“…Other outcome measures that were used were: cumulative spinal load, expressed as the energy stored in the lumbar spine [van der Molen et al, 2007a], the duration of a certain intensity of compression forces [Hartmann and Fleischer, 2005], perceived discomfort of the lower back , mean compression forces on L5/S1 [Fleischer, 2002;Vink et al, 2002], stature loss [de Looze et al, 1996], and time-integrated compression [de Looze et al, 1996]. An increase of the weight handled (up to 20 kg) and decrease of the height at which the block is handled, led to a statistically significantly higher peak L5/S1-compression forces [de Looze et al, 1996;Naqvi et al, 2000]. Compression forces up to nearly 6 kN were calculated [Naqvi et al, 2000].…”