The use of electromyography and kinematic measurements of the lumbar spine during ergonomic intervention among workers of the production line of a foundry

Abstract

Purpose Workers who perform repetitive movements are exposed to many risk factors leading to the occurrence of lumbar back pain. The aim of the research was to answer the question whether the ergonomic instruction conducted by a physiotherapist would change the tested range of motion of the segments of lumbar spine and the symmetry of the work of the torso and upper limbs muscles during work performed by foundry employees. Methods The study included 12 foundry production line workers with musculoskeletal pain. The workstation was built in the laboratory that perfectly simulates work on the production line. The workers performed two activities from their daily work, i.e. transferring and moving a casting. They were then given ergonomic instruction by a physiotherapist and performed the assigned tasks again. During the activities, the electromyographic signal from five muscles was recorded in terms of symmetry of their work. The maximum angular ranges of the motor segments of the lumbar spine were measured using gyroscopes. Results After the ergonomic instruction, the contralateral imbalance of muscle activity decreased statistically significantly during the first phase (p = 0.0004), second phase (p = 0.0002) and the third phase (p = 0.0069) of transferring the casting. While moving the casting , only erector spinae showed statistically significantly (p = 0.0131) more symmetrical work after the ergonomic instruction. During the transfer of the casting, statistically significantly lower values of the ranges of motion between the segments were obtained after carrying out the ergonomic instruction for the left (p = 0.0231) and right (p = 0.0032) lateral flexion. The ranges of movement between the segments differed statistically significantly for the flexion (p = 0.0117), extension (p = 0.0469) and left (p = 0.0031) and right lateral flexion movements (p = 0.0012). Conclusion Conducting ergonomic instruction consisting in teaching the correct performance of a movement task reduced the contralateral imbalance of muscle activity and changes the ranges of movement of L1-S1 segments. The task of optimizing the load on the musculoskeletal system, including the lumbar spine, should be carried out by means of appropriate ergonomic instruction and multi-pronged measures, including analysis of the health of employees, their working environment and physical activity outside the workplace. Electromyography and measurements of the range of movement of the lumbar spine appear to be good tools for the evaluation of workplace ergonomics.

Symmetry of the Neck Muscles’ Activity in the Electromyography Signal during Basic Motion Patterns

“…Another factor that could influence the higher activity of the left upper trapezius and left sternocleidomastoid during rotational movements was the direction of the movement, as it started from the right rotation, and once activated, the muscle remained active throughout the whole movement. Błaszczyk and Ogurkowska [37] confirmed the existence of contralateral muscle imbalances in the lumbar spine during transferring of the load. So far, no other publications concerning the symmetry of neck muscle activation have been found.…”

Investigating Inter-Day Variations in the Physical Effects of Exoskeletons: Requirements for Long-Term Biomechanical Studies

“…In addition to others, the measurement of MA using surface electromyography (sEMG) and the assessment of movement patterns using wearable sensors, such as inertial measurement units (IMUs), are suitable for this purpose [10]. Both measurement systems enable the comparison of workloads and movement patterns between different individuals and days [11,12] and are reported as being reliable during static [9,13,14] and dynamic conditions [9,15,16].…”