Wrist postures and forces in tree planters during three tree unloading conditions.

The aims of this study were to investigate wrist postures and forces while operating the shovel during tree planting and to determine if different tree unloading techniques result in variations in wrist postures and forces. Experienced tree planters performed the planting task in a laboratory environment for three conditions: (1) symmetric tree unloading, and asymmetric unloading resulting in (2) right-loaded planting bags and (3) left-loaded planting bags. An optoelectric system and a shovel instrumented with strain gauges captured wrist posture and forces at the wrist, respectively. Wrist extension of up to 45° was observed, and this posture, in combination with varying degrees of wrist deviation, may be a primary risk factor for musculoskeletal pain. Average resultant forces at the wrist were moderately high (>30 N) for each unloading condition, indicating increased risk for the development of repetitive strain injuries such as carpal tunnel syndrome. No significant differences in wrist posture or forces existed between unloading conditions. PRACTITIONER SUMMARY: Wrist pain is a major musculoskeletal complaint among tree planters. This study measured wrist postures and forces at the wrist while operating the shovel during tree planting. The wrist extension observed, in combination with deviation, may be a key risk factor for musculoskeletal pain. Forces at the wrist indicate increased risk for repetitive strain injuries.

Musculoskeletal symptoms in tree planters in Ontario, Canada.

UNLABELLED: Tree planting is extremely physical, seasonal, repetitive work with high risk for musculoskeletal injuries. OBJECTIVES: (1) To assess musculoskeletal symptoms in tree planters as they develop over the course of the planting season. (2) To investigate the effect of pre-season level of physical activity on development of musculoskeletal symptoms. PARTICIPANTS: 132 tree planters from two reforestation camps participated in the study. METHODS: Three questionnaires were completed prior to the first work day of the planting season. Questionnaires included the International Physical Activity Questionnaire, a body map to report areas of musculoskeletal symptoms (MSS questionnaire), and a series of questions about planter demographics. A subset of study participants (n=14) also completed the MSS questionnaire each work shift during the planting season. Musculoskeletal symptoms in each area of the body were compared pre-and-post season using a paired t-test on data from the MSS questionnaire. RESULTS AND CONCLUSIONS: Areas of the body with the greatest amount of musculoskeletal pain and discomfort were the feet, wrists and back, whereas areas with the highest frequency of reported pain were the upper, middle and lower back. Musculoskeletal symptoms worsened significantly over the course of the work season. Pre-season level of physical activity could not be correlated with development of musculoskeletal symptoms.

Evaluation of forearm support provided by the Workplace Board on perceived tension, comfort and productivity in pregnant and non-pregnant computer users.

The aim of the study was to evaluate the effect of forearm support provided by the Workplace Board on perceived tension, comfort and productivity among pregnant and non-pregnant female computer workers. Ten pregnant and 18 non-pregnant women participated in the study. Participants completed three sets of tension/discomfort questionnaires at two week intervals. The first set was completed prior to any workstation intervention; the second set was completed after two weeks working with an ergonomically adjusted workstation; the third set was completed after two weeks working with the Workplace Board integrated into the office workstation. With the Workplace Board, decreased perceived tension was reported in the left shoulder, wrist and low back in non-pregnant women only. The Board was generally liked by all participants, and increased comfort and productivity in all areas, with the exception of a negative effect on productivity of general office tasks. The board is suitable for integration in most office workstations and for most users, but has no special benefits for pregnant women.