Introduction: Obesity is a growing health concern worldwide and low back pain (LBP) is the leading cause of disability globally. LBP is an area of concern in obese populations performing manual handling tasks, due to potentially higher muscle forces and altered lifting dynamics. The aim of this review was to investigate biomechanical differences between obese and non-obese groups performing manual handling activities.

Methods: An electronic search was undertaken of three databases using a series of keywords based on three concepts: obesity; manual handling and biomechanics. Studies were included if they were experimental, involved manual handling, compared an obese with non-obese population, and reported on one or more biomechanical measures. Studies were evaluated for the risk of bias.

Results: Of the 1,037 articles identified, 15 met the inclusion criteria. Body Mass Index (BMI) was most frequently used to differentiate between a control and obese population. There was consistent evidence of increased net moments, compression forces and shear forces at L5/S1 in handlers classified as obese compared to non-obese. Inconsistent or no evidence was found for differences between populations for sagittal trunk flexion and acceleration, knee flexion angle and load separation.

Conclusions: Obesity increases loads on the musculoskeletal structures of the spine when handling loads which likely increases the risk of back injuries. Limited evidence of changes in the kinematics of lifting in obese populations has implications for the delivery and content of training, and preventative measures necessary to reduce risks to obese workers.