The Influence of Hand Dominance on Neur

The Influence of Hand Dominance on Neuromuscular Reaction Time

Abstract
Neuromuscular reaction time may be influenced by hand dominance. This study examined whether hand dominance could influence the measurements of neuromuscular response by catching a meter stick in free-fall. A total of 9 subjects were examined with respect to hand dominance. The mean of the neuromuscular reaction time of the dominant and non-dominant hand was 268 mm and 314 mm, respectfully. The neuromuscular reaction time of the dominant hand was 46 mm quicker which agreed with the hypothesis. Introduction
The results from the following experiment examine the details as to whether hand dominance affects neuromuscular reaction time. Most people are not ambidextrous and usually have a dominant hand, referred to as “right or left handedness.” The purpose of this experiment was test whether a test subject’s dominant hand was able to react faster than their non-dominant counterpart.

Materials
Meter Stick

Methods
Each lab group designated a group member to drop a meter stick and a subject to catch it with their dominant hand. The designated member held the meter stick in front of and just above the subject’s wide open dominant hand. The subject’s dominant hand was positioned just off the edge of the table while the elbow was resting in a 90 degree position on the table. When the meter stick was dropped, the subject then caught the meter stick with their dominant hand as fast as rapidly as possible. The measurement was taken where the index finger was placed upon capture of the meter stick. This method was repeated twice more with the dominant hand. Then, this procedure was repeated using the non-dominant hand allowing for 18 group data points total. All three lab groups in the class repeated a similar method. The data was gathered from all 3 lab groups in the class. The subject’s average of neuromuscular reaction time with respect to dominant and nondominant hands were calculated.
Results:

Table-A. Individual Profile and Experimental Reaction Times.

Reaction Time (mm) I------- Trial -------I
Subject Gender Musician Hand Athlete 1 2 3 Avg.(mm)
FH M N D Y 330 200 160 230
JB M N D Y 210 240 240 230
JN F Y D N 330 280 240 283
FH M N ND Y 270 150 150 190
JB M N ND Y 240 320 270 276
JN M Y ND N 300 280 250 276
EL F N D N 370 615 211 397
AV F N D N 345 80 211 183
MW F N D Y 100 170 125 171
EL F N ND N 340 620 315 425
AV F N ND N 280 380 175 280
MW F N ND Y 625 205 250 360
NA F N D Y 340 330 280 317
BT M N D Y 200 230 230 220
NL M N D Y 220 270 340 277
NA F N ND Y 490 320 290 367
BT M N ND Y 290 290 280 288
NL M N ND Y 340 410 330 360

Annotations:

Subject = Individual Initials
N = No
Y = Yes
M = Male
F = Female
D = Dominant Hand
ND = Non-Dominant Hand

Sample Calculation:

Average (mm) = (Trial 1 (mm) + Trial 2 (mm) + (Trial 3 (mm)) / Total Number of Trials

230 mm avg. = (330 mm + 200 mm + 160 mm)/ 3 Trials

Table-B. Class Reaction Time (mm) Averages:

Subject Dominant Hand (mm) Non-Dominant Hand 1. FH 230 190 2. JB 230 276 3. JN 283 276 4. EL 397 425 5. AV 183 280 6. MW 171 360 7. NA 317 367 8. BT 320 288 9. NL 277 360

Table-C. Class Overall Reaction Time (mm) Average:

Avg. Reaction Time (mm) =

∑ (Subject 1 avg. (mm) + Subject 2 avg. (mm) + ... + Subject 9 avg. (mm)) Total Subjects (9)

Dominant Hand Class Avg. = 2408/9 = 267.5 mm. ≈ 268 mm.

Non-Dominant Hand Class Avg. = 2822/9 = 313.5 mm. ≈ 314 mm.

Table-D. Dominant Hand vs. Non-Dominant Hand Reaction Time Difference (mm):

Non-Dominant Hand (mm) - Dominant Hand (mm) = Reaction Time Difference

314 mm - 268 mm = 46 mm (faster with dominant hand)

Discussion: “Hand-dominance” is terminology commonly used to express an individual’s preference of using one hand or the other when conducting gross and fine motor movements. These movements may include tasks such as writing, playing an instrument, throwing a ball, or, as in the case of our experiment, grasping a free-falling meter stick. If a person’s right hand is dominant, they are referred to as “right-handed.” Likewise, if an individual is left hand dominant, he or she is referred to as “left-handed.” The exact influence of whether a person in right- or left-hand dominant is subject to debate, although some research has proposed that the cause(s) may result from a combination of both biological and genetic factors. Nonetheless, it is known that person's reaction time in grasping a free-falling meter is linked to neurological pathways involving the eyes, brain, and muscle motor-neurons. This experiment attempted to assess whether a person’s self-proclaimed hand dominance influenced the rate at which he, or she, would react to a falling meter stick and fully grasp it. The rate of catching the meter stick was inferred by the length of the free-fall measured in millimeters (mm).
The results of our experiment supported the hypothesis that the dominant hand of the subject would react more quickly in grasping the meter stick than that of the non-dominant hand. This was demonstrated by the experimental results. The results indicated that the class, overall, was able to react to and catch the meter stick with an average reaction time of 268 mm utilizing the dominant hand (Table-C). Alternatively, the results indicated a class overall average reaction time of 314 mm (Table-C) using the non-dominant hand. The difference of the two class mean reaction time values was 46 mm, in favor of dominant hand use (Table-D). This data confirmed the hypothesis that neuromuscular responsiveness to grasping a falling meter stick is influenced by hand dominance.
Several other variables were also included in the test subject profiles. These were not considered in the testing procedure or analysis. These additional variables included: gender, whether the subject was a musician, and whether a subject is an athlete (Table-A). Further testing utilizing any of these accessory variables might indicate a departure from the results of this particular experiment and would require the development and testing of a new hypothesis. Other valid variables of neuromuscular reaction time which were not included in the test subject profiles might also encompass age, ocular acuity (whether a subject requires prescription eyewear), or history of a remote neuromuscular injury or pathology. These variable are beyond the scope of this experiment and would require more subject demographic history and data to perform the experiment and analyze the results. Future experiments which assess the relatedness of hand dominance to neuromuscular reaction time should include a more complete test subject questionnaire. A more complete subject history would allow for more variables to be taken into consideration when forging a hypothesis and developing the experimental procedure. The data, and data analysis acquired from experiments involving additional demographic, independent variables would permit a more comprehensive assessment. With additional assessments and further data analysis, alternate hypotheses and/or conclusions might be generated.

Conclusion: The association between hand dominance and neuromuscular reaction time was tested in this experiment. The hypothesis of this experiment stated that neuromuscular reaction time may be influenced by hand dominance. After testing was accomplished using a meter stick drop test, data was collected and analyzed. The individual subject mean and the class overall mean values were calculated. These data values were compared. The results indicate that there does exist a positive correlation between neuromuscular reaction time and hand dominance. The results indicated that overall, test subjects displayed a much more rapid reaction time in fully grasping a meter stick during free-fall with their self-proclaimed dominant hand than they did using their non-dominant hand. Various other subject demographic variable data were collected during the course of the experiment, but were excluded in the final analysis. Further testing including other subject demographic data may further support the findings of this experiment.