12
COMPARISON OF ARM WORK TO LEG WORK
When comparing arm ergometry or arm exercise to
leg ergometry, there are several physiologic considera-
tions. The maximum work that a muscle is able to per-
form is related to its size. Obviously, the muscle mass
of the arms is considerably smaller than the legs and
therefore the maximum work and maximum ozygen
consumption of the legs will be greater. Hershfield and
others added that the mechanical differences in the
shoulder and hip joints increase metabolic demands
when arm work is performed. (1)
Reybrouck and others found that at workloads below
the ”anaerobic threshole”, when adequate oxygen is
supplied to meet all the muscle´s requirements, the
oxygen consumption from arm work matches closely
the oxygen consumption during equivalent leg work.
(2) They noted that heart rate and ventilation were
higher during arm work at the same oxygen consump-
tion in leg ergometry.
In rehabilitation or evaluation of disability, the expec-
ted sustained work capability of an individual is ap-
proximately 40% of maximum work and below the
anaerobic threshold. (3) To use the equivalent work
tables which have been published (reference 4), divide
the V02 at the subject´s workload by the patient´s
weight in kilograms. Divide this V02 ml/kg by 3.5.
This will give the equivalent METs and then evaluate
the tasks of which they are capable of performing at
that MET level.
REFERENCES
1. Hershfield S, et al. Relative effects on the heart by
muscular work in the upper and lower extremities.
Arch Phys Med Rehab. Pages 249-257, May 1968.
2. Reybrouck T, el al. Limitations to maximum oxy-
gen uptake in arm, leg and combined arm-leg er-
gometry. J Appl Physiol 38:774-669, 1975.
3. Becklage MR. Organic or functional impairment.
Am Rev Resp Dis 129:S96-100, 1984.
4. Physician´s Handbook for Evaluation and Physi-
cal Fitness. Tennesse Heart Association, Physical
Exercise Committee, 1972, pgs 44-45.
5. Jones NL, Campbell EJM. Clinical exercise testing.
WB Saunders Publishing, Phila, PA. Page 86, 1975.