Different Pressure Tissue Flossing Combined With Exercise for Chronic Ankle Instability (CAI-FLOSS)

Effects of Different Tissue Flossing Pressures Combined With Exercise Training on Ankle Function in Patients With Chronic Ankle Instability: A Three-Arm Randomized Controlled Trial

This study will evaluate whether tissue flossing with different pressure levels, when combined with exercise training, improves ankle function in young adults with chronic ankle instability. Forty-eight participants will be randomly assigned to one of three groups: a control exercise group, a 150 mmHg tissue flossing plus exercise group, or a 200 mmHg tissue flossing plus exercise group. All groups will complete the same 6-week rehabilitation program, three times per week. Outcomes will be assessed at baseline and after the intervention, and long-term follow-up data will also be collected.

Study Overview

• Status: Not yet recruiting
• Conditions: Chronic Ankle Instability; Ankle Instability
• Intervention / Treatment: Behavioral: Exercise Training; Device: Tissue Flossing at 150 mmHg; Device: Tissue Flossing at 200 mmHg

Detailed Description

Chronic ankle instability is characterized by recurrent ankle sprains, a feeling of giving way, pain, swelling, reduced function, and impaired balance control. Exercise-based rehabilitation is a cornerstone of nonoperative management, but adjunctive strategies that may enhance recovery remain of interest.

Tissue flossing is a compression-based intervention in which an elastic band is wrapped around the target joint or limb segment during exercise. It may influence mobility, neuromuscular control, proprioception, and symptom perception. However, the optimal pressure level for long-term rehabilitation in chronic ankle instability remains unclear.

This single-center, assessor-blinded, three-arm parallel randomized controlled trial will be conducted at Chengdu Sport University. A total of 48 young adults with chronic ankle instability will be allocated in a 1:1:1 ratio to a control exercise group, a 150 mmHg tissue flossing plus exercise group, or a 200 mmHg tissue flossing plus exercise group. All participants will complete the same 6-week rehabilitation program, with 3 sessions per week and 18 sessions in total. The two tissue flossing groups will receive pressure-calibrated flossing during the main training phase, while the control group will perform the same exercises without compression.

The primary outcome will be the change in Foot and Ankle Ability Measure Activities of Daily Living score from baseline to 6 weeks. Secondary outcomes will include sport-related foot and ankle function, functional movement screening, ankle range of motion, ankle isometric strength, Biodex balance-related measures, pain, long-term follow-up outcomes, adherence, and adverse events.

• Study Type: Interventional
• Enrollment (Estimated): 48
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Weiyang Zhang; Phone Number: 15196279571; Email: weiyangz@cdsu.edu.cn

Study Locations

• China
  • Sichuan
    • Chengdu, Sichuan, China
      • Chengdu Sport University
      • Contact: Weiyang Zhang; Phone Number: +8615196279571; Email: weiyangz@cdsu.edu.cn

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Young adults aged 18 to 30 years.
• History of at least one recurrent ankle sprain or repeated episodes of ankle giving way in the affected limb.
• Subjective ankle instability, with or without pain, swelling, or activity limitation.
• Reduced balance ability, movement ability, or foot and ankle function on screening assessment.
• Symptoms lasting at least 6 months.
• No recent structured ankle rehabilitation before enrollment.
• No plan for vigorous additional exercise during the intervention period.
• Willing to participate and able to provide informed consent.

Exclusion Criteria:

• Latex allergy or intolerance to floss band material.
• Previous ankle dislocation, fracture, complete ligament rupture, or other severe structural injury.
• Most recent ankle sprain within 1 month before enrollment.
• Recent ankle surgery or acute ankle injury.
• Receipt of other ankle-related treatment, rehabilitation, or additional training during the study period.
• Diabetes, hyperlipidemia, or other conditions that may affect vascular status.
• Neurological disease, major musculoskeletal disease, vestibular disorder, visual disorder, or other lower-limb conditions that could affect assessment.
• Determined by the study physician or investigator to be unsuitable for participation.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control Exercise Training; Participants will complete a 6-week ankle rehabilitation exercise program, 3 sessions per week, without tissue flossing compression.	Behavioral: Exercise Training; All groups will perform the same supervised ankle rehabilitation program for 6 weeks, 3 sessions per week, 18 sessions in total, approximately 30 minutes per session. The program will include warm-up, forward lunge ankle mobility training, resistance exercises for dorsiflexion, plantarflexion, inversion, and eversion using an elastic band, double-leg vertical jumping, single-leg balance training, and cool-down. From week 4 onward, the balance task will be progressed to eyes-closed single-leg stance.
Experimental: 150 mmHg Tissue Flossing Plus Exercise Training; Participants will complete the same 6-week ankle rehabilitation exercise program as the control group, with tissue flossing applied to the affected ankle at 150 mmHg during the main training phase.	Behavioral: Exercise Training; All groups will perform the same supervised ankle rehabilitation program for 6 weeks, 3 sessions per week, 18 sessions in total, approximately 30 minutes per session. The program will include warm-up, forward lunge ankle mobility training, resistance exercises for dorsiflexion, plantarflexion, inversion, and eversion using an elastic band, double-leg vertical jumping, single-leg balance training, and cool-down. From week 4 onward, the balance task will be progressed to eyes-closed single-leg stance.; Device: Tissue Flossing at 150 mmHg; During the main exercise phase, tissue flossing will be applied to the affected ankle using an elastic floss band calibrated with a pressure gauge to 150 mmHg. Wrapping will start distally over the dorsum of the foot and follow a figure-of-eight pattern covering the ankle joint region and extending to the distal lower leg. The floss band will be removed immediately after training. If numbness, severe pain, or pallor occur, the compression will be removed immediately.
Experimental: 200 mmHg Tissue Flossing Plus Exercise Training; Participants will complete the same 6-week ankle rehabilitation exercise program as the control group, with tissue flossing applied to the affected ankle at 200 mmHg during the main training phase.	Behavioral: Exercise Training; All groups will perform the same supervised ankle rehabilitation program for 6 weeks, 3 sessions per week, 18 sessions in total, approximately 30 minutes per session. The program will include warm-up, forward lunge ankle mobility training, resistance exercises for dorsiflexion, plantarflexion, inversion, and eversion using an elastic band, double-leg vertical jumping, single-leg balance training, and cool-down. From week 4 onward, the balance task will be progressed to eyes-closed single-leg stance.; Device: Tissue Flossing at 200 mmHg; During the main exercise phase, tissue flossing will be applied to the affected ankle using an elastic floss band calibrated with a pressure gauge to 200 mmHg. Wrapping will start distally over the dorsum of the foot and follow a figure-of-eight pattern covering the ankle joint region and extending to the distal lower leg. The floss band will be removed immediately after training. If numbness, severe pain, or pallor occur, the compression will be removed immediately.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biodex Limits of Stability Overall Directional Control Score	Dynamic postural control will be assessed using the Biodex Balance System SD Limits of Stability Test. Higher overall directional control scores indicate better balance control. Change is calculated as the Week 6 score minus the baseline score.	Baseline and 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biodex Postural Stability Test Overall Stability Index	Static postural stability will be assessed using the Biodex Balance System SD Postural Stability Test under eyes-open and stable-platform conditions. Lower Overall Stability Index scores indicate better postural stability. Change is calculated as the Week 6 score minus the baseline score.	Baseline and 6 weeks
Biodex Fall Risk Test Overall Stability Index	Dynamic postural stability will be assessed using the Biodex Balance System SD Fall Risk Test. Lower Overall Stability Index scores indicate better stability and lower fall-related balance risk. Change is calculated as the Week 6 score minus the baseline score.	Baseline and 6 weeks
Biodex Athlete Single-Leg Stability Test Overall Stability Index	Dynamic single-leg postural stability will be assessed using the Biodex Balance System SD Athlete Single-Leg Stability Test. Lower Overall Stability Index scores indicate better single-leg stability. Change is calculated as the Week 6 score minus the baseline score.	Baseline and 6 weeks
Active Ankle Dorsiflexion Range of Motion	Active dorsiflexion range of motion of the involved ankle will be measured three times using a joint goniometer, and the mean value will be recorded in degrees. Change is calculated as the Week 6 value minus the baseline value.	Baseline and 6 weeks
Maximum Isometric Ankle Eversion Strength	Maximum isometric eversion strength of the involved ankle will be measured three times using a microFET3 handheld dynamometer, and the maximum value will be recorded in newtons. Higher values indicate greater muscle strength. Change is calculated as the Week 6 value minus the baseline value.	Baseline and 6 weeks
FAAM Activities of Daily Living Subscale Score	Daily foot and ankle function will be assessed using the Foot and Ankle Ability Measure Activities of Daily Living subscale. Scores are converted to a scale from 0 to 100, with higher scores indicating better function. Change is calculated as the Week 6 score minus the baseline score.	Baseline and 6 weeks
FAAM Sports Subscale Score	Sports-related foot and ankle function will be assessed using the Foot and Ankle Ability Measure Sports subscale. Scores are converted to a scale from 0 to 100, with higher scores indicating better sports function. Change is calculated as the Week 6 score minus the baseline score.	Baseline and 6 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Adverse Events During the 6-Week Intervention	Adverse events occurring during the 6-week intervention will be recorded, including numbness, severe pain, pallor, swelling, increased pain, dizziness, shortness of breath, recurrent injury, and other unfavorable events. Results will be reported as the number and percentage of participants experiencing at least one adverse event.	During the 6-week intervention

Collaborators and Investigators

• Sponsor: Chengdu Sport University

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: June 6, 2026
• First Submitted That Met QC Criteria: June 21, 2026
• First Posted (Actual): June 25, 2026

Study Record Updates

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

More Information

Terms related to this study

• Keywords: Exercise Therapy; Tissue Flossing; Chronic Ankle Instability; Ankle Rehabilitation; Floss Band
• Additional Relevant MeSH Terms: Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Exercise
• Other Study ID Numbers: CSU-CAI-FLOSS-2025-01; 2025-128 (Other Identifier: Chengdu Sport University Ethics Committee)

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