Between High-Tech and Usability: How Modern Myoelectric Hand Prostheses Transform Daily Life, Control, and Bodily Experience

Myoelectric hand prostheses enable individuals with arm amputations or congenital limb deficiencies to partially regain both the appearance and essential functions of the hand. They are controlled by muscle activity, which is detected using surface electromyography (EMG). While basic standard hand prostheses (SHPs) typically allow only opening and closing motions using antagonistic muscle pairs, modern multi-grip prostheses (MHPs) offer more refined control and various grip modes through multiple motorized fingers. However, the actual benefit of these advanced prosthetic technologies is contested: many users report high costs, increased complexity, and a certain fragility, which means everyday usability is not always ensured. Previous studies on this topic often suffered from small and non-diverse samples, leading to inconsistent results.

The study by Kerver et al. (2023) addresses this issue by comparing SHP and MHP users using the ICF model, which defines health as the interplay of body functions, activities, and social participation. A key focus was whether modern MHPs can reduce compensatory movements, such as excessive shoulder or trunk motion. In addition, the study examined usability in daily life, user satisfaction, and psychosocial aspects. Participants were recruited through orthopedic workshops, rehabilitation centers, and patient organizations in the Netherlands. Included were individuals with transradial or wrist-level amputations who were at least 18 years old and had used their respective prosthesis in everyday life for at least six months.

The study included 14 MHP users and 19 SHP users. On average, the SHP group had nearly eight years of experience with their prosthesis, while the MHP group had about four years. Both groups completed motor skill tests, including the Box-and-Blocks Test (BBT), the Southampton Hand Assessment Procedure (SHAP), and the Red-Cell Ring Test (RCRT), supplemented by surveys on quality of life, satisfaction, and prosthesis experience. MHP users also took part in a direct comparison: they tested their own MHP and a standardized SHP, which they used in daily life for one week. In a lifting task, MHP users took about 12.5 seconds, while SHP users needed only about 10 seconds. In other tasks, such as dexterity tests, there were few differences. Approximately three-quarters of MHP users moved their joints similarly to how they did with the standard prosthesis, while one-quarter showed different compensatory movements. Overall user satisfaction was comparable in both groups. SHP users praised the robustness and simplicity of use, whereas MHP users highlighted the versatile grip options and finer control. Nevertheless, perceived quality of life tended to be slightly higher in the SHP group.

Complementing this, the study by Chapell et al. (2025) provides new insights into myoelectric control and sensory feedback. Central to the research is a newly developed controller for the OLYMPIC Hand 4, capable of simultaneously controlling three active degrees of freedom (DOFs) - including precision and power grips as well as forearm rotation. A key innovation is a redesigned haptic armband that provides users with continuous proprioceptive feedback on each motor's position, force, and finger posture. This system was tested in a study involving 28 healthy participants and 10 individuals with limb loss. Participants were assigned to one of four control groups: open/discrete (OLDC), closed/discrete (CLDC), open/continuous (OLCC), and closed/continuous (CLCC). The 10 participants with amputations tested only the CLCC configuration.

First, isolated control tasks were carried out, including position matching across 30 single-DOF and 20 dual-DOF movements, as well as force matching for 20 target force levels. The results showed clear differences: in dual-DOF position matching, the OLCC group had a 54% higher mean absolute error (MAE) than the CLCC group. Similarly, force matching errors were significantly higher in the OLCC group - on average by 22.3%. Remarkably, some participants with limb loss even outperformed the healthy control group, particularly in complex dual-DOF tasks. In a sensory object identification task, the CLCC group also performed well, achieving nearly the same accuracy as the discretely controlled OLDC group - highlighting the effectiveness of the proprioceptive feedback. As expected, participants with sensory impairments had lower recognition rates.

In real-life tasks - such as the Box-and-Blocks Test or the Jebsen-Taylor Hand Function Test - there were no significant differences between the groups. Some participants with amputations completed certain tasks with high skill, while others were hindered by anatomical limitations or short residual limbs. Subjective experiences of prosthesis use were measured using standardized questionnaires. In early test phases, users of continuous control reported higher physical strain. However, in the final test phase, the CLCC group reported the lowest physical burden of all groups - despite the additional weight of the haptic armband. Perceived performance increased significantly in the CLCC group, while frustration and mental strain decreased. The strongest correlations were found between frustration and perceived performance. Participants with limb loss tended to report greater physical strain, partly due to limited prosthesis experience or increased demands on the residual limb.

A central aspect of the study was the sense of embodiment - the feeling that the prosthesis becomes part of one's own body. This feeling increased over the course of the test phases in most participants, especially in the CLCC group. However, some users with amputations reported that using the prosthesis heightened their awareness of the loss and decreased their sense of bodily completeness. Others described an increasingly positive integration of the prosthesis into their body image.

In summary, the two studies show that technical complexity alone is not enough to make prostheses suitable for everyday use. What truly matters is how intuitive the control is and how well user feedback is integrated. MHPs offer fundamentally greater possibilities but only reach their full potential when control and sensory feedback are closely synchronized - as demonstrated by the closed, continuous control with proprioceptive feedback. The findings suggest that future developments should focus on better user integration, reduced physical strain, and a stronger sense of control and embodiment. Only then can modern prostheses fulfill their promise in everyday life.

Source:

Chappell, D., Yang, Z., Clark, A. B., Berkovic, A., Laganier, C., Baxter, W., Bello, F., Kormushev, P., & Rojas, N. (2025). Examining the physical and psychological effects of combining multimodal feedback with continuous control in prosthetic hands. Scientific Reports, 15(1), 3690. Source

Kerver, N., Schuurmans, V., van der Sluis, C. K., & Bongers, R. M. (2023). The multi-grip and standard myoelectric hand prosthesis compared: Does the multi-grip hand live up to its promise? Journal of NeuroEngineering and Rehabilitation, 20(1), 22. Source