Prediction equations for handgrip strength in healthy Indian male and female subjects encompassing a wide age range

Primary objective: Handgrip strength is a simple index of skeletal muscle function and a functional index of nutritional status. A major lacuna in the use of handgrip strength is the limited availability of normative data. The main objective of this paper was to develop prediction equations for handgrip strength in Indians covering a wide age range. Methods: Handgrip strength and basic anthropometric parameters were measured in 1024 healthy Indian subjects of both genders (613 males, 411 females) between the ages of 5 and 67 years. The sample was randomly divided into two sets; one set (n = 677) was used to develop the prediction equations for handgrip strength and the other (n = 347) was used to validate the equations. Each data set was further divided into two subsets (adults > 18 years, sub-adults <18 years), since separate equations were developed for adults and sub-adults. Simple models that included one of the following variables: height, forearm circumference and age as well as a full model that included all three variables were developed. Gender was included in all models. Results: In general, all simple models predicted handgrip strength better in sub-adults (R-2 = 0.78-0.81) as compared to adults (R-2 = 0.52-0.57). The best simple model in sub-adults was that which included age and gender (R-2 = 0.81), while for adults it was that which included forearm circumference and gender (R-2 = 0.57). The full model explained a further 3.4-6.5% of the variance in handgrip strength in sub-adults and a further 6.3-13.3% in adults. Conclusions: The simple and full model equations for handgrip strength had high predictive power in the sub-adults, while they were less predictive in adults. The equations will be of particular use in physiological studies assessing muscle strength and in clinical investigations of patients with malnutrition and neuromuscular disorders.