Assessing the physiological strain of physical therapists according to work experience: A cross-sectional study

Objectives: This cross-sectional study aimed to assess the physiological response of physical therapists to compare the physiological workload within three groups of varying work experience and their comparative physiological responses during a 15-min recovery period. Methods: Thirty therapists participated in the present study. They were divided into three groups with varying levels of work experience based on the number of years they had been in active employment: 1) Early Career (EC) group = 2-6 years); 2) Mid-Career (MC) group = 7-11 years), and 3) Late career (LC) group = over 11 years). Each group included 10 subjects comprised of both males and females. To conduct the measurements, each therapist treated one hemiplegic patient for 20 min using a passive range of motion protocol and then rested for 15 min. The maximum voluntary contraction on trapezius and deltoid muscles were tested using electromyography before and after treatment. During treatment, the muscle workload, muscle fatigue, and cardiovascular load were measured. The perceived workload was assessed using a subjective workload index (SWI) questionnaire following treatment. Results: The three work experience groups of physical therapists performed a similar workload. The SWI corresponded well with physiological measurement. The muscle capacity after treatment of the EC group was significantly lower than that of the MC group (p < 0.05). Notably, the right deltoid of the LC group was significantly lower than that of the MC group. Conclusions: The physical therapists worked with a moderate, objectified workload. A 15-min rest period brought the cardiovascular load below 30% and lowered fatigue in the right deltoids. This result may indicate a musculoskeletal disorder warning signal for the physical therapists. (C) 2019 Published by Elsevier Ltd.