Improving Well-being in Amputees Using Modern Prosthetic Technology

    Every year approximately 185,000 people in the United States will have a limb amputated as a result of disease, trauma, and cancer.  Amputation has many negative consequences including phantom limb pain, changed self-image, and an inability to perform the same daily tasks as before the amputation. There is also a stigma around disability that can cause shame and decreased self-worth that accompanies amputation. These can affect the general wellbeing and life satisfaction of individuals who have undergone limb amputations.

              An article titled ‘Activity and Participation, Bimanual Function, and Prosthesis Satisfaction are Strong Predictors of General Well-Being Among Upper Limb Prosthesis Users’ by Phillip Stevens et al. looked at patient outcomes after undergoing upper limb amputation procedures.  They found that the strongest predictors of positive well-being in patients were prosthesis satisfaction, the ability to be active and engage in social participation, and pain interference. 

              Traditional prostheses are not powered and require physical manipulation to operate.  A person may have to use their chest and shoulder to operate a prosthetic which can be uncomfortable and awkward to operate without training and practice. This can both reduce the satisfaction patients have with their prosthesis as well as cause them to withdraw from social engagement out of shame. Dr. Levi J. Hargrove has been working to improve modern prosthetics to help eliminate some of these problems. 

In the article ‘Robotic Leg Control with EMG Decoding in an Amputee with Nerve Transfers’ Dr. Hargrove et al. explore the use of EMG and pattern recognition algorithms to interpret patient’s movements to provide intuitive control of a leg prosthetic. Electromyographic (EMG) signals are the signals from the brain to the muscles that cause them to relax or contract.  They collect EMG data from surgically reinnervated muscles near the amputation site and the pattern recognition algorithms predict how the patient is going to move next in order to shift the mode of operation of the prosthesis from walking on flat ground, up stairs, or on a ramp. This eliminates the need for mechanical switches that can make traditional prosthetics awkward and uncomfortable to use and gives patients greater control over their movement by eliminating the unnecessary motions required to change the walking mode.  Another benefit of this is that the reinnervation surgery has been shown to reduce and potentially eliminate phantom limb pain. 

The work Dr. Hargrove is doing directly addresses the findings of the Stevens et al article. By designing prosthetics that use the same neural signals used to control limbs before amputation they are working towards prosthetics that can be operated just by thinking about moving them.  This technology could also lead to more precise movements allowing for greater recovery of function which would increase prosthesis satisfaction and prevent social withdrawal as a result of shame from loss of function.  While the Hargrove article states that the robotic prosthetics still have to be improved to become more reliable and more comfortable for the users, they are making positive strides in prosthesis technology which will improve the lives and well-being of amputees across the country.

Resources:

Hargrove, L. J., Simon, A. M., Young, A. J., Lipschutz, R.D., Finucane, S. B., Smith, D. G., Kuiken, T. A. (2013). Robotic Leg Control with EMG Decoding in an Amputee with Nerve Transfers. The New England Journal of Medicine 369(13). https://doi.org/10.1056/NEJMoa1300126

Stevens, P. M., England, D. L., Todd, A. E., Mandacina, S. A., Wurdeman, S. R. (2023). Activity and Participation, Bimanual Function, and Prosthesis Satisfaction are Strong Predictors of General Well-Being Among Upper Limb Prosthesis Users. Archives of Rehabilitation Research and Clinical Translation 5(2). https://doi.org/10.1016/j.arrct.2023.100264