EVALUATION OF CALF MUSCLE ENDURANCE: A COMPARISON BETWEEN STANDING
HEEL-RISE TEST AND SUPINE ANKLE PLANTAR FLEXION TEST USING THE BIODEX
DYNAMOMETER
Justine Brown SPT, Rachel Feinberg SPT, Karin G. Silbernagel, PT, ATC, PhD
The work was completed at Department of Physical Therapy, Samson College of Health Professions,
University of the Sciences in Philadelphia, PA.
(Address of the presenter: Department of Physical Therapy, Samson College of Health Professions,
University of the Sciences, 600 S. 43rd Street, Philadelphia, PA 19104)
Abstract:
Background: Achilles tendon injury is common among runners and other physically active people.
Decreased muscular strength and endurance occur after an Achilles tendon injury and may prevent a
patient from returning to their prior level of function. For evaluating calf muscular strength and endurance
both the use of dynamometers and a standing heel-rise test are described in the literature. However we
have not found any study that has compared the results of the two different types of tests when evaluating
calf muscle endurance.
Purpose: The purpose of this study was to evaluate and compare calf muscle endurance using Biodex
dynamometry with the standing heel-rise test. We sought to compare the work and repetition outcomes of
these tests.
Methods: Study Design: Descriptive methodological study. 10 healthy individuals: 9 females and 1 male
were included in the study. Consent forms regarding testing participation, the Foot and Ankle Ability
Measure (FAAM) with both ADL and Sports subscales and a physical activity questionnaire were
administered prior to testing. Ankle dorsiflexion and plantar flexion range of motion, manual muscle
testing of the ankle plantar flexors and dorsiflexors, height, weight, and pain level using the visual analog
scale for both pre and post testing were also obtained. Calf muscle endurance was evaluated using both
the Biodex and the standing heel rise test. The subjects were evaluated twice; once with each test
technique, with 2 weeks in between each testing trial. The maximal number of repetitions and the total
amount of work performed was documented.
Results: The subjects mean (SD) age was 21.6 (1.4) years, height was 64.3 (3.8) inches, and weight was
158.7 (27.7) lbs. In the end all subjects were able to complete both tests. There was a significant
difference (p<0.01) between the numbers of repetitions on the Biodex, mean (SD) of 35 (8), and the heelrise test, mean (SD) value of 25 (6) repetitions with a poor level of agreement (ICC=-0.07). However, for
the Biodex the mean (SD) work performed was lower, 974.9 (503.3) joules, compared to a mean (SD)
value of 1883.1 (552.5) joules of work performed on the heel rise test and this was significantly different
(p<0.01) with a poor level of agreement (ICC=0.30). The greatest contributing factor to this difference
was that the mean (SD) resistance used on the Biodex was 48.0 (20.9) ft-lbs whereas the mean resistance
for the heel rise test was 64.2 (14.8) ft-lbs.
Conclusions: Unlike our initial hypothesis, the results of this study demonstrate a significant difference
between the amount of work and repetitions done in the heel rise test and the Biodex test with poor level
of agreement. Further research needs to be done to determine each test’s clinical utility, effectiveness, and
patterns of muscle recruitment.
Clinical Relevance: The standing heel rise test may be a useful test because it is less expensive less
extensive in set-up, and more functional. However, the Biodex method may be more useful with patients
where weight-bearing, strength, or balance may be an issue
k.silbernagel@usciences.edu
Research, Poster