The Optimal Downhill Slope for Acute Overspeed Running

2008 ◽  
Vol 3 (1) ◽  
pp. 88-93 ◽  
Author(s):  
William P. Ebben

Purpose:This study evaluated a variety of downhill slopes in an effort to determine the optimal slope for overspeed running.Methods:Thirteen NCAA Division III college athletes who participated in soccer, track, and football ran 40-yd (36.6-m) sprints, on downhill slopes of 2.1°, 3.3°, 4.7°, 5.8°, and 6.9° in random order. All sprints were timed using the Brower Timing System Speedtrap II. Data were analyzed with SSPS 15.0. A 1-way repeated-measures analysis of variance revealed significant main effects for the test slopes (P = .000). Bonferroni-adjusted pairwise comparisons determined that there were a number of differences between the hill slopes.Results:Analysis reveals that 40-yd sprints performed on hill slopes of approximately 5.8° were optimal compared with flatland running and the other slopes assessed (P < .05). Sprinting on a 5.8° slope increased the subjects’ maximal speed by an average of 0.35 s, resulting in a 6.5% ± 4.0% decrease in 40-yd sprint time compared with fatland running. Compared with the 4.7° slope, the 5.8° slope yielded a 0.10-s faster 40-yd sprint time, resulting in a 1.9% increase in speed.Conclusions:Those who train athletes for speed should use or develop overspeed hills with slopes of approximately 5.8° to maximize acute sprinting speed. The results of this study bring into question previous recommendations to use hills of 3° downhill slope for this form of overspeed training.

2013 ◽  
Vol 103 (5) ◽  
pp. 394-399 ◽  
Author(s):  
Alfred Gatt ◽  
Nachiappan Chockalingam ◽  
Owen Falzon

Background: Although assessment of passive maximum foot dorsiflexion angle is performed routinely, there is a paucity of information regarding adolescents’ foot and foot segment motion during this procedure. There are currently no trials investigating the kinematics of the adolescent foot during passive foot dorsiflexion. Methods: A six-camera optoelectronic motion capture system was used to collect kinematic data using the Oxford Foot Model. Eight female amateur gymnasts 11 to 16 years old (mean age, 13.2 years; mean height, 1.5 m) participated in the study. A dorsiflexing force was applied to the forefoot until reaching maximum resistance with the foot placed in the neutral, pronated, and supinated positions in random order. The maximum foot dorsiflexion angle and the range of movement of the forefoot to hindfoot, tibia to forefoot, and tibia to hindfoot angles were computed. Results: Mean ± SD maximum foot dorsiflexion angles were 36.3° ± 7.2° for pronated, 36.9° ± 4.0° for neutral, and 33.0° ± 4.9° for supinated postures. One-way repeated-measures analysis of variance results were nonsignificant among the 3 groups (P = .70), as were the forefoot to tibia angle and hindfoot to tibia angle variations (P = .091 and P = .188, respectively). Forefoot to hindfoot angle increased with the application of force, indicating that in adolescents, the forefoot does not lock at any particular posture as portrayed by the traditional Rootian paradigm. Conclusions: Participants had very flexible foot dorsiflexion, unlike those in another study assessing adolescent athletes. This finding, together with nonsignificant statistical results, implies that foot dorsiflexion measurement may be performed at any foot posture without notably affecting results. (J Am Podiatr Med Assoc 103(5): 394–399, 2013)


2021 ◽  
pp. 002242942110604
Author(s):  
David S. Miller

This study had two primary purposes: (1) to investigate the effect of register, direction, and magnitude on musicians’ evaluation of chamber ensemble intonation, and (2) determine whether a novel nonparametric technique, ordinal pattern analysis (OPA), was a viable alternative to repeated-measures analysis of variance (rANOVA). I digitally mastered a recording of a string quartet performing a phrase from Capriol Suite by altering the intonation of the violin or cello voice ±20 and 30 cents sharp and flat. Participants ( N = 72) completed a discrimination task and an evaluation task with the recordings, with task order, and within-task item order presented in a random order. Analysis using rANOVA revealed significant differences due to register, direction, and magnitude: Excerpts with cello errors were rated as more in tune than excerpts with violin errors; excerpts with flat errors were rated as more in tune than excerpts with sharp errors, and excerpts with 20-cent magnitude errors were rated as more in tune than excerpts with 30-cent magnitude errors. OPA results were consistent with rANOVA results. Substantive implications for music teaching and learning are discussed alongside methodological considerations and implications for music education research using repeated-measures designs.


2021 ◽  
pp. 1-6
Author(s):  
B.P. Dieter ◽  
C.J. Macias ◽  
T.J. Sharpe ◽  
B. Roberts ◽  
M. Wille ◽  
...  

The dipeptide carnosine consists of β-alanine and L-histidine. It plays a major role in skeletal muscle metabolism, especially as an intracellular buffer and antioxidant. Increasing intramuscular carnosine has been shown to improve recovery from exercise and increase anaerobic threshold and time-to-exhaustion. Dietary supplementation with carnosine does not effectively increase intramuscular carnosine due to the presence of carnosinase in the blood. However, an effective transdermal delivery process could expediently increase intramuscular concentrations of carnosine. This study’s objective was to examine the efficacy of a transdermal system for delivering carnosine into the skeletal muscle of horses, using a randomised, placebo controlled, crossover study. Carnosine plus a proprietary transdermal delivery agent or the agent alone (placebo) were applied to the middle gluteal muscles of 10 Thoroughbred racehorses, and muscle biopsies were taken before and 30, 60, and 120 min after application. Muscle carnosine concentration was measured using an enzyme-linked immunosorbent assay. A two-way repeated measures analysis of variance was used to test for the main effects of time and treatment (placebo or carnosine) as well as an interaction between time and treatment. Independent F-tests examined the change in intramuscular carnosine levels from baseline to each time point (30, 60, and 120 min). There was a significant main effect of treatment (P=0.004), no significant main effect for time (P=0.18), and a non-significant interaction of treatment with time (P=0.08). Mean intramuscular carnosine concentrations increased from baseline to 120 min. Compared to concentrations following placebo application, carnosine was greater by ~35% at 30 min (P=0.002) and ~46% after 60 min (P=0.044), but not at 120 min (P=0.20). The results indicated that intramuscular carnosine can be increased using a transdermal delivery system within 60 min of application which could have important implications for the health of horses, and their capacity to perform and recover from physical activity.


1981 ◽  
Vol 52 (2) ◽  
pp. 479-483 ◽  
Author(s):  
Helen H. Mills ◽  
Joseph C. Bledsoe

A 55-item inventory of preferences for leisure activities mentioned in the literature was administered to 235 conference participants and responses factor analyzed. Six factors accounted for 47.2% of the total variance. Four items were discarded. A repeated-measures analysis of variance indicated no significant differences in preferences for Passive, Physically Active, Social, and Learning-related activities, but these four factors were preferred to mental activities, which in turn were preferred over creative activities. Main effects for general (undifferentiated) activities of age, income, sex, race, occupation, and education were non-significant, but significant interactions between these main effects and the six activities factors indicated that the inventory may provide insight into preferences related to these effects.


1997 ◽  
Vol 11 (2) ◽  
pp. 190-200 ◽  
Author(s):  
Scott R. Johnson ◽  
Andrew C. Ostrow ◽  
Frank M. Perna ◽  
Edward F. Etzel

The purpose of this study was to examine the effects of group and individual goal setting versus a control condition on bowling performance (BP), personal goals (PG), and perceived goal difficulty (PGD) across five weeks. Novice bowlers (N = 36) were randomly assigned to one of the three goal conditions. Three separate 3 × 5 (Goal Condition × Time: Weeks of Study) repeated measures analysis of variance (ANOVA) revealed significant main effects for time on BP and PGD, and significant group by time interaction effects on BP and PG. The significant group × time interaction effects revealed that participants in the group goal setting condition increased both BP and PG relatively more than participants in the other goal setting conditions. Therefore, group goal setting may enhance performance in an individual sport by potentially increasing personal goal setting under difficult performance demands.


Author(s):  
ARMIA ABDO ◽  
HANI AL-NAKHLI

Objective: Currently, there are multiple bed-making tools utilized by consumers and businesses with the intention of increasing safety and reducing time to make a bed. In this study, we will compare musculoskeletal stress, time, and preference of making a bed using the EasyTuck pad versus three other bed-making tools and making a bed without any bed-making tool. Methods: A sample of ten subjects performed the task of making a queen size mattress bed with one bottom fitted sheet and one top flat sheet, using the EasyTuck pad versus three other bed-making tools, and making a bed without any bed-making tool, in a random order. Time to make the bed, forces on the low back, shoulders and wrist, and the number of times each individual bent forward were measured during each trial. In addition, subjective preferences were measured using a simple questionnaire. Results: Repeated measures analysis of variance was used to analyze the differences between the five different procedures. There were significant differences for all the measured variables. Regarding the time needed to make one bed, the EasyTuck pad had the least time range (80.6 s±4.3), which was approximately 40 s less than making the bed with no tool (p<0.001). Furthermore, for the overall lumbar spine impulse force, the EasyTuck pad had the largest overall reduction in this category (90.6%). Regarding the subjective data, the EasyTuck pad had an overall rating of 9.4 out of 10, compared to the other tools with ratings of 5.9, 5.1, and 3.4 out of 10, which was a statistically significant difference (p<0.001). Conclusion: Making beds on a regular basis poses risk of injury, especially for those who are required to perform this for their occupation. However, using assistive tools for bed-making, could minimize, and prevent injuries and overload to the lower back, and other parts of the body, making the bed-making task safer. Based on our findings, the EasyTuck pad was by far the most efficient and safest tool to assist in making beds, with the lowest possible risk of injury when compared to all the other tools tested.


Author(s):  
Valerie J. Rice ◽  
Michelle Murphy ◽  
Marilyn Sharp ◽  
Bob Mello ◽  
Randal Bills

Psychophysical techniques for establishing lifting guidelines are used by industry and the military. The instructions used during industrial research refer to maximum acceptable lifts (MAL), while the military uses maximum capacity lifts (MCL). The purpose of this study was to determine male and female soldiers' load selections using two sets of instructions (MAL and MCL) and two lift heights (floor-knuckle and knuckle-shoulder) for three lifting tasks (one-repetition maximum, 1-hr and 8-hr repetitive lifting). Thirteen male and 13 female soldiers participated in this study. A repeated measures analysis of variance identified main effects. Newman-Keuls Comparison of Means were used to examine significant interactions. Results revealed no difference due to instructions. Men selected a greater load than women, and greater loads were selected for floor-knuckle versus knuckle-shoulder (p < 0.05). Although slight differences were seen between loads selected by industrial workers vs. soldiers, the research results appear comparable for repetitive lifting but not for single lifts.


1980 ◽  
Vol 51 (3_suppl2) ◽  
pp. 1203-1214
Author(s):  
Philip Friedman ◽  
Karen P. Alster ◽  
Juanita Y. Reaves

Percentages of correctly imitated grammatical constructions were examined within a framework of reinforcement theory. Four small treatment groups, each of 4 language-delayed children, were repeatedly observed interacting with different student-clinicians. The Therapy Reinforcement Schedule was used to obtain frequency counts of verbal and non-verbal reinforcements so that within each language group the students could be objectively divided into those who frequently and infrequently were reinforcing, and the children into those for whom peer-reinforcement was high or low. The resulting 4 groups were compared for proportions of accurately imitated constructions with a repeated-measures analysis of variance design (student-clinicians' reinforcement × peers' reinforcement × trials). Correctly scored imitations increased significantly over trials. In addition, children interacting with frequently reinforcing students received higher imitation scores than those with infrequently rewarding ones. Significant main effects of reinforcement by the peer group were not observed, although a reliable interaction of student-clinicians' reinforcement × peers' reinforcement was present. Regression analyses indicated the importance of certain types of reinforcements in predicting accuracy of imitation.


1993 ◽  
Vol 15 (3) ◽  
pp. 333-355 ◽  
Author(s):  
Ronald P. Leow

This study investigates the effects of simplification, type of linguistic item, and second language experience on learners' intake of linguistic items contained in written input. Learners at two levels of language experience were exposed to one of the following four conditions: a simplified or unsimplified reading passage with the present perfect tense form or a simplified or unsimplified reading passage with the present subjunctive form. To measure learners' intake, a repeated-measures analysis of variance was performed on the raw scores obtained on a task consisting of a pre- and posttest. The tests were a multiple-choice recognition assessment task. Significant main effects were found for type of passage and language experience, and there was a significant interaction between type of passage and task. Results suggest that simplification does not have a facilitating effect on learners' intake and that learners at different levels demonstrate a different pattern of performance while internalizing written input. Implications for pedagogical written materials and future research are also discussed.


2016 ◽  
Vol 11 (8) ◽  
pp. 1094-1099 ◽  
Author(s):  
Katrina Taylor ◽  
Jeffrey Seegmiller ◽  
Chantal A. Vella

Purpose:To determine whether a decremental protocol could elicit a higher maximal oxygen consumption (VO2max) than an incremental protocol in trained participants. A secondary aim was to examine whether cardiac-output (Q) and stroke-volume (SV) responses differed between decremental and incremental protocols in this sample. Methods:Nineteen runners/triathletes were randomized to either the decremental or incremental group. All participants completed an initial incremental VO2max test on a treadmill, followed by a verification phase. The incremental group completed 2 further incremental tests. The decremental group completed a second VO2max test using the decremental protocol, based on their verification phase. The decremental group then completed a final incremental test. During each test, VO2, ventilation, and heart rate were measured, and cardiac variables were estimated with thoracic bioimpedance. Repeated-measures analysis of variance was conducted with an alpha level set at .05. Results:There were no significant main effects for group (P = .37) or interaction (P = .10) over time (P = .45). VO2max was similar between the incremental (57.29 ± 8.94 mL · kg–1 · min–1) and decremental (60.82 ± 8.49 mL · kg–1 · min–1) groups over time. Furthermore, Q and SV were similar between the incremental (Q 22.72 ± 5.85 L/min, SV 119.64 ± 33.02 mL/beat) and decremental groups (Q 20.36 ± 4.59 L/min, SV 109.03 ± 24.27 mL/beat) across all 3 trials. Conclusions:The findings suggest that the decremental protocol does not elicit higher VO2max than an incremental protocol but may be used as an alternative protocol to measure VO2max in runners and triathletes.


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