Grip Strength as an Indicator for Health
In this article, I try to make the case for training grip strength as part of a hanging protocol.
As someone who works with people in their 50s-70s, studies like these routinely cross my desk. Grip Strength (GS) is well researched resulting in many studies. If you open a browser window and type in PubMed or Google Scholar and then do a search for Grip Strength (and variations thereof), you will get access to many (PubMed shows almost 40,000). If that doesn’t sound like your idea of an exciting afternoon, I got you covered; read on.
For the purposes of this article I reference two because they are easy to read and free access, links below. The article by Richard Bohannon citing various studies lists 143 references alone. That’s a big rabbit hole. Just to clarify, I am not a researcher, a scientist, nor am I expert in reading studies, other than I do as much of it as I can, reading and cross referencing and re-reading until I can understand as much as my limited training allows.
Hand Grip Strength is measured in these studies with a dynamometer, which is a practical device you can squeeze and it measures your force output, which provides an objective measurement that can then be used statistically. These numbers were then compared to results from other tests for various tasks such as carrying, walking, and various significant health changes such as mastectomy, stroke, bone density changes, diabetes, gastrointestinal cancer, cognitive decline (depression) and malnutrition, to name a few. It was shown that there is a correlation between grip strength and these various test results, (there’s even a correlation between decreased GS and hip fractures) leading the researchers to conclude that GS is in itself an accurate predictor of current and future health.
Here is the abstract for the article I use here:
Grip strength has been proposed as a biomarker. Supporting this proposition, evidence is provided herein that shows grip strength is largely consistent as an explanator of concurrent overall strength, upper limb function, bone mineral density, fractures, falls, malnutrition, cognitive impairment, depression, sleep problems, diabetes, multimorbidity, and quality of life. Evidence is also provided for a predictive link between grip strength and all-cause and disease-specific mortality, future function, bone mineral density, fractures, cognition and depression, and problems associated with hospitalization. Consequently, the routine use of grip strength can be recommended as a stand-alone measurement or as a component of a small battery of measurements for identifying older adults at risk of poor health status.
Wow! That’s quite a list — grip strength can show you all that? And if GS is an indicator of health, can improving your grip strength then improve your general health? Well yes, and no. Really it depends on how you go about improving your grip strength, and those two questions are related.
If GS as shown on a dynamometer is enough to indicate health status, would training grip strength with such a device, or one of the alternatives commonly found in the fitness stores such as squishy balls of varying density, be enough to improve your overall health? Not much, unless you walked to that fitness store and it was 10 miles away, uphill, in a snowstorm. In other words, the fact that your hand is strong is a by-product of your overall behaviour and hand strength in isolation is not enough to make your whole body strong (or else why would we bother with Peleton or Pilates or anything else if we could simply sit and squeeze our way to health?).
Grip Strength is a safe, cheap, practical, easy to measure, objective and well studied tool that can be applied in various environments (doctor’s offices, PTs offices, etc) in countries all over the world, to every population imaginable. For that reason it is one good tool that provides applicable information about a person’s health status. But it is the health status that creates the GS, not the other way around. In most people, the making of a robust, healthy body involves the use of the hand for many activities and because the hand depends on the arm, shoulder, shoulder girdle, upper body (thorax) for most of what it does, any change to any of those body parts will affect the hand strength.
Here’s an example that I think a lot of people will relate to: I have a very large cast iron pot that I love to cook with. When it’s filled with stew it can be quite heavy! The ability to carry that pot full of stew depends not just on my hands, but my arms and my upper back too. Imagine trying to lift a heavy object out of the oven to the counter if you are stooped over. The ability of the upper back to straighten allows part of that weight to be carried by the muscles of the trunk and not just the muscles of the hand and forearm. It’s the upper body equivalent of a squat that uses more posterior (butt) muscles to extend the hip and less anterior (quad) muscles to stand. The role of the big latissimus back muscle and the muscles along the spine that help stabilise the spine makes that pot lift possible.
We know that hyperkyphosis (excessive curvature of the upper back) is related to a diagnosis of osteoporosis. So it stands to reason that if one has low bone density, one’s ability to lift heavy objects starts to decline and with it, the grip strength of the hand. The hand is the reflection of the arm, shoulder, and trunk strength (for one).
Let’s imagine someone who has decreased use of their legs or lower body due to low back pain, sciatica, foot issues such as diabetes, knee or hip OA, osteoporosis of the spine (fractures) etc., and becomes more chair-bound as a result. Those activities might have included sports like golf, gardening, hiking, travelling and so on. It’s not hard to imagine someone who can no longer do all the activities they used to do becoming depressed. Perhaps that person has a fear of moving due to heart irregularities or a diagnosis of high blood pressure or risk of stroke. They are afraid or unable to lift something heavy, even the groceries, or making their own meals. As the list of activities decreases, so potentially does the Grip Strength as the arms lift nothing heavier than the tv remote and the body weakens from hours of sedentary behaviour. I’m not outlining this to create fear or judgement, it’s something I see a lot as people age — and thus allows us to understand how GS is an accurate reflection of health and future health.
For whole body strength that includes the ability of the hand and the forearm, shoulder, girdle and trunk muscles, there is no better exercise (in my opinion) than hanging, swinging, pulling etc. This involves full overhead reach (ultimately) which moves the shoulder through a range of motion that we don’t commonly access any other way (certainly not in most daily activities) thereby strengthening all the associated muscles at their end range. It’s also a body weight activity which means you are self regulated by your own ability to hold your weight, involving finger, wrist, forearm, shoulder and trunk strength (including core) and ultimately if the feet are off the ground, leg muscles too. Your GS increases as the culmination of those parts strengthen and your ability to hang full body weight is gradually attained. It’s a whole body exercise that starts and ends with grip strength.
If someone has poor Grip Strength, does that always mean they have a poor health status or outcome? Of course not. There are people who have had arm amputations and still use their upper body. There are people who have RA or OA in their hands who still have healthy bodies because they have lifestyles that involve many various movements of the arms, shoulders and trunk. When a body part is injured or not healthy, it creates challenges to move in ways that circumnavigate that part, but as someone who spent several weeks in a cast, I found more ways to move around the house than I currently use with my whole body! It’s even possible that you would be healthier than someone who doesn’t have as big a repertoire of movement alternatives. There are always going to be exceptions to the rule.
