3D-Printed Mobile Phone Holder for Individuals With Upper Limb Impairments

Design and Implementation of a 3D-Printed Mobile Phone Holder Selection and Fitting Process for Individuals With Upper Limb Functional Impairments

Individuals with upper limb functional impairments, such as those resulting from stroke, spinal cord injury, musculoskeletal disorders, or degenerative joint disease, often experience difficulties operating smartphones. Standard devices typically require bilateral, precise fine motor control, which can limit independence, participation, and access to digital communication for this population. Although assistive products such as phone stands, straps, or styluses are available, they are often designed as "one-size-fits-all," lack individualization, and may not be well integrated into daily life.

Three-dimensional (3D) printing offers advantages of customization, modularity, low cost, and rapid production, and may support better matching between users and assistive devices. However, in clinical practice, the use of 3D-printed assistive technology is constrained by the lack of an integrated resource platform and standardized fitting procedures.

This exploratory intervention study aims to develop a 3D assistive device selection interface and a standardized fitting process for smartphone-related devices targeting adults with upper limb dysfunction. Approximately 30 outpatients will be recruited from a regional teaching hospital in northern Taiwan and will receive a 1-week intervention using a 3D-printed mobile phone holder or related assistive device, with occupational therapist support. Pre- and post-intervention assessments will examine smartphone task performance and satisfaction with the assistive technology. Feasibility, usability, and preliminary effectiveness will be evaluated to inform the development of a sustainable clinical service model.

Study Overview

• Status: Not yet recruiting
• Conditions: Upper Limb Dysfunction; Hand Function Impairment; Musculoskeletal Disorders Affecting Hand Function; Difficulty Operating Smartphones Due to Upper Limb Impairment

Detailed Description

Upper limb dysfunction due to neurological, musculoskeletal, or degenerative conditions frequently interferes with the performance of fine motor tasks, including smartphone operation. Many individuals with unilateral weakness, limited range of motion, pain, or grip instability find it difficult to hold a phone securely, touch the screen accurately, or perform multi-step operations such as dialing, messaging, or taking photos. As smartphones have become central tools for communication, information access, and social participation, these limitations can widen the "digital divide" and negatively affect independence and quality of life.

Although a variety of commercial assistive devices exist (e.g., generic phone stands, straps, styluses, and gripping aids), they are often designed for the "average user" and may not accommodate severe deformities, contractures, or complex motor coordination problems. Many users and clinicians must improvise or modify existing devices, which is time-consuming and may compromise stability and safety. Clinical decision-making regarding assistive device selection frequently relies on individual therapist experience rather than standardized procedures or objective criteria, and patients often lack access to systematic information about available options, features, and indications.

Three-dimensional (3D) printing provides a promising avenue for developing lightweight, modular, and customizable assistive devices that can be tailored to each user's anatomy and functional needs. Prior research has demonstrated that 3D-printed assistive devices can improve functional performance, reduce pain, and increase satisfaction in populations with upper limb impairments. However, in routine rehabilitation practice, the implementation of 3D-printed assistive technology is hindered by (1) the absence of an integrated platform that consolidates design models, indications, and material/safety guidance, and (2) the lack of standardized fitting workflows and validated evaluation tools, which limits reproducibility and wider adoption across therapists and settings.

Objectives

This study is designed as an exploratory intervention to:

Develop an internal 3D assistive device selection interface (menu system) that consolidates smartphone-related assistive resources suitable for individuals with upper limb movement difficulties.

Establish a standardized fitting process (SOP) for smartphone operation supports (e.g., single-hand or bilateral phone holders).

Modify and modularize 5-8 commonly used smartphone assistive devices (e.g., holders, straps, desk or forearm-mounted supports) to enhance functional usability and convenience.

Evaluate the clinical feasibility and preliminary effectiveness of these devices in terms of functional performance, user satisfaction, and efficiency, and use these findings to inform a sustainable service model.

Study Design and Setting

The study adopts a single-group, pre-post exploratory intervention design. Participants will be recruited from the outpatient rehabilitation department of a regional teaching hospital in northern Taiwan. Eligible participants will be adults with upper limb functional impairments who experience difficulties using a smartphone and are able to follow instructions and provide informed consent.

Intervention

After baseline assessment, each participant will undergo a structured selection and fitting process using a 3D-printed smartphone assistive device (e.g., custom mobile phone holder or related support). An internal 3D device menu/interface will support therapist-patient joint decision-making based on functional needs and hand function status.

Participants will be instructed to use the assigned 3D-printed assistive device for at least 10 minutes per day over 1 week in their daily environment. During the intervention period, an occupational therapist will provide two individual follow-up sessions (approximately 15 minutes each) to:

Review the participant's functional abilities and goals.

Explain and demonstrate correct device use and recommended practice activities.

Monitor compensatory patterns, provide posture and movement corrections, and adjust the device or training tasks as needed.

Participants will be asked to complete a brief daily log documenting device usage (e.g., whether used, duration), activity examples, and any discomfort or adverse events.

Outcome Measures

Assessments will be conducted at baseline (pre-intervention) and at the end of the 1-week intervention (post-intervention) by trained occupational therapists who are not involved in the fitting process.

Primary outcomes will include:

Smartphone operation task performance, assessed through standardized tasks such as:

Searching the contact list and making a call

Dialing a phone number using the keypad

Answering a call

Sending a text or instant message

Taking a photo Performance metrics will include completion time, observable errors, and task completion.

Secondary outcomes will include:

User satisfaction with the assistive device, measured using the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST).

Feasibility indicators, such as adherence to daily device use (from logs), therapist-rated fitting feasibility, and the occurrence and nature of adverse events.

Data Analysis

Descriptive statistics will be used to summarize participant characteristics, device use patterns, and feasibility indicators. Non-parametric tests will compare pre- and post-intervention functional performance and satisfaction scores. Adverse event rates will be calculated to describe safety and tolerability. Linear regression and general linear model-based univariate analyses may be used to explore associations between baseline factors and changes in functional outcomes, where appropriate. Statistical analyses will be performed using SPSS 26.0, with the significance level set at α < 0.05.

The findings of this exploratory trial will inform the refinement of the 3D-printed device library, the standardized fitting process, and the clinical workflow, with the long-term goal of developing a scalable and sustainable 3D-printed assistive technology service model for individuals with upper limb functional impairments.

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

• Study Contact: Name: Fen-Ling Kuo, Master; Phone Number: +88622490088; Email: 08655@s.tmu.edu.tw
• Study Contact Backup: Name: Chieh-Yu Pan, Master; Phone Number: 022490088; Email: 08411@s.tmu.edu.tw

Study Locations

• Taiwan
  • New Taipei
    • New Taipei City, New Taipei, Taiwan, 235
      • Taipei Medical University Shuang Ho Hospital
      • Contact: Fen-Ling Kuo, Master; Phone Number: 022490088; Email: 08655@s.tmu.edu.tw

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This study will recruit adults with upper limb functional impairments who are currently receiving occupational therapy in the Department of Physical Medicine and Rehabilitation. Eligible participants must have an onset of more than three months, report difficulties or functional needs related to smartphone use due to upper limb impairment, and demonstrate adequate cognitive ability to follow instructions (Montreal Cognitive Assessment [MoCA] score > 24). Individuals younger than 18 years, those with severe visual or hearing impairments, or those with unstable medical conditions that may interfere with participation will be excluded.

Description

Inclusion Criteria:

• Currently receiving occupational therapy in the Department of Physical Medicine and Rehabilitation.
• Onset of condition > 3 months.
• Presence of upper-limb functional impairment that causes difficulty or limitations in smartphone use.
• Able to understand instructions for using the assistive device.
• Montreal Cognitive Assessment (MoCA) score > 24.

Exclusion Criteria:

• Age younger than 18 years.
• Severe visual or hearing impairments that would affect the ability to perform smartphone tasks.
• Unstable medical condition that may interfere with participation in the study.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
3D-Printed Assistive Device Group; Participants will use a 3D-printed smartphone assistive device for at least 30 minutes daily for 1 week. Therapists will provide two intervention sessions for instruction, activity adjustment, and monitoring. Participants will record daily usage and upload photos via an online platform to support adherence and follow-up.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Smartphone Functional Performance Test	A task-based performance assessment designed to evaluate the efficiency of smartphone hardware operations. Tasks include: (1) calling a contact, (2) dialing a number, (3) answering a call, (4) sending a text message, and (5) taking a photo. Outcome metrics include completion time, number of steps, error rate, and step completeness. Each task is scored on a scale from 0 to 6, with higher scores indicating better smartphone-operating performance.	Baseline and 1 week after intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Modified Ashworth Scale (MAS)	Assesses upper-limb muscle tone on a 0-4 scale, where higher scores indicate more severe spasticity. Used to monitor whether muscle tone influences device use.	Baseline and 1 week
Active Range of Motion (AROM) of Shoulder, Elbow, Wrist, and Fingers	Angle goniometry measuring shoulder flexion (0-180°), abduction (0-180°), external rotation (0-90°), internal rotation (0-70°), and elbow flexion (0-150°). Greater ROM indicates better joint mobility (Gerhardt et al., 2001).	Baseline and 1 week
Daily Usage and Activity Log	Participants record daily device usage duration, practice activities, and any adverse events (skin redness, pressure pain, slippage, pinching injury, etc.). Used to monitor adherence and safety throughout the intervention.	Daily for 1 week
NASA Task Load Index (NASA-TLX)	A multidimensional subjective workload assessment measuring mental demand, physical demand, temporal demand, performance, effort, and frustration. Each domain is rated on a scale from 0 to 100. Higher scores indicate higher perceived workload.	Baseline and 1 week
Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST)	A user-rated questionnaire measuring satisfaction with assistive technology device characteristics, including dimensions, weight, ease of use, comfort, and effectiveness. Each item is rated on a 5-point Likert scale. Total scores range from 12 to 60, with higher scores indicating greater satisfaction with the assistive device.	1 week

Collaborators and Investigators

• Sponsor: Taipei Medical University Shuang Ho Hospital
• Investigators: Study Chair: Fen-Ling Kuo, Master, Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University

Publications and helpful links

General Publications

• Baronio G, Harran S, Signoroni A. A Critical Analysis of a Hand Orthosis Reverse Engineering and 3D Printing Process. Appl Bionics Biomech. 2016;2016:8347478. doi: 10.1155/2016/8347478. Epub 2016 Aug 9.
• Pollock A, Farmer SE, Brady MC, Langhorne P, Mead GE, Mehrholz J, van Wijck F. Interventions for improving upper limb function after stroke. Cochrane Database Syst Rev. 2014 Nov 12;2014(11):CD010820. doi: 10.1002/14651858.CD010820.pub2.
• Widehammar, C., Lidström, H., & Hermansson, L. (2019). Environmental barriers to participation and facilitators for use of three types of assistive technology devices. Assistive technology, 31(2), 68-76. https://doi.org/10.1080/10400435.2017.1363828
• MA, L., & PAN, Z. (2018). The Chinese version of the subjective load assessment method and the US National aeronautics and space administration task load index scales for assessing the reliability and validity of physicians' mental loads in tertiary hospitals. Chinese General Practice, 21(33), 4127. https://doi.org/10.12114/j.issn.1007-9572.2018.00.236
• Lu, E. C., Wang, R., Huq, R., Gardner, D., Karam, P., Zabjek, K., Hébert, D., Boger, J., & Mihailidis, A. (2011). Development of a robotic device for upper limb stroke rehabilitation: A user-centered design approach. Paladyn, Journal of Behavioral Robotics, 2(4), 176-184. https://doi.org/10.2478/s13230-012-0009-0
• Kim, J. J., Lee, J., Shin, J., & He, M. (2022). How are high-tech assistive devices valued in an aging society? Exploring the use and non-use values of equipment that aid limb disability. Technology in Society, 70, 102013. https://doi.org/10.1016/j.techsoc.2022.102013
• Khantan, M., Avery, M., Aung, P. T., Zarin, R. M., Hammelef, E., Shawki, N., Serruya, M. D., & Napoli, A. (2023). The NuroSleeve, a user-centered 3D printed hybrid orthosis for individuals with upper extremity impairment. Journal of NeuroEngineering and Rehabilitation, 20(1), 103. https://doi.org/10.1186/s12984-023-01228-2
• Jinghong, C., & Hu, X. (2024). Mobile Phone Accessibility Solution for People with Upper Limb Dysfunction. Human Factors in Design, Engineering, and Computing, 159(159). https://doi.org/10.54941/ahfe1005653
• Hart, S. G., & Staveland, L. E. (1988). Development of NASA-TLX (Task Load Index): results of empirical and theoretical research. In Advances in psychology (Vol. 52, pp. 139-183). Elsevier. https://doi.org/10.1016/S0166-4115(08)62386-9
• Hands., A. (2025). Active Hands: Gripping aids for disabled people. Active Hands. https://www.activehands.com/
• Godeau, D., Fadel, M., & Descatha, A. (2022). Factors associated with limitations in daily life and at work in a population with shoulder pain. BMC musculoskeletal disorders, 23(1), 777. https://doi.org/10.1186/s12891-022-05638-6
• Gerhardt JJ, Rondinelli RD. Goniometric techniques for range-of-motion assessment. Phys Med Rehabil Clin N Am. 2001 Aug;12(3):507-27.
• Fitzpatrick, A. P., Mohanned, M. I., Collins, P. K., & Gibson, I. (2017). Design of a patient specific, 3D printed arm cast. KnE Engineering, 135-142.
• Equip2Adapt. (n.d.). Cell phone accessibility. Equip2Adapt. https://equip2adapt.com/blog/cell-phone-accessibility/ Fairman, A. D., Indradhirmaya, F. A., Osal, R. B., & Saptono, A. (2025). Iterative user-centered design of the mobile device assessment tool (MoDAT). Technologies, 13(8), 358. https://doi.org/10.3390/technologies13080358 Fitzpatrick, A. P., Mohanned, M. I., Collins, P. K., & Gibson, I. (2017). Design of a patient specific, 3D printed arm cast. KnE Engineering, 135-142. Gerhardt, J. J., Rondinelli, R. D. J. P. m., & America, r. c. o. N. (2001). Goniometric techniques for range-of-motion assessment. 12(3), 507-528. Godeau, D., Fadel, M., & Descatha, A. (2022). Factors associated with limitations in daily life and at work in a population with shoulder pain. BMC musculoskeletal disorders, 23(1), 777. https://doi.org/10.1186/s12891-022-05638-6 Hands., A. (2025). Active Hands: Gripping aids for disabled people. Active Hands. https://www.activehands.com/ Hart, S. G., & Staveland, L. E. (1988). Development of NASA-TLX (Task Load Index): results of empirical and theoretical research. In Advances in psychology (Vol. 52, pp. 139-183). Elsevier. https://doi.org/10.1016/S0166-4115(08)62386-9 Hunzeker, M., & Ozelie, R. (2021). A Cost-Effective Analysis of 3D Printing Applications in Occupational Therapy Practice. The Open Journal of Occupational Therapy, 9(1), 1-12. iAccessibility. (n.d). Hawkeye Access. https://www.iaccessibility.com/apps/mobility/index.cgi/product?ID=288 Jang, H.-Y., Chung, D., Oh, E., & Hong, G.-R. S. (2025). Experiences of individuals with severe disabilities using assistive devices: A qualitative study. Disability and Health Journal, 101833. https://doi.org/10.1016/j.dhjo.2025.101833 Janson, R., Burkhart, K., Firchau, C., Hicks, K., Pittman, M., Yopps, M., Hatfield, S., & Garabrant, A. (2020). Three-dimensional printed assistive devices for addressing occupational performance issues of the hand: A case report. Journal of Hand Th
• Dorrington, P., Wilkinson, C., Tasker, L., & Walters, A. (2016). User-centered design method for the design of assistive switch devices to improve user experience, accessibility, and independence. Journal of Usability Studies, 11(2).
• Chan, N. H., & Ng, S. S. (2025). Contribution of Perceived Upper Limb Function to the Participation and Activity Levels Among Community-Dwelling People With Chronic Stroke. Annals of Rehabilitation Medicine. https://doi.org/10.5535/arm.240122
• Bonanno, M., Saracino, B., Ciancarelli, I., Panza, G., Manuli, A., Morone, G., & Calabrò, R. S. (2025). Assistive technologies for individuals with a disability from a neurological condition: A narrative review on the multimodal integration. Healthcare,
• Batkuldinova, K., Abilgaziyev, A., Shehab, E., & Ali, M. H. (2021). The recent development of 3D printing in developing lower-leg exoskeleton: A review. Materials Today: Proceedings, 42, 1822-1828. https://doi.org/10.1016/j.matpr.2020.12.191
• Alghadir, A. H., Gabr, S. A., Rizk, A. A., Alghadir, T., Alghadir, F., & Iqbal, A. (2025). Smartphone addiction and musculoskeletal associated disorders in university students: biomechanical measures and questionnaire survey analysis. European Journal of Medical Research, 30(1), 274. https://doi.org/10.1186/s40001-025-02413-w
• Marrie RA, Cutter GR, Tyry T, Cofield SS, Fox R, Salter A. Upper limb impairment is associated with use of assistive devices and unemployment in multiple sclerosis. Mult Scler Relat Disord. 2017 Apr;13:87-92. doi: 10.1016/j.msard.2017.02.013. Epub 2017 Feb 20.

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): December 30, 2026
• Study Completion (Estimated): December 30, 2026

Study Registration Dates

• First Submitted: April 24, 2026
• First Submitted That Met QC Criteria: April 24, 2026
• First Posted (Actual): May 1, 2026

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: TMU-JIRBN202510077

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No