Shoulder pain influences kinematics during farm work tasks: An in-field study

Abstract

Background: Work-related musculoskeletal disorders (MSDs) are prevalent among agricultural producers. Upper limb MSDs, especially in the shoulder and neck, are common, yet research on their development and prevention is limited. This study aims to investigate the influence of shoulder pain, age, and sex on shoulder kinematics during farm work tasks. Methods: Farmers in Saskatchewan were recruited and divided into groups with and without shoulder pain. Participants performed four tasks (Overhead Drill, Climb Seeder, Seed Bag Lift, Shovel) while wearing inertial measurement units (IMUs) to track humeral and scapular movements. Data were analyzed using linear regression and Kruskal-Wallis tests (p < .05) to assess the effects of pain, age, and sex on shoulder kinematics. Results: Forty-two participants (23 without pain, 19 with pain) completed the study. Pain significantly influenced shoulder kinematics during the Overhead Drill, Seed Bag Lift, and Shovel tasks. During the Overhead Drill, the pain group exhibited higher scapular upward rotation (p = .04, +5.1°) and females showed lower maximal humeral elevation (p = .049, −11.7°). In the Seed Bag Lift, the pain group had lower scapular upward rotation (p = .012, −18.7°) and higher humeral internal rotation (p = .04, +12.0°). Humeral elevation was also lower in the pain group during the Shovel task (p = .019, −12.7°). Conclusions: Shoulder pain affects shoulder kinematics in farm work tasks, with variations depending on the task. Pain-related compensations can be both protective and harmful. These findings highlight the potential risk for shoulder injury in many aspects of farm work.