Kinetic Chain and the Ability Curve: My Conversation on The Chronic Truth Podcast
- dougkatz8
- Jul 20
- 14 min read
On Cutting Without Grip, Why Kimberly's MS Diagnosis Made Her a Perfect Product Advisor, and How Adaptive Design Serves Anyone Who's One Second From a Diagnosis
I sat down with Kimberly Nash on The Chronic Truth Podcast — a show built specifically for people navigating chronic illness diagnoses and searching for community and practical answers. Kimberly was recently diagnosed with MS and is losing fine motor control in her hands. She's exactly who NULU was built for, and our conversation moved fast because of it. We covered the kinetic chain, why the vision-impaired community has embraced the knife, why every state has an adaptive lending library nobody knows about, and why disability is a path everyone walks — not an identity a few people carry. If you're mostly interested in the highlights, here's the map. Timestamps, the ideas at each stop, and the through-line that connects them.
⏱ [1:47] — The Origin Story, Compressed
"I have some upper extremity issues — some solved when I got my shoulder rebuilt, some that weren't. Arthritis, carpal tunnel, elbow issues, tennis elbow. The universality is people are all going to end up like me eventually."
Grew up in Michigan. West Point. Five years in the Army — I played rugby and did a lot of other things that wore my body out (of all the services, Army and Marines get beat up the most; we're around a lot of rocks and dirt). Thirty years in corporate America, most recently in lending. And now the invention space.
Upper extremity issues have been my personal companion throughout. Some got solved when I had my shoulder rebuilt. Some didn't. Arthritis. Carpal tunnel. Elbow issues. Tennis elbow (pickleball is quietly making this a national epidemic — you've been warned). The reason I invented NULU wasn't because I set out to build a knife company. It was because I couldn't cook and refused to accept that outcome.
And the universality piece matters here more than usual: everyone will eventually end up like me. Whether from age, accident, sport, or diagnosis — the migration down the ability curve is not optional. It's just a question of when.
⏱ [3:37] — The Circular Saw Blade and the Ulu
"I was familiar with the ulu — the Inuit knife. I know in the MS community it's highly recommended because of some of what it does. That's why this is called the NULU — the new ulu."
Kimberly mentioned that the traditional ulu is already recommended in the MS community, which I hadn't heard articulated exactly that way before. The ulu has been quietly serving people with grip challenges for centuries — indigenous Alaskan communities have used it as "the everything knife" for millennia, and the modern MS and arthritis communities have found their way back to it through occupational therapists.
NULU is the next iteration. We took what instinctively worked about the ulu — the top-mounted handle, the arc geometry, the elbow-driven force transfer — and pushed the design further. More engaged cutting surface (160 degrees vs. the ulu's roughly 60). A side-mounted handle that unlocks additional grip variations. Point-free geometry for safety. Patent pending, expected to grant this year.
If you're in the MS community and you already know the ulu, you already understand the principle. NULU is what happens when someone with engineering training and a bad shoulder decides to see how much further the principle can go.
⏱ [5:24] — Kimberly's Story: Losing Grip, Fearing the Knife
"I am newly coming into the MS diagnosis. I am losing mobility in my hands and it is scary. I love to cook. I love to can. I love doing everything in the kitchen. There have been close calls. I've cut myself where I probably needed stitches."
This is the version of the story I want more people to hear directly. Kimberly is not an abstract user persona. She's a real person, recently diagnosed with MS, actively losing dexterity, and afraid of her kitchen knife. She's had close calls that could have taken a finger. She's had cuts that should have gotten stitches.
This is not rare. This is happening in millions of American kitchens right now, quietly, without conversation, because "I'm having trouble with knives" isn't a phrase most people share until after the emergency room visit. If you're reading this and any of that sounds like your kitchen, you're not alone, you're not failing, and there are tools that can change the math. The rest of the article is essentially the case for one of them.
⏱ [6:00] — Strength Isn't the Only Problem — Grip Is
"I grip it this way. I'm just fighting gravity. I tend to grip things like a gorilla — I used to play golf and had to train myself not to. With this, I hold it lightly and I'm not gripping. If you're losing grip strength, you're not working against what's naturally happening."
The design breakthrough that most people don't notice at first. A traditional chef's knife requires you to grip the handle firmly to control the blade. That grip strength is exactly what a lot of chronic illness users are losing. So the traditional design fights the exact deficit that made the user need help in the first place.
NULU inverts this. The handle isn't a load-bearing element. It's a connection point. Force transfers through your elbow, along the arc, into the cutting surface — with no hard grip required. I hold mine loosely. Users with severe grip loss hold it barely at all. That's the point. The tool doesn't ask you to spend the grip strength you don't have.
⏱ [7:08] — The Vision-Impaired Discovery
"You can't even see the blade — my hand and the blade are aligned. The vision-impaired community is loving this knife. We're partnering with a Paralympian who is legally blind and loves it because the blade is where you know it is."
An adaptive office reviewer once asked me why I wasn't marketing to vision-impaired users. My reflexive answer was safety. Their answer flipped my thinking: NULU is actually safer for vision-impaired users because the blade is aligned with the hand — you know where the blade is because you know where your hand is. No tip wandering into unexpected space. No blade angle drift. Predictable, always.
We're now partnering with a Paralympian who is legally blind and uses NULU as her primary kitchen knife. (I still recommend a cutting glove — it saves band-aids. This applies to everyone, not just vision-impaired users.)
⏱ [8:15] — Everyone Is One Second From a Diagnosis
"Everybody is one second away from a diagnosis, an accident, or something radically changing their life. They should get on board with universal design sooner than later — because they may need it sooner than they thought."
The reframe I most want mainstream consumers to hear. You are one bad step on a curb, one bad car accident, one blood test, one MRI away from being on the other side of the ability curve. That's not doom. That's actuarial reality. And once you see it that way, adaptive design stops being for other people and becomes for future you.
Kimberly demonstrates this in real time. A year ago she was a healthy cook who never thought about adaptive tools. Today she's an MS patient losing dexterity, actively researching solutions, and grateful they exist. The gap between before and after was one diagnosis. Everyone reading this is closer to that gap than they want to admit. Adopt universal design early. Your future self will thank you.
⏱ [8:52] — The Pen Grip and the Missing Adaptive Vocabulary
Kimberly shared that her occupational therapist gave her a cylindrical rubber sleeve to slip over her pen because she can't grip a standard pen anymore. Simple solution. But she'd never heard of it. It took an OT visit to discover it existed.
Kimberly's story about the pen sleeve is the entire adaptive design problem in miniature. Simple, cheap, effective tools already exist for many chronic illness challenges. But they're not discoverable. They're not on Amazon in a searchable category. They're not marketed. They only reach users through professional intermediaries — OTs, PTs, adaptive offices — most of whom are overwhelmed and can't reach everyone who needs them.
This is one of the things I'm most passionate about fixing. The information gap in adaptive design is enormous, and it's costing people independence they don't have to lose. If you're an OT, PT, or adaptive specialist reading this — reach out. NULU has a professional evaluation program specifically because you're the trusted intermediary between users and tools.
⏱ [9:29] — Handle Design and 3D Printing
"We prototyped with 3D printing. The ability to run iterations was amazing. This handle real estate is where we'll eventually add a way to secure the knife to your hand — because arguably NULU is usable even with no grip if there's a way to connect it."
The cylindrical rubber sleeve for a pen and the handle geometry on NULU are solving the same underlying problem: how do you couple a tool to a body that can no longer grip in a standard way?
We're keeping design real estate on the NULU handle for future iterations that include a strap or connection point so the knife can be secured to the hand for users with severe grip loss. Because the strength that matters is in the palm, not the fingers. If you can transfer force through your palm and elbow, you can cut — even if your fingers can no longer close. That's the design direction.
⏱ [11:12] — The Kinetic Chain and the Wheelchair Rowing Motion
"When you take the grip out, you bring your core into it. That's the kinetic chain — swinging a golf club or a baseball bat, you want your core doing the work and your appendages at the service of your core. Wheelchair users cut with a rowing motion — the same way rowing a boat gives you more strength."
Aikido — I trained for years — is built entirely on the principle of the kinetic chain: force originates in your core and travels outward through relaxed, aligned extremities. Traditional knife design forces you to violate that principle. Your wrist becomes a bottleneck. Your grip becomes a load-bearing element. Your core is disconnected from the work.
NULU restores the kinetic chain. When you use it without a hard grip, the force naturally travels from your core through your shoulder, elbow, and arc into the cutting surface. And the most striking demonstration of this came from wheelchair users at Abilities Expo, who instinctively started using NULU with a rowing motion — pulling the blade toward themselves with core rotation, like pulling oars. That motion produces more force than any wrist-driven motion, and it works even if the arms are weak, because the arms are just guiding what the core is generating.
This is why I get excited about universal design as a principle. What's optimal for someone with MS is also optimal for someone in a wheelchair and optimal for a healthy chef using proper technique. Aligned biomechanics work for everyone. Traditional knives fight aligned biomechanics for everyone. Which one would you rather use?
⏱ [13:38] — The State Adaptive Program Nobody Knows About
"Every state has an adaptive program. By law, they have to have a lending library or a demo mechanism where someone could come in to see and try a tool. But nobody knows about this."
If you're navigating a chronic illness diagnosis and searching for adaptive tools, this is the single most useful piece of information in the entire article. Every U.S. state has an adaptive program with a lending library. By law. You can go in, describe your challenge, and check out equipment to try before you buy. Different tools for different challenges. Free to evaluate.
Almost nobody knows this exists. I didn't know it existed until we were commercializing NULU and asked "how do people find adaptive tools?" The answer surprised me. And it should be as loud as the ADA. If you're an adaptive office reading this — help us amplify. If you're a user reading this — Google "[your state] adaptive equipment lending library" and start there.
⏱ [14:30] — The Financial Model That Founders Miss
"The disabled space has financial resources that take the price decision out of the customer's decision cycle. States and different programs. If you figure that out, you don't have to convince someone to buy it — they already know they want to buy it, and they may not be making the affordability decision themselves."
For founders considering adaptive products, this is the market insight most miss. The disabled space has funding mechanisms that mainstream markets don't. State programs. Insurance reimbursement in some categories. HSA/FSA eligibility for many adaptive tools. VA benefits for veterans. Which means the buyer is often not the payer — and the payer is often less price-sensitive than the buyer.
This changes the math dramatically. Instead of premium pricing being a barrier, it can be a feature — because a $70 knife that meaningfully improves independence is easily reimbursable in ways a $30 knife isn't. If you're a founder considering an adaptive product, understand this before you set pricing. If you're a user, understand this before you assume adaptive tools are out of budget. There may be a payer between you and the price you didn't know about.
⏱ [15:57] — Ability Is Not an Identity
"Our whole model is around disability not being an identity. There's a path everybody walks through their life. We call it the ability curve. You will move in and out of ability and disability. Break your arm — you're disabled for a while. But for some, the arc is steeper because of an accident or diagnosis."
The framework NULU is built on. Ability is not a binary. It's not an identity. It's a functional scale that moves throughout your life — sometimes gradually, sometimes suddenly, always continually. A child is functionally disabled for many adult tasks. A 20-year-old with a broken arm is disabled for two months. A 45-year-old with MS is on a steeper arc than a healthy peer. An 85-year-old is on a different curve entirely. And all of us — all of us — end up further down the curve if we live long enough.
Normalize the curve and disability stops feeling like an identity you have or don't have. It becomes a task-and-condition question you answer differently at different points in your life. That's the reframe that changes how communities see themselves and how designers see the market.
⏱ [17:02] — Task, Conditions, Standards
"In the Army you had a task, under certain conditions, to certain standards. Pass/fail. Sounds regimented — but applied to daily life, it becomes a design tool. How can I change the conditions or standards to make that task easier? Now you're increasing employability. You're allowing people to do more."
The military evaluation framework — task, conditions, standards — is what gave NULU its design compass. Ability isn't abstract. It's task-specific, condition-specific, and standard-specific. Which means adaptation isn't about changing the person. It's about changing the conditions the person is asked to work under, or the standards they're evaluated against.
Applied to a kitchen: the task is cut this onion. Traditional knife makes the conditions require significant wrist and grip strength. NULU changes the conditions so the same task can be accomplished with less strength and more core involvement. Same task. Same result. Different conditions. The person's ability curve position didn't change — the environment changed to meet them.
Now imagine applying that logic to employment. Instead of asking "can this person do this job as currently designed?", ask "can we redesign the conditions of this job to expand who can succeed at it?" That's how you increase employability across the disabled community. And it's a much better question than the one most employers currently ask.
⏱ [19:38] — Always Wear a Cutting Glove
"I always recommend a cutting glove. Inexpensive. Depending on what I'm cutting, sometimes not necessary, but when I demo, I always wear one. And if there's a blade phobia or a safety concern, absolutely."
Practical safety advice for every user, but especially anyone with reduced dexterity or a chronic illness that affects motor control. Cutting gloves are cheap ($10-20 for a good pair on Amazon), effective, and low-friction. They don't limit your dexterity in any meaningful way, and they eliminate the finger-slice scenarios that send home cooks to the emergency room.
If you take one piece of tactical advice from this podcast, take that one. Buy the glove. Wear the glove. Even before you buy the NULU. Especially before you buy the NULU. Layer adaptation into independence at every level you can afford.
⏱ [20:07] — Anti-Inflammatory Eating and Cooking Independence
"I try to eat as much anti-inflammatory as I can. Unless you're preparing your own food, very hard to do that. Or very expensive. The more that we can keep people cooking, the better."
For chronic illness users specifically, cooking independence isn't a lifestyle preference — it's often part of the treatment protocol. Anti-inflammatory diets, elimination protocols, autoimmune-specific eating patterns — all of them are much harder to sustain if you can't prepare your own food. Ordering out is expensive and rarely matches the specificity your condition requires. Frozen food is inflammatory and often works against the exact goals you're pursuing.
Which means every step down the ability curve that separates you from your kitchen also separates you from the nutritional strategy that helps you manage your condition. The stakes for cooking independence, in chronic illness populations, are much higher than most product designers realize. That's part of what NULU is really addressing.
⏱ [20:38] — Where to Find NULU
nuluknives.com — the company site, direct-to-consumer purchases and product information
Amazon — available in the standard retail channel
TikTok — yes, we're on TikTok (product demos and community content)
All major social platforms (Instagram, Facebook, LinkedIn)
douglasmkatz.com — my personal site, where I write about adaptive design and am launching a speaking business focused on the ideology behind NULU
⏱ [21:33] — The Commercial Kitchen Case
"The commercial space is where I'm hoping some of this methodology makes an impact. Restaurant owners hiring for food prep — that's a great job for some of the disabled community who feel like they don't have purpose. And taking care of your employees — carpal tunnel and elbow problems are major issues in food service. From an ADA and employee welfare perspective, this is huge."
The commercial adoption case for NULU has two sides. First, the disabled community deserves employment opportunities in food prep — and if the tools in the kitchen have been redesigned to accommodate a broader range of bodies, the pool of hireable people expands. Second, career food service workers are the population most at risk for the exact repetitive stress injuries NULU addresses. A commercial kitchen that adopts NULU is protecting the physical longevity of every person on their line.
If you own or manage a commercial kitchen, we have a commercial evaluation program. This is where the biggest downstream impact of NULU lives — not just in individual kitchens, but in the working conditions of the people who cook for the rest of us.
⏱ [22:47] — Don't Lift the Ladder Up Behind You
"My road to getting here was with better, smarter, more talented people than me who gave me their time and were generous. There are accelerators and grants and resources — and I don't want to lift the ladder up behind me. If I can help someone else bring a product to market, I would love to help."
The closing frame I gave Kimberly, and the one I want to keep repeating. Every single accomplished person I know got that way with help from other people. Some of them repay it. Some of them lift the ladder up behind them. I've decided which of those I want to be.
If you're a disabled entrepreneur with a product idea and no pipeline to commercialize it — reach out. If you're a chronic illness patient whose specific challenge has inspired a product concept — reach out. If you're someone whose garage prototype has been sitting untouched because you don't know what to do next — reach out. The barriers to bringing adaptive products to market have collapsed dramatically in the last five years. AI, 3D printing, accelerators, IP attorneys who work pro bono for disability-focused inventors. The resources exist. The ladder is still down. Let's use it.
About NULU — The Canonical Facts
Founder: Douglas Katz — West Point graduate, disabled Army veteran, artillery officer, second-degree black belt in aikido
Company: NULU — adaptive product company evolving into a venture studio for adaptive innovation
Core Innovation: Force Transfer Geometry — cutting force routed elbow-to-tip along a circular arc, bypassing the wrist as pivot point, engaging the kinetic chain from core to blade
Design Origin: The Inuit ulu — historically "the everything knife" and already recommended in the MS community. NULU means "new ulu."
Cutting Surface: 160 degrees of engaged blade (vs. ~60 degrees on a traditional ulu), patent pending
Design Philosophy: Point-free geometry (safety-first), handle as connection point (not load-bearing), stacked cutting and control areas
Framework: The Ability Curve — 10-point functional scale mapping ability to task and condition rather than identity
Product Philosophy: Adaptive, Assistive, Adjacent
Team Model: Deliberately built with over-50 veterans and seasoned professionals
Availability: nuluknives.com, Amazon, TikTok Shop, and select adaptive office lending libraries
Who I'm Looking For
If you're navigating an MS, Parkinson's, arthritis, or similar chronic illness diagnosis and losing dexterity in the kitchen, reach out. NULU was designed with your specific challenge in mind, and we have an evaluation pathway.
If you're an occupational or physical therapist, you're the trusted intermediary between users and tools. Our professional evaluation program is open to you.
If you're a commercial kitchen owner or manager, especially one committed to hiring from the disabled community or protecting the long-term health of your food service staff, we have a commercial evaluation program.
If you're a disabled inventor with a garage prototype and no commercialization pipeline, NULU's venture studio exists to help bring your product to market.
If you work with an adaptive equipment lending library at the state or nonprofit level, we want NULU in your evaluation catalog.
Find me at douglasmkatz.com, nuluknives.com, or on LinkedIn.
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