A survey of those features of hand tools relevant to the physical interaction between the implement and the human operator. Concepts basics to the optimization of forces are mentioned, followed by a description of some of the more common physiological problems and musculoskeletal complaints associated with improper hand tool and design and usage. An account of the distribution of contact pressures and possible consequences, if these are excessive, is followed by a description of the role of working gloves as related to ergonomic problems and their possible relationships to occupational diseases of the hand and wrist. Some aspects of anatomy and anthropometry pertinent to the optimization of posture, motion patterns and tool size precede a list of desirable features for power tools. A glossary is included as an aid to the reader. The concepts and situations described are applicable to the design and use of the vast majority of hand tools.