Grip Strength as a Vital Sign: Testing, Averages, & Optimization

Grip strength is a core OT assessment—and one we hope you consider as a vital sign of your health. 

That’s because this simple metric is a holistic measure that provides unique insight into your current health status, and your risk for future health challenges. 

(As you’ll see below, it is about so much more than your hand strength! Grip strength can tell a story of your health overtime.) 

In this article, we’ll share:  

• How you can test and track grip strength
• Information about averages and norms
• And, finally, ways you can improve your grip strength

Hand Grip Strength Measurement

One of the perks of hand grip strength measurement is that it is relatively simple.

Grip strength is tested by squeezing a device called a “dynamometer”with your full strength. The word dynamometer means “power measure.” 

Using a handheld dynamometer can either be done with your therapist, or you could buy a dynamometer to do this test at home. 

It is important to note that norms for each dynamometer are slightly different. 

Comparison of Grip Strength Dynamometers

Dynamometer Name	Price per Unit	Population	Features
Jamar Hydraulic Hand Dynamometer	$270.53*	Ages 6 – 75+	Considered the “gold standard” by American Society of Hand Therapists, with excellent test-retest reliability. Low initial cost, though requires frequent maintenance and recalibration to maintain accuracy.
Jamar Plus Digital Hand Dynamometer	$427.87*	Ages 6 – 75+	More efficient than its hydraulic counterpart. Automatic digital display reduces risk of user error.
Squegg Smart Dynamometer	$109.00	Ages 18 – 87	Small, comfortable, and does not require frequent recalibration. Compatible with Squegg companion app, which includes engaging hand strengthening games.
Takei Digital Hand Dynamometer	$450.00	Marketed for use among ages 10 – 70. Clinical trials compare Takei to Jamar using these normative values	Validated for use with pediatric populations, ages 10 and up. Automatic digital display reduces risk of user error.
KINVENT K-Grip Hand Dynamometer	$490.00*	Validated for use among adults 20+	Use with associated app KINVENT Physio App subscription for better efficiency and data analysis, starting at $350 per year. Requires fewer calibrations and less maintenance than hydraulic dynamometers. Research suggests this tool may underestimate grip strength when compared to Jamar products.
Activforce 2	$449.00	Not specified.	Use with associated ActivForce companion app. Attachments can be used for additional testing including muscle movement and range of motion.
*These products require frequent professional recalibration, which may significantly increase their lifetime costs. Recalibration costs are typically under $150.

Protocols for Measuring Grip Strength

After you choose your dynamometer, it is important how you position your arm for the test. (We call this the testing protocol). Testing in different positions, measures different things. 

One important distinction is sitting versus standing measurement.

Testing in a seated position targets the strength of smaller muscle groups of the hand and wrist, with the result being an indicator of upper body strength. (See the ASHT and Southampton protocols for seated grip strength compared here.)

Testing in a standing position, on the other hand, captures lower body and core strength (which is used in balance and exertion of force). Results of this testing method are indicative of overall strength.

Grip Strength Norms and Averages

As mentioned above, you want to use the norms from your specific dynamometer. 

Here are the norms as shared by the CEO of Squegg, Gabriella Francis, OTR/L, ATC:

It is important to note that many countries have published their own norms. For example, Great Britain, Australia, Canada, Korea, Germany, and Japan each have their own distinct normative values.

There are also different cut points in percentiles for weakness based on country of origin (please see the chart here for more details).

Factors Influencing Hand Grip Strength

In this article, authors go in-depth on different factors that can influence grip strength, including:

• hand dominance
• age
• gender
• socio-economic status
• ethnicity
• education level
• employment
• physical fitness
• nutritional status

For example, several studies showed grip strength peaking in people ages 30–39. According to this study, the majority of right-handed subjects tested 10% higher in grip strength on their dominant side. Men also consistently had higher overall grip strength than women. In this study from Brazil, men had 57% higher grip strength than women.

Associations of Hand Grip Strength with Morbidity and Mortality

Grip strength is associated with so many things that it’s hard to sum it up briefly. So, I’m going to borrow from this study, and divide the associations into two overall categories:

First, grip strength can be used as a marker of a client’s current overall:

• strength
• upper limb function
• bone mineral density
• fracture susceptibility
• fall risk
• malnutrition risk
• cognitive impairment
• depression risk
• sleep quality
• risk of diabetes
• multimorbidity
• quality of life

Grip strength can also be predictive of future:

• all-cause and disease-specific mortality
• function
• bone mineral density
• fractures
• cognition and depression
• problems associated with hospitalization

Lots of specific diagnoses are mentioned in this section that I encourage you to check out, including correlations with:

• type 2 diabetes
• cardiovascular disease
• chronic kidney disease
• chronic liver disease
• stroke
• some cancers
• sarcopenia

Improving and Optimizing Your Grip Strength

There is much research out there on improving your grip strength and the benefits of doing so. We’ll be adding a table with some of that information next week!

Conclusion: Hand grip strength as a vital sign of health

Given the many associations grip strength has with other conditions, it’s no surprise that it has already been called an important biomarker of health.

And, as outlined in this article, grip strength deserves your consideration as a vital sign for its value in :

Comprehensive Health Assessment: Grip strength assessment would add to the other cardiovascular and respiratory vital signs by providing additional insight into musculoskeletal health.

Early Disease Detection: Because low grip strength is associated with so many chronic conditions, it could help practitioners identify health issues early—enabling more timely interventions.

Predictive Value: Because grip strength also has predictive value, this measurement could aid in risk stratification and prevention strategies.

Serial Measurements: This measure lends itself to continuous tracking over time.

Patient Engagement: Because this measurement is so simple and easy to understand, patients can monitor changes in their own wellbeing. It also gives them a motivating number to track.

Cost-effective and Non-invasive: Again, the simplicity of this measure allows it to be collected without any significant burden on the healthcare system.Diverse Applications: Grip strength has been studied throughout the lifespan and can be adapted to support healthy aging or track rehabilitative progress.