This
supports the contention of Young (116), who previously
highlighted this problem. Many studies did not include, or
did not clearly report, a test reliability analysis, which is a
major concern because it reduces the validity of the findings.Data presented in many of the included studies were collected during both control (rest) and experimental (stretch)
conditions, and statistical analyses were then performed on
the data sets to determine the level of significance between conditions. One problem, however, is that statistics for reliability were rarely presented, so the potential exists for the
magnitude of between-condition differences to have been
within the limits of data variability, resulting from learning,
motivation variability, fatigue, or some other external influence, and were not solely influenced by the stretch intervention