Last Updated: April 2026 | Written by Joel Smith, inventor of the Freedom Leg (hands-free crutch) and the original steerable knee scooter
The Freedom Leg (hands-free crutch) is a non-weight-bearing mobility device invented by Joel Smith — the same engineer who invented the original steerable knee scooter in 2006. After a decade watching patients struggle with the device he created, Smith identified three critical failures: stairs were inaccessible, both hands were occupied, and many patients with compromised knees couldn't use it at all. The Freedom Leg transfers load to the posterior thigh, enabling hands-free mobility on any terrain.
In 2006, I created what became the global standard for non-weight-bearing mobility. By 2012, I stopped recommending it to patients.
That's not a statement you hear often from an inventor. But after a decade of watching real patients struggle with the device I created, I couldn't ignore what the data—and the stories—were telling me.
Here's how I got here, and why it led me to spend the next ten years engineering something better.
From Boeing to Bicycles to Medical Devices
I never set out to work in medical devices. After leaving Boeing as a mechanical engineer, I founded a bicycle design and manufacturing company. By 2003, I'd begun developing high-performance wheelchairs—applying the same principles of lightweight design, durability, and biomechanics that I'd learned in aerospace and bicycle engineering.
In 2006, a local medical device manufacturer approached me with a problem: knee scooters were primitive. Four wheels that didn't turn. A kneeling pad and a handle. To change direction, you had to lift the entire device off the ground and pivot it.
They wanted something better. Lightweight, durable, easy to manufacture, and most importantly—steerable.
I drew on everything I'd learned: aerospace precision, bicycle design, manufacturing efficiency, and wheelchair biomechanics. The result was the first truly steerable knee scooter. It worked. By 2008, it had become the global standard.
I thought I'd solved the problem.
The original steerable knee scooter, 2006
What Are the Limitations of a Knee Scooter?
Almost immediately after designing the knee scooter, I began seeing its limitations. Transferring all your weight to the knee for extended periods wasn't ideal—the knee wasn't designed to bear the full body weight of the user. Many people had compromised knees that couldn't tolerate the load even for short periods. It also limited utility to just foot or ankle injuries.
In 2008, I designed the Voyager Seated Scooter—the same layout as the knee scooter, but with a bicycle seat post and seat instead of a kneeling pad. This transferred weight to the user's buttocks and allowed off-loading for the entire leg, not just the foot and ankle.
Joel Smith on the Voyager Seated Scooter, 2008
But in 2009, something happened that changed everything.
My wife suffered a knee injury and needed to be non-weight-bearing for six weeks. She was a gymnastics coach. Our home had multiple flights of stairs. And neither device I'd designed—the knee scooter or the seated scooter—would work for her life.
She couldn't navigate stairs. She couldn't move around the gym on uneven surfaces. She couldn't continue coaching.
And I realized: I'd been solving the wrong problem.
The Three Problems Every Knee Scooter User Faces
Watching my wife struggle made the limitations crystal clear:
Stairs are non-negotiable. She needed to access every level of our home safely.
Hands aren't optional. She needed to carry equipment, spot gymnasts, and demonstrate techniques.
Four wheels don't fit everywhere. Gyms have mats, beams, uneven surfaces—wheeled devices were useless.
The knee scooter and seated scooter worked beautifully for patients with single-story homes, wide doorways, and the ability to rest. But for patients who needed to maintain their independence, continue working, care for children, or navigate real-world environments? They were almost as limiting as crutches.
And as an engineer married to someone who needed a solution now, I couldn't look away from that.
What If Non-Weight-Bearing Didn't Require Wheels?
What if we could achieve 100% non-weight-bearing mobility without occupying the hands, without requiring four-wheel stability, and without making stairs inaccessible?
To help my wife, I needed to compress a decade of research, prototyping, and biomechanical testing into a couple of weeks.
The answer wasn't another wheeled device. It was a fundamental rethinking of how we transfer load during non-weight-bearing recovery.
How Proximal Weight Transfer Works
Crutches transfer load distally—through the hands, wrists, shoulders, and underarms. This creates upper-body strain, instability, and a high fall risk.
Knee scooters transfer load to the knee and hands, but they require a platform and wheels, which limits mobility.
The Freedom Leg takes a different approach: transferring load proximally—to the posterior thigh and hip. The hip and thigh are part of the body's natural load-bearing structure. By transferring the patient's body weight to the posterior thigh during the swing phase of gait, the Freedom Leg achieves true non-weight-bearing status without upper-body strain, without wheels, and without sacrificing the patient's ability to navigate stairs, carry objects, or sit normally.
How the Freedom Leg Was Engineered
The breakthrough came from rethinking the entire approach. Instead of wheels and platforms, weight transfers to the posterior thigh and down rigid side rails to the ground. This kept the legs in alignment, allowed for normal gait on any terrain, and left the hands completely free.
The original Freedom Leg prototype — engineering load transfer to the posterior thigh
I built the first Freedom Leg prototype for my wife. She was able to continue coaching her gymnastics team. She could safely climb stairs. She could carry items and perform tasks of daily living.
It worked.
Turning a prototype into a commercial medical device took years:
- Biomechanical analysis to ensure zero load on the injured foot
- Material selection for a lightweight, durable structure supporting patients from 4'4" to 6'4" and up to 275 lbs
- Ergonomic testing for all-day comfort
- Clinical trials validating safe stair navigation and activities of daily living
- FDA registration
Early prototypes were too heavy. Others were uncomfortable for extended wear. We had to solve for adjustability, ease of fitting, and the reality that most patients would be donning the device themselves at home.
By 2012, we began production. Over the following years, we gathered clinical data showing higher satisfaction rates, better protocol compliance, and fewer secondary injuries compared to crutches or knee scooters.
Early Freedom Leg in the field — stairs, hands free
Is the Freedom Leg Ready for Clinical Use?
After thirteen years of development and refinement and over 10,000 satisfied customers, the Freedom Leg is ready for widespread clinical adoption.
But here's the challenge: most surgeons don't know it exists.
That's not a criticism—it's a reality of the medical device industry. Surgeons are focused on surgical outcomes, not on the nuances of post-operative mobility aids. And until recently, we've been a small company focused on product development rather than marketing.
The clinical evidence is strong enough, and the patient outcomes compelling enough, that it's time to change that. The Freedom Leg is covered under insurance billing code L2136 — it's not a premium add-on, it's a reimbursable medical device.
If you're an orthopedic surgeon, podiatrist, or physical therapist who's ever had a patient struggle with crutches or knee scooters during NWB recovery, the Freedom Leg is worth knowing about.
The Inventor's Dilemma
Here's the truth about being an inventor in the medical device space: you don't get credit for what you create. You get credit for the outcomes your device enables.
I'm proud of the knee scooter. It helped tens of thousands of patients recover more comfortably than they would have on crutches.
But I'm prouder of the fact that I was willing to acknowledge its limitations and spend a decade engineering something better.
Because at the end of the day, this work isn't about defending a legacy. It's about giving patients the independence and safety they deserve during one of the most vulnerable periods of their recovery.
And that's worth starting over for.
Frequently Asked Questions
Q: Why did Joel Smith stop recommending the knee scooter?
A: After observing patients for nearly a decade, Smith identified three critical failures: stairs were inaccessible, both hands were occupied, and patients with compromised knees couldn't tolerate the load. He stopped recommending it in 2012 and spent the next ten years engineering the Freedom Leg.
Q: What is the Freedom Leg and how does it work?
A: The Freedom Leg is a hands-free, FDA-registered non-weight-bearing mobility device. It straps to the thigh and lower leg, transferring body weight to the posterior thigh through rigid side rails. The injured foot is elevated and never touches the ground. Users walk normally, climb stairs, and carry objects with both hands free.
Q: Can the Freedom Leg be used on stairs?
A: Yes. Stair navigation was one of the three core design requirements. The Freedom Leg allows users to ascend and descend stairs safely — something neither crutches nor knee scooters handle reliably for most patients.
Q: Is the Freedom Leg covered by insurance?
A: The Freedom Leg is covered under HCPCS billing code L2136 and may be reimbursable through Medicare, Medicaid, and many private insurers. Contact your provider or visit FreedomLeg.com to confirm coverage.
Q: What injuries is the Freedom Leg designed for?
A: The Freedom Leg is designed for any condition requiring non-weight-bearing recovery of the lower leg — including Achilles tendon rupture, ankle fractures, foot fractures, and post-surgical recovery. Unlike the knee scooter, it can also be used for patients with compromised knees.
Joel N Smith is a mechanical and biomedical engineer and the inventor of the steerable knee scooter and the Freedom Leg (hands-free crutch alternative). He is the founder of Forward Mobility and has spent 18 years focused on improving non-weight-bearing recovery outcomes. Learn more about the Freedom Leg or connect with Joel on LinkedIn.
Related reading: Freedom Leg vs. iWALK — Which Hands-Free Crutch Is Right for You? | A Guide to Achilles Tendon Repair and Recovery
