[123RF]
[123RF]

Some days, a jar lid just won't budge. It's easy to laugh it off with a "my hands aren't what they used to be," but doctors say that small signal deserves a closer look. Grip strength, it turns out, carries far more health information than most people realize.

Doctors view grip strength as an indirect measure of whole-body muscle strength — covering not just the upper body but the lower body as well — the Wall Street Journal reported Thursday (local time). Mark Peterson, a professor of physical medicine and rehabilitation at the University of Michigan Medical School, said the measurement "is not about the forearm muscles themselves," adding that "people with very low grip strength are at very high risk of systemic frailty and weakness."

The test itself is straightforward. A person squeezes a handheld device called a dynamometer for a few seconds, and the reading appears on a dial in kilograms. Both hands are typically tested two or three times each, with the highest value recorded. The whole process takes only a few minutes, and the equipment is inexpensive — consumer models are available for under $100.

Research shows the median grip strength for a 50-year-old man is about 48 kilograms, and about 29 kilograms for a woman of the same age. However, the figures vary considerably by age, sex and body size. What matters most is not who scores highest, but who scores unusually low.

A grip strength dynamometer [Wall Street Journal]
A grip strength dynamometer [Wall Street Journal]

Peterson said grip strength predicts cardiovascular disease better than blood pressure does. People with weak grip strength have also been found to face higher risks of heart disease, type 2 diabetes, osteoporosis, stroke and dementia. The link between grip strength and cardiovascular and metabolic health has even been observed in children. Michael Fredericson, a professor at Stanford University School of Medicine, described grip strength as "another vital sign" — which is why the University of Michigan Medical School measures patients' grip strength across multiple departments.

Muscle loss is a natural part of aging, and it becomes particularly pronounced from one's 50s and 60s onward. Sarcopenia — the gradual decline in muscle mass, strength and physical function — is a prime example. Grip strength is used to identify those at risk and to anticipate frailty that can lead to falls and difficulty with daily activities. Linda Fried, a professor at Columbia University's Mailman School of Public Health, said weak grip strength signals "a risk of losing physical function and mobility, falling and becoming frail."

That is why building strength early matters. Fredericson said people need a reserve so that even if an injury or hospitalization causes muscle loss, it does not plunge them into sarcopenia territory. "Once you get to that level, things can deteriorate very quickly," he said.

But does that mean simply training grip strength is enough? Experts say no. A study Peterson published three years ago found that people with stronger grip strength had a lower "biological age," but Fredericson cautioned that improving grip strength alone does not extend lifespan. Grip strength, he said, is not a replacement for existing health metrics — it adds one more piece of information to the picture.

That is not to say hand strength is unimportant. Opening jar lids and turning stiff locks are everyday tasks that genuinely require hand and forearm strength. However, Ryan McGrath, an associate professor at North Dakota State University, said that repeatedly squeezing a tennis ball alone will not improve overall body strength. A better approach is to put the ball down, pick up a dumbbell and do squats. Grip strength, he said, will follow naturally from there.


mokiya@heraldcorp.com