International norms developed for 'handgrip strength', robust indicator of current, future health

New Delhi: Researchers have developed the "most comprehensive" norms for handgrip strength, or how hard one can squeeze, the first international ones for individuals across age groups and genders.

The norms, published in The Journal of Sport and Health Science, can be used for tracking healthy aging by monitoring how handgrip strength changes over time, they said.

A total of 140 authors, led by researchers at the University of South Australia, have created the norms based on 100 studies involving 24 lakh adults aged 20 to over 100, from 69 countries and representing over 70 per cent of the world's population.

"Our research has established robust international norms that enable clinicians and exercise professionals to interpret and relate results in a percentile ranking," lead researcher Grant Tomkinson, a research professor at the University of South Australia, said.

According to the norms, adults below the 20th percentile are considered to have 'low' strength and those at or above the 80th percentile having 'high' strength. Those between 20-39th percentiles have 'somewhat low' strength, while those in the 40-59th percentiles and 60-79th percentiles have 'moderate' and 'somewhat high' strength, the authors said.

"Muscle strength, which reflects the ability of the muscles to produce force maximally, is a powerful biomarker of current and future health," Tomkinson said.

A low handgrip is known to be related with a higher risk of death, including that due to heart disease, and a higher chance of physical disability.

Grip strength improves throughout early adulthood, peaks between age 30 and 39, and then drops off as people age, especially in late adulthood, the researcher explained.

Handgrip strength is measured by gripping a handgrip dynamometer and squeezing to record the highest force a person can exert over a few seconds.

Tomkinson said the norms will help clinicians better identify people who may be at risk of poor health and in need of interventions.

"So, what we have developed is an international guideline and benchmark that enables clinicians to compare and track muscle strength -- and therefore, potential health risks -- across the adult lifespan," the lead researcher said.