• Kinematics and Muscle Activity of the Upper Extremity While Performing Cleaning Tasks

      Pipher, Zachary; Applied Health Sciences Program
      In Canada, occupations including janitors, caretakers, and building superintendents are the fourth most prevalent occupational group among men in the labour force, while cleaners are the 10th most prevalent occupational group among women (Statistics Canada, 2008). Cleaning tasks, typically labor-intensive, are characterized by a combination of static muscle loads (mainly involving bending and twisting of the back) and repetitive movements of the arms and hands requiring high physical exertion. Tasks such as lifting, mopping, and vacuuming often involve awkward postures with both dynamic and static muscular activities. These types of prolonged static and repetitive muscle activities cause muscle fatigue and may lead to musculoskeletal disorders. Therefore, the purpose of this study was to examine the effects of custodial cleaning tasks on upper extremity muscle activity and to assess changes in kinematics throughout the duration of a shift. Ten custodians employed at Brock University performed six cleaning tasks during two different sessions (pre-shift and post-shift). Kinematics of the upper extremity were collected, and muscle activity was recorded from 8 upper extremity muscles. Our results showed no significant changes in mean joint angles or joint range of motion pre-shift to post-shift. However, significant changes were observed in mean and peak EMG amplitudes as a result of time. Higher muscle activity was observed in the upper trapezius and FDS while lower muscle activity was found in the anterior deltoid, posterior deltoid, and EDC post-shift compared to pre-shift. This suggests that custodians use different muscular strategies to maintain task performance over the duration of a work shift. This may imply they are experiencing fatigue due to insufficient rest. This work acts as a stepping-stone into future investigations of custodial work and the adaptations over time.