Evaluation of Safety and Efficacy of a Digital Therapeutic Device to Improve Strength in Sarcopenia (Sarc-DTx)

A Multicenter, Prospective, Randomized, Parallel-Group, Double-blinded, Confirmatory Clinical Trial to Evaluate the Safety and Efficacy of a Digital Therapeutic Device for Improving Muscle Strength in Patients With Sarcopenia

This clinical trial aims to demonstrate that the use of a digital therapeutic device (exoDTx) in patients with sarcopenia is superior to self-exercise in terms of muscle strength improvement and safety.

Study Overview

• Status: Recruiting
• Conditions: Sarcopenia
• Intervention / Treatment: Device: exoDTx; Behavioral: Self-exercise (Educational Material)

Detailed Description

Background Sarcopenia is a condition characterized by progressive loss of skeletal muscle mass and strength, which is closely associated with functional decline, falls, and increased mortality.Conventional first-line treatment involves resistance training; however, in older adults, low adherence and practical challenges often limit its effectiveness.Recently, digital therapeutics (DTx) have emerged as promising tools by providing personalized exercise programs, automatic adjustment of intensity, and integrated recording and monitoring functions. These features are expected to overcome the limitations of selfdirected exercise.Therefore, this study seeks to validate the effectiveness and safety of DTx in improving muscle strength and physical function through a randomized controlled trial (RCT). Research Hypothesis In patients with sarcopenia, the group using digital therapeutics (DTx) will demonstrate superior outcomes in muscle strength improvement and safety compared to the self-exercise group.

• Study Type: Interventional
• Enrollment (Estimated): 130
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Sangui Choi, CPO; Phone Number: +82-10-3028-7759; Email: tkddml30@exosystems.io
• Study Contact Backup: Name: Eun Ji Lee, AP; Phone Number: +82-10-5205-8976; Email: eunjilv7@gmail.com

Study Locations

• South Korea
  • Bucheon-si, South Korea
    • Recruiting
    • Bucheon St. Mary's Hospital
    • Contact: Ji-Su Hong, Clinical Research Coordinator; Phone Number: 8210-3279-3106; Email: tlaak23@hanmail.net
    • Contact: Eun Ji Lee, Clinical Assistant Professor; Phone Number: 8210-5205-8976; Email: eunjilv7@gmail.com
    • Principal Investigator: Sun Im, Professor
  • Suwon, South Korea
    • Recruiting
    • St.Vincent's hospital
    • Contact: Mi-Jeong Yoon, Assistant Professor; Phone Number: +8210-9507-2638; Email: allogen@naver.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria

• Individuals diagnosed with sarcopenia according to both the European Working Group on Sarcopenia in Older People (EWGSOP) criteria and the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria
• Individuals with reduced muscle strength, defined as at least one of the following:
• Handgrip strength < 28 kg for men or < 18 kg for women
• Five-times Sit-to-Stand Test time > 12 seconds without arm support
• Individuals with reduced muscle mass, defined as at least one of the following:
• Skeletal Muscle Mass Index (SMI) < 7.0 kg/m² for men or < 5.4 kg/m² for women measured by DXA
• Skeletal Muscle Mass Index (SMI) < 7.0 kg/m² for men or < 5.7 kg/m² for women measured by BIA
• Individuals able to independently perform sit-to-stand movements
• Individuals with sufficient physical and cognitive capacity to participate in the exercise program
• Individuals able and willing to provide written informed consent
• Individuals able to operate a mobile phone independently or with assistance from a caregiver

Exclusion Criteria

• Individuals with cognitive impairment, defined as a Mini-Mental State Examination (MMSE) score < 20, or those unable to participate due to cognitive decline
• Individuals with an implanted cardiac pacemaker or other implanted electronic medical device
• Individuals with uncontrolled cardiovascular disease despite appropriate medical management
• Individuals who have undergone lower-limb surgery within the past 6 months and are unable to ambulate independently
• Individuals with moderate-to-severe musculoskeletal pain or functional limitations that interfere with objective functional assessments
• Individuals with severe obesity, defined as a body mass index (BMI) > 50 kg/m²
• Individuals currently receiving active cancer treatment or experiencing severe systemic frailty
• Individuals with hemiplegia that prevents participation in the prescribed exercise program
• Individuals who are anticipated by the investigator to be unable to complete the study procedures or follow-up assessments
• Individuals unable to understand or comply with study instructions provided in Korean
• Individuals considered unsuitable for study participation at the discretion of the investigator for any other reason

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental Device Group (Home-based DTx exercise group after training); Participants perform personalized resistance exercises using a digital therapeutic device (mobile application) at home for 12 weeks, with sessions conducted at least 3 times per week, 50 minutes per session (≥150 minutes/week). The program includes exercise automatic intensity adjustment, exercise recording/analysis, and physician monitoring	Device: exoDTx; Experimental group (exoDTx): After baseline on-site training, participants perform personalized resistance exercises at home using a mobile app ≥3 times/week, 50 min/session, for 12 weeks (≥150 min/week). The program provides grip strength-based automatic intensity adjustment, exercise recording, feedback, and physician monitoring. Delivery: Nonpharmacological, non-invasive, home-based exercise program. The experimental group uses a mobile app; the control group uses educational materials. Initial instruction occurs on-site. Visits & Monitoring: Screening/Baseline (week 0), In-treatment (weeks 4, 8), Post-treatment (week 12), and Follow-up (week 24).
Active Comparator: Control Group (Self-exercise); No mobile application is used. Participants perform the same type of exercise using QR code-based educational materials, self-regulating their exercise time, at least 3 times per week, 50 minutes per session, for a total of 12 weeks, with frequency and duration identical to the experimental group.	Behavioral: Self-exercise (Educational Material); Control group (Self-exercise): No app is used. Participants perform the same exercise guided by QR code-based educational materials, ≥3 times/week, 50min/session, for 12 weeks, maintaining exercise logs without automatic adjustment or remote monitoring. Delivery: Non-pharmacological, non-invasive, homebased exercise program. The experimental group uses a mobile app; the control group uses educational materials. Initial instruction occurs on-site. Visits & Monitoring: Screening/Baseline (week 0), In-treatment (weeks 4, 8), Post-treatment (week 12), and Follow-up (week 24).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in peak knee extension strength (Nm) from baseline to 12 weeks	Between-group comparison of mean change in knee extensor strength measured by lower extremity dynamometer.	12 weeks after Visit 1 (treatment initiation)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in peak isometric knee extension strength (Nm) from baseline to 4, 8, and 24 weeks	To evaluate longitudinal changes in knee extensor muscle strength at weeks 4, 8, and 24 compared with baseline using an lower extremity dynamometer.	Baseline, 4 weeks, 8 weeks, and 24 weeks after Visit 1 (treatment initiation)
Change in Manual Muscle Test (MMT) scores of major limb muscles	To assess changes in muscle strength based on standardized MMT grading (0-5 scale) after 12 weeks of intervention..	12 weeks after Visit 1 (treatment initiation)
Change in Fugl-Meyer Assessment (upper/lower extremities; CNS-related sarcopenia subgroup)	To examine motor recovery and coordination improvements using the Fugl-Meyer Assessment in participants with CNS-related sarcopenia.	12 weeks after Visit 1 (treatment initiation)
Change in Functional Ambulation Category (FAC) score	To assess improvement in walking independence level using the Functional Ambulation Category (0-5 scale).	12 weeks after Visit 1 (treatment initiation)
Change in Berg Balance Scale (BBS) and Timed Up and Go (TUG) performance	To evaluate dynamic and static balance performance using BBS score and TUG test time.	12 weeks after Visit 1 (treatment initiation)
Change in Short Physical Performance Battery (SPPB) total score and subscores (chair stand, gait speed, balance)	To assess lower extremity function using SPPB, including 5-time chair stand, 6-meter gait speed, and balance tests. SPPB - 5-time chair stand (time) 6-meter gait speed (SPPB gait speed) SPPB balance - score SPPB balance - time in seconds	12 weeks after Visit 1 (treatment initiation)
Change in Muscle Function Index (MFI) from surface EMG analysis	To quantify changes in muscle fatigue characteristics derived from surface electromyography (EMG) during resistance exercises.	12 weeks after Visit 1 (treatment initiation)
Change in Self-Efficacy for Home Exercise Programs Scale score	To evaluate participants' confidence in independently performing prescribed home-based exercises.	12 weeks after Visit 1 (treatment initiation)
System Usability Scale (SUS) total score of the exoDTx mobile application	To assess user satisfaction and perceived usability of the exoDTx digital therapeutic application using SUS.	12 weeks after Visit 1 (treatment initiation)
Change in body composition (skeletal muscle mass index, fat mass)	To evaluate changes in muscle and fat mass measured by dual-energy x-ray absorptiometry(DXA) or bioelectrical impedance analysis (BIA) after 12 weeks of intervention.	12 weeks after Visit 1 (treatment initiation)
Change in handgrip strength (kg) from baseline	To assess longitudinal changes in handgrip strength measured by hand dynamometer at weeks 4, 8, 12, and 24.	Baseline, 4 weeks, 8 weeks, 12 weeks, and 24 weeks
Change in calf circumference (cm) from baseline	To assess longitudinal changes in calf circumference measured at the maximum girth of the dominant or less-affected lower leg at weeks 4, 8, 12, and 24.	Baseline, 4 weeks, 8 weeks, 12 weeks, and 24 weeks
Change in 30-second chair stand test (repetitions) from baseline	To assess changes in lower limb functional strength and endurance measured by the number of sit-to-stand repetitions completed in 30 seconds after 12 weeks of intervention.	12 weeks after Visit 1 (treatment initiation)
Change in EuroQol Five-Dimension Five-Level (EQ-5D-5L) Questionnaire Score	To assess changes in self-reported health-related quality of life using the full EuroQol Five-Dimension Five-Level (EQ-5D-5L) questionnaire. The EQ-5D-5L consists of 5 items, each scored from 1 to 5, resulting in a total score ranging from 5 to 25, with lower scores indicating better health-related quality of life and higher scores indicating greater health impairment.	12 weeks after Visit 1 (treatment initiation)
Change in Strength, Assistance with walking, Rise from a chair, Climb stairs, and Falls Questionnaire Score	To assess changes in self-reported sarcopenia risk using the full Strength, Assistance with walking, Rise from a chair, Climb stairs, and Falls questionnaire. The SARC-F consists of 5 items, each scored from 0 to 2, resulting in a total score ranging from 0 to 10, with higher scores indicating worse sarcopenia severity and greater functional limitation.	Baseline, 4 weeks, 8 weeks, 12 weeks, and 24 weeks
Change in Sarcopenia Quality of Life score	To measure sarcopenia-specific quality of life changes using Sarcopenia Quality of Life total score and domain subscores. Sarcopenia Quality of Life contains 55 items generating a total score from 0 to 100, with higher scores indicating better quality of life.	Baseline, 4 weeks, 8 weeks, 12 weeks, and 24 weeks

Collaborators and Investigators

• Sponsor: Exosystems
• Collaborators: The Catholic University of Korea
• Investigators: Principal Investigator: Sangui Choi, CPO, Exosystems

Publications and helpful links

General Publications

• Song K, Eun Shin H, Park W, Lee D, Jang J, Yang Shim G, Choi S, Kim M, Lee H, Won Won C. Digital Biomarker for Muscle Function Assessment Using Surface Electromyography With Electrical Stimulation and a Non-Invasive Wearable Device. IEEE Trans Neural Syst Rehabil Eng. 2024;32:3048-3058. doi: 10.1109/TNSRE.2024.3444890. Epub 2024 Aug 26.

Study record dates

Study Major Dates

• Study Start (Actual): November 28, 2025
• Primary Completion (Estimated): June 20, 2026
• Study Completion (Estimated): September 25, 2026

Study Registration Dates

• First Submitted: November 20, 2025
• First Submitted That Met QC Criteria: December 21, 2025
• First Posted (Actual): January 6, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neuromuscular Manifestations; Pathological Conditions, Anatomical; Muscular Atrophy; Atrophy; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Sarcopenia
• Other Study ID Numbers: HC25DDDS0072

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