The Evolution of Handheld Dynamometry in Athlete Testing
- Jo Clubb
- Jul 24
- 5 min read
This post explores the science and application of handheld dynamometry and how modern advancements, like the VALD DynaMo range, are bringing greater reliability, accessibility, and insight to strength testing in applied sport and health environments.
The concept of a dynamometer isn’t new. In fact, handheld dynamometry has been used for over a century, particularly in clinical settings, to assess muscle strength. But recent technological advances have transformed the device from a basic clinical tool to a valuable component of high-performance athlete monitoring.
This post outlines how dynamometers work, what types are available, where they fit within athlete testing systems, and key metrics like peak force, asymmetries, and rate of force development (RFD).
This post is part of our Athlete Testing Series, produced in collaboration with VALD, to share discussions on interpreting data from commonly used athlete assessments.
What Is a Dynamometer?
A dynamometer is a device used to measure force, typically the force exerted during muscular contractions. The most common application in sport science is isometric strength testing, where the athlete pushes or pulls against the device without movement.
At its core, the device houses a load cell, which converts mechanical force into an electrical signal. That signal is then translated into a force value, usually expressed in Newtons, though it can be converted into kilograms or pounds.
This process is grounded in Newton's Third Law: for every action, there is an equal and opposite reaction. When an athlete pushes against the device, the device pushes back with an equal force, providing a reliable measurement of strength if protocols are followed correctly. This of course, is similar to the theory underpinning force plates, as discussed in our force plates explained post.
Newton's Third Law: for every action, there is an equal and opposite reaction
Traditional handheld dynamometers were analogue, but today’s models include digital and app-integrated options. Modern devices are smaller, more accurate, and able to integrate seamlessly with software platforms like the VALD Hub.
Types of Strength Tests with Dynamometry
Dynamometers are typically used in three testing formats:
Grip Strength Testing – Measures hand and forearm strength.
Compression Testing – The athlete pushes against the device, often with the assessor holding it to resists the athlete’s force (e.g., hip abduction tests).
Tension Testing – The device is fixed (e.g., to a wall or rack) and the athlete exerts force against it (e.g., standing hip extension or an isometric mid-thigh pull).
Some devices also feature an inclinometer, allowing range-of-motion (ROM) measurements during assessments.
These tests are widely used to monitor unilateral strength, limb asymmetries, and rehabilitation progress. Many of the assessments are those we’ve explored previously in this Athlete Testing Series, such as hip and groin strength testing, shoulder assessments, and the isometric mid-thigh pull.
The Challenge of Reliability with Handheld Dynamometers
A major criticism of handheld dynamometry - especially compression-based testing - has been inter- and intra-tester reliability. When the tester is required to match the athlete’s force, even slight variations in position, bracing, or cueing can influence results. Differences can be further exacerbated if changing between different testers.
That’s where protocol standardisation becomes essential. Consistent setup, instructions, and positioning are key to reducing human error and improving test-retest reliability.
The VALD Dynamo app includes built-in video protocols to guide practitioners through consistent setup and execution, helping to improve both the reliability and repeatability of tests. In addition, the VALD Academy includes introductory and intermediate courses on DynaMo protocols and more, free of charge to VALD clients.
The VALD DynaMo Range
VALD offers three handheld dynamometers, all using the same underlying technology but suited to different use cases:
DynaMo Lite – The most compact model. It lacks a digital display but connects via Bluetooth to the VALD app. Ideal for quick, portable assessments.
DynaMo Plus – Includes an integrated digital screen for immediate feedback, and connects with VALD smart attachments to support a broader range of test types.
DynaMo Max – The newest and most robust option, with enhanced internal components, extended battery life, and capacity to measure forces up to 10,000 N, enabling isometric mid-thigh pull testing.
All devices integrate with VALD Hub, allowing seamless storage, analysis, and visualisation of results alongside other VALD tech systems.
Key Metrics from Dynamometry
Dynamometers provide more than just a single strength reading. Here are some of the key metrics you can monitor:
Peak Force – The highest force value recorded. This is the core indicator of maximum isometric strength.
Asymmetry – Useful for identifying strength asymmetry differences between limbs (e.g., left vs. right) or muscle group imbalances (e.g., adductor vs. abductor). These values must always be interpreted in context - individual baselines and trends over time matter more than arbirtary thresholds.
Time to Peak Force – How quickly an athlete reaches their maximum force. Particularly useful in rehab settings, but if interested in this metric you must cue the individual to push as quickly as possible.
Rate of Force Development (RFD) – The speed of force generation within specific time windows (e.g. 0–100 ms, 0–200 ms). This can be useful for assessing explosiveness but often presents with questionable repeatability, as we explored in more detail in my RFD post.
Practical Considerations for Use
Dynamometers provide an accessible, portable alternative to more complex systems like force plates and ForceFrames. They are ideal when testing on the road, in clinic environments, or in field settings with limited space or resources.
However, to maximise their value:
Use consistent protocols for positioning, cueing, and timing.
Understand your limitations: compression testing requires skilled assessors.
Combine metrics: consider a number of metrics to get a more complete picture.
When used correctly, handheld dynamometry can offer actionable, individualised insights with minimal logistical burden.
Final Thoughts
Dynamometers have come a long way since their origins in clinical testing. Today’s app-enabled devices like the VALD DynaMo range combine accurate force measurement with smart integration into athlete monitoring systems.
They are particularly useful for assessing muscular strength, tracking rehab progress, and identifying asymmetries—without the cost, space, or setup time required for more advanced systems.
To explore each device in the range or request a demo, visit:
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And for deeper dives into related topics - including asymmetry analysis, isometric testing, and rate of force development - check out the rest of the videos in our Athlete Testing Series on the Global Performance Insights YouTube channel.
FAQs about Handheld Dynamometers
What is a handheld dynamometer?
A handheld dynamometer is a portable device that measures force during isometric muscle contractions. It is commonly used to assess muscle strength and joint function in both clinical and sports performance settings.
How does a handheld dynamometer work?
The device contains a load cell that converts mechanical force into an electrical signal, which is then displayed as force output—typically in Newtons, kilograms, or pounds. It often includes an inclinometer for assessing joint range of motion.
What types of strength tests can be performed with a dynamometer?
Common test types include compression (manual testing), tension (fixed-point testing), and grip strength. These are used to assess the strength of different muscle groups or monitor symmetry between limbs.
Is handheld dynamometry reliable?
Modern handheld dynamometers, especially digital and app-integrated models like VALD’s Dynamo range, have improved reliability. However, tester consistency and standardised protocols remain critical due to the influence of human error during manual testing.
What metrics can be obtained from the VALD Dynamo devices?
Key outputs include peak force, time to peak force, rate of force development (RFD), and strength asymmetry measures. These support both performance profiling and rehabilitation monitoring.
Which Dynamo model is right for me?
Dynamo Lite:Â Best for portable, fast field assessments
Dynamo Plus:Â Adds a digital display and compatibility with smart attachments
Dynamo Max:Â Offers enhanced internal components, higher force capacity (up to 10,000 N), and supports isometric mid-thigh pull testing
Stay tuned for more insights on athlete testing in our series sponsored by VALD Performance. Subscribe to our blog to stay updated!
This article is support by VALD Performance. For more information, about their technology, visit their website.