Quantifying Upper Extremity Vibration Exposures During Arborist Tree Abatement Tasks

Abstract

The purpose of this thesis was to examine chainsaw vibration exposures during various tree cutting tasks. Participants consisted of 18, healthy, male active arborists, with an Ontario Chainsaw Certification. Vibration was measured using two accelerometers, one placed on the hand and another on the tool to determine exposures during four different chainsaw cutting tasks (bore cut, down cut, up cut, idle and hold). To better understand chainsaw physical demands, surface electromyography was recorded bilaterally from six forearm muscles and whole-body kinematics were assessed using an inertial measurement system. Additionally, resting tremor, pain and discomfort, manual dexterity, and grip strength were assessed to determine performance effects from exposures. During all cutting tasks, vibration exposures from both the saw and hand exceeded recommended industry threshold limits (Bore saw: 9.62±4.10 m/s2; Bore hand: 8.72±5.02 m/s2; Down saw: 9.29±3.82 m/s2; Down hand: 9.87±6.60 m/s2; Up saw: 9.30±3.14 m/s2; Up hand: 7.47±3.03 m/s2; Idle saw: 5.96±1.25 m/s2; Idle hand: 5.65±1.09 m/s2). Resting tremor and pain and discomfort became increased after exposures as well, indicating chainsaw vibrations during cutting tasks as a risk factor in this working population.