Effectiveness and Efficiency of an Upper Limb Active-Passive Exoskeleton Robot in Patients With Frozen Shoulder

Frozen shoulder, also known as adhesive capsulitis, is a common chronic shoulder disorder with symptoms including shoulder pain, limitations in both active and passive range of motion, and muscle weakness, which significantly affects daily functional abilities. The investigator applied upper limb exoskeleton-assisted therapy. This experiment used a randomized controlled trial to assess the clinical rehabilitation effects of exoskeleton-assisted range of motion and resistance training on patients with frozen shoulder.

Study Overview

• Status: Not yet recruiting
• Conditions: Frozen Shoulder; Adhesive Capsulitis of the Shoulder
• Intervention / Treatment: Procedure: General physical therapies; Procedure: Traditional physical therapies; Procedure: Upper limb exoskeleton-assisted therapy

Detailed Description

Frozen shoulder, also known as adhesive capsulitis, is often described as a common chronic shoulder disorder where the course may last from several months to years, which significantly affects daily functional abilities and mental health due to shoulder pain, limitations in both active and passive range of motion, and muscle weakness. The therapeutic standard requires extensive intervention, and generally, physical therapy is the most widely used, evidence-supported, and non-invasive treatment. The common treatments are manual joint mobilization, range of motion exercises, and resistance training, but the therapeutic outcome largely depends on the therapist's professional skills and time investment, which can impose a considerable workload on clinicians.

In previous applications, they proposed that exoskeleton robots can provide healthcare professionals with a standardized tool to assist in therapy and thereby reduce clinical workload. Other studies have predominantly focused on patients with neurological conditions, such as stroke, though exoskeleton robots have also been applied clinically in the rehabilitation of patients with adhesive capsulitis. However, systematic evidence regarding their clinical use and rehabilitation outcomes remains limited. We will conduct a randomized controlled trial to investigate the efficacy of exoskeleton-assisted therapy on frozen shoulder. 40 participants will be randomized into two groups: one is traditional active-passive exercises and theraband-based resistance training combined with conventional physical therapy (control group) and the other one is upper limb active-passive exoskeleton-assisted range of motion and resistance training combined with conventional physical therapy (experimental group). The intervention will last for four weeks, with at least three sessions per week, each lasting approximately 60-75 minutes.

The outcome measurement tools including the Visual Analogue Scale (VAS) for pain, active and passive shoulder range of motion, shoulder muscle strength (measured using a handheld dynamometer), and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire were used to compare two groups with regard to the rehabilitation outcomes and sustained effects after a two-week follow-up period in subjects with frozen shoulder.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Li-Wei Chou, MD, PhD; Phone Number: 7305/ 7301 +886-4-22053366; Email: chouliwe@gmail.com
• Study Contact Backup: Name: Yueh-Ling Hsieh, PT, PhD; Phone Number: 7312 +886-4-22053366; Email: sherrie@mail.cmu.edu.tw

Study Locations

• Taiwan
  • Wufeng Dist.
    • Taichung, Wufeng Dist., Taiwan, 413
      • Asia University Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

-

1. Patients aged 20 years or older diagnosed by a clinician with primary or secondary frozen shoulder or adhesive capsulitis:

1. Patients diagnosed by a clinician with frozen shoulder or adhesive capsulitis in the stiff phase.
2. The patient has a loss of at least 50% of passive joint range of motion (including of shoulder flexion, abduction, internal rotation, and external rotation) on the affected shoulder compared to the relatively healthy shoulder.

Exclusion Criteria:

1. Individuals with osteoarthritis or other skeletal conditions of the shoulder joint.
2. Individuals with any contraindications to treatment, such as joint fusion, severe osteoporosis, or symptoms of any peripheral nerve compression.
3. Individuals with untreated joint dislocations, fractures, or tendon ruptures.
4. Individuals who have received steroid injections within the month prior to the study.
5. Individuals who are uncommunicated or cognitively impaired.
6. Pregnant women.
7. Patients who refuse recruitment will also be excluded.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Upper limb exoskeleton-assisted therapy combine with general physical therapy; In this treatment, subjects perform exoskeleton-assisted shoulder range of motion (ROM) training, passive stretching, and resistance training. The movements encompass shoulder flexion, abduction, internal rotation, and external rotation. The exoskeleton intervention lasts for 15 to 20 minutes per session, with joint angles determined based on the patient's tolerance and pain level. The general physical therapies will be combined with upper limb exoskeleton-assisted therapy. And general physical therapies include manual joint mobilization (Maitland oscillatory techniques applied to the glenohumeral joint) and conventional physical therapy modalities such as thermotherapy, infrared therapy, interferential current therapy (IFC), transcutaneous electrical nerve stimulator (TENS). The treatment session lasts 45-60 minutes. Totally, there will 60-75 minutes, and at least 3 times treatments a week for 4 weeks, in total at least 12 times treatments.	Procedure: General physical therapies; The general physical therapies include manual joint mobilization (Maitland oscillatory techniques applied to the glenohumeral joint) and conventional physical therapy modalities such as thermotherapy, infrared therapy, IFC, TENS. The treatment session lasts 45-60 minutes and is conducted at least 3 times weekly for 4 weeks.; Procedure: Traditional physical therapies; In this arm, the subjects will receive the intervention of traditional active-assisted/passive exercises, resistance training at least 3 times a week for 4 weeks, in total at least 12 times treatments (approximately 15 to 20 minutes per session).
Active Comparator: Traditional physical therapies combine with general physical therapy; In this arm, the subjects will receive the intervention of traditional active-assisted/passive exercises, resistance training at least 3 times a week for 4 weeks, in total at least 12 times treatments (approximately 15 to 20 minutes per session). The general physical therapies will be combined with traditional physical therapies. And general physical therapies include manual joint mobilization (Maitland oscillatory techniques applied to the glenohumeral joint) and conventional physical therapy modalities such as thermotherapy, infrared therapy, IFC, TENS. The treatment session lasts 45-60 minutes. Totally, there will 60-75 minutes, and at least 3 times treatments a week for 4 weeks, in total at least 12 times treatments.	Procedure: General physical therapies; The general physical therapies include manual joint mobilization (Maitland oscillatory techniques applied to the glenohumeral joint) and conventional physical therapy modalities such as thermotherapy, infrared therapy, IFC, TENS. The treatment session lasts 45-60 minutes and is conducted at least 3 times weekly for 4 weeks.; Procedure: Upper limb exoskeleton-assisted therapy; The upper limb exoskeleton robot used is the NimBo joint mobility robot (FREE Bionics), paired with a tablet. In this treatment, the exoskeleton assists subjects in performing shoulder range of motion training (flexion, abduction, internal and external rotation), passive stretching (flexion, extension, abduction, internal and external rotation), and muscle strength training including both isometric and isotonic contractions. The movements are performed in a sitting position, with repetitions, hold times, and rest intervals carefully structured. Joint angles are determined based on the patient's tolerance and pain level. The exoskeleton intervention lasts for 15 to 20 minutes per session, with joint angles determined based on the patient's tolerance and pain level. And it is conducted at least 3 times a week for 4 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Shoulder joint Range of Motion	Besides shoulder pain, a key clinical manifestation of shoulder adhesive capsulitis is the progressive limitation of active and passive joint range of motion, which significantly impacts daily living functions. Shoulder joint range of motion can be considered an indicator of treatment effectiveness in frozen shoulder patients. A plastic universal goniometer is a commonly used tool for measuring range of motion. It can be used to measure joint range of motion on various joints. We used this simple tool to measure the anterior flexion, extension, abduction, external rotation, and internal rotation angles of the subject's shoulder joint.	1 day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subjective Pain Intensity: Visual Analog Scale (VAS)	Participants were asked to describe the intensity of their current shoulder pain or soreness. Pain intensity was expressed using the visual analog scale. The visual analog scale is a tool for assessing pain intensity based on the participant's self-reported pain levels and is widely used in clinical practice to track improvements in musculoskeletal pain. Visual analog scale is evaluated using a 10-cm ruler. Patients move an indicator between a "smiley face" (indicating no pain) and a "grimacing face" (indicating extreme, unbearable pain) to reflect their current pain level. The researcher then records the corresponding 0-10 cm score from the back of the ruler.	1 day
Muscle strength of shoulder joint	In the clinical manifestations of shoulder adhesive capsulitis, the progressive limitation of active joint range of motion is partly due to insufficient muscle strength. However, the pain in shoulder adhesive capsulitis patients often causes muscle spasms and weakness in the muscles around the affected shoulder, which may also exacerbate the pain and further restrict movement and function. Therefore, the muscle strength of the shoulder joint can also be considered one of the indicators of the cure of shoulder adhesive capsulitis patients. Strength of the shoulder flexors, extensors, abductors, and internal/external rotators is evaluated using a handheld dynamometer. Subjects are verbally encouraged to "push as hard as possible," maintaining a maximum voluntary isometric contraction for 3 seconds. The final recorded value (in pounds) is the average of three trials, with a 1-minute rest interval between each trial.	1 day
Disabilities of the Arm, Shoulder and Hand questionnaire (DASH)	The Arm, Shoulder, and Hand Disability questionnaire has been widely used for patients with various upper limb disorders. This questionnaire is reliable and effective for patient populations with various upper limb disorders. The questionnaire mainly consists of a 30-item disability/symptom scale. The questionnaire evaluates upper extremity disability and symptoms using a 30-item module, with each item scored from 1 to 5. A valid total score requires completing at least 27 items. The final score is calculated using the formula: [(sum of all completed responses / number of completed items) - 1] × 25. Higher scores indicate greater symptom severity and functional impairment.	1 day

Collaborators and Investigators

• Sponsor: China Medical University Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): March 16, 2026
• Primary Completion (Estimated): March 15, 2027
• Study Completion (Estimated): March 15, 2027

Study Registration Dates

• First Submitted: March 16, 2026
• First Submitted That Met QC Criteria: March 16, 2026
• First Posted (Actual): March 19, 2026

Study Record Updates

• Last Update Posted (Actual): March 25, 2026
• Last Update Submitted That Met QC Criteria: March 21, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Rehabilitation; Adhesive capsulitis; Frozen shoulder; Robot-assisted rehabilitation; Exoskeleton robots
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Joint Diseases; Bursitis
• Other Study ID Numbers: CMUH114-REC2-178

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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