Safe Maximal Carry, Endurance Carry and Push/Pull Activities
(see equations p. 57)
Safe
Maximal Carrying Testing
Reason for performing
test:
The test is to determine the safe maximal carry (SMC) load to be performed over an
eight (8) hour day. This can be carried out as a unilateral carry (R) or (L) or a
bilateral carry.
Bilateral Carry:
- Set box at bench height with appropriate weight for the test. Other heights can be
utilized however to more accurately simulate work requirements.
Take beginning heart rate and pain levels.
Demonstrate the type of lift to be performed both visually and verbally (see safe
manual handling for directions )
Prepare to start stopwatch. Start client and
stopwatch together.
Have the client take the box from bench height and carry it the appropriate distance,
turn around and return to original position.
A minimum distance of 5 7 meters should be performed.
After each carry distance performed, an extra weight is added - see SML procedure.
Weights should be added in 2.5 kg increments until an additional 2.5 kg is too much,
then use .5 kg weights to get as close to max as possible.
The client is asked prior to beginning the next weight, "I have increased the
weight, would you like to continue?"
Continue until maximum weight is carried.
This is repeated until:
1) The client refuses to continue with the reason then being recorded.
2) The evaluator ceases the test due to inherent dangers developing during the test.
(i.e., unsafe lifting, heart rate or blood pressure exceeds predetermined limits for the
individuals safety, or compensatory lifting techniques are observed)
Unilateral Carry:
Use bucket / tool box or similar for this test
Place at appropriate height.
Procedure as above.
Repeat for opposite side.
Equipment required:
- Boxes
- Shelving
- Weights
- Heart Rate Monitor
- Stopwatch
- Tape Measure
- Bucket
Hint:
Use 50% of S.M.L. weight for the starting point of the Safe Maximal Carry (bilateral)
and 25% for S.M.C.(unilateral). This will reduce the testing time without altering the
result.
Use of BABI monitoring and careful observation of substitution patterns will ensure
accurate cut-off points for safe maximal carry values.
It is convenient to take the heart rate for B.A.B.I. at the completion of each weight
increment.
Endurance Carry
- Use same method as endurance lift test with submaximal weight i.e., 50% of the S.M.C.,
- Set boxes or shelving at optimum work related height for the task in question
- Start with weight chosen by client in box or crate
- Take a Baseline Heart Rate
- Demonstrate the type of carry to be performed both visually and verbally (see safe
manual handling )
- Prepare to start stopwatch. Start client and stopwatch together.
- Have the client perform continuous repetitions of the safe carry until he/she can
no longer safely continue performing the task.
- Repeat the Carry. At the end of each carry distance, the box may be momentarily placed
at bench height and the fingers released to reduce fatigue. This should not interrupt the
cadence of the test.
- Cease testing at the evaluators discretion and be sure to count the repetitions.
- See Endurance lift for protocol in this area.
Push/Pull
Accurate determination of values depends on equipment available and its use during this
testing procedure.
Due to the combined forces used during pulling, it is very difficult to accurately test
these activities. Until further research is done into testing methods, three (3) options
are advised.
- Static push/pull activities are observed and monitored for
kinesiophysical signs as well as heart rate, perceived exertion and
pain levels.
- Dynamic push/pull activities using a loaded sled and comparing to the
work evaluation.
- The client is asked to push the sled a distance of at least two (2)
metres with a certain load. The sled can then be pulled back the same distance and the
weights then increased. At the point where the safe maximal push or pull is reached, the
force is measured and compared to the worksite requirements.
Hint:
In order for a push/pull test to be valid, the worksite situation must be carefully
measured prior to testing including the velocity, distance and frequency required by the
task.
Testing at the worksite using the actual work task can sometimes be possible. This will
give the most accurate idea of the client's ability but may not be practical in some
situations. Tasks such as pushing a wheelbarrow of a certain load over a certain distance
could be actually tested away from the actual worksite.