Walk It Out

Designers: Ellie Hwang, Soo Choi, Laura Ferraro

Client Coordinators: Kyle Covington, PT

Supervising Professors: Kevin Caves and Richard Goldberg

INTRODUCTION

Regina is a 21 year old female who sustained a traumatic brain injury at a young age.  She has trouble coordinating her muscles and she has significant spasticity in her movements.   As a result, Regina uses a manual wheelchair for mobility, but she is working with a therapist to use a walker.  She has several types of walkers but they all are difficult to use because of the same problem: as she leans onto the walker for support, it moves away from her, putting her at risk of falling.  In addition, Regina has several postural problems that make using a walker difficult.  In therapy sessions, two individuals are required to help Regina walk, one to spot her to prevent a backward fall, the other to apply a stopping force to the walker if it lunges forward.

The goal of this project is to modify a walker for Regina, to provide both safe and independent use. The modified walker incorporates a new handlebar, a ski brake for

resistance, a reminder bar for her posture and a walking bar for inhibiting crossing of her legs. When the client uses the modified walker, she holds a handle bar directly facing her, similar to that of a shopping cart. As she walks forward and applies downward force on the bar, the braking system activates and increases the stopping resistance on the walker.

This successfully slows the client down, prevents her from falling forward, and allows her to walk independently. Meanwhile, the posture bar corrects the client’s posture by preventing her hips from moving too far forward. Overall these changes help her use the walker independently.

SUMMARY OF IMPACT

Here is a quote from the client: “I can’t wait to use my new and improved walker. It will be so nice to walk around without someone (MOM) hanging on to my walker so it doesn’t go crashing into something because I can’t control it. I am hoping that I will be able to get up and walk across the room with no help. I like how you made the walker slow down so it doesn’t go out-of-control fast. I like that I can just stand there so I don’t always have to sit down. It will make my legs stronger. I really want to thank you for putting so much work into it, and not giving up when it didn’t work at first.”

TECHNICAL DESCRIPTION

We used the client’s commercially available U-Step walker, which employs a handlebar cable braking system.  The brakes work in a manner similar to bicycle brakes.  The client activates a brake lever, which pulls on a cable and causes a brake pad to press against the rear wheels on the walker, which slows it down. The brake cables on the U-step meet at the front of the walker at a joint called the junction bar.  When she activates either hand brake, the cable pulls the junction bar which rotates and activates both brake pads.  The client can also activate the brakes by pushing down on a curved bar across the front of the walker. This existing bar has a gentle curve which does not allow Regina to spread her hands widely on the bar.  Therefore, we fabricated and installed a new braking bar that is ergonomically more suitable for the client, and therefore provides a wider grip for Regina to give her more stability.  The bar is padded using foam and bike grip tape.

When the client presses either the brake lever or the braking bar, brakes will be applied to both rear wheels.  However, the braking force is not enough to prevent the lunging of the walker for our client.  As a result, we developed a ski brake to apply additional braking force.  This is made of wood with cushion on the bottom to provide more friction.  It rests on the floor and is attached to the front of the walker.  A new junction bar was fabricated with an additional metal lever that runs to the top of the ski brake.  When the client engages the brakes, the junction bar rotates and the lever presses down on the top of the ski brake, increasing the downward force on the ski, thus increasing the braking force to the walker.

Two postural bars were incorporated into the modified walker.   A pelvic reminder bar was attached to the walker in front of Regina facing her hips.  During walking, Regina tends to arch her back and push her hips forward, making her prone to falls.  The reminder bar is positioned so that if Regina’s hips move forward, the sensation of contact with the bar will remind her to correct her posture.  Similarly, the walking bar is positioned horizontally at knee level, connected to the back of the walker, passing between her knees and continuing about 2 feet past her.  The walking bar provides a tactile reminder to Regina to not internally rotate her legs.

The modified walker has greatly improved the client’s ability to walk independently. The new braking system successfully slows down the walker before it slides forward, and it is easy for the client to use effectively. The posture bars improve Regina’s walking postures leading to a noticeable improvement in the client’s balance and ability to steer the walker.

The cost to develop the device was $153.

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