Book excerpt: Manual Materials Handling MMH creates special problems for many different workers worldwide. Labourers engaged in jobs which require extensive lifting/lowering, carrying and pushing/pulling of heavy materials have suffered increasing rates of musculo-skeletal injury, especially to the back.; This guide is intended to include all activities involved in MMH lifting, pushing, pulling, carrying and holding. Recommendations are provided in the form of design data that can be used to design different MMH work activities. The guide is divided into two parts. Part I outlines the scope of the problem, discusses the factors that influence a person's capacity to perform MMH activities and / or should be modified to reduce the risk of injuries, and reviews the various design approaches to solving the MMH problem. Part II provides specific design data in six distinct chapters. The seventh chapter of Part II of the guide describes various mechanical devices that are available to aid MMH activities.; The guide is aimed at all concerned with the health impact of MMH activities; occupational health and safety workers; senior human resource managers; ergonomists; workers' compensation lawyers; union representatives.