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INTRODUCTION
Effective use of the hands to engage in daily occupational activities is dependent on a complex interaction
of hand skills, postural mechanisms, cognition, and visual perception. The term visual-motor integration is used to refer
to the interaction of visual skills, visual perceptual skills, & motor skills. The term hand skills may be used interchangeably
with the term fine motor coordination or fine motor skills
Hand skills are those patterns that normally rely on both
tactile-proprioceptive and visual information for accuracy. However, these skills may be accomplished without visual feedback
if somatosensory functions provide adequate information. The patterns include basic reach, grasp, carry, release, and the
more complex skills of in hand manipulation and bilateral hand use.
(Exner charlotte E.)
EXPERIMENTAL DEFINITION
Dexterity, defined as the skillful manipulation of the hands.4 dexterity depends on powerful, distributed neural networks
and includes two concepts of speed and accuracy. It is therefore necessary to couple the two broad divisions of hand dexterity,
i.e. Hand-object coupling and bimanual coordination with speed and accuracy for the purpose of evaluation.
Thus skillful
manipulation of an object by hands often involves reach, grasp, carry, release, and in hand manipulation and bimanual coordination.
Also nails have significant contribution to the hand function or skill. Its contribution is obvious when one has nail bed
or fingertip injury or amputation of finger or thumb. Its importance is even noted when one trims nails recently-may be uneasiness
or temporary drop in function/limited use of hands for limited duration.
In brief, hands are remarkable for their deftness
& in order to evaluate this quality of hand, Rivet & Eyelet Deftness Test (RED test) was devised9, 10. It is non verbal
in nature that tests for both unilateral (stage I through IV) & bimanual tasks (stage V through VII).
AIMS
& OBJECTIVES
1.To evaluate norms on the dexterous task (RED Test) of school & college going students, who
have not yet engage in formal occupation & study variation across the different age groups.
2.To analyze the
factors involved in dexterous task.
Hypothesis
There is variation in hand dexterity across the different
age groups.
METHODOLOGY
Selection criterion-
Age group, between the age of 5 to 25 years of age
Sex,
male and female
Student of school and college, not engaged in any formal occupation
No history of any accidental injury
to hand or upper extremity or not suffering from any disease or chronic disabling condition (no orthopedic or neurological
dysfunction, no congenital abnormality).
Ability to follow the test instructions thereby signifying an average intelligence.
Functional visual acuity
No history of recently trimmed nails of hands
All Indian children from urban setup (Mumbai
& Navi Mumabi)
Consent to undergo the test was taken from the subject. Once ready, explain to the subject the
purpose of test. Also the procedure to be followed is explained. (See the Stages below in Sequence of procedure) Subject is
sitting on the chair with the table in the front on which test equipment is placed. The Wooden test platform is placed vertically
on the table. The platform has the two columns of holes (25 holes on each side). The holes are drilled in such a way that
there is a gap after every five holes so that the counting becomes easier. The depth of the hole is adequate for the height
of the rivets to be inserted. On the far end of the platform there are four containers for the storage of the rivets &
eyelets. Each time the subject has to pick up the rivet or eyelet from these containers. Sitting arrangement made comfortable.
Practice test was given so that the subject is acquainted with the test & can perform well and the test score is
not affected. Also the test is taken in quite room so the distraction can be avoided. Data is recorded with one trial procedure.
This tests assessment categories are divided into seven stages that yields seven separate scores.
Sequence of
procedure
Stage I RIGHT HAND INSERTION (with right hand only).
Preparation: All the holes on the wooden testing
platform should be empty.
Take out one rivet at a time from the container on right side and put it into hole on the right
side of the platform (start from the hole which is nearer to the subject) only with right hand. Repeat the procedure till
the examiner tells to stop. (Duration 60 seconds only).
If the entire column on right hand side of the platform is
complete, then the subject is allowed to continue in column on left hand side of the platform. (Start from the hole which
is nearer to the subject).
Stage II RIGHT HAND REMOVAL (with right hand only).
Preparation: All the holes on
the wooden platform should be filled with the rivets.
Remove the rivet, one at a time, from the holes only with right
hand & putting back into the rivet compartment. Repeat the procedure till the examiner tells to stop (Duration 60 seconds
only).
If the entire column on right hand side of the platform is empty, then the subject is allowed to continue in
column on left hand side of the platform. (Start from the hole which is nearer to the subject).
Stage III LEFT HAND
INSERTION (with left hand only)
Preparation: All the holes on the wooden testing platform should be empty.
Take out
one rivet at a time from the container on left side and put it into hole on the left side of the platform (Start from hole
which is nearer to the subject) only with left hand. Repeat the procedure till the examiner tells to stop. (Duration 60seconds
only)
If the entire column on left hand side of the platform is complete, then the subject is allowed to continue in
column on right hand side of the platform. (Start from the hole which is nearer to the subject)
Stage IV LEFT HAND
REMOVAL (with left hand only)
Preparation: All the holes on the wooden platform should be filled with the rivets.
Remove the rivet, one at a time, from the holes only with left hand & putting back into the rivet compartment. Repeat
the procedure till the examiner tells to stop (Duration 60 seconds only)
If the entire column on left hand side of the
platform is empty, then the subject is allowed to continue in column on right hand side of the platform. (Start from the hole
which is nearer to the subject)
Stage V BOTH HAND INSERTION (with both hands)
Preparation: All the holes on the
wooden testing platform should be empty.
Simultaneously take out one rivet at a time from the container on right side
and from the container on left side with the help of right and left hand respectively. Then simultaneously put each one into
hole on the right side of the platform and hole on left side of the platform respectively. (Start from hole that is nearer
to the subject). Repeat the procedure till the examiner tells to stop. (Duration 60 seconds only)
Stage VI ASSEMBLY
(with both hands)
Preparation: All the holes on the wooden testing platform should be empty.
Take out one eyelet
with one hand & one rivet with another hand and assembling it in such a way that the eyelet is inserted into rivet, so
that the broader end of eyelet is facing below. With such an assembly put the rivet into the hole on the platform (which is
nearer to the subject). (Duration 60 seconds only)
If the entire column on one side of the platform is complete, then
the subject is allowed to continue in column on other side of the platform. (Start from the hole which is nearer to the subject)
Stage VII ASSEMBLY REMOVAL (with both hands)
Preparation: All holes on the wooden platform should be filled with
assembly units as mentioned in Stage VI
Remove the assembly created in the Stage V from the hole, one assembly at a
time & separating eyelet and rivet and the putting them back into the respective containers. (Duration 60 seconds only)
If the entire column on one side of the platform is empty, then the subject is allowed to continue in column on the
other side of the platform. (Start from the hole which is nearer to the subject)
Scoring-the numbers of holes completed
successfully (insertion or removing) are counted & entered on score sheet.
Instructions
Dont allow taking
the rivet or eyelet dropped outside the container. The subject has to collect the rivet or eyelet from the container only.
The subject has to stop the procedure as soon as the examiner says him/her to stop.
For the evaluation of handedness
the questionnaire from Edinburgh Handedness Inventory was used.
OBSERVATIONS & DISCUSSION, CONCLUSION
After
data analyses the findings indicate that there was significant difference in the scores of on different Stages of RED Test
that measured hand dexterity between the age of 5 to 15 years in males & females (at the 0.050 level). Older students
had more scores than the younger students. These findings correlated with the findings of Smith YA et al6 (2000), who evaluated
norms for fine motor dexterity skills on elementary school children of ages 5 through 10.
Bimanual coordination
tended to increase with significant difference as the age increases in both males and females, from 5 through 20 years of
age (at the 0.050 level) (on combined analysis of male & female scores). This finding is similar as with Livia et al8
(1989), who studied the bilateral motor coordination in 5 to 9 year old children. In her study also the sex differences were
not significant up to age of 9.
Score tended to increase with significant difference as the age increases in both
males and females, also for two of the unilateral tasks, up to age of 20 (at the 0.050 level) (on combined analysis of male
& female scores).
Females performed better than males on unilateral & bimanual task of RED Test between
the ages of 10 and 25 but the males performed better between the ages of 5 and 10 years.
However, sex differences for
hand dexterity, (as per the performance on the RED Test) were noteworthy after the age of 15 through 25 (at the 0.050 level).
These sex differences were not evident for left hand insertion of RED Test for the same age groups.
Also hand preference
and asymmetries in motor proficiency are strongly related, as there is better proficiency in right hand than its counterpart.
This finding correlate with the studies done by Pramita et al2 (1996) Triggs WJ et al5 (2000). Triggs WJ et al (2000) defined
handedness as preference or hand difference in task performance and examined hand asymmetries on Purdue Pegboard performance
and Edinburgh Handedness Inventory.
Some of the significant observations include that right & left hand rivet
removal (STAGE II &IV) have more score than arranging the rivets in holes with left and right hand. (STAGE I & III).
This might be because of the time taken for manipulation while picking up rivets from container, when other conditions are
constant like position of test platform & the subject, the distance that the arm movement is covering etc. In STAGE III,
&I the subject has to select a rivet from the bunch of rivets in the container. Thus he/she has to sort it out from the
bunch that takes more time. But at the same time in STAGE II & IV, person has to pick up the rivet directly from holes.
This time he/she does not have to sort it out and requires lesser degree of manipulation.
Also the STAGE III &
I involves arranging the rivets accurately in holes rather than putting them into the container (STAGE II & IV) that is
comparatively easier. Thus the complexity of dexterous task makes the difference in time taken for completing the task.
The next observation that the score of arranging rivets with both hands is always more than with only one hand either
left or right in fixed duration of 60 seconds. This mean that both hands working simultaneously can give rise to greater productivity
than working with one hand or preferred hand or dominant hand on similar kind of task.
Another important observation
was about assembly (STAGE VI). Even though assembly of eyelet and rivets require both hand usage, the score achieved in this
task is lower than arranging rivets with both hands simultaneously. The reason for this can be viewed with respect to the
complexity of the dexterous task that can include following components,
1.The subject has to manipulate & sort two
different objects with both hands, i.e. rivet with one hand and eyelet with another.
2.The condition that broader
end of the eyelet should be facing down.
3.the manipulation of eyelet & rivet with both hands to form an assembly.
4.The number of steps involved in task.
But it is observed some subjects whom I havent considered in data
analyses, were not able to pick up rivets in STAGE II & IV.The only reason was of recently trimmed nails. Thus the nails
have their contribution & importance in hand dexterity in their own way.
The test-retest reliability of the
all the Stages of RED Test was found to be high & content validity was tested. Also experimental hypothesis of variation
in hand dexterity across the different age groups was accepted.
Other uses of this RED Test can be
Pre employment
screening & selection tool = an applicants performance on RED Test can indicate their ability to perform in a job/task
that requires hand dexterity.
In hand therapy set up to obtain baseline data on patient, to compare the pre and post
treatment results
To evaluate eye hand coordination & fine motor coordination
To assess bimanual coordination.
To determine subjects ability & aptitude for certain work related applications & for recommending placement in
job that require manual dexterity.
To determine the effects of drugs on motor coordination in pharmaceutical company
drug trials
Assessing candidates for vocational rehabilitation
Study of Improvement of manual dexterity through
training
Features of the RED Test
All the Stages of the RED Test have fixed duration for performance
that enables easy for comparison between different kind of task like unilateral, bimanual, simple, complex
Helps in assessment
of ability in unilateral, bimanual, simple, complex task on the single platform.
Requires manipulation by nails (Stage
II & IV), thus stresses the importance of nails in hand dexterity.
Test materials itself present the complexity of
task (Stage V)
Findings and observations of the study will be helpful in activity analyses in hand therapy set up.
Also the RED Test will be helpful for the objective evaluation of dexterity. Further study is definitely needed with larger
population along with the standardization of the newly developed test.
Specifications of the testing instrument
Length of the wooden test platform = 59 centimeter
Distance between the two holes in series = 1cm
Gap after every
five hole series = 2.5 cm
Diameter of the container = 5.5 cm
Number of containers = 4
Holes in column on right
side = 25 in number
Holes in column on left side = 25 in number
Distance between the two columns = 10 cm
Distance
of the column from the edge of the wooden platform on each side
1.right = 4 cm
2.left = 4 cm
Diameter of each
hole drilled in the wooden platform = 4 mm
Distance between first hole of column & edge of the wooden platform = 5
cm
Distance of the container from the edge = 2 cm
Distance between the two containers = 1 cm
Depth of the container
= 1.1cm
Thickness of the wooden platform = 2.7 cm
Height of the Aluminum rivet = 1.3 cm
Height of the eyelet =
5 mm
Diameter of the smaller end of the eyelet = 6 mm
Diameter of the broader end of the eyelet = 9 mm
REFERENCES
1.Ruth Humphry et al Development of in hand manipulation and relationship with activities, American Journal of Occupational
Therapy, (Sept. 1995) vol-49, no.8 page 763-771
2.Pramita Shenoy et al, Study of manual dexterity & grip strength
in flexor tendon injuries of hand, (August 1996) Indian Journal of Occupational Therapy, VOL.XXV, NO.2, 4-8.
3.Pratt,
P.N. & Allen, A.S. (1996) Occupational therapy for children (3rd d.): Development of Hand skills, Charlotte E.Exner, St.
Louis, Baltimore, and Toronto: The C.V.Mosby Company.
4.Wiesendanger M, Serrien DJ.Toward a physiological understanding
of human dexterity. News Physiol Sci 2001 Oct; 16:228-33 5.Triggs WJ, Calvanio R, Levine M, Heaton RK, Heilman KM. Predicting
hand preference with performance on motor tasks Cortex 2000 Dec; 36(5): 679-89
6.Smith YA, Hong E, Presson C. Normative
and validation studies of the Nine-hole Peg Test with children. Percept Mot Skills 2000 Jun; 90(3 Pt 1): 823-43
7.Clerke,
A. & Clerke, J. (2001), A literature reviews of the effect of handedness on isometric grip strength difference of the
left & right hands. American Journal of Occupational Therapy, 55,206-211.
8.Livia C.Magalhaes et al, (1989) bilateral
motor coordination in 5 to 9 year old children: A pilot study American Journal of Occupational Therapy, vol.43, No.7
9.Lafayette
instrument, (revised edition 1999) Quick reference guide for the Purdue Pegboard#32020,Test Administrators Manual.
10.Mark
V.Johnston et al (1992) Measurement standards for interdisciplinary medical rehabilitation, Archieves of Physical Medicine
& Rehabilitation, Vol73, No.12-S.
ACKNOWLEDGEMENT
Words have their own handicaps. At no time is this
more apparent than when one tries to put in words his feeling of gratitude for those who have helped in a trying venture.
This work nevertheless, shall be incomplete, if I dont put or record my heart felt gratitude.
I would like to convey
my sincere thanks to Dr.Mrs.Shashi Oberoy, Head of Department, Padmashree Dr.D.Y.Patil College of Occupational Therapy and
Dr.Mukund Ketkar, Dean, Padmashree Dr.D.Y.Patil Medical College, for allowing me to conduct this study in the institute.
I also express my sincere gratitude to Mr. J.C.Sharma for guiding me regarding statistics of the study.
Last but not
the least, I give a million thanks to my subjects who participated in this study.
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