Mid-portion Achilles TendinopathyEM-MATNCT06969859
Pulsed Electro-Magnetic Field Therapy for Treatment of Midportion Achilles Tendinopathy
A study testing PEMF and Alfredson eccentric training program in people with Mid-portion Achilles Tendinopathy, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
This is a multi-centre, randomised, double-blind, placebo-controlled trial with two parallel groups in a 1:1 allocation to study the efficacy of Pulsed Electromagnetic Field Therapy (PEMF) in patients with mid-portion Achilles tendinopathy. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Mid-portion Achilles Tendinopathy
- What is being tested?
- PEMF and Alfredson eccentric training program
- Type of treatment
- Medical device, Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 200 participants
- Where
- 1 siteHong Kong
- Study dates
- 15 Oct 2025to 31 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults (>18 years of age)
- Clinical diagnosis of mid-Achilles tendinopathy
- VISA-A score of <60
- Ultrasound evidence of Achilles tendinopathy (thickening >7mm)
Who cannot join
- Previous invasive treatment to the Achilles tendon (e.g. rupture repair, PRP injection etc)
- Contraindication to PEMF (e.g. pregnancy, pacemakers)
- Physical or psychological comorbidities impairing the ability to complete assessments (eg neurological deficits etc.)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Hong Kong1 site, 1 recruiting
- Recruiting
Prince of Wales Hospital
Shatin, New Territories, 000000
WENJIE PAN, 852-26364171, wenjiepan@cuhk.edu.hk
About this study
Official title: Multicentre Randomised Controlled Trial of Pulsed Electro-Magnetic Field Therapy for Treatment of Midportion Achilles Tendinopathy（EM-MAT Trial)
This is a multi-centre, randomised, double-blind, placebo-controlled trial with two parallel groups in a 1:1 allocation to study the efficacy of Pulsed Electromagnetic Field Therapy (PEMF) in patients with mid-portion Achilles tendinopathy. All participants will be randomly divided into two groups: an intervention group (active PEMF and standard rehabilitation exercise) and a control group (sham PEMF and standard rehabilitation exercise). All self-reported, functional, and ultrasound findings will be evaluated by the investigator at baseline assessment, 1-month, 2-month, 3-month, 6-month and 12-month follow-up after initiating the intervention.
The researcher will obtain written consent from all participants before the start of this study. All eligible participants will be informed about this study and given enough time to consider whether or not to participate; the clinician/research staff will answer all questions asked by the participants. The trial will be conducted in accordance with the Declaration of Helsinki and the ICH-GCP. Clinical research ethics approval for the trial will be obtained from the Joint Clinical Research Ethics Committee of The Chinese University of Hong Kong. All participants will be recruited from the clinics and centres of the participating institutions.
- Conditions
- Mid-portion Achilles Tendinopathy
- Being tested
- PEMF, Alfredson eccentric training program
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PEMFDevice
The PEMF will be delivered using a BIXEPS device (Quantum Tx, Singapore) ; It is utilised by the patient placing the leg into the machine. This device is operated by participant individualized NFC cards, which will be centrally programmed to deliver either active PEMF (uniform 1mT, 50Hz) or sham PEMF (0mT, 0Hz) for 30 minutes. Because this biophysical intervention is non-invasive, and the electromagnetic fields emitted into the legs do not generate any sensation (e.g. heat, sound), participants will be blinded to the treatment. The protocol will be 180 minutes of PEMF therapy, performed in six 30-minute sessions 3 times a week and completed in 2 weeks.
Alfredson eccentric training programBehavioural
All participants will be subject to a standardised rehabilitation exercise region consisting of stretching and eccentric exercises following the Alfredson protocol. The 12-week program will be taught by a physiotherapist or athletic trainer and supplemented by video tutorials. The regime begins with three 30-second static stretches for the gastrocnemius (knee extension) and soleus (knee flexion) muscles with 1-minute rest between each stretch. The 2nd part is eccentric exercises to the calves following the Alfredson protocol. This will be three sets of eccentric exercises lasting 12 weeks, with 15 sets twice a day. If participants are unable to complete three sets of 15 repetitions, they can start with fewer repetitions and sets (at least 2 sets of 10 repetitions each) and gradually increase to the total number of sets. Participants will perform the static stretching exercises from Step 1 at the end of each session
| Study group | Role | What they receive |
|---|---|---|
| PEMF Therapy + Exercise | Experimental | Not described Receives: Device: PEMF; Behavioral: Alfredson eccentric training program |
| sham Therapy + Exercise | Sham comparator | Not described Receives: Behavioral: Alfredson eccentric training program |
What is being measured
The primary outcome is the main question the study is designed to answer.
Victorian Institute of Sports Assessment (VISA-A)
The primary outcome measure will be the Victorian Institute of Sport Assessment (VISA-A) questionnaire, available in either the original English or validated Chinese version, depending on the participant's native language. This specific scoring system developed for the Achilles tendon is the most widely used score for clinical Achilles research. The VISA-A is scored on a scale of 0 to 100; lower scores indicate more severity of symptoms, while a score of 100 indicates a healthy and pain-free Achilles tendon.
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Secondary outcomes (8)
Numeric Pain Rating Scale (NPRS)
Numeric Pain Rating Scale (NPRS) is a pain screening tool, commonly used to assess pain severity using a 0-10 scale, with zero meaning "no pain" and 10 meaning "the worst pain imaginable
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Foot and Ankle Outcome Scores (FAOS)
The FAOS is a validated patient-reported scoring system used for general foot and ankle problems. It is split into five categories: symptoms, pain, daily activities, sporting function, and quality of life. Scores range from 0 to 100, with 100 denoting no problems and 0 denoting severe problems.
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Achilles tendon resting angle (ATRA)
The ATRA will measure participants' tendon length/tension. Participants should be positioned in a prone position with the knee flexed to 90 degrees. The assessor will use a dynamic joint goniometer to measure the angle at which the foot passively falls.
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Tendon thickness
Using B-mode ultrasound scanning, the probe is moved from the medial to the lateral aspect of the Achilles tendon until a planar image of the Achilles tendon is clearly shown. The probe was adjusted straight perpendicular to the tendon fibres. A greyscale sonogram is acquired, and the tendon thickness is measured using the maximum thickness. Less than 5.3 mm was considered a healthy value for the Achilles tendon.
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Tendon cross sectional area
The cross-sectional area will be measured using B mode. After identifying the region of interest (the thickest portion or pathological site) in the longitudinal view, the transducer is rotated 90° to switch to the short-axis view (axial ultrasound view, as shown in the figure) for cross-sectional measurement. The cross-sectional area (CSA) is then recorded.
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Tendon vascularity
Vascularity will be documented using the Ohberg score. Using the Doppler mode on the ultrasound machine, the transducer is placed vertically to obtain a sagittal view of the softest area of the Achilles tendon. Pressure on the skin from the transducer should be kept to a minimum to prevent occlusion of blood vessels. The colour box is focused on the dorsal aspect of the tendon. The assessor will spend one minute exploring the blood flow over the tendon to find the area of maximum Doppler flow. After locating the area, sonograms are taken to determine the Öhberg score. Higher scores indicate more Doppler blood flow in the peritendinous and intratendinous tissues. Healthy tendons (Ohberg score of 0) have no blood vessels in the Achilles tendon.
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Tendon elasticity
Shear wave elastography (SWE) can be used to quantify soft tissue stiffness. Once the optimal scan plane of the tendon is determined, the SWE function is activated. It enters penetration mode and the measured stiffness range is normalized to 0-600 kPa. The SWE color card (H × W: 1.4 cm × 1.3 cm) is placed immediately above the upper edge of the calcaneus. After the color signal stabilized for five seconds, the electrogram was recorded and stored. Tendon stiffness was measured using a Q-box stiffness meter. Depending on the size of the tendon, the diameter of the circular measuring area (Q-box) is set to 2 mm, which covers the Achilles tendon and excludes other adjacent soft tissues. The Q-box is located in the center of the tendon on the SWE color map. For each Q-box, the average tendon stiffness (in kPa) is measured.
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Calf muscle strength
The hand-held dynamometer will be used to quantify isometric muscle strength (in kilograms) during ankle dorsiflexion and plantarflexion. Participants will maintain a maximal voluntary isometric contraction for 3 seconds. Three trials will be performed for each movement, with 30-second rest intervals between trials to minimize fatigue.
Measured: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 May 2025
- Study start15 Oct 2025
- Primary completion1 Jun 2026 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mid-portion Achilles TendinopathyStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Samuel KK Ling, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06969859
- Sponsor's protocol ID
- 2025.193
- Acronym
- EM-MAT
- Status last verified
- Mar 2026
- First submitted
- 24 Apr 2025
- Last updated
- 25 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: only IPD used in the results publication
Study at a glance
From the registry record, last updated by the sponsor on 25 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Multicentre Randomised Controlled Trial of Pulsed Electro-Magnetic Field Therapy for Treatment of Midportion Achilles Tendinopathy（EM-MAT Trial)
- ClinicalTrials.gov ID
- NCT06969859
- Acronym / sponsor ID
- EM-MAT / 2025.193
- Conditions
- Mid-portion Achilles Tendinopathy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 15 Oct 2025 (actual)
- Primary completion
- 1 Jun 2026 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 14 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a multi-centre, randomised, double-blind, placebo-controlled trial with two parallel groups in a 1:1 allocation to study the efficacy of Pulsed Electromagnetic Field Therapy (PEMF) in patients with mid-portion Achilles tendinopathy. All participants will be randomly divided into two groups: an intervention group (active PEMF and standard rehabilitation exercise) and a control group (sham PEMF and standard rehabilitation exercise). All self-reported, functional, and ultrasound findings will be evaluated by the investigator at baseline assessment, 1-month, 2-month, 3-month, 6-month and 12-month follow-up after initiating the intervention.
The researcher will obtain written consent from all participants before the start of this study. All eligible participants will be informed about this study and given enough time to consider whether or not to participate; the clinician/research staff will answer all questions asked by the participants. The trial will be conducted in accordance with the Declaration of Helsinki and the ICH-GCP. Clinical research ethics approval for the trial will be obtained from the Joint Clinical Research Ethics Committee of The Chinese University of Hong Kong. All participants will be recruited from the clinics and centres of the participating institutions.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| PEMF Therapy + Exercise | Experimental | Device: PEMF, Behavioral: Alfredson eccentric training program |
| sham Therapy + Exercise | Sham comparator | Behavioral: Alfredson eccentric training program |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults (>18 years of age)
- Clinical diagnosis of mid-Achilles tendinopathy
- VISA-A score of <60
- Ultrasound evidence of Achilles tendinopathy (thickening >7mm)
Key exclusion criteria (3 listed)
- Previous invasive treatment to the Achilles tendon (e.g. rupture repair, PRP injection etc)
- Contraindication to PEMF (e.g. pregnancy, pacemakers)
- Physical or psychological comorbidities impairing the ability to complete assessments (eg neurological deficits etc.)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PEMFThe PEMF will be delivered using a BIXEPS device (Quantum Tx, Singapore) ; It is utilised by the patient placing the leg into the machine. This device is operated by participant individualized NFC cards, which will be centrally programmed to deliver either active PEMF (uniform 1mT, 50Hz) or sham PEMF (0mT, 0Hz) for 30 minutes. Because this biophysical intervention is non-invasive, and the electromagnetic fields emitted into the legs do not generate any sensation (e.g. heat, sound), participants will be blinded to the treatment. The protocol will be 180 minutes of PEMF therapy, performed in six 30-minute sessions 3 times a week and completed in 2 weeks. | Device | PEMF Therapy + Exercise |
| Alfredson eccentric training programAll participants will be subject to a standardised rehabilitation exercise region consisting of stretching and eccentric exercises following the Alfredson protocol. The 12-week program will be taught by a physiotherapist or athletic trainer and supplemented by video tutorials. The regime begins with three 30-second static stretches for the gastrocnemius (knee extension) and soleus (knee flexion) muscles with 1-minute rest between each stretch. The 2nd part is eccentric exercises to the calves following the Alfredson protocol. This will be three sets of eccentric exercises lasting 12 weeks, with 15 sets twice a day. If participants are unable to complete three sets of 15 repetitions, they can start with fewer repetitions and sets (at least 2 sets of 10 repetitions each) and gradually increase to the total number of sets. Participants will perform the static stretching exercises from Step 1 at the end of each session | Behavioural | PEMF Therapy + Exercise, sham Therapy + Exercise |
Primary outcome
Victorian Institute of Sports Assessment (VISA-A)
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
The primary outcome measure will be the Victorian Institute of Sport Assessment (VISA-A) questionnaire, available in either the original English or validated Chinese version, depending on the participant's native language. This specific scoring system developed for the Achilles tendon is the most widely used score for clinical Achilles research. The VISA-A is scored on a scale of 0 to 100; lower scores indicate more severity of symptoms, while a score of 100 indicates a healthy and pain-free Achilles tendon.
8 secondary outcomes
Numeric Pain Rating Scale (NPRS)
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Foot and Ankle Outcome Scores (FAOS)
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Achilles tendon resting angle (ATRA)
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Tendon thickness
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Tendon cross sectional area
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Tendon vascularity
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Tendon elasticity
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Calf muscle strength
Time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Mar 2026.
- Individual participant dataSharing planned: Yes. only IPD used in the results publication
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PEMF and Alfredson eccentric training program in people with Mid-portion Achilles Tendinopathy, run by Chinese University of Hong Kong at 1 site in Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 25 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Samuel Ling, Dr. (852-35052010, samuel.ling@cuhk.edu.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Victorian Institute of Sports Assessment (VISA-A) (time frame: Baseline;2-month;3-month;6-month;12month follow-up after initiating the intervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Mar 2026.