Gender difference and lifting technique under light load conditions: a principal component analysis

摘要

The majority of lifting research uses male subjects, and thus it is necessary toninvestigate if gender differences exist in lifting technique that may limitnextrapolation of these studies. Three-dimensional kinematics of the ankle, knee,nhip and lumbar and thoracic spine were collected for 30 subjects (15 males andn15 females) during lifting trials under two load conditions: 0% and 10% ofnmaximum isometric back strength. Applying a principal component analysisn(PCA) to the lifting waveforms, 30 principal components (PCs) were retainednusing a 90% trace criterion. There was a significant effect of load on PC2 ofnlumbar spine flexion and PC2 of hip rotation, but no effect of gender on any ofnthe PCs. Therefore, independent of gender, under loaded conditions individualsndemonstrated a semi-squat lifting technique. By employing a sophisticatednstatistical method such as PCA and standardising load to the individual’s strengthncharacteristics, there was no significant effect of gender on lifting technique.