Breaking News
January 19, 2019 - Highly effective protocol to prepare cannabis samples for THC/CBD analysis
January 19, 2019 - Prinston Pharmaceutical Inc. Issues Voluntary Nationwide Recall of Irbesartan and Irbesartan HCTZ Tablets Due to Detection of a Trace Amount of Unexpected Impurity, N-Nitrosodiethylamine (NDEA) in the Products
January 19, 2019 - How does solid stress from brain tumors cause neuronal loss, neurologic dysfunction?
January 19, 2019 - $14.7 million partnership to supercharge vaccine development
January 19, 2019 - Ian Fotheringham receives Charles Tennant Memorial Lecture award
January 19, 2019 - Brain vital signs detect neurophysiological impairments in players with concussions
January 19, 2019 - Lack of job and poor housing conditions increased likelihood of people attending A&E
January 19, 2019 - Novel targeted drug delivery system improves conventional cancer treatments
January 19, 2019 - Rutgers study finds gene responsible for spread of prostate cancer
January 19, 2019 - Complications Higher Than Expected for Invasive Lung Tests
January 19, 2019 - 3-D printed implant promotes nerve cell growth to treat spinal cord injury
January 19, 2019 - Automated texts lead to improved outcomes after total knee or hip replacement surgery
January 19, 2019 - Poor cardiorespiratory fitness could increase risk of future heart attack, finds new study
January 19, 2019 - Drinking soft drinks while exercising in hot weather may increase risk of kidney disease
January 19, 2019 - Formlabs 3D prints anatomical models
January 19, 2019 - Heart-Healthy Living Also Wards Off Type 2 Diabetes
January 19, 2019 - Teaching Kids to Be Smart About Social Media (for Parents)
January 19, 2019 - Metabolite produced by gut microbiota from pomegranates reduces inflammatory bowel disease
January 19, 2019 - Researchers examine how spray from showers and toilets expose us to disease causing bacteria
January 19, 2019 - Behavioral experiments confirm that additional neurons improve brain function
January 19, 2019 - New study compares performance of real-time infectious disease forecasting models
January 19, 2019 - Obesity can be risk factor for developing renal cell carcinoma, confirms study
January 19, 2019 - New regulation designs on cigarette packs direct smokers’ attention to health warnings
January 19, 2019 - QIAGEN receives first companion diagnostic approval in Japan
January 19, 2019 - Study explores role of Dunning-Kruger effect in anti-vaccine attitudes
January 19, 2019 - Newly identified subset of immune cells may be key to fighting chronic inflammation
January 19, 2019 - New immune response regulators discovered
January 18, 2019 - Poor blood oxygenation during sleep predicts chance of heart-related death
January 18, 2019 - First international consensus on the diagnosis and management of fibromuscular dysplasia
January 18, 2019 - Rapid resistance gene sequencing technology can hasten identification of antibiotic-resistant bacteria
January 18, 2019 - Researchers develop artificial enzymatic pathway for synthesizing isoprenoids in E. coli
January 18, 2019 - Scientists advise caution in immunotherapy research
January 18, 2019 - How children across the world develop language
January 18, 2019 - Columbia Medical Student Receives McDonogh Scholarship
January 18, 2019 - Secretive ‘Rebate Trap’ Keeps Generic Drugs For Diabetes And Other Ills Out Of Reach
January 18, 2019 - Plant based diet could be the best option for the planet says commission
January 18, 2019 - New conservation practice could reduce nitrogen from agricultural drainage, study shows
January 18, 2019 - UIC researchers receive $1.7 million NCI grant to study Southeast Asian fruit
January 18, 2019 - New study determines the fate of DNA derived from genetically modified food
January 18, 2019 - Scientists develop new gene therapy that prevents axon destruction in mice
January 18, 2019 - Study finds critically low HPV vaccination rates among younger adolescents in the U.S.
January 18, 2019 - Brain cells involved in memory play key role in reducing future eating behavior
January 18, 2019 - Risk for Conversion of MS Varies With Different Therapies
January 18, 2019 - Investigational cream may help patients with inflammatory skin disease
January 18, 2019 - Medical school news office receives six writing awards | News Center
January 18, 2019 - County By County, Researchers Link Opioid Deaths To Drugmakers’ Marketing
January 18, 2019 - Research reveals risk for developing more than one mental health disorder
January 18, 2019 - Scientists discover a dramatic pattern of bone growth in female mice
January 18, 2019 - Study finds link between lengthy periods of undisturbed maternal sleep and stillbirths
January 18, 2019 - New nuclear medicine method could improve detection of primary and metastatic melanoma
January 18, 2019 - Combination therapy shows high efficacy in treating people with leishmaniasis and HIV
January 18, 2019 - Health Tip: Don’t Ignore Changes in Skin Color
January 18, 2019 - Dietary Recommendations for Healthy Children
January 18, 2019 - Eliminating the latent reservoir of HIV
January 18, 2019 - Pain From The Government Shutdown Spreads. This Time It’s Food Stamps
January 18, 2019 - Newly discovered regulatory mechanism helps control fat metabolism
January 18, 2019 - New rapid blood tests could speed up TB diagnosis, save the NHS money
January 18, 2019 - Researchers develop intelligent system for ‘tuning’ powered prosthetic knees
January 18, 2019 - Monoclonal antibody pembrolizumab prolongs survival in patients with squamous cell carcinoma
January 18, 2019 - New research detects mosquito known to transmit malaria for the first time in Ethiopia
January 18, 2019 - Researchers identify new genes linked to development of age-related macular degeneration
January 18, 2019 - Computerized method helps better protect pharma patents
January 18, 2019 - New guidelines to make swallowing safer for people in Australian nursing homes
January 18, 2019 - Lumex Instruments’ RA-915AM monitor installed at Hg treatment plant in Almadén, Spain
January 18, 2019 - ACCC survey finds multiple threats to growth of cancer programs
January 18, 2019 - Meeting the challenge of engaging men in HIV prevention and treatment
January 18, 2019 - Furloughed Feds’ Health Coverage Intact, But Shutdown Still Complicates Things
January 18, 2019 - Experts discuss various aspects on health risks posed by fumigated containers
January 18, 2019 - Researchers use gene-editing tool CRISPR/Cas9 to limit impact of parasitic diseases
January 18, 2019 - Alpha neurofeedback training could be a means of enhancing learning success
January 18, 2019 - Innovative ‘light’ method demonstrates positive results in fight against malignant tumors
January 18, 2019 - The cytoskeleton of neurons found to play role in Alzheimer’s disease
January 18, 2019 - New resource-based approach to improve HIV care in low- and middle-income countries
January 18, 2019 - Bedfont appoints Dr Jafar Jafari as first member of the Gastrolyzer Medical Advisory Board
January 18, 2019 - New study shows link between secondhand smoke and cardiac arrhythmia
January 18, 2019 - DZIF scientists reveal problems with available diagnostics for Zika and chikungunya virus
January 18, 2019 - Breast cancers more likely to metastasize in young women within 10 years of giving birth
January 18, 2019 - Over 5.6 million Americans exposed to high nitrate levels in drinking water
January 18, 2019 - Blood vessels can now be created perfectly in a petri dish
January 18, 2019 - Study identifies prominent socioeconomic and racial disparities in health behavior in Indiana
Amputees using powered prosthetics can avoid energetic costs by cranking up power settings

Amputees using powered prosthetics can avoid energetic costs by cranking up power settings

image_pdfDownload PDFimage_print

Amputees who use powered prosthetic ankles may be able to avoid the energetic costs typically associated with prosthetics by cranking up the power provided by their devices.

A UCF engineering professor recently published a study in Scientific Reports that shows that people with transtibial amputations – the loss of a limb below the knee – may improve their walking ability if they change the power-setting on their devices. Hwan Choi, who received his doctorate in engineering from the University of Washington, is an assistant professor in the UCF department of Mechanical and Aerospace Engineering.

According to a study conducted by the National Institutes of Health, approximately 185,000 amputations occur in the United States every year and 49-95% of lower-limb amputees reportedly use a prosthesis. Most of those on the market are passive prosthetics. On average, amputees spend up to 30% more energy than unimpaired individuals when performing tasks such as walking. This could be due to the fact that most ankle prostheses are passive-elastic, meaning that they can store and release energy when they come in contact with the ground but are unable to perform positive net ankle work that allows for muscle shortening contractions to occur. In fact, these prostheses are only able to provide one eighth of the power of the intact gastrocnemius and soleus muscles, the key muscles that support and propel the body during walking.

As passive prostheses increase the energetic demand on the user, individuals may have to compensate by increasing muscular effort in the residual or intact limb. Powered ankle prostheses, on the other hand, use actuators to reduce the increased metabolic costs placed on amputees by delivering positive work. BiOM (now known as EMPOWER), the only commercially available powered ankle prosthetic, uses a visual display that allows the wearer to tune the power setting on the device. Ideally, they would select a power setting between 0% and 100% that best approximates that of a healthy ankle at the user’s preferred walking speed. But the question remains: how much power should the prosthesis provide?

Too little power and they may experience the same metabolic costs of those using passive prostheses, but too much and they may experience problems such as knee hyperflexion and increased energy absorption in the knee that can raise the metabolic costs of the user.

Choi, along with coauthors Kimberly Ingrahm, David Remy, Emily Gardinier, and Deanna Gates from the University of Michigan, tested ten individuals with transtibial amputations. They measured the metabolic cost of transport (COT) and the BiOM’s net ankle work at different power settings, while the amputees walked on a treadmill with the BiOM ankle.

Choi said that they discovered that the ideal power that reduced metabolic cost was actually greater than biological norms. In other words, the best tested setting actually decreased the amount of excess energy used by the subject more than the prosthetist-chosen power setting.

“The key finding of this study was that none of the subjects had the minimum metabolic cost when they walk with unimpaired individuals work or power. When they had greater power, then the impaired individuals actually reduced metabolic cost.”

Across participants, power settings greater than 50% resulted in lower COT, but the best tested power setting was actually higher than the prosthetist-chosen setting.

In fact, on average, the power setting that minimized energy costs corresponded to approximately double the net ankle work of the biological ankle. So while powered ankles may be more beneficial than passive prosthetics, amputees can actually increase their activity level when prosthetists change their goal from achieving approximate biological ankle kinetics to minimizing metabolic costs.

According to Choi, with minimized metabolic costs, transtibial amputees have a greater chance of remaining active, improving their quality of life, and preventing a number of health consequences, including diabetes and cardiac disease.

Tagged with:

About author

Related Articles