Injury to the central or peripheral nerves can lead to limited hand function and further affect the ability of writing. The use of assistive devices can assist writing performance. However, the habit of holding the pen and the ability of the individual case will affect the selection of aids and the efficiency of writing. The 3D printing aids can be individually designed and adjusted to different angles and types. There is no criterion for 3D printing aids decision, often using a case-by-case trial subjective way to confirm, matching takes more time. Aim: To compare the applicability and efficiency of different types of 3D-printed writing aids in nerve injury cases, and to explore which factors affect the choice of aids.

Background: Injury to the central or peripheral nerves can lead to limited hand function and further affect the ability of writing. The use of assistive devices can assist writing performance. However, the habit of holding the pen and the ability of the individual case will affect the selection of aids and the efficiency of writing. The 3D printing aids can be individually designed and adjusted to different angles and types. There is no criterion for 3D printing aids decision, often using a case-by-case trial subjective way to confirm, matching takes more time. Aim: To compare the applicability and efficiency of different types of 3D-printed writing aids in nerve injury cases, and to explore which factors affect the choice of aids.

Methods: Thirty subjects were recruited from outpatient rehabilitation of neurologically injured patients with limited hand function. Their basic information was recorded, including basic abilities, palm and finger size, and pen-holding posture, etc. Using three different angles of 3D printing writing aids, the writing efficiency and the satisfaction of the aids are evaluated by the writing task and the Satisfaction with Assistive Technology. Collected data were analyzed by SPSS (Version 20.0). The significance level of the statistical value is set at 0.05. The basic data and evaluation items of the subjects are observed by descriptive statistical analysis. All the analyzed values will be presented in the form of mean ± standard deviation. The Wilcoxon test is used to compare before and after the use of assistive devices. Data between different aids were analyzed by one-way analysis of variance (ANOVA) with Bonferroni adjustment; basic data and aids choice were analyzed by Pearson's Chi-Square correlation analysis; liner regression was used, and Backward regression was used to confirm whether the variable was removed (p>0.1), and univariate analyses in a general linear manner were used to analyze whether the independent variables of the basic data affected the choice of assistive devices.

Inclusion Criteria:

• The medical record shows that the diagnosis is central or peripheral nerve injury, and the onset is more than three months
• The trunk is well controlled and can sit stable on the chair
• The affected hand can control the lifting of the shoulder and the bending of the elbow, and the forearm can be controlled.
• The affected hand is the dominant hand and has difficulty writing

Exclusion Criteria:

• Aged over 75 and under 20
• Cognition or visual perception impairment that affects their ability to copy
• Patients suffer from other diseases of the nervous, cardiopulmonary, and musculoskeletal systems that affect the subject's performance of the movements required by this test.

In cases of central or peripheral nerve injury, symptoms such as sensory paralysis, limited joint mobility, insufficient muscle strength, abnormal tension, unsmooth movements, and lack of segmental movement control may result, affecting the voluntary control of muscles, and showing weak and inaccurate movements. , slowing down, affecting their hand performance, which in turn affects writing tasks