Targeting Muscle Strength Loss Due to Hospitalization in Older Adults by Blood-flow Restriction Combined With an Electromyography-driven Serious Game.

NCT07294131 | Not Yet Recruiting Phase 2 DMC FDA Device

• 2 other identifiers: CIV-25-06-053274T000425N
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 3

Brief Summary

This study investigates a new training method designed to help older adults preserve their muscle strength during hospitalization. When older adults are admitted to the hospital and spend long periods in bed, their muscles can weaken very quickly. This condition is known as hospital-associated disability (HAD), and it can lead to longer hospital stays, reduced independence, and an increased risk of complications or even death. Conventional strength training with heavy weights is often too demanding or unsafe for frail patients, especially just after surgery or illness. As a safer alternative, this study combines light muscle exercises with a medically validated technique called blood flow restriction (BFR), which gently reduces blood flow to the leg to boost the effects of light exercises. To make training more engaging and personalized, the GHOSTLY+ system was developed. This system consists of a game played on a tablet that responds to muscle activity through sensors placed on the skin. While playing, patients perform isometric muscle contractions (exercises where the muscles tighten without moving the joint) that help to maintain and rebuild strength. The system was carefully designed in collaboration with patients and therapists, and it has already been tested in a smaller pilot study at UZ Brussel. The current study is a multicenter randomized controlled trial, taking place at UZ Brussel, UZ Antwerpen, and UZ Leuven. A total of 120 patients aged 65 or older will be recruited, all of whom are hospitalized and are unable to bear weight or transfer (e.g., from lying to seated position). Participants will be randomly assigned to one of two groups. One group receives standard physiotherapy. The other group receives standard therapy plus the GHOSTLY+ training program. Those in the GHOSTLY+ group will train at least five times per week for two weeks, or until discharge from the hospital. Each training session lasts approximately 30 minutes and involves three sets of 12 muscle contractions, guided by the game. The difficulty is adapted to the individual's muscle strength, which is measured at the beginning of the training using a built-in calibration protocol. During the session, a smart cuff is applied to the upper leg to partially restrict blood flow - a technique shown to safely enhance muscle adaptation. The cuff is inflated to 50% of the individual's arterial occlusion pressure and deflated after the session ends. Before beginning, participants receive a short training session with a physiotherapist. Our pilot study (Debeuf et al., 2025) shows that most patients can use the system independently after about one hour of instruction. Measurements and evaluations take place at three timepoints: before starting the training, after one week, and again at discharge. The main goal is to assess leg muscle strength, which will be measured using a handheld device called a dynamometer. In addition, researchers will collect information on:

• Muscle mass, via ultrasound of the thigh muscle
• Functional capacity, using a 30-second sit-to-stand test and a walking scale (Functional Ambulation Category)
• An index of independence in activities of daily living (Katz scale)
• Cognitive functioning, using the Mini-Mental State Examination (MMSE)
• Time spent bedridden and total length of hospital stay
• Therapy adherence and user experience, via usage data and questionnaires
• Muscle activity signals, such as fatigue, recorded during gameplay
• Implementation outcomes (collected via surveys, interview, site logbooks) The study will also assess how easily the GHOSTLY+ system can be implemented in real hospital environments. This includes evaluations of user satisfaction, therapist feedback, and how consistently the system is used across hospital settings. Information will be gathered through structured interviews, surveys, and data logs from the app. These insights are crucial to understanding whether GHOSTLY+ can be broadly adopted in other hospitals in the future. Blood flow restriction training is considered very safe when applied correctly and is already used in rehabilitation clinics and sports medicine worldwide. Over 300,000 sessions have been conducted internationally, with a very low rate of complications. Minor discomfort, such as temporary tightness or muscle fatigue, may occur, but the risk of serious side effects is extremely small. By participating in this study, patients may benefit from improved muscle strength, reduced time spent in bed, and greater physical independence at discharge. The study also contributes to the development of more effective and enjoyable rehabilitation methods for older adults in hospitals.

Conditions

Immobility; Older Adults (65 Years and Older); Hospital Associated Disability

Keywords

hospital-associated disability; HAD; muscle strength loss; blood flow restriction; BFR; serious games; EMG-driven rehabilitation; geriatric rehabilitation; older adults; lower-limb strength; non-weight-bearing; randomized controlled trial; RCT; physical deconditioning; hospitalization; electromyography; digital rehabilitation; implementation science; rehabilitation technology; exergaming; inpatient rehabilitation; strength training; GHOSTLY+

Outcome Measures

Primary Outcomes (1)

• Maximal isometric muscle strength

  Maximal isometric muscle strength of the lower limbs will be assessed using a handheld dynamometer (MicroFET or equivalent). The test involves measuring the peak isometric force generated by the quadriceps muscle group during a voluntary contraction against resistance, while the participant is in a standardized seated position. Each participant will perform three maximal voluntary contractions (MVCs) with sufficient rest between trials. The highest recorded peak force (Newtons) will be used as the representative value. Testing will be conducted at three time points: baseline (T0), after one week (T1), and at two weeks or at the time of hospital discharge, whichever occurs first (T2). Outcome assessors are blinded to group allocation. The change in maximal isometric quadriceps strength (Newtons) from baseline to discharge will serve as the primary endpoint to evaluate the intervention's effectiveness in preserving muscle strength during hospitalization.

  From enrollment to the end of treatment at 2 weeks (or until hospital discharge if earlier).

Secondary Outcomes (16)

• Electromyography (EMG) Signal Analysis

  At the end of week 1, and the end of treatment at 2 weeks (or until hospital discharge if earlier).

• Cross-sectional area of the Rectus Femoris Muscle

  From enrollment to the end of treatment at 2 weeks (or until hospital discharge if earlier).

• Functional performance - 30 second sit-to-stand test

  From enrollment to the end of treatment at 2 weeks (or until hospital discharge if earlier).

• Functional ambulation category (FAC)

  From enrollment to the end of treatment at 2 weeks (or until hospital discharge if earlier).

• Time spent bed- or chair-ridden

  From enrollment to the end of treatment at 2 weeks (or until hospital discharge if earlier).

Other Outcomes (6)

• Implementation Outcome: Acceptability

  From the start of the study until maximally one year later.

• Implementation Outcome: Adoption

  From the start of the study until maximally one year later.

• Implementation Outcome: Fidelity

  From the start of the study until maximally one year later.

Study Arms (2)

Control Arm

ACTIVE COMPARATOR

Participants in the control group will receive standard physiotherapy according to the usual clinical care procedures at the participating hospital site. No additional strength training, exercise tools, or exergaming interventions will be provided. Participants will be encouraged to remain active according to standard rehabilitation protocols but will not engage with the GHOSTLY+ system or any equivalent unsupervised strength training intervention.

Other: Standard Physiotherapy

Intervention Arm

EXPERIMENTAL

Participants randomized to the intervention group will receive standard physiotherapy according to hospital protocol, supplemented with the GHOSTLY+ system.

Device: Gamified isometric strength training with blood flow restriction; Other: Standard Physiotherapy

Interventions

Standard Physiotherapy OTHER

Usual standard-of-care physiotherapy as per hospital guidelines. This typically consists of supervised therapeutic sessions prescribed by the clinical team, including mobility exercises, transfer practice, and functional strengthening, depending on the patient's clinical needs and recovery stage. Participants do not perform structured lower-limb strength training outside of formal therapy sessions.

Also known as: Standard Care

Control Arm; Intervention Arm

Gamified isometric strength training with blood flow restriction DEVICE

GHOSTLY+ is an interactive, EMG-driven serious game combined with blood flow restriction (BFR) therapy. Participants will undergo isometric quadriceps contractions guided by gameplay, with each session consisting of 3 sets of 12 contractions at 75% of their maximum voluntary contraction (MVC), as determined by in-app calibration. BFR will be applied using a smart cuff inflated to 50% of the participant's arterial occlusion pressure (AOP). Sessions will be performed independently by the patient during non-therapy time, with a minimum of 5 sessions per week over a 2-week period (or until discharge).

Also known as: GHOSTLY+

Intervention Arm

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Hospitalized, and expected to remain hospitalized for approximately 14 days
• + yrs
• Unable to bear weight or transfer independently and at high risk of muscle strength loss due to prolonged immobility

You may not qualify if:

• Contraindications for physical exercise as assessed by the treating physician using the risk assessment tool proposed by Kacin et al. (2015) (can be overruled by the physician)
• Contraindications for blood flow restriction as assessed by the treating physician (can be overruled by the physician)
• Cognitive impairment (MMSE score \< 19)
• Any condition that renders the patient unable to understand instructions or safely interact with the GHOSTLY+ system
• THERAPISTS
• Therapists will be included if
• They are licensed physiotherapists employed at one of the three participating clinical sites
• They are involved in the daily rehabilitation of hospitalized older adults.
• Therapists will be excluded from participation if
• They are unable or unwilling to complete the GHOSTLY+ training
• They are not directly involved in the care of eligible patients during the study period
• They express any conflict of interest or ethical concern that may compromise the integrity of the study

Sponsors & Collaborators

• Vrije Universiteit Brussel: lead
• Universitair Ziekenhuis Brussel: collaborator
• University Hospital, Antwerp: collaborator
• Universiteit Antwerpen: collaborator
• Universitaire Ziekenhuizen KU Leuven: collaborator
• KU Leuven: collaborator

Study Sites (3)

Universitair Ziekenhuis Antwerpen

Antwerp, Belgium

Location

Universitair Ziekenhuis Brussel

Brussels, Belgium

Location

Universitair Ziekenhuis Leuven

Leuven, Belgium

Location

MeSH Terms

Interventions

Standard of Care

Intervention Hierarchy (Ancestors)

Quality Indicators, Health Care; Quality of Health Care; Health Services Administration; Health Care Quality, Access, and Evaluation

Study Officials

• Eva Swinnen, prof. dr.

  Vrije Universiteit Brussel

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Eva Swinnen, prof. dr.

CONTACT

+32 (0)2 477 45 27; eva.swinnen@vub.be

Mahyar Firouzi, Dr.

CONTACT

+32 472 55 47 56; mahyar.firouzi@vub.be

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: prof. dr.

Model Details: This is a multicenter, two-arm, parallel-group randomized controlled trial (RCT) using a Hybrid Type 1 effectiveness-implementation design.

Study Record Dates

• First Submitted: December 17, 2025
• First Posted: December 19, 2025
• Study Start: January 1, 2026
• Primary Completion (Estimated): January 1, 2029
• Study Completion (Estimated): January 1, 2029
• Last Updated: December 19, 2025

Record last verified: 2025-12

Locations

BE (3)