Kinvent KForce Review: What’s Changed

Force plates have been growing in popularity in the performance and rehabilitation world due to their unique metrics that may inform player safety and preparedness. Their popularity has expanded beyond research labs now that well-known companies like Vald and Hawkin Dynamics have integrated software to make the user experience much more approachable. Kinvent is newer to this market.

At the end of the day, all force plates measure force; there are, however, little nuances with software that may make one brand desirable over another based on preferences and operations, says MuyVienDPT. Share on X

Kinvent is an interesting addition in the sense that it began with a clinical approach to its software and hardware. In contrast, brands like Vald started from a performance-driven perspective and just recently branched out to the clinical side with Vald Health. Yes, at the end of the day, all force plates measure force; there are, however, little nuances with software that may make one brand desirable over another based on preferences and operations. This review will give you an idea of what to expect with the Kinvent KForce plate and help you decide if this is the right purchase for your current operations.

Technical Specifications

The elephant in the room cannot be ignored: you cannot perform jumps on KForce plates. Due to reports of calibration, collection, and syncing issues with the generation 2 plates, the company removed the feature for new users. If prior users with the function attempt to jump on them, the company won’t cover any damages or malfunctioning of the plates caused by the jumps. Although the company offers the more expensive Delta force plates, the removal of the jumping ability still leaves users with more to desire, given that the company sells a “jump frame” for these force plates and more than doubled the load capacity. If these could handle jumps, these would be a bargain at the current price range (as were their generation 2 plates before all the issues).

Because of the inability to assess jumps, I don’t recommend KForce plates for performance coaches or rehab specialists in high performance. However, they do perform well for the majority of rehab specialists and fitness specialists who find data from stationary movements valuable.

Given its relatively low price, these third-generation KForce plates offer a good middle ground for those looking for a device to measure non-impact forces, balance, and weight shift. Share on X

With the removal of jumps, it is hard to decide whether to compare these to force mats or force plates (figure 1). They are cheaper than force mats, yet more practical and applicable, but they are less useful than their more expensive competitors. Given their relatively low price, they offer a good middle ground for those looking for a device to measure non-impact forces, balance, and weight shift (figure 2). However, the customer must determine whether they desire that middle ground.

The removal of the jump assessment is a large disappointment—however, users can still utilize the increased load capacity with isometric mid-thigh pulls. Their previous load capacity was not high enough for elite athletes and was not at the standard capacity of their competitors. Additionally, their sampling rate is now as high as competitors, with an upgrade from 75 Hz to 1,000 Hz; 1,000 Hz is recommended for human movement assessments.¹ Kinvent suggests the sampling rate can be programmed up to 4,000 Hz; however, most users will not need that high of a sampling rate.

Kinvent’s battery life continues to be legendary, and they have upgraded it from the generation 2 force plates. To give an example, I’ve heavily used the generation 2 force plates for nine months and only had to charge them twice. The batteries never completely ran out, either.

These generation 3 force plates carry on with this trend, as no charge has been required for more than a month. USB-C ports have also been added, which is very welcome since most devices use the same cord. The package arrives with two charging cords; however, users in the United States will have to purchase the standard United States outlet adapters.

Kinvent’s battery life continues to be legendary, and they have upgraded it from the generation 2 force plates. These generation 3 force plates carry on with this trend, says MuyVienDPT. Share on X

The biggest complaint with the generation 2 force plates was their inability to sync consistently. Errors occurred several times, with one or both force plates losing sync with the tablet before, during, and right after tests. This was extremely frustrating, as users were advised to reinstall the app, restart the plates, recalibrate the plates, or even all of the above. This is not good when you have lines of athletes waiting to be tested or a busy clinic full of patients who need your attention, or you need to keep reps consistent for research.

Users also had to completely close and re-open the app to test a new user because the force plates would not sync once one user was complete. All that negative feedback led the engineers to focus significantly on the device’s connectivity, and generation 3 units are much improved in that area. An app restart is still needed at times when switching between users, and the force plates still lose sync—however, these errors occur far less frequently.

Hardware

In regard to the hardware, the force plates are a great size—they even accommodate size 15 shoes—yet they remain light and small enough to carry in a backpack (figure 3). This makes them versatile for many athlete and patient populations while also accommodating those who may have concierge services or travel to local teams for monitoring and screening.

Figure 3. Pictured are size 15 shoes on the third-generation force plates. Although they may be perceived as small, large-footed athletes can still perform all the compatible tests without issues.

Although the technical specifications have been upgraded from the second generation, the build quality did not significantly improve (figure 4). The formerly robust and durable surface was replaced with a thinner plastic that does not seem like it can handle impacts over time. The power button was replaced with a rubber button that may be more aesthetically pleasing but is not very pressure-sensitive. Users will have to push the button hard to feel the “click” of the actual button underneath and may sometimes even need to push it with a pen. The LED lights on the top and side remain from the generation 2 version, making it easy for users to see if the plates are on, synced, or charging.

The new Kinvent force plates are a great size—they even accommodate size 15 shoes—yet they remain light and small enough to carry in a backpack, says MuyVienDPT. Share on X

Of note, I evaluated two sets, each made with slightly different materials (figure 4). One came as a part of a kit, and the other came as a standalone set. Overall, the force plates that came with the kit feel more robust and of higher quality. It is undetermined if two different types will exist or if the company will commit to manufacturing just one type.

The Software

A short time before the generation 3 release, Kinvent released the K-physio app and discontinued support for their KForce app. The K-physio app is a significant upgrade and is what all Kinvent users will want. It gives you a host of metrics, such as center of pressure, impulse, peak force, and rate of force development at specific time intervals. The software comes with three different options. The starter package is the best option for KForce users since it gives you access to the most popular tests that these force plates can measure.

The software provides great data visualization, and you can easily save test results to a customized PDF, depending on the software package purchased. This is a nice feature, but it has room for improvement given that competitors allow users to customize exactly which metrics and groups to show/hide—this is important when data is delivered to stakeholders.

While they offer a web platform for desktops, it is lacking (figures 5 and 6). Users who access their data will be missing out on 90% of the mobile app’s functionality. Among the missing features at the time of this review are inabilities to:

• Delete test sessions.
• Edit users.
• See advanced metrics (for jumps).
• Customize reports.
• Make/sort groups.

Most importantly, there is no ability to administer a test.

The desktop app does not pick up or allow the entry of participants’ demographic info. This hinders the daily operations of rehab specialists who need to document and multitask on their laptops.

Training on these plates is a strong point since they offer excellent games. Karl the Kangaroo is their mascot, and the games are goofy enough to get anyone smiling and competitive about it. Users can adjust the difficulty, amount of anteroposterior weight shift, and amount of mediolateral weight shift. I’ve had more than dozens of postoperative athletes, within and between session changes to squat weight shifting, who have been quick and effective with these games.

Lastly, the software is fast-evolving, and Kinvent’s developers seem to release a fix or brand-new feature each month. Although there could be improvement based on the above summary, the software team acts quickly and will likely enhance features even more after the publication of this review.

Score: 7.5/10

These force plates were made for those in clinical settings who, at most, want to measure squatting, balance, and isometric strength objectively. The build quality leaves much to be desired compared to Kinvent’s previous iteration. Still, the new hardware brings technical specifications up to date with their competitors at a relative bargain price.

These force plates were made for those in clinical settings who, at most, want to measure squatting, balance, and isometric strength objectively, says MuyVienDPT. Share on X

The software provides and visualizes enough data for users to make well-informed decisions but lacks the advanced analytic functions of its competitors; the desktop version is severely lacking. Overall, I recommend this more for those in a clinical setting, but anyone working with athletes should look into Kinvent’s Delta force plates, Vald’s Force Decks, or Hawkin Dynamics’ force plates, since they offer the ability to test jumps.

Since you’re here…
…we have a small favor to ask. More people are reading SimpliFaster than ever, and each week we bring you compelling content from coaches, sport scientists, and physiotherapists who are devoted to building better athletes. Please take a moment to share the articles on social media, engage the authors with questions and comments below, and link to articles when appropriate if you have a blog or participate on forums of related topics. — SF

Reference

1. Beckham G, Suchomel T, and Mizuguchi S. “Force plate use in performance monitoring and sport science testing.” New Studies in Athletics. 2014;29(3):25–37.