Age, gender and side-stratified grip strength norms and related socio-demographic factors for 20–80 years Iranian healthy population: Comparison with consolidated and international norms

Abstract

As an index for many adverse health outcomes, normative values on handgrip strength are established for many populations. The aim of this study was to establish handgrip strength (HGS) norms for the Iranian population and to compare them with other existing norms. Related variables affecting HGS were also determined in order to provide appropriate prediction models. The sample consisted of 4282 Iranian 20–80 years adults; divided into 5-year intervals, male/female and dominant/non-dominant hand. Results were compared to consolidated data and those of some other countries. To ensure a valid and comparable dataset, HGS was measured using the JAMAR® hydraulic dynamometer following the standardized procedure. Hand length, palm length, palm width, forearm length, wrist circumference, forearm circumference, height and weight were measured, and BMI was calculated. HGS norms for Iranian adults were established. Inverted U-shaped lifespan profiles were found with mean maximum values of about 53 kg for males (35–39 years) and 31 kg for females (40–44 years). Two regression models (by hand dominance) were developed. The mean values of HGS in Iran were weaker than consolidated norms but greater than in some Asian countries. Applying normative data specific to each population is more accurate than international or multinational norms. It is recommended to investigate the causes of accelerated age-related decline in HGS of Iranian elders in future studies.