Objectives: Muscle volume may reflect both strength
and functional capability and hence is a parameter
often measured to assess the effect of various interventions. The aim of the current study was to determine
the sensitivity of muscle volume calculations on participant postural position and hence gauge possible errors
that may ...
Objectives: Muscle volume may reflect both strength
and functional capability and hence is a parameter
often measured to assess the effect of various interventions. The aim of the current study was to determine
the sensitivity of muscle volume calculations on participant postural position and hence gauge possible errors
that may arise in longitudinal studies, especially those
where an intervention leads to large muscle changes and
potentially the degree of spinal curvature.
Methods: Twenty healthy participants (22–49 years, 10
male and 10 female), were recruited and MRI images
acquired with them lying in four different positions;
neutral spine (P1), decreased lordosis (P2), increased
lordosis (P3) and neutral spine repeated (P4). Images
were analysed in Simpleware ScanIP, and lumbar muscle
volume and Cobb’s angle, as an indicator of spine curvature, determined.
Results: After comparing volume determinations,
no statistically significant differences were found for
P1 - P2 and P1 - P4, whereas significant changes were
determined for P2 - P3 and P1 - P3. P2 and P3 represent
the two extremes of spinal curvature with a difference
in Cobb’s angle of 17°. However, the mean difference
between volume determinations was only 29 cm3. These
results suggest the differences in muscle volume determinations are generally greater with increasing differences in curvature between measurements, but that
overall the effects are small.
Conclusions: Thus, generally, spinal muscle volume
determinations are robust in terms of participant
positioning.
Advances in knowledge: Differences in muscle volume
calculations appear to become larger the greater the
difference in spinal curvature between positions. Thus,
spinal curvature should not have a major impact on the
results of spinal muscle volume determinations following
interventions in longitudinal studies.
