Normative reference values and predicting factors of handgrip strength for dominant and non-dominant hands among healthy Malay adults in Malaysia.

Introduction: Handgrip strength (HGS) measures the maximum voluntary force of the hand, which has been used to assess individual health status indirectly. Although several factors related to HGS have been identified, studies among adults in Malaysia are lacking. This study aimed to provide the normative reference HGS values and determine its predictor factors among healthy adults of Malay ethnic in Malaysia.

Methodology: This study was a part of the Prospective Urban Rural Epidemiology (PURE) study carried out among adults aged between 35 to 70 years old residing in urban and rural Malaysian communities. A standardised questionnaire was used to assess the socio-demographic information and physical activity level of respondents who provided written informed consent to participate in this study. HGS was measured using Jamar's dynamometer. A total of 3,446 healthy adults of Malay ethnic were included in this study. Descriptive data were used to derive the normative reference values for HGS using means and standard deviations stratified by age and gender. The predictors of HGS were determined using a general linear model (GLM).

Results: Mean HGS ranged from 38.48 (± 9.40) kg for the dominant hand of men aged 35-40 years to 16.53 (± 5.69) kg for the non-dominant hand of women aged 61-70 years. The ANOVA indicated that there was a significant descending trend of HGS as age increased for both genders (p < 0.05). The ANOVA also revealed that participants working in blue- or white-collar jobs had higher HGS than their counterparts who are homemakers (p < 0.05). The GLM shows that, age, occupation type, socio-economic status (SES), physical activity level and BMI significantly predicted dominant HGS among male and meanwhile, only age, SES and BMI significantly predicted dominant HGS among female.

Conclusion: HGS normative values provided herein can serve as a guide for interpreting HGS measurements obtained from healthy Asian adults especially Malay ethnic. The clinicians and researcher can use the established HGS reference values as comparison in their patients or participants. Furthermore, during a rehabilitation process, the clinicians and researchers could use the normal score ranges to document the progress of HGS and provide feedback to the patients. Further study with prospective study design is needed to determine the causal effect association of the predictors and HGS.