Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Muscle strains are one of the most common injuries affecting athletes. Most muscle injuries are caused by contusion (bruising) or excessive strain of the muscle, especially in sports that require sprinting or jumping activities. The best treatment for muscle strains is still not known. Various treatments are being used with limited evidence. Current approaches include rest, ice, compression and elevation (RICE) together with a short period of immobilization during the early stage after injury. Despite these, the time to full recovery is still lengthy (between 6 weeks to never). The median time to full return to play in Malaysian athletes was 45 days. Within the last 5 years, there has been a growing interest in the use of platelet-rich plasma (PRP) for muscle injuries. Several reports have suggested that PRP may accelerate muscle healing and allow earlier return to play. The main aim of this study is to determine the effectiveness of a single injection of platelet-rich plasma (PRP) for the treatment of muscle injury.

Who can participate?
Patients aged 18 and over who have been diagnosed with a muscle injury within the last 5 days

What does the study involve?
After giving your written consent to participate in the study you will be asked to fill in a set of questionnaires about yourself and your injury. An ultrasound examination will be conducted to confirm your injury. Participants diagnosed with grade 2 muscle injury will be randomly divided into two groups. Participants in both groups will need to follow a standard muscle injury rehabilitation program under the supervision of a sports physiotherapist at the Sports Clinic, University Malaya Medical Centre. In addition, 50 ml of blood will be withdrawn from patients in Group 2. The blood will be processed to obtain platelet-rich plasma (PRP). The PRP obtained will be injected under ultrasound guidance into the injured muscle. A small amount of local anaesthetic will be given prior to PRP injection. Participants are allowed to take paracetamol when necessary. Participants from both groups will be monitored on a weekly basis until full recovery or the end of week 16.

What are the possible benefits and risk of participating?
You may recover from the injury faster, and since the PRP is extracted from your own blood and the injection is done using a clean technique we do not anticipate any major risk for any of the participants in this study. Participants may experience some pain during PRP injection or during the blood taking process.

Where is the study run from?
The Sports Medicine Clinic, University Malaya Medical Centre, organizes the study.
Two outpatient clinics are involved: the Sport Medicine Clinic at the University Malaya Medical Centre, and the Sports Clinic at the National Institute of Sports of Malaysia.

When is the study starting and how long is it expected to run for?
The study will be open to participants from November 2011 until January 2013.

Who is funding the study?
University of Malaya (Malaysia).

Who is the main contact?
Dr Mohamad Shariff A Hamid

Trial website

Contact information



Primary contact

Dr Mohamad Shariff A Hamid


Contact details

Unit of Sports Medicine
Faculty of Medicine
University of Malaya
Kuala Lumpur
+60 (0)3 7967 4968

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Platelet-rich plasma (PRP) injection for the treatment of grade 2 muscle injury: a randomised single-blinded clinical trial



Study hypothesis

1. There is a significant difference in the recovery time following acute muscle injury in patients receiving platelet-rich plasma (PRP) injection therapy compared with patient receiving rehabilitation therapy only.
2. The PRP intervention group will demonstrate a faster duration to return-to-play (RTP) than the control group.

Ethics approval

Medical Ethics Committee, University Malaya Medical Centre, 25/02/2011, MEC Ref. No: 835.11

Study design

Randomised single-blinded trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Muscle injury


Eligible injured athletes were randomised using computer block randomisation software into two groups:
1. Control group (C)
2. PRP group (PRP)

Control group
Participants in the control group will receive a standard physiotherapy treatment (attended by a trained sports physiotherapist). This consists of the use of cryotherapy, range of motion (ROM) and muscle strengthening exercises. In addition the use of non-steroidal anti-inflammatory drugs (NSAIDs) will not be allowed throughout the study. The use of oral paracetamol however is allowed.

PRP group
In addition to the standard physiotherapy treatment participants in this group will receive a single PRP (3 mls) injection into the site of injury. The PRP will be extracted from participant’s own blood. The use of non-steroidal anti-inflammatory (NSAIDs) will not be allowed throughout the study. The use of oral paracetamol however is allowed.

Intervention type



Not Applicable

Drug names

Primary outcome measures

1. Duration to full recovery (return-to-play)
Criteria for RTP:
1.1. Muscle strength: at or near pre-injury levels or symmetrical with unaffected site
1.2. Range of motion: at or near pre-injury levels or symmetrical with unaffected site
1.3. Tenderness: injury site should be non-tender
1.4. Inflammation or swelling: no swelling or inflammation

Outcomes are measured on a weekly basis until full recovery of the end of week 16

Secondary outcome measures

1. Level of platelets - blood and PRP
2. Level of growth factors in PRP
2.1. Insulin-like growth factor (IGF-1)
2.2. Transforming growth factor (TGF)-beta
2.3. Basic fibroblast growth factor (FGF)
2.4. Platelet-derived growth factor (PDGF)
3. Isokinetic muscle strength
4. Brief pain inventory - Short form (BPI-SF)

Outcomes are measured on a weekly basis until full recovery of the end of week 16

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. 18 years old and above
2. Acute muscle injury (less than 1 week)
3. Able to understand study protocol and informed consent

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Received any form of injection therapy
2. Using non-steroidal anti-inflammatory drugs (NSAIDs) within 1 week prior to randomisation
3. Unable to fulfill follow-up schedule
4. Significant cardiovascular, renal, hepatic disease, malignancy, history of anemia or previous muscle surgery

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Unit of Sports Medicine
Kuala Lumpur

Sponsor information


University Malaya Medical Centre (Malaysia)

Sponsor details

Unit of Sports Medicine
Faculty of Medicine
University of Malaya
Kuala Lumpur
+60 (0)3 7967 4968

Sponsor type

Hospital/treatment centre



Funder type


Funder name

University of Malaya (Malaysia)

Alternative name(s)

University of Malaya, UM

Funding Body Type

government organisation

Funding Body Subtype

government non-federal



Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2012 protocol in:

Publication citations

  1. Protocol

    A Hamid MS, Mohamed Ali MR, Yusof A, George J, Platelet-rich plasma (PRP): an adjuvant to hasten hamstring muscle recovery. A randomized controlled trial protocol (ISCRTN66528592)., BMC Musculoskelet Disord, 2012, 13, 138, doi: 10.1186/1471-2474-13-138.

Additional files

Editorial Notes