Affiliations: [a] Department of Anatomy, Human Performance
Laboratory, | [b] Department of Physiology, | [c] Department of Statistics, Trinity College Dublin,
Dublin 2, Ireland
Abstract: The reliability of gravity corrected average and peak isokinetic
moment of the shoulder elevators in the scapular plane, was assessed in 22 male
college students without shoulder or neck pathology. Measurements were
performed on two occasions, 7 days apart, by the same examiner. Both dominant
and non-dominant sides were examined at 60 and
120°·s^{-1}, using Kin Com II
dynamometer. Each volunteer was assessed in the seated position, elevating the
shoulder between 30--90° with the elbow in extension
and the forearm in pronation. Reliability of both non-free and free of
transient moment-oscillations (TMO) peak and average moment data (data selected
from the entire range and the range of motion where isokinetic velocity was
constant and equal to the pre-selected angular velocity, respectively) was
determined using the intraclass correlation coefficient (ICC 3,1). The
variability of isokinetic moment data associated with normal fluctuations of
strength performance over repeated measurements (inter-session variability) was
determined using the standard error of measurement (SEM) and the limits of
agreement (LOA). The ICC (3,1) values ranged between 0.86--0.95. Inter-sessions
variability of isokinetic moment data calculated using 95% Both SEM and LOA
revealed lower variability for average compared to peak moment data, non-free
compared to free of TMO average moment and for free compared to non-free of TMO
peak moment data. Higher ICC values and lower variability was also obtained for
peak moment data at the isokinetic velocity of 60 compared to
120°·s^{-1}and for most of the
moment data recorded on the dominant compared to the non-dominant side. The
present findings suggest that strength changes observed over repeated
isokinetic measurements of the shoulder elevators in the scapular plane, may be
better identified under certain conditions but they should only be considered
as significant changes if they are lower or greater than
inter-session variability of isokinetic moment data.
