less successful paddlers. Their blade tip and joint center paths were more consistent across trials. More successful paddlers entered their blade well forward and closer to the longitudinal axis of the kayak than did less successful paddlers, and moved the blade a large distance laterally from the kayak and only a small distance backward with respect to the water.
Sports Viewing: A Theoretical Approach
Authors: Frandsen Kirsten
Published: August 2016

The article presents a theoretical discussion of the entertainment value inherent to viewing televised sports. By combining different theories that consider sports events and television as essentially presentational symbolic forms, sports as a game phenomenon, and sports events as rituals, one obtains a more elaborate understanding of the potential attractions related to watching sports. The author argues that because of the very nature of sports, it becomes crucial to give prominence to a conception of the audience as active and meaning producing. In order to understand and acquire knowledge about both these meaning-producing processes, and the more general significance of televised sports, a comprehensive, rather than a purely individual, approach is required. Knowledge sharing and discussion of the implications of the acts on the field are, among various social groups, as important as the viewing experience itself.
Sport Sponsorship, Internal Communications, and Human Resource Management: An Exploratory Assessment of Potential Future Research
Authors: Pichot Lilian , Tribou Gary , O’Reilly Norm
Published: August 2016

Successful sponsorship activities in sport often rely on the integration of relationship marketing, internal marketing, external corporate promotion, and strategic management. Although traditional marketing objectives such as brand integration and consumer targeting remain key components of promotional activities in sport, the use of sport sponsorship in today’s environment increasingly implicates personnel issues in the both the sponsor and the sponsee. In fact, sport sponsorship has become a useful tool for some sponsors and sponsees who seek to motivate and involve their employees more in company activities. Therefore, the focus of this commentary is on the internal-communication and human-resources management functions involved in sport sponsorship decisions. The use of mini-case analyses and a dual-perspective (external and internal objectives) approach allows for informed discussion, and suggestions are made for future research.
Fan–Athlete Interaction and Twitter Tweeting Through the Giro: A Case Study
Authors: Kassing Jeffrey W. , Sanderson Jimmy
Published: August 2016

This case study examines how fans can experience a major sporting event (cycling’s Tour of Italy) through a particular new communication technology platform—Twitter. To explore this possibility the authors tracked the “tweets” sent out by a selection of American and English-speaking riders during the 3-wk race. Their analysis of these texts revealed that Twitter served to increase immediacy between athletes and fans. This occurred as athletes provided commentary and opinions, fostered interactivity, and cultivated insider perspectives for fans. These activities position Twitter as a powerful communication technology that affords a more social vs. parasocial relationship between athletes and fans.
Audience Perceptions of Female Sports Reporters: A Social-Identity Approach
Authors: Baiocchi-Wagner Elizabeth A. , Behm-Morawitz Elizabeth
Published: August 2016

Attempts at investigating female sports reporters’ credibility and persuasiveness from the audience’s perspective are limited and outdated. This study, grounded in social identity theory, fills the gap in media literature. A quasi-experiment tested respondents’ perceptions of male and female sports reporters’ credibility and persuasiveness as a function of salient gender identity and reporter and athlete sex. Respondents’ sports fandom, frequency of sports-media usage, and general perceptions of news-media credibility also were examined. Results of a MANOVA indicated no significant differences in respondents’ perceptions of a male and female reporter, even when controlling for respondent gender; however, sports fandom and general perceptions of news-media credibility did have a significant impact on perceptions.
Discourses of the “Too Abled”: Contested Body Hierarchies and the Oscar Pistorius Case
Authors: Corrigan Thomas F. , Paton Jamie , Holt Erin , Hardin Marie
Published: August 2016

Using Foucault’s ideas about discourse and the body, this study explores coverage of Oscar Pistorius’s quest to compete in the 2008 Summer Olympics. The authors used textual analysis of coverage in The New York Times and Time magazine, two popular and influential general-interest U.S. publications, to interrogate fairness as the primary rationale in discourse about Pistorius. Journalists also privileged a medical view of disability, used descriptions of prosthetics to reflect cultural assumptions about “normal” bodies, and reinforced fear of the “cyborg.” Media discourses around Pistorius, as contested sites for meanings inscribed on the body, reinforced the body hierarchy and positioned progress for athletes with disabilities as threatening to the institution of sport and its values. The authors suggest alternative discursive strategies, such as those that question the Paralympic/Olympic divide or focus on the rights of athletes with disabilities to compete, as ways to radically challenge the exercise of biopower reinforcing the status quo.