Reaction time norms as measured by ruler drop method in school-going South Asian children: A cross-sectional study

The establishment of a population-specific reference value for the ruler drop test for the clinical assessment of reaction time

BACKGROUND

Reaction time (RT) is the interval between a stimulus and an appropriate voluntary response in an individual. Alcohol is known to result in delayed RT. In Sri Lanka, an alleged drunken driver is legally subjected to a medico-legal examination to confirm or exclude impairment. The guideline for examining a drunk person in Sri Lanka includes the ruler drop test (RDT) as a test of RT. RDT is a simple test of visual reaction time in which the subject attempts to stop a falling ruler, and the height fallen is used to determine the time taken to react to the event. However, a formal study has yet to be carried out to establish population-specific reference values to interpret RDT results.

METHODS

A cross-sectional descriptive study was conducted using 903 adults ≥18 years. A nonparametric approach was applied for deriving the reference values based on an inter-percentile interval.

RESULTS

The study population consisted of 56.6% females, and the mean age of the participants was 41.6 years. Most (95%) of the study population could catch the ruler at or less than 40.0 cm of average height. The average height on RDT increased from younger to older age groups. However, subgrouping based on other variables, including sex, age, and alcohol consumption, did not show any statistically significant difference.

CONCLUSIONS

The population-specific cut-off limit to identify alcohol intoxication by RDT in a Sri Lankan adult is 'average height' >40 cm.

The Impact of Age, Gender and Technical Experience on Three Motor Coordination Skills in Children Practicing Taekwondo

The study aim was to investigate the age, gender and technical level on motor coordination abilities of Taekwondo children. One hundred and fifteen children (83 male, 32 female), aged 7.76 ± 1.71 years, divided in three different groups, under 8 (5–7 years), under 10 (8–9 years) and under 12 (10–11 years), underwent three coordination skills tests: the ruler drop test (RDT), assessing visual reaction time, the hexagonal test (HT), assessing agility, and the target kick test (TKT), assessing kicking ability. MANOVA showed significant gender differences for TKT, in which females showed higher scores than males (p = 0.033). Significant differences were found in HT and TKT, where the under 12 group showed higher scores than younger athletes (p < 0.001). No differences amongst different age groups were found in RDT, showing that this could be a good predictor of Taekwondo performance, assessed at an early stage. High-level athletes showed better scores in all the tests than the low levels, as it was expected. Coordinative performance improves with age and is positively influenced by practicing a sports activity. The predisposition to a particular sport with a well-planned training may lead to a motor proficiency comparable to that reached by older athletes and better than same-age athletes.

The impact of fatigue on agility and responsiveness in boxing

Study aim: To assess the effects of fatigue on agility and responsiveness in boxing.

Material and methods: Agroup of 20 amateur boxers aged 14–45 years participated in the study. Ditrich’s test and acomputer test, both measuring the speed of reaction to avisual stimulus, as well as agility run and 4 × 10 m shuttle run with carrying blocks, both measuring agility, were performed. Running agility and reaction speed were measured at 3levels of fatigue expressed by the heart rates. The capacity to maintain the highest possible level of measured variables was assessed by applying the performance index (PI) (mean value of three or four (in the case of Ditrich’s test) repetitions to the maximum one). Student’s t-test for dependent data and Pearson’s correlation coefficients were used in data analysis, the level p ≤ 0.05 being considered significant.

Results: Both running agility and responsiveness markedly decreased with mounting fatigue, e.g. running speed from 1.73 ± 0.12 m/s to 1.55 ± 0.11 m/s.

Conclusion: Developing anaerobic endurance would markedly improve agility skills and speed of reaction to external stimuli. Measuring the performance index (PI) from short, maximal, repeated exertions spaced with constant intermissions may be a valuable tool in directing training activities towards development of selected elements of boxers’ physical fitness.

Reaction Times of Preschool Children on the Ruler Drop Test: A Cross-Sectional Study With Reference Values

Reaction time (RT) tasks assess several brain functions, and a slow RT can be due to various brain diseases, disorders, and acquired conditions. This study examined age and gender differences in RTs of Spanish preschool children on the ruler drop test (RDT) and presents norm-referenced results. Participants were 3,741 children (1,845 girls and 1,896 boys; mean [M] age = 55.93, standard deviation [ SD] = 11.14 months; M body mass index = 15.94, SD = 1.91 kg/m²), selected from 51 schools in southern Spain. We measured RT with the RDT, and we collected both right- and left-hand data. We expressed normative mean RDT values of both hands according to gender and age in percentiles. Based on mean RDT scores, girls exhibited a poorer performance than boys aged 4 years ( p = .032, Cohen's d = - 0.122) and 5 years ( p = .001, Cohen's d = -0.194). For the whole group, RDT performance was faster with increased age, from the age of five years.

Increasing cardiopulmonary aerobic activity improves motor cognitive response time: An inference from preliminary one-group pretest-posttest quasi-experimental study

Motor cognitive response time (MCRT) is the time elapsed between presenting a stimulus and the time taken by that individual to respond to that stimulus through a motor performance. After completing aerobic exercise, there are various changes that takes place, one of which might be change in cognitive function. Whether cardiopulmonary aerobic activity/capacity has an impact on MCRT is not explored yet.