Background: The interval between stimulus and response is called reaction time. It measures the sensorimotor function and performance of an individual. It involves stimulus processing, decision making and response programming. Many factors such as age, gender, handedness, physical fitness, sleep, fatigue, distraction, personality type and type of stimulus have been shown to affect reaction time. Thus the aim of this study was to assess the effect of body mass index, handedness and gender on reaction time.Methods: A cross-sectional study was conducted in the Department of Physiology, Kathmandu University School of Medical Sciences, from October 2019 to December 2019, among 113 student volunteers. Height and weight were recorded and body mass index was then calculated. In ruler drop method, the students were made to sit with their forearm resting on a flat horizontal table surface, with their open hand at the edge of the surface. When the examiner suspended and released the ruler vertically the students were instructed to catch it as quickly as possible.Results: Females had a faster reaction time than males when testing either hand (178.46±17.56 Vs 195.99±15.67; right hand) and (184.25±17.02 Vs 199.57±15.91; left hand). In females, right hand responded faster than left hand. In both gender, reaction time was faster in normal weight compared to overweight individuals but it was statistically insignificant.Conclusions: Females responded faster than males. Right hand had shorter reaction time than left hand in females. Reaction time was insignificantly prolonged in overweight individuals. Keywords: Body mass index; reaction time; ruler drop method

Introduction: Driving is a highly demanding profession requiring heightened alertness while remaining in an ergonomically constrained position and also associated with exposure to vehicular pollution and whole body vibration. We explored whether drivers’ reaction time is different to student group who also remain in sitting position for long hours but not exposed to other factors. Materials and methods: Drivers with at least one year of occupational history and under/post-graduate students were randomly selected. Their reaction time in seconds (RT) was measured by the ruler drop method (RDM) and compared with independent t test. Right vs left hand RTs were compared within groups by paired t test. Results: Thirty students (21.8±2.25 years) and 37 drivers (33.73±9.77 years) participated in the study. The drivers had RT of 2.03±0.2s on both the hands; students’ RT were 2.01±0.16s on right and 2.02±0.17s on left hands. For both hands, the differences were not significant between drivers and students (p>0.5). Right and left RT were also comparable for both groups (p>0.5). Conclusions: Bus drivers with at least one year occupational exposure have reaction times ruler drop stimulus not significantly different from controls (students).

Background: Public transport drivers are constantly being exposed to stimuli and are at risk of disorder of peripheral nervous system which can be further complicated by comorbidities. Thus, we wanted to examine intactness of tactile discriminatory ability in healthy drivers by comparing it to healthy samples of non-driving population. Since two point discrimination (TPD) test is frequently used for neurological assessment of tactile stimulation we determined and compared various locations in hands of two populations. Methods: Participants were asked to answer whether they feel one point or two points touch by blunted end of simple compass divider in their hand. The minimum distance between the points at which the participants could answer correctly was noted as two point discrimination value. Results: Drivers had TPD range of 2-4mm with mean 2.53±0.62 and, 1-4mm with mean 2.6±0.72 at middle finger of right and left hand respectively. Following t-test between drivers versus students, significant difference in the mean TPD value in the proximal palm supplied by median nerve (p=0.016) and proximal palm corresponding to ulnar nerve (p=0.032) on the right hand was found. On the left hand, significant difference in the mean TPD value is found in the proximal palm corresponding to median nerve (p=0.008) and ulnar nerve (p=0.043) respectively.   Conclusion: Healthy public transport drivers have less tactile discriminating prowess at proximal palmar surface of hand. Examined distal phalanges and distal palm showed no significant difference in mean of TPD values for healthy drivers versus students.

Reaction time is an indirect index of the processing speed of the central nervous system. It is affected by several factors including dominant and non-dominant hands and obesity. Obesity can be measured by body mass index. Thus, the aim of this study was to find out the relationship between body mass index, dominant and non-dominant hand with visual reaction time in healthy young females. A cross-sectional study was conducted in the Department of Physiology, among 89 females. The height and weight were recorded, and the body mass index was calculated. The subjects were divided into four groups, underweight, normal weight, overweight, and obese according to WHO criteria. Visual reaction time was measured using the ruler drop method in milliseconds. The data were analyzed by using the paired t-test and one-way ANOVA using the IBM Statistical Package for the Social Sciences version 22. Out of 89 participants, 26 (29.21%) were underweight, 47 (52.80%) had normal weight, 12 (13.48%) and four (4.49%) were overweight and obese with mean reaction time in the dominant hand and non-dominant hand were (176.75±16.68 vs. 186.58±16.21), (175.12±15.03 vs. 185.43±15.64), (188.74±16.07 vs. 190.70±17.88), and (200.7±9.77 vs. 210.50±9.50) respectively. All participants were right-handers. In right-handers, the right hand reacted faster than the left hand. Reaction time was prolonged in underweight, overweight,and obese; when compared with normal weight individuals. Our study showed that the reaction time of people appears to be influenced by body mass index, dominant, and non-dominant hand, which was an indirect measure of the sensory motor association.