Isokinetic lifting simulation: A normative data study

Abstract

This article describes a system for data collection using an isokinetic lifting task simulation device and reports normative data findings based on a standardized lifting posture. The test population included 2688 normal subjects (1236 females, 1452 males; ages 10-79 years) from five different occupational categories who were tested on a Liftask® device using a flexed knees-flexed back lifting posture. Testing consisted of four maximal lifting repetitions preceded by three gradient submaximal repetitions plus one maximal effort at the speeds of 6, 12, 18, 24, 30, and 36 inches/sec. Data on peak force, peak force as percent of body weight, height or peak force, average force, average force as percent of body weight, average power, and total work were categorized by sex and age decade for reporting as normative experimental results. In general, overall performance decreased in an inverse proportion to test speed while height of peak force and average power increased in direct proportion to speed. Also, subject performance increased from the 10-19 decade to the 20-29 decade before decreasing with age through the 70-79 decade. The results may be useful for clinical reference purposes as normative data for the purposes of performance comparisons during isokinetic lifting with a flexed knee-flexed back posture.