Muscle Strength
Protocol 150301
Id
Version
#
1
Descripti Hand grip strength is measured with a device called a hand-held dynamometer. The
on of
technician follows a script and asks the participant about hand surgery or pain that
Protocol may influence the results. The technician asks the participant to sit in a chair and rest
his/her arm on the table with the elbow on top of a mouse pad and arm held at a
right angle. The technician adjusts the grip size of the dynamometer to the
participant’s hand size and explains how the device works. The participant squeezes
the dynamometer twice during practice trials. Now, starting with the right hand the
participant is asked to squeeze as hard as possible. Two trials are attempted with
each hand with all results recorded on a form. Results should be recorded to the
nearest 2 kilograms.
Specific This protocol is specific to the Jamar dynamometer. The following dynamometers
Instructi have also produced valid and reliable hand grip test results: Takei Grip A
ons
dynamometer, Model 68812, Lafayette Instruments 50//100 and 100 kg / 220lb Hand
Grip Dynamometer set, and TKK digital hand dynamometer (TKK 5101 Grip-D Model).
The grip setting on the dynamometer (adjustment for hand size) should be recorded,
especially for repeated (longitudinal) measurements.
The technician should utilize the dynamometer manufacturer’s user manual for
proper use and maintenance of the dynamometer and check the calibration of the
device with known weights once a week.
Protocol
Text
GRIP STRENGTH
Hand-Held Dynamometry
1. Background and rationale
Muscle strength is an indicator of muscle function and therefore an important
outcome of this study. Fiatarone et al. [Ref. 1] have postulated that strength is a
more important limiting factor than cardiovascular endurance in the ability of older
individuals to maintain an independent lifestyle.
Muscle strength decreases with age but little is known about the influence of changes
in muscle mass, fat mass, and physical activity on this decrease.
Grip strength is a commonly used measure of upper body skeletal muscle function and
has been widely used as a general indicator of frailty. Grip strength in both hands will
be measured using an adjustable, hydraulic grip strength dynamometer.
2. Equipment and supplies
• Jamar Hydraulic Hand Dynamometer which registers maximum kilograms of force
during a trial, with adjustable handgrip
• Standard chair
• Table (moveable tray table preferred)
• Mouse pad
Use and Maintenance: For routine maintenance, follow the instructions in the Jamar
dynamometer owner’s manual.
To use the dynamometer:
1. Please remember that it is a precision instrument and its accuracy can be impaired
by abuse. Never force the handles or subject the instrument to unnecessary impact.
2. Set the adjustable handle to the desired spacing. (Before moving the handle from
one position to another, note that the handle clip is located at the lower (furthest)
post from the gauge. If the handle is not replaced in the correct position, the readings
will not be accurate.)
3. Rotate the red peak-hold needle counter-clockwise to 0. Always look straight ahead
at the dial when reading.
4. After the participant has used the instrument, reset the peak-hold needle to zero
before attempting a new reading.
Service Tips: To make sure the instrument is reading accurately, it’s a good idea to
make a few checks each month, as listed below. If you detect a problem, report this
to the quality control (QC) officer.
Posts: Remove the adjustable handle and check that each post moves up and down
freely (through a very small distance, about 1/8") within the plastic aperture (the
guide) even when you exert pressure on the side of the post. About once a year, place
a small amount of grease on the two guides. If excessive friction exists between the
post and guide, return the dynamometer to the QC officer.
Hydraulics: To check the hydraulic mechanism, first remove the adjustable handle.
While watching the top post, push down on the bottom post. Normally, both posts
should move about 1/8", with top and bottom posts moving in opposite directions.
Movement less than 1/16" indicates a probable leak in the hydraulic system, which
requires service. Return the dynamometer to the QC officer.
Handle: Grasp the instrument normally and look carefully at the way the forks of the
adjustable handle are supported on the posts. Each fork should touch the post at
approximately its mid-point. If this is not the case, return the instrument to your
supervisor.
Peak-Hold Needle: Check for excessive friction in the peak-hold assembly by turning
the peak-hold knob counter-clockwise. If the peak-hold needle causes the gauge
needle to move, return the gauge for service.
If the peak hold needle is knocked off its support pin, it can readily be repositioned.
Unscrew the crystal and turn it upside down. Locate the brass pin in the center of the
crystal (the pin is part of the chrome knob on the outside of the crystal). Locate the
slot on the brass pin and place the peak-hold needle into this slot.
Calibration check:
Every week: Check the calibration of the grip strength dynamometer by hanging 5 kg
and 20 kg (or 10 and 50 lb) weights across the handle using two velcro straps, one
strap on each side of the dynamometer handle, or one wide strap that covers the
whole handle. Lift the weights slowly from the floor while they are strapped to the
dynamometer handle and record the maximum kilograms registered. The lifting
motion should be very slow and smooth, and the weight should remain evenly
distributed between the two sides of the handle. Repeat the procedure three times
and record each result.
Average the three calibration trials. The dynamometer should be accurate within � 2
kgs for the average of the three calibration trials. If the calibration check is not
within these limits, notify the QC officer. It may be necessary to send the
dynamometer to the manufacturer for repair and recalibration. DO NOT attempt to
recalibrate the dynamometer yourself. Calibration problems can be caused by
dropping the dynamometer or by leaks in the hydraulic system.
Recalibration Directions for QC Officer: To get the dynamometer recalibrated, call 1800-323-5547 (Sammons-Preston). They give out an authorization number which you
then put on the outside of the box in which you’ve packaged the dynamometer. Do
not send in the dynamometer without the authorization number. Send the box to
Sammons Preston, Attn: Tech. Services; 2010 East High Street; Jackson, MI 49203.
They will return the dynamometer within 5 to 7 days.
3. Safety issues and exclusions
This test should not be performed in the affected hand of the participant:
• has undergone fusion, arthroplasty, tendon repair, synovectomy, or other related
surgery of the upper extremity in the past 3 months.
If only one side is affected, test the unaffected side.
The test can be performed if the participant has a current flare-up of pain in their
wrist or hand; for example arthritis or tendonitis. Be sure to record this information
on the data collection form.
4. Participant and exam room preparation
The participant should be seated at a standard height table or on a seat with a
moveable tray table attached.
5. Detailed measurement procedures
5.1 General issues/description
Grip strength will be measured in two trials of each hand (unless there are
extenuating circumstances - see above) using a hydraulic, isometric dynamometer.
5.2 Administration
1) Determine if the participant has had surgery on their hands or wrists in the past
three months.
Script: "Have you had any surgery on your hands or wrists in the past three months?"
If the participant says "Yes," ask them which hand or wrist was operated on, and
do not test that hand. Record this information on the data collection form.
2) Determine if the participant has an acute or recent flare of arthritis in their hands.
Script: "Has any pain or arthritis in your right hand gotten worse recently?"
Record answer on form. Then, if they answer "Yes," ask:
Script: "Will the pain keep you from squeezing as hard as you can?"
Record answer on form. Then ask:
Script: "Has any pain or arthritis in your left hand gotten worse recently?"
Record answer on form. Then, if they answer "Yes," ask:
Script: "Will the pain keep you from squeezing as hard as you can?"
Record answer on form.
Pain or arthritis that has gotten worse recently is not an exclusion for this test. If the
participant is willing to have the grip strength test, test the participant and record
the results on the data collection form.
3) Demonstration and practice
The examination is done with the participant in the sitting position with the arm to be
tested resting on the table and the elbow held at approximately a right angle. The
dynamometer is held in the hand to be tested and is resting on a mouse pad.
Script: "I’d like you to take your right/left, arm, rest it on the table, and bend your
elbow. Grip the two bars in your hand, like this. Please slowly squeeze the bars as
hard as you can."
Demonstrate the correct grip and arm position. As you demonstrate, instruct the
participant to squeeze the hand maximally.
Adjust the grip size so that the participant holds the dynamometer comfortably (this
will almost always be the second setting). If the handle hits the participant’s hand
distal to the second knuckle the grip size should be smaller. Allow
one submaximal practice trial to determine if the procedure is understood by the
participant and the grip size properly adjusted. If the participant’s finger nails are
hitting their palm the dynamometer needs to be adjusted to a larger grip size.
Script: "Now try it once just to get the feel of it. For this practice, just squeeze
gently. It won’t feel like the bars are moving, but your strength will be recorded. Are
the bars the right distance apart for a comfortable grip?"
Show dial to participant. Adjust the handgrip again, if necessary.
4) Test grip.
Script: "We’ll do this two times. This time it counts, so when I say squeeze, squeeze
as hard as you can. Ready. Squeeze! Squeeze! Squeeze! Now, stop."
Have the participant perform the test, starting with the right hand. Set the
dynamometer to zero prior to each attempt:
Record the kilograms pulled from the dial to the nearest 2 kilograms. If the reading is
exactly between two readings on the scale, round up to the next higher even number.
Reset the dial to "0" after each trial.
Perform two trials with at least 15 to 20 sec rest in between.
Script: "Now, one more time. Squeeze as hard as you can. Ready. Squeeze! Squeeze!
Squeeze! Now, stop."
5) Repeat the procedure on the left side, unless contra-indicated.
6. Procedures for performing the measurement at home
No modifications required.
7. Alert values/follow-up/reporting to participants
When the test is completed tell the participant how many kilograms were read on the
dial and that they did just fine.
Record maximum kilograms for each side on participant’s results form.
8. Quality assurance
8.1 Training requirements
The technician requires no special qualifications for performing this assessment. The
training should include:
• Read and study manual
• Attend Health ABC training session on techniques (or observe administration by
experienced examiner)
• Practice on other staff or volunteers
• Discuss problems and questions with local expert or QC officer
8.2 Certification requirements
•
•
•
•
•
•
Complete training requirements
Demonstrate maintenance check of dynamometer
Demonstrate the proper adjustment of dynamometer handles
Demonstrate the calibration check procedures
Recite exclusions
Conduct exam on 2 volunteers:
- According to protocol, as demonstrated by completed QC checklist
- � 2 kgs on repeat assessment of volunteer
8.3 Quality assurance checklist
[
[
[
[
[
[
[
[
[
[
[
[
[
] Participant is asked about recent surgery on hands
] Participant is asked about pain and arthritis in hands
] Correct instructions given while demonstrating procedure
] Recording dial reset to zero after sub maximal practice
] Sub maximal practice; grip adjusted if necessary
] Forearm resting on table, elbow bent to approximate right angle
] Standard encouragement (motivation and feedback) offered to participant
] Recording dial (peak hold needle) reset to zero after first trial
] Measurement taken twice on each side (unless contra-indicated)
] Key points from script delivered clearly
] Correctly completes form
] Reviews form for completeness
] Log indicates calibration check up to date
9. Reference
Fiatarone, M. A., Marks, E. C., Ryan, N. D., Meredith, C. N., Lipsitz, L. A., & Evans,
W. J. (1990). The etiology and reversibility of muscle dysfunction in the aged. Journal
of the American Medical Association, 263, 3029-3034.
__________________________________________________________________________
__________________________________
Acknowledgment. This chapter is adapted from the Fracture Intervention Trial
(FIT) Operations Manual.
10. Data collection form
HABC Enrollment ID # Acrostic
Type of
Annual
Contact
Start ID#
○ Year 8 ●
Year 10
GRIP STRENGTH
(Hand-Held Dynamometry)
1. Have you had any surgery on your hands or wrists in the past 3 months?
○ Yes
○ No
○ Don’t Know ○ Refused
Which hand?
○ Right
○ Left
Do NOT test right.
○ Both Left & Right
Do NOT test left.
Do NOT test either hand.
Go to Questions #4 and #5 on next
page and mark "Unable to
test/exclusion/didn’t understand."
2. Has any pain or arthritis in your right hand gotten worse recently?
○ Yes
○ No
○ Don’t Know ○ Refused
Will the pain keep you from squeezing as hard as you can?
○ Yes
○ No
○ Don’t Know
3. Has any pain or arthritis in your left hand gotten worse recently?
○ Yes
○ No
○ Don’t Know ○ Refused
Will the pain keep you from squeezing as hard as you can?
○ Yes
○ No
○ Don’t Know
Script: "I’d like you to take your right/left arm, rest it on the table, and bend your elbow.
Grip the two bars in your hand, like this. Please slowly squeeze the bars as hard as you
can."
Examiner Note: Hand the dynamometer to the participant. Adjust if needed.
Script: "Now try it once just to get the feel of it. For this practice, just squeeze gently. It
won’t feel like the bars are moving, but your strength will be recorded. Are the bars the
right distance apart for a comfortable grip?"
Examiner Note: Show dial to participant.
Script: "We’ll do this two times. This time it counts, so when I say squeeze, squeeze as
hard as you can. Ready. Squeeze! Squeeze! Squeeze! Now, STOP."
4. Right Hand ○ Unable to test/exclusion/didn’t understand
Trial 1
kg
○ Refused ○ Unable to complete
Examiner Note: Wait 15-20 seconds before second trial.
"Now, one more time. Squeeze as hard as you can. Ready. Squeeze! Squeeze! Squeeze!
Now, STOP."
Trial 2
kg
○ Refused ○ Unable to complete
Repeat the procedure on the left side.
5. Left Hand ○ Unable to test/exclusion/didn’t understand
Script: "Now we’ll test your left side. When I say squeeze, squeeze as hard as you can.
Ready. Squeeze! Squeeze! Squeeze! Now, STOP."
Trial 1
kg
○ Refused ○ Unable to complete
Examiner Note: Wait 15-20 seconds before second trial.
"Now, one more time. Squeeze as hard as you can. Ready. Squeeze! Squeeze! Squeeze!
Now, STOP."
Trial 2
kg
○ Refused ○ Unable to complete
Selection This hand grip protocol is relatively easy to administer and was used during a major
Rational epidemiology study of more than 3,000 participants. The American Society of Hand
e
Therapists (ASHT) recommends that the hand grip strength test should be performed
with the elbow flexed at 90°, which is the procedure described.
Source
National Institutes of Health. National Institute on Aging. The Health, Aging and Body
Composition (Health ABC) Study. Operations Manual Volume XII. Grip Strength. 2006.
Languag
e
English
Participa Age 8+
nt
Personne
l and
Training
Required
Technician trained to properly maintain and check the calibration of a dynamometer.
The technician should read the dynamometer user’s manual and the study procedures
manual and practice the grip strength test with volunteers. Problems with the device
should be directed to an expert or QC officer.
Equipme Jamar Hydraulic Hand Dynamometer which registers maximum kilograms of force
nt Needs during trial, with adjustable hand grip.
Other equipment needed includes: Standard chair
Table (moveable tray table preferred)
Mouse pad
Standard
s
Standard
Name
ID
Source
Common Data Elements (CDE)
Person Hand Grip muscle
strength Kilogram Value
3061229 CDE Browser
Logical Observation Identifiers
Names and Codes (LOINC)
Muscle strength proto
62821-4 LOINC
General Luna-Heredia, E., Mart�Pe�a, G., & Ruiz-Galiana, J. (2005). Handgrip dynamometry
Referenc in healthy adults. Clinical Nutrition. 24(2): 250-8.
es
Newman, A. B., Haggerty, C. L., Goodpaster, B., Harris, T., Kritchevsky, S., Nevitt,
M., Miles, T. P., Visser, M. & Health Aging And Body Composition Research Group
(2003). Strength and muscle quality in a well-functioning cohort of older adults: the
Health, Aging and Body Composition Study. Journal of the American Geriatric
Society. 51(3): 323-30.
Newman, A. B., Kupelian, V., Visser, M., Simonsick, E. M., Goodpaster, B. H.,
Kritchevsky, S. B., Tylavsky, F. A., Rubin, S. M., & Harris, T. B. (2006). Strength, but
not muscle mass, is associated with mortality in the health, aging and body
composition study cohort. J Gerontol A Biol Sci Med Sci. 61(1): 72-7.
Rantanen, T., Harris, T., Leveille, S. G., Visser, M., Foley, D., Masaki, K., & Guralnik,
J. M. (2000). Muscle strength and body mass index as long-term predictors of
mortality in initially healthy men. J Gerontol A Biol Sci Med Sci. 55(3): M168-73.
Rantanen, T., Guralnik, J. M., Foley, D., Masaki, K., Leveille, S., Curb, J. D., &
White, L. (1999). Midlife hand grip strength as a predictor of old age disability.Journal
of the American Medical Association. 281(6): 558-60.
Schl�ssel, M. M., dos Anjos, L. A., de Vasconcellos, M. T., & Kac, G. (2008).
Reference values of handgrip dynamometry of healthy adults: a population-based
study. Clinical Nutrition. 27(4): 601-7.
Trudeau, F., Laurencelle, L., & Shephard, R. J. (2009). Is fitness level in childhood
associated with physical activity level as an adult? Pediatr Exerc Sci. 21(3): 329-38.
Wind, A. E., Takken, T., Helders, P. J., & Engelbert, R. H. (2010). Is grip strength a
predictor for total muscle strength in healthy children, adolescents, and young
adults? Eur J Pediatr. 169(3):281-7.
Protocol Physical Measurement
Type
Derived None
Variables
Require
ments
Requirement Category
Required
Average time of greater than 15 minutes in an unaffected individual
No
Average time of greater than 15 minutes in an unaffected individual
Major equipment
No
This measure requires a specialized measurement device that may not be
readily available in every setting where genome wide association studies
are being conducted. Examples of specialized equipment are DEXA,
Echocardiography, and Spirometry
Specialized requirements for biospecimen collection
No
This protocol requires that blood, urine, etc. be collected from the study
participants.
Specialized training
This measure requires staff training in the protocol methodology and/or in
the conduct of the data analysis.
No