Upper Limb Amputation

The goal of this experimental study is to investigate the somatosensory system through intraneural recording and stimulation of the median nerve in healthy volunteers and participants with upper-limb amputation. The main questions it aims to answer are: * How does median nerve activity encode tactile perception during different types of mechanical tactile stimulation in healthy subjects? * How can tactile information be artificially encoded and restored through intraneural microstimulation in both healthy subjects and upper-limb amputee participants? How rich and functionally meaningful is the restored sensory information? * What are the neurophysiological mechanisms underlying tactile stimulus processing and the associated patterns of brain activation during tactile stimulation? Participants will undergo median nerve recordings using microneurography during controlled mechanical tactile stimulation, as well as intraneural microstimulation with specific patterns to evoke near-natural tactile sensations. They will perform perceptual reporting tasks related to stimulus type, intensity, and localization, as well as psychophysical tests under different stimulation conditions. When possible, they will also undergo non-invasive recordings of brain activity using electroencephalography during sensory stimulation.

This observational study aims to examine the relationship between the percentage of limb loss and functional outcomes in individuals with unilateral upper limb amputation. Upper limb amputation can affect posture, balance control, pain levels, daily living activities, hand function, and reaction time. However, limited research has investigated how the amount of limb loss influences these outcomes. Participants between 18 and 65 years of age who use a myoelectric or bionic prosthesis will undergo a series of assessments. These assessments include measurements of postural control using a force platform, posture analysis, evaluation of neck and low back pain using a visual analog scale, daily living activities using a validated questionnaire, hand dexterity using the Box and Block Test, and reaction time using a visual stimulus device. The study does not involve any intervention or treatment. All evaluations will be performed during a single assessment session. The results of this study may help improve rehabilitation planning and provide better understanding of functional changes associated with different levels of limb loss in people with upper limb amputation.

The goal of this clinical trial is to test a new one-handed video game controller adapter to determine if it helps improve how video games are played and enjoyed in children with an upper limb difference on one side. The main questions it aims to answer are: * Is performance improved while playing video games with the adapter? * Is user satisfaction or enjoyment improved while playing video games with the adapter? Participants will: * Answer questions about their limb difference and other demographics * Be interviewed about their current and past video game playing experiences * Learn how to use the adapter and have their performance with it evaluated * Take the adapter home to use for 1 week, and be asked to record their experiences * Have their performance with the adapter re-evaluated after a week of practice * Be interviewed about their experience with the adapter

This observational study aims to compare myoelectric and bionic hands in terms of upper extremity function, body image and satisfaction. The main questions it aims to answer are: \- Does upper extremity function differ between bionic and myoelectric hands? The main questions it aims to answer are: Does upper extremity function differ between bionic and myoelectric hands?

The investigators propose to validate a non-invasive upper limb prosthesis capable of combining: 1) intuitive movement control through machine learning applied to myoelectric signals, and 2) vibrotactile sensory feedback in response to touch and object release events. The prosthesis is composed at the minimum of skin-surface electrodes for myoelectric signals, vibrotactile actuators, a multi-articulated and instrumented hand prosthesis and a centralized control system. Such system is validated for several weeks in non-supervised environments.