Myo Arm Opens New Vistas

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"I was scared at first, because I thought that I would need surgery to use a myoelectric arm. It's really cool. I can now do more things for myself, like holding a cup and pouring myself a glass of water, and I am excited to go to college and study sign language."

This is how Melissa Reyes, 20, felt after being fitted with a new myoelectric prosthesis. Melissa was just two years old when the family car she was riding in was struck by a military truck in Honduras. The accident left her paraplegic, and a subsequent infection led to the amputation of her left arm above the elbow. Despite disability, Melissa has done well in life and is planning to enroll in Florida's Miami Dade Community College.

To help Melissa regain the most function possible, Otto Bock HealthCare, Minneapolis, Minnesota, donated the components for her prosthetic arm and myoelectric hand. Two local prosthetists--Jim Fenton, CPO, Fenton Brace & Limb Co. Inc., and Dennis Henkel, CPO, Miami Orthotics & Prosthetics--teamed up to donate their time and expertise to fit the new prosthesis.

Tests were performed to pinpoint Melissa's most controllable arm muscle signals, using the actual electrodes that are part of her prosthesis. Placed in her key muscle contact positions, the electrodes allow her to proportionally control her SensorHand", opening and closing it, based on the task she is attempting. The speed and grip force are controlled by the strength of her muscle contractions. "Proportional Dynamic Mode Control makes Melissa's hand one of the most versatile prosthetic hands in the world," notes Otto Bock.

Melissa also uses Otto Bock's custom cushion. The cushion is fit with the Otto Bock Shape System (OBSS), which consists of software, a special fitting bag, and an imaging stand that allows a therapist to map out a model for a custom cushion. The 3-D model is e-mailed to Otto Bock and the cushion is carved out.

Path to New Prosthesis

Melissa's OBSS custom wheelchair cushion started her on the path to her new myoelectric prosthesis.

This type of cushion is usually used for people with severe cerebral palsy and spinal deformities. However, Melissa is a small person, and all her wheelchair cushions were far too wide for her and didn't provide the lateral support she needed, explains Kathy Weber, Otto Bock. In order to sit up straight, Melissa had to use her residual limb to prop herself up, plus she was very uncomfortable.

After being fit with her new cushion, Melissa could sit up straight without using the limb and thus could begin to explore options for her residual left arm. Serendipitously, Katy Schultz, a doctor of physical therapy, had worked with Melissa before joining Otto Bock as a sales representative. After coming aboard at Otto Bock, Schultz realized what was available in upper-extremity prostheses.

Course Is an Eye-Opener

Katy invited Melissa to a course conducted in the Orlando, Florida, area by Otto Bock for physical and occupational therapists. The course is designed to introduce therapists to upper-extremity therapists. Patient models provide a chance to learn "hands-on" therapy with real people.

Although Melissa had been leery of having a prosthetic arm--since she thought surgery was involved--after the course, she was excited about the prospect. Also, she had met two other amputees during the course and learned from them.

Says Katy Schultz: "Melissa's excitement at being able to drive her wheelchair and hold a soda at the same time&the look on her face, her newfound confidence. It's been very rewarding watching her discover her new abilities and increase her function and independence one task at a time--even small tasks which we take for granted.