Background and Aim: Measuring the hand's grip strength and comparing it with its normative data is a valid method for detecting intensity of the numerous damages of hand. In addition, co mparing grip strength of people in different regions can reveal hidden facts resulting from genetic and environmental factors . Therefore , the present study was carried out with the aim of comparing grip strengths and three types of pinch (tip, key and palmar) strengths of healthy people living in five Iranian cities and determining normative data of grip strengths of citizens of these cities.

  Materials and Methods: This was an applied cross-sectional study. The study population included 1008 healthy adults (526 males and 482 females) from the Fars (Persian) ethnic populations in five cities of Iran ( Mashhad, Isfahan, Shiraz , Kerman and Yazd ). The American Society of Hand Therapists (ASHT) recommendations were followed to establish normative data of grip and pinch strengths . Jamar dynamometer and Seahan pinch gauge were used to measure grip and pinch strengths. In addition, the effect of body mass index (BMI) and other anthropometric variables (hand length, height and weight) on grip strengths was assesed.

  Results: In the present study, no significant differences were found between grip and pinch strengths of adults in the five cities. From among the parameters studied , height and hand length had the most influence on the grip strengths .

  Conclusion: The findings of this study show that populations of any particlular ethnic group have similar grip strength despite living in different geographical areas. The normative data of grip strength obtained in this study are important for ergonomists helping them to optimize work programs and designing tools, as well as for therapists helping them to reach the goals of treatment, assessing the body response to medical treatment, and detecting good function of the upper extremities .