Research pick: A gesture towards managing phantom limb pain - "An insight into phantom sensation and the application of ultrasound imaging to the study of gesture motions for transhumeral prosthesis"

Research in the International Journal of Biomedical Engineering and Technology has revealed a promising area of research for the management of phantom limb pain, a common experience for amputees that can be challenging to treat. The research focuses on transhumeral amputees, who are missing a significant portion of one or both of their arms.

Phantom limb pain is a phenomenon that occurs in people who have had a limb partially or wholly amputated. Despite the loss of the limb, individuals may experience sensations such as pain, itching, and tingling as if the missing limb is still part of their body. It can be a persistent and distressing condition that has a significant and detrimental impact on quality of life.

The study, conducted by a team of researchers from the United Kingdom has utilized human motor control theory and Penfield homunculus to provide a comprehensive review and new perspective on phantom limb sensations and pain, and the potential for therapy and prosthetics. Control experiments were undertaken in the clinic with intact individuals using ultrasound imaging along the bone of the upper arm, the humerus, while the participants were instructed to produce a variety of hand movements.

Human motor control theory focuses on how the brain and nervous system control movement in the body. It seeks to understand the processes and mechanisms involved in the planning, execution, and control of movement, ranging from simple actions such as reaching for an object to complex activities such as playing a musical instrument. The famous Penfield homunculus is a neurological “map” of the human body developed in the 1930s. It represents the regions of the brain that control movement and sensation for different body parts, with the hands and face represented in greater detail at greater scale.

Ejay Nsugbe of Nsugbe Research Labs in Swindon and radiologist Carol Phillips of the University Hospitals Bristol, UK, found that compound gesture motions that involve bulk muscular recruitment can be detected along the humerus. This discovery could have significant implications for clinical rehabilitation prosthetists, who can use these gestures to explore the mobility and sensation of phantom limbs. The work could have implications for individuals struggling with phantom limb pain and it could provide a new avenue for therapy as well as leading to improved design of prosthetic limbs to make them more responsive to the user’s needs.

There are implications for developing more effective treatments for phantom limb pain, such as physical therapy or medication, which may improve the quality of life of amputees. Additionally, by gaining a better understanding of the underlying mechanisms of phantom limb pain, researchers may be able to identify new targets for drug development, ultimately leading to better pain management for those experiencing this condition.

Nsugbe, E. and Philips, C. (2023) ‘An insight into phantom sensation and the application of ultrasound imaging to the study of gesture motions for transhumeral prosthesis’, Int. J. Biomedical Engineering and Technology, Vol. 41, No. 3, pp.258–271.