Comparing action regarding different physical methods, such as position, were also not seen to be effective; however, such assays were frequently small and had little power for detecting true effects if indeed they did exist.
Tampoco mostraron ser efectivas otras comparaciones entre métodos físicos diferentes como la posición, pero con frecuencia estos ensayos fueron pequeños y tuvieron poco poder para detectar efectos verdaderos, en caso de que existieran."