Biomechanical evaluation of manual weeding postures in nursery and landscaping tasks

Manual weeding is a physically demanding task in nursery and landscaping work, often involving awkward postures that increase the risk of work-related musculoskeletal disorders (WRMSDs). This study examined the biomechanical demands of five common weeding postures: standing and bending; kneeling on one knee; kneeling on both knees; crouching; and sitting on a bucket. Twenty participants (55% male; aged 18-29 years, average age 21.5 ± 3.69 years) completed simulated weeding tasks while motion capture and surface electromyography (EMG) recorded joint motion and muscle activity. Standing and bending produced the greatest lumbar load, while crouching imposed the highest shoulder, arm and knee demands. Kneeling on both knees reduced lumbar flexion but increased lateral bending and spinal asymmetry. Sitting on a bucket showed the lowest spinal muscle activation with moderate joint loading. These findings support posture alternation and work-rest cycles to reduce ergonomic strain and inform future intervention strategies.