Upper limb load as a function of repetitive task parameters: part 2--an experimental study.

The aim of the study was to compare the theoretical indicator of upper limb load with the physiological indicator of musculoskeletal load, which is present while performing a repetitive task (a normalized electromyography [EMG] amplitude recorded from the muscles of the upper limb involved in the performed task). In an experimental study of a repetitive task, the EMG signal from 5 main muscles of the shoulder girdle, arm and forearm was registered: extensor carpi radialis longus, flexor carpi ulnaris, deltoideus anterior, biceps brachii caput breve and trapezius descendent. The results of the study showed a strong correlation between the theoretical indicator (Integrated Cycle Load) and the physiological indicator (root mean square of a normalized EMG amplitude from the 5 muscles). This proves that the developed theoretical indicator can be accepted as an indicator of upper limb musculoskeletal load during a work task.