Rapid Upper Limb Assessment(RULA) INSY 3021 Spring 2005
History and Benefit of RULA • Developed by Dr. E. Nigel Corlett and Dr. Lynn McAtamney of University of Nottingham’s Institute for Occupational Ergonomics • Developed to “investigate the exposure of individual workers to risk factors associated with work-related upper limb disorders” • “It is straight forward and can be used with a minimum of training.”
What is RULA • RULA is a quick survey method for use in ergonomic investigations of workplaces where MSD’s are reported. • RULA is a screening tool that assesses biomechanical and postural loading on the body. • RULA focuses on the neck, trunk and upper limbs, and is ideal for sedentary workers e.g. computer workplaces.
What is RULA (cont.) • RULA has been validated on groups of computer users and sewing machine operators. • RULA is quick and easy to complete. • RULA scores indicate the level of intervention required to reduce MSD risks. • RULA compliments other ergonomic methods.
RULA Scoring Classification • CLASS I (1 or 2) • Posture is acceptable if it is not maintained or repeated for long periods • CLASS II (3 or 4) • Further investigation is needed • CLASS III (5 or 6) • Further investigation and changes are required soon • CLASS IV (6+) • Investigate and change now
Interpretation of RULA • Gives a total job assessment that suggests directions for modifying body positions to reduce the possibility of hazards • Does not provide exact Engineering controls or work activity changes.
How to Do a RULA Estimation • RULA is a simple diagnostic tool that allows you to survey various tasks involving the upper limbs at work. • Focuses on use of arms, wrists, position of the head, and the posture of the upper body.
RULA Estimation (cont.) • Procedure • Records the position of the upper limbs and the head, trunk and legs with two separate number codes. • The codes are entered into the relevant boxes. • An initial score is found in the appropriate tables, A and B. • The score is modified according to the use of the limbs.
RULA Estimation (cont.) • The final A and B scores are calculated. • Using the final scores a Grand Score, using table C, is determined.
Upper Arms • Add 1 if shoulder is raised • Add 1 if upper arm is abducted • Subtract 1 if leaning or supporting the weight of the arm.
Lower Arm • Add 1 if working across the midline of the body or out to the side.
Wrist Twist • Mainly in handshake • Twisting away from handshake position.
Neck Twist • Add 1 if neck is twisting
Neck Side-Bend • Add 1 if neck is side-bending.
Trunk Twisting • Add 1 if trunk is twisting.
Trunk Side-Bend • Add 1 if trunk is side-bending.
Lower Limbs • Legs and feet are well supported and in an evenly balanced posture (add 1). • Legs and feet are not evenly balanced or supported (add 2).
Muscle Use Score • Raise the score by 1 if the posture is” • Mainly static, e.g. held for longer than 10 minutes. • Repeated more than 4 times/minute.
References • McAtamney, L. & Corlett, E.N. (1993) RULA: a survey method for the investigation of work-related upper limb disorders, Applied Ergonomics, 24, 91-99 • http://www.ergonomics.co.uk/Rula/Ergo/ index.html