Mobility Technology For Amputees Pushes Forward
22 Feb 2017
The majority of orthotic and prosthetic devices today are focused on helping people overcome deficiencies of the lower extremities – ankle-foot orthoses, below-knee and above-knee prosthetic limbs, and diabetic footwear being the most prevalent.
Thus it comes as no surprise that the lion’s share of O&P research and development addresses improving the mobility of amputees and individuals with various other lower-limb deficiencies.
This article reports on two emerging concepts that, though not yet in the rehabilitation mainstream, show promise for helping physically challenged patients return to their former active and pain-free lifestyle.
Push-off Power for Amputees
Perhaps the most significant barrier to full mobility for lower limb amputees is fatigue resulting from the considerable effort and energy-expenditure of powering a prosthetic limb through the gait cycle. Even with a dynamic-response prosthetic foot, amputees use substantially more effort to position their leg and propel themselves forward than their non-amputee counterparts.
The iWalk BiOM is the world’s first leg prosthesis to provide powered plantar flexion as well as real-time terrain adaptation. In so doing, the system delivers a near-normalized symmetrical gait for amputees at roughly the same metabolic demand of non-amputees… an important breakthrough.
In place of the passive spring core of the typical contemporary prosthetic foot, the battery-powered BiOM incorporates microprocessors, gyroscopes and motors to sense the wearer’s ambulatory purpose and respond with the appropriate positioning and force, effectively replacing the function of the absent calf muscle and Achilles tendon.
Another important feature is the BiOM’s ability to absorb ground impact at heel strike. An estimated 80 percent of lower-limb prosthesis-wearers experience significant back pain and encounter joint deterioration within five years. The BiOM’s engineering reduces unnatural impact stress, pain, pressure within the prosthetic socket and joint trauma. At the end of the day, BiOM users report they have more energy, less pain, and the feeling of having their leg back. The BiOM is now available for above- as well as below-knee applications.
A remarkable success story is being written at the Center for the Intrepid at San Antonio’s Brooke Army Medical Center, where many of our country’s wounded warriors come to put their lives back together.
One of the cruel realities of “modern” warfare is the IED – improvised explosive device – which has turned hundreds of U.S. warriors into amputees, both lower- and upper-extremity. But thanks to America’s commitment to help its wounded servicemen and women regain a positive quality of life and research connected to that effort, some legs that almost assuredly would have been amputated are now being saved by a unique brace called the IDEO – Intrepid Dynamic Exoskeletal Orthosis.
Through advanced surgical techniques, doctors now are able to save combat-damaged limbs that formerly would have been amputated on the spot. Yet, the lost muscle function, nerve damage and joint immobility that often follow the initial surgery have produced pain and mobility limitations that caused many warriors to opt for subsequent amputation anyway.
The IDEO is not only changing that outcome, but also helping return many warriors to active duty. The lightweight IDEO consists of a footplate connected to a leg cuff by carbon-fiber rods incorporating the energy-storing properties of contemporary leg prostheses. The construction offloads the limb during ambulation, allowing the wearer to move in a way that avoids pain. Energy stored at heel strike is released at toe-off to propel the foot forward, helping the patient to walk, run, even jump out of airplanes again.
Statistics reported in May 2012 showed that 97 of 219 warriors fitted with the IDEO were returned to active duty…quite a story!