Innovative assistive device to enhance wrist drop treatment in patients

Wrist drop is a global condition that impairs wrist and hand movement, making it challenging for individuals to extend their hands fully. Existing treatments primarily involve medications, surgical procedures, or the use of wrist braces. However, traditional braces offer passive support, relying on elastic properties without aiding rehabilitation. Motorized joint support offers active actuation but comes with limitations such as sensor-triggered controls, continuous power requirements, potential malfunctions, and a lack of complete control. Taking these factors into account, this paper proposed a cost-effective innovative solution involving passive activation, combining support to hold the wrist. The design justifications for incorporating a ratchet-locking mechanism have been explained in detail. The assistive device has mainly two modes; in assistive mode, it supports the hand to move against gravity during exercises whereas in locking mode, this mechanism provides resistance using a ratchet lock and effectively stabilizes the wrist in a predetermined position. This paper also presents a technical evaluation of the proposed design, assessing its functional capabilities and potential impact on wrist drop treatment.

1 DeCastro, A., and Keefe, P.: Wrist Drop. (2022) Available at: www.ncbi.nlm.nih.gov/books/NBK532993/#:~:text=Wrist%20drop%20is%20a%20disorder (accessed: 27/10/2023).
2 Cunha, J.P. (2022) Can Wrist Drop Be Cured? Treatment, Symptoms, Causes. Available at: https://www.emedicinehealth.com/can_wrist_drop_be_cured/article_em.h... (accessed: 24th May 2023).
3 Ali M.A., Freilich S.: Wrist drop after a fall onto the shoulder. BMJ; 380 :e070708 doi:10.1136/bmj-2022-070708, (2023).
4 Akhtar, A. and Ng, C.Y.: Cement extrusion and radial nerve palsy during revision shoulder and elbow arthroplasty: Beware of the cortical breach. Journal of Clinical Orthopaedics and Trauma, 16, pp.226-229, (2021).
5 Abdelmegeed, M., Lohman, E., Daher, N., Kume, J. and Syed, H.M.: Effect of Ulnar-Based Orthotics and Strengthening Exercises on Subjects With Ulnar Wrist Pain. Journal of Sport Rehabilitation, 29(2), pp.206-212, (2020).
6 Montagnani, F., Controzzi, M. and Cipriani, C.: Independent long fingers are not essential for a grasping hand. Scientific Reports, 6(1), p.35545, (2016).
7 Sabeo, Neurorehabilitation; What Are Some of the Things We Know? 2020. Available at: https://www.saebo.com/blog/neurorehabilitation-what-are-some-of-thin... – Saebo (accessed: 27/10/2023).
8 Vivomed, Push sports wrist brace. Available at: https://www.vivomed.com/product/braces-supports/wrist-support/wrist-... (accessed: 27/10/2023).
9 Moon, H., Hoang, N., Robson, N.P. and Langari, R.: Human arm motion planning against a joint constraint. In 2012 4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob) (pp. 401-406). (2012) IEEE.
10 Saini, V.: Average forearm size for men and women. Available at: https://fitnessvolt.com/average-forearm-size/#:~:text=The%20average%20male%20forearm%20length (accessed: 27/10/2023), (2023).
11 Frothingham, S.: What’s the average hand size for men, women, and children? Available at: https://www.healthline.com/health/average-hand-size#adultsn (accessed: 27/10/2023), (2019).