Effects of different bed heights on the physical burden of physiotherapists during manual therapy: an experimental study

TSUJI
 Shuji
 TSUJIMURA
 Hiroji
 SHIRAHOSHI
 Shin-ichi 
 TAODA
 Kazushi
 KITAHARA
 Teruyo

This study aimed to determine the effect of physiotherapists' physical burden caused by different bed heights during manual therapy. Thirty-three male physiotherapists performed tasks simulating lumbar massage and passive hip abduction range-of-motion exercise (ROM) on the beds with low height (LH) and adjusted height (AH)
 with each task performed three times. The anterior inclination angle of the physiotherapist's trunk was measured
 the surface electromyograms of the erector spinae and trapezius muscles were recorded
 and perceived stress was assessed. The indexes obtained were statistically compared for different bed heights. Additionally
 the lumbar disc compression force and flexion torque were estimated. The lumbar burden caused by the excessive bending and the biomechanical burden and perceived stress were stronger at LH than AH. In ROM tasks using the right hand
 the muscle activity was lower at the left lumbar region at LH than at AH. At LH
 the anterior inclination angle increased and the lumbar muscle activity declined as the number of tasks increased. The burden on the shoulders was not significantly different by bed heights. Our results showed that
 when physiotherapists perform manual therapy
 it is necessary to adjust the bed height to reduce physical burden and ensure higher quality of service. Key words: Physiotherapist
 Physical burden
 Bed height
 Manual therapy
 Trunk anterior inclination angle
 Surface electromyogram
 Lumbar disc compression force
 Lumbar flexion torque

Industrial Health

National Institute of Occupational Safety and Health

61

3

0019-8366
 1880-8026

10.2486/indhealth.2022-0038