Physiological and neuromotor changes induced by two different stand-walk-sit work rotations

Area of Science:

• Occupational Health
• Ergonomics
• Physiology

Background:

• Prolonged static postures (standing/sitting) contribute to muscle fatigue and musculoskeletal disorders (MSDs).
• Posture rotation is proposed to mitigate these adverse effects.
• Previous research often focuses on prolonged standing, with less on integrated rotation strategies.

Purpose of the Study:

• To evaluate the physiological and neuromotor effects of two stand-walk-sit posture rotation schedules.
• To compare the impact of different rest-break distributions within posture rotations.
• To assess the recovery of lower-leg muscle function and discomfort post-work exposure.

Main Methods:

• Twenty-two participants engaged in 5.25-hour work exposures involving standing, walking, and sitting rotations.
• Lower-leg muscle twitch force (MTF), volume, force control (RMSE), and discomfort were measured.
• Measurements were taken during and after work, with follow-ups at 1 and 15 hours post-exposure.

Main Results:

• Both rotation schedules induced significant muscle fatigue, reduced force control, and increased discomfort after 5.25 hours.
• Significant recovery of all measured parameters was observed 1 and 15 hours post-exposure.
• No significant differences in effects or recovery were found between the two rotation schedules.

Conclusions:

• Stand-walk-sit posture rotation effectively promotes recovery from muscle fatigue and discomfort.
• This rotation strategy appears more beneficial for preventing muscle fatigue accumulation than prolonged standing.
• Workplace interventions should consider incorporating posture rotation to improve worker health and reduce MSD risk.