Quantifying high flexion postures in occupational childcare as they relate to the potential for increased risk of knee osteoarthritis

Ergonomics. 2022 Feb;65(2):253-264. doi: 10.1080/00140139.2021.1969041. Epub 2021 Aug 31.


High knee flexion postures, despite their association with increased incidences of osteoarthritis, are frequently adopted in occupational childcare. This study sought to define and quantify high flexion postures typically adopted in childcare to evaluate any increased likelihood of knee osteoarthritis development. Through video analysis of eighteen childcare workers caring for infant, toddler, and preschool-aged children, eight high knee flexion postures were identified and quantified by duration and frequency. An analysis of postural adoption by task was subsequently performed to determine which might pose the greatest risk for cumulative joint trauma. Childcare workers caring for children of all ages were found to adopt kneeling and seated postures for extended durations and at elevated frequencies, exceeding proposed thresholds for incidences of knee osteoarthritis development. Structured activities, playing, and feeding tasks demanded the greatest adoption of high flexion postures and should be evaluated to minimise the potential childcare-related risks of osteoarthritis. Practitioner summary: High knee flexion postures (kneeling, squatting, etc.) have been associated with increased incidences of knee injury yet are commonly adopted in childcare. Childcare workers' postures were examined through video analysis revealing that proposed adoption thresholds for knee health are commonly exceeded when caring for children of all ages. Abbreviations: OA: osteoarthritis; WSIB: workplace safety insurance board; CAD: Canadian Dollar; DK: dorsiflexed kneeling; PK: plantarflexed kneeling; SAK: single arm supported kneeling; DAK: double arm supported kneeling; FS: flatfoot squatting; HS: heels up squatting; FLRS: floor sitting; SS: side sitting or leaning; STLS: stool sitting; BR: bending and reaching.

Keywords: Occupational ergonomics; daycare; high knee flexion; kneeling; squatting.

MeSH terms

  • Canada
  • Child
  • Child Care
  • Child, Preschool
  • Humans
  • Knee Joint
  • Osteoarthritis, Knee* / epidemiology
  • Osteoarthritis, Knee* / etiology
  • Posture
  • Range of Motion, Articular