A research team from Brown University, Providence, Rhode Island, has unveiled a new index, the Activities Measure for Upper Limb Amputees (AM-ULA), to help physical and occupational therapists, prosthetists, and physicians assess the progress that patients make during training with their new prosthetic limb. They describe the measure in an article published online October 19 in the Archives of Physical Medicine and Rehabilitation.
In the best cases of treatment, patients work with teams of physicians, prosthetists, and therapists to learn how their new limbs can help them regain function and quality of life. But clinicians have had few tools to assess whether that teaching and learning process is going well because of a lack of standardized measurements to use with adults with upper-limb amputations. The AM-ULA provides standardized methods and criteria for clinicians to grade patients’ performance, speed, and skill using any kind of prosthetic arm to do 18 everyday tasks. The AM-ULA includes tasks such as putting on and removing a shirt, serving soda from a can, combing hair, tying shoes, and using a spoon. They are the kinds of tasks adults need to be able to complete independently to care for themselves and others.
“Patients can’t just take a prosthesis out of the box and start using it skillfully,” said lead author Linda Resnik, PhD, PT, OCS, an associate research professor in public health at Brown and a research scientist at the Providence Veterans Affairs Medical Center (VAMC). “Physical and occupational therapists train people to use adaptive equipment and prosthetic devices. We need measures to let us know if our patients are improving the way that we expect them to. When they get a new device, what are the benefits? Are they able do more with it?”
Resnik, who directs a prosthetics research program at the Providence VAMC’s new Center for Neurorestoration and Neurotechnology, led the development of the new measure to aid her testing of a prosthetic arm developed by DEKA Research and Development, Manchester, New Hampshire. She and the team tested the metric with 49 veterans at U.S. Department of Veterans Affairs (VA) facilities in Tampa, Florida, and New York and at the U.S. Army’s Fort Sam Houston, Texas; the VA provided funding for the study.
Some existing measures are self-assessments where patients report how they are doing on a standardized scale, but Resnik said while those are essential, they don’t tell clinicians everything they need to know. For instance, the patient might subconsciously use other body parts to compensate for an insufficiency with a prosthetic arm.
“This particular tool…considers aspects of movement quality that might not be picked up in a self-report,” she said. “We look at the amount of body compensation used to perform a task-how much bending or use of other more proximal joints is involved in an activity. That’s important, because we know that upper-limb amputees often develop problems in their neck and back.”
One of the key methods of refining the metric and ensuring its reliability was determining whether two independent raters, observing the same patient performance, arrived at the same ratings or strongly disagreed. The researchers also determined when raters differed with themselves when the test was administered twice within a short period of time.
The researchers also validated the measure by making sure that the results made sense, based upon what was known clinically. For instance, scores of the AM-ULA were highest for people with amputation of the hand, lower for those with a transradial amputation, and lowest for amputees with a transhumeral amputation.
To help clinicians interpret changes in AM-ULA scores in individual patients, the team analyzed the statistics to calculate how much of a change in the overall score could be considered more than just natural “noise” in the data. For example, a patient whose scores change more than 3.7 points between sessions is likely to have truly changed.
Although Resnik was inspired to develop the metric for her own research, she said she hopes the metric will become a commonly used, standard tool in the field.
“Outcome measures are needed in all areas of healthcare, but particularly so in…prosthetic rehabilitation,” Resnik said. “Most insurance companies restrict the amount of money allowable for prosthetic devices and the amount of therapy that’s available to people. It is important to have sensitive and responsive methods to objectively assess the benefits of prosthetic devices and training.”
Editor’s note: This story was adapted from materials provided by Brown University.