1. Healthy Young Adults:
Inclusion Criteria:
* (1) Age between 20 and 29 years,
* (2) Right-hand dominance, and
* (3) Ability to understand three consecutive verbal instructions.
Exclusion Criteria:
* (1) Currently a student or faculty member of the Department of Occupational Therapy at National Cheng Kung University, or a staff member of the Department of Physical Medicine and Rehabilitation, National Cheng Kung University Hospital,
* (2) History of surgery on the right upper limb,
* (3) Presence of neuromusculoskeletal disorders that may affect sensory or motor function of the right upper limb, such as stroke or shoulder impingement syndrome, and
* (4) Uncorrected hearing problems, such as hearing loss.
2. Healthy Adults:
Inclusion Criteria:
* (1) Age between 30 to 39, 40 to 49, or 50 to 59 years,
* (2) Right-hand dominance, and
* (3) Ability to understand three consecutive verbal instructions.
Exclusion Criteria:
* (1) Currently a student or faculty member of the Department of Occupational Therapy at National Cheng Kung University, or a staff member of the Department of Physical Medicine and Rehabilitation, National Cheng Kung University Hospital,
* (2) History of surgery on the right upper limb,
* (3) Presence of neuromusculoskeletal disorders that may affect sensory or motor function of the right upper limb, such as stroke or shoulder impingement syndrome, and
* (4) Uncorrected hearing problems, such as hearing loss.
3. Healthy Older Adults:
Inclusion Criteria:
* (1) Age between 60 to 69, 70 to 79, or 80 to 89 years,
* (2) Right-hand dominance, and
* (3) Ability to understand three consecutive verbal instructions.
Exclusion Criteria:
* (1) Score below the 5th percentile on the Color Trails Test-Chinese Version (CTT-C),
* (2) Currently a student or faculty member of the Department of Occupational Therapy at National Cheng Kung University, or a staff member of the Department of Physical Medicine and Rehabilitation, National Cheng Kung University Hospital,
* (3) History of surgery on the right upper limb,
* (4) Presence of neuromusculoskeletal disorders that may affect sensory or motor function of the right upper limb, such as stroke or shoulder impingement syndrome, and
* (5) Uncorrected hearing problems, such as hearing loss.
4. Stroke:
Inclusion Criteria:
* (1) Age between 20 and 89 years,
* (2) Right-hemispheric hemorrhagic or ischemic stroke with lesions involving proprioceptive pathways or the primary somatosensory cortex, potentially resulting in difficulties with body position, movement, or force perception, or with fine tactile perception (e.g., localization, two-point discrimination, object recognition),
* (3) Right-hand dominance, and
* (4) Ability to understand three consecutive verbal instructions.
Exclusion Criteria:
* (1) Score below the 5th percentile on the Color Trails Test-Chinese Version (CTT-C),
* (2) Upper limb still in acute pain stage,
* (3) Muscle tone severe enough to affect right upper limb movement (e.g., score ≥ 1+ on the Modified Ashworth Scale),
* (4) Uncorrected hearing problems, such as hearing loss.
5. Shoulder Impingement Syndrome:
Inclusion Criteria:
* (1) Age between 20 and 89 years,
* (2) Diagnosis of shoulder impingement syndrome in the right upper limb,
* (3) Right-hand dominance, and
* (4) Ability to understand three consecutive verbal instructions.
Exclusion Criteria:
* (1) Score below the 5th percentile on the Color Trails Test-Chinese Version (CTT-C),
* (2) Upper limb still in acute pain stage,
* (3) Uncorrected hearing problems, such as hearing loss.
6. Diabetes (DM):
Inclusion Criteria:
* (1) Age between 20 and 89 years,
* (2) Diagnosis of diabetes mellitus by a specialist physician, based on one of the following:
1. Fasting plasma glucose (FPG) ≥ 126 mg/dL or 7.0 mmol/L;
2. Hemoglobin A1C (HbA1c) ≥ 6.5%;
3. Plasma glucose ≥ 200 mg/dL or 11.1 mmol/L at 2 hours during an oral glucose tolerance test (OGTT);
4. Presence of hyperglycemia symptoms (polyphagia, polyuria, polydipsia, and unexplained weight loss) with a random plasma glucose ≥ 200 mg/dL.
Diagnosis of diabetes is confirmed if any two of items (a-c) are met, or if any one of them remains positive on repeat testing; fulfillment of item (d) alone is also sufficient for diagnosis.
* (3) Right-hand dominance, and
* (4) Ability to understand three consecutive verbal instructions.
Exclusion Criteria:
* (1) Score below the 5th percentile on the Color Trails Test-Chinese Version (CTT-C),
* (2) History of surgery on the right upper limb,
* (3) Presence of other neuromusculoskeletal disorders that may affect sensory or motor function of the right upper limb, and
* (4) Current skin infection, and
* (5) Uncorrected hearing problems, such as hearing loss.
