DISCUSSION:
This study demonstrated that the evaluation of the upper limb muscle
strength with an isometric dynamometer showed almost perfect reliability
as well as reproducibility. In the study by Saccol et
al.21, reproducibility of HHD for the internal and
external shoulder rotators was evaluated in 20 volunteers placed in
supine position using a manual method and in sedestation position using
a fixed method, with a rigid device. The ICC values of the non-fixed
method determined in this current study, were higher than those
determined by Saccol et al.22.
In a study with 12 volunteers, Awatani et al.24measured the reproducibility and reliability of HHD with a non-fixed
method for the internal and external shoulder rotators. The
intra-examiner ICC value (ICC: 0.94, 95% CI [0.81-0.98]) for the
measurement of shoulder internal rotator strength determined by Awatani
et al. was lower than the ICC value of 0.96 determined in this current
study. On the contrary, the inter-examiner ICC value (0.96 [95% CI:
0.87-0.99]) was higher than the value of 0.93 found in this study.
Dowman et al.25 evaluated the reproducibility of HHD
with a non-fixed method for the measurement of elbow flexor and knee
extensor strength in 30 patients with interstitial lung disease. The
evaluation protocol for the elbow flexors was similar to that of this
study. As a result, the reproducibility ICC values were similar to those
of this study, ICC 0.98, 95% CI [0.96-0.99] and ICC of 0.97
[0.93-0.99], respectively. This supports the notion that the
reproducibility of HHD for evaluation of elbow strength in diverse
populations remains high.
This is the first study to evaluate the reproducibility and reliability
for ten different upper limb movements, thus demonstrating the clinical
importance of this publication. Study limitations include: the absence
of non-dominant limb measurements, which is justified by the extension
of the evaluation protocol to the ten main upper limb muscle groups; as
well as the absence of measurements such as pronation and supination of
the elbow, and radial and ulnar deviation of the wrist.
The reproducibility of the evaluation of the upper limb muscle strength
with HHD was very good, as was the reliability. The comparison of the
fixed and non-fixed method of HHD assessment demonstrated the superior
reproducibility and reliability of the non-fixed method in comparison to
the fixed method. Only HHD for elbow extensors and external shoulder
rotators showed equivalence between the evaluation methods.