A Pilot Study of Feasibility and Exploratory Study for a Definitive Randomised Controlled Trial of Foot-Ankle Versus Walking Exercises in Patients With Diabetes Mellitus: Effects on Neuropathy, Stress, and Quality of Life

Intervention Description Foot-Ankle Exercise Intervention The intervention is adapted from prior research and from exercises developed by the Indonesian Endocrinology Association. Participants receive brief DM and foot-ankle education, a leaflet, and supervised simulation to ensure correct technique. Independent practice is performed 2-3 sessions/day for 12 weeks. Target exercises ≥150 minutes/week.

The structured foot-ankle exercise program consists of 10 seated movements involving toe flexion, heel raises, circular ankle motions, knee extension with toe mobility, synchronized bilateral movements, and functional foot tasks (e.g., manipulating newspaper sheets).

Walking Exercise Intervention The walking program adapts protocols from previous studies. Participants receive DM and walking-exercise education plus a leaflet. They walk independently for ≥150 minutes per week (≥10 minutes/session) while avoiding two consecutive non-exercise days during the 12-week period.

Active Control Participants receive usual DM education (30 minutes) and a leaflet. No structured exercise program is provided.

All groups continue receiving standard public-health services. Weekly monitoring and adverse-event checks are performed.

Content Validity Procedures

A content-validity assessment was conducted to ensure standardization of intervention procedures, educational materials, and measurement protocols (foot sensation, vibration, height, weight, blood pressure, ABI). Six experts (physicians or nurses with ≥5 years of DM-related experience) completed item-level ratings using a 1-4 scale. Content Validity Index (CVI) thresholds:

Item-level (I-CVI) ≥ 0.80 Scale-level (S-CVI) ≥ 0.83 Items below threshold were revised based on expert feedback until satisfactory CVI values were achieved. The CVI results showed I-CVI of >0.90 and S-CVI of 0.96.

Participant Recruitment Recruitment was conducted in partnership with the District Health Office and three Public Health Centers (PHCs) in Yogyakarta operating the Chronic Disease Management Program (PROLANIS). PHCs identified potentially eligible adults with DM and supported initial contact. Interested individuals received standardized information regarding study procedures, risks/benefits, confidentiality, and voluntary participation. Those willing attended a screening and informed-consent session. After consent, participants were enrolled and added to the communication group.

Participants received travel reimbursement of IDR 25,000 per data-collection visit. Recruitment materials were approved by the Institutional Review Board (IRB). Participation was voluntary and did not affect access to routine services.

Sample Size A total of 108 participants (36 per group) were enrolled, accounting for an estimated 20% attrition rate. Sample size was selected for feasibility assessment and to provide preliminary, hypothesis-generating estimates for DPN, stress, and DR-QoL outcomes; it was not used to determine the sample size of the subsequent definitive RCT.

Actual Completion Numbers Week 6: control n=35, foot-ankle n=35, walking n=33 Week 12: control n=32, foot-ankle n=34, walking n=34 Per-protocol: control n=31, foot-ankle n=33, walking n=31

Randomization and Allocation Concealment Randomization was performed by independent personnel not involved in recruitment or data collection. A computer-generated sequence with random permuted blocks (sizes 3, 6, and 9) was used with a 1:1:1 allocation ratio.

Assignments were placed in sequentially numbered, sealed, opaque envelopes stored securely and inaccessible to outcome assessors..

Intervention Delivery Control group The active control group was given health education on the topic of DM for 30 minutes and then given a leaflet.

Foot-ankle exercise group

Participants were given health education on DM and foot-ankle exercise after the allocation procedure, followed by simulation and practice lasts 60 minutes. Participants were also given leaflets. Afterward, participants practiced independently without supervision for 12 weeks. Foot-ankle exercise consists of 10 movements. When doing foot-ankle exercises, participants sit comfortably without leaning, and the soles of their feet touch the floor and barefoot. These movements are:

A 1. Lift the soles while heels touch the floor. 2. Flex toes downward (clawing motion). 3. Repeat 10 times. B

1. Lift the soles while heels touch the floor.
2. Lower soles and raise heels while toes touch the floor.
3. Repeat 10 times. C

1. Lift the soles while heels touch the floor.
2. Perform inward-to-outward circular motions.
3. Repeat 10 times. D

1. Lift both heels while toes touch the floor. 2. Perform inward-to-outward circular motions. 3. Repeat 10 times. E

1. Lift and extend the right knee; left leg remains in original position.
2. Move toes forward and backward.
3. Repeat 10 times; repeat on left leg. F

1. Lift and extend the right knee.
2. Move toes toward the face.
3. Repeat 10 times; repeat on left leg. G

1. Lift and extend both knees.
2. Move toes toward the face simultaneously.
3. Repeat 10 times. H

1. Lift and extend both knees.
2. Move both legs forward.
3. Repeat 10 times. I

1. Lift and extend the right knee; left leg remains in place.
2. "Write" numbers 1-10 using the right foot.
3. Repeat with the left foot. J

1. Place a sheet of newspaper under both feet. 2. Crumple into a ball using both feet. 3. Open it back into a sheet. 4. Tear into two parts using both feet. 5. Tear one part into small pieces and gather onto the other sheet. 6. Crumple into a ball again. 7. Dispose of the newspaper ball in the trash.

Walking exercise group Participants were given health education for 30 minutes, on DM and walking exercises and leaflet after the allocation procedure. Participants practiced walking exercises independently for 12 weeks.

Health education for all groups is delivered by a certified DM educator. To minimize contamination, group education is conducted on separate days. All participants are added to a moderated WhatsApp group for communication, scheduling, and reminders..

Interventionist dan Outcome Investigators

Interventions are delivered by a health professional with:

- a master's degree in nursing,

• ≥5 years of clinical/educator experience, and
• certification as a DM educator. Each site includes ≥1 outcome investigator who is a registered health worker.

Monitor for Adverse Events Potential adverse events included fatigue, muscle soreness, pain, and dizziness. Participants self-recorded events and reported them during weekly telephone monitoring. If excessive or concerning adverse events were identified, the intervention was stopped and appropriate care provided.