11-154X-X 11-154X-X 178.99

SERF Strap


Availability: In stock

Attention Medicare Patients

A revolutionary approach to help relieve and manage patellofemoral pain.

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Product Details

Product Description

Is the SERF Strap right for me?

Ideal for those suffering with patellofemoral or anterior knee pain resulting from excessive hip internal rotation, adduction, and/or knee valgus. May use when running or performing other sports. Try our Brace Advisor for personalized product recommendations to meet your needs!

An Approach to Managing Patellofemoral Pain

Developed in conjunction with Dr. Christopher Powers at the University of Southern California, the S.E.R.F. Strap™ is the FIRST patellofemoral brace designed to help alleviate patellofemoral pain stemming from abnormal hip motion(s). The S.E.R.F. Strap™ utilizes a unique 3-point hip-leg anchor to help alleviate patellofemoral pain caused by excessive hip internal rotation, adduction, and/or knee valgus. Made of thin Breathe-O-Prene®, the S.E.R.F. Strap™ is lightweight, breathable, and designed to be worn underneath clothing. The S.E.R.F. Strap™ can be used to control abnormal hip motion during leisure/sport activities and as a training tool in the clinic. The DonJoy S.E.R.F. Strap™...Ride the wave of change!

Traditional treatment of patellofemoral pain (PFP) has been based on the premise that abnormal patellar tracking and/or malalignment is the primary cause of symptoms. While this theory may hold true in some instances, it is not always the case. In fact, the true etiology of PFP remains somewhat controversial... until now.

Research conducted by Dr. Christopher Powers at the University of Southern California has suggested that abnormal patellar tracking may be the result of excessive internal rotation of the femur (i.e. the femur moving under the patella). 1dj Ortho has worked with Dr. Powers to create a brace that supports alignment of the hip. The S.E.R.F. Strap™ stabilizes the patellofemoral joint and reduces pain through external rotation of the femur.

The S.E.R.F Strap™ is the first patellofemoral brace designed to help alleviate PFP stemming from abnormal hip motion(s). If you suspect that your patient's PFP is related to poor proximal control, the S.E.R.F Strap™ is the right choice. The S.E.R.F. Strap™ can be used to control abnormal hip motion during leisure/sport activities and can be used as a training tool in the clinic.

S. E. R. F. = Stability thru External Rotation of the Femur Indications

  • Patellofemoral or anterior knee pain resulting from excessive hip internal rotation, adduction, and/or knee valgus
  • Chronic lower extremity conditions resulting from abnormal hip motion(s) and/or poor proximal control

Features and Benefits:

  • 3-point hip-leg anchor reduces PFP by externally rotating the hip
  • Thin Breathe-O-Prene
  • Contoured design limits migration during activity
  • Re-Application markers for easy re-application and improved patient compliance
  • 6 month warranty

Instructions for Use

How to Put on the DonJoy SERF Strap - PDF
Size Chart & Fit Help

See height-weight index chart below for sizing.

Product Questions (41)

Product Questions

DonJoy SERF Strap

Product Questions

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  • Danielle Oleson at 1/11/2017 6:06 PM
    • I am 5'5 and weigh 118 pounds what size would work best for me?
    • Based on your height and weight you would be a Large.
  • Lauren at 8/18/2016 8:25 AM
    • I forgot to ask if this is compatible with an afo brace? I see the strap below the knee would be right above my brace.
    • The DonJoy Serf Strap is compatible with an AFO brace.
  • Lauren at 8/18/2016 8:20 AM
    • I have spina bifida ( L5S1) and have a recent patella tendinitis injury. When I walk, due to spina bifida, my right knee leans inward. Im told i have weak/no abductors and glutes. Can this help relieve some pressure on my injured knee to help it heal? Or maybe even improve my waddle walking? Finally...can this be bought through an orthopedist so insurance helps?
    • The DonJoy SERF Strap may help by rotating the hip outward, reducing the pressure on that knee. You would have to check with your orthopedist regarding insurance coverage.
  • Diana at 8/13/2016 12:52 PM
    • Both of my legs are weak and go inwards. My hips are also internally rotated. How would I choose which leg gets to utilize the strap?
    • You may purchase 2 SERF STAPS ,to help you provide the support you are looking for. You may try this out for 60 day and return it for a full refund
  • Gabby at 6/14/2016 12:49 PM
    • I am 5"1 and my Weight is 150 what is the best size. I feel my right leg weak. Would this help support it?
    • The Serf strap is ideal for those suffering with patellofemoral or anterior knee pain resulting from excessive hip internal rotation, adduction, and/or knee valgus. Based on the Size Chart you fall in a size Medium.
  • Matthew at 5/5/2016 12:41 PM
    • I have bilateral genu valgum (knock knees). Will these straps help to "straighten out" my knees so they don't bow inward as much going from flexion back to extension? If not, do you offer a brace that would provide the realignment I am looking for (perhaps an OA brace)? My goal is to be able to perform heavy squats and other movements that place significant weight on the knee, without exacerbating my valgus deformity.
    • The Don Joy SERF Strap will rotate the hip outward so that the knee will be aligned correctly when walking, going down stairs etc. The strap will not correct genu valgum. You may want to look at our OA braces and the lateral unloader will pushe against the insie of your knee towards the outside to correct that position. The braces are different based on severity of OA. The OA Reaction is for mild OA and is a low profile brace that may work for you.
  • Linda at 3/24/2016 6:51 PM
    • 5'9", 265 lbs. Will the strap work/fit me? I was hoping to use it in conjunction with the Webtech Knee Brace. Because my Right Knee measures 27" 20" 20" I have a difficult time keeping knee braces up. Sleeves are out of the question. If this won't work, would you have have a recommendation. After to ACL replacements, I experience a lot of paing front and sides of the knee
    • You would need to try the large size. If a soft brace won't stay up you might be able to try a rgid knee brace like the SE-4
  • Ryan at 1/14/2016 8:52 AM
    • I have a right hip labral tear, how would this strap help with that?
    • The SERF Strap is a support for the knee but also involves the hip. Internal hip rotation can put stress on the structures of the knee so the SERF Strap externally rotates the hip so that the hip and knee can align properly to decrease knee pain. If bringing your hip into an externallly rotated position decrease the pain in your hip then the SERF Strap may help.
  • Lowell Smith at 11/25/2015 2:12 PM
    • I'm 6'4" and weigh 190. I tried a loaner Serf strap that was a medium. It seemed to do the trick for my bone-on-bone pain in my right knee. Would there be an advantage in going to the recommended large size?
    • Lowell
      If you used the medium and it fit fine you can get that size , however according to the size chart you would fit into the large
  • Marc at 11/14/2015 8:44 AM
    • Hi I'm 5'8, 120-125 would I be a small or medium? I don't have knee pain, but my leg rotates internally making my stride awkward, would this help with that? Thank you.
    • Marc
      Yes you can use this strap to get your leg to stay aligned correctly. You will order the medium
  • Anella at 9/25/2015 8:00 PM
    • Hello!

      For a while now, my hip has been making a popping noise whenever I kick for dance. It has never caused me to have knee pain until this year. So, I was wondering, would this brace help my pain and keep my hip from popping?
    • Anella
      The SERF Strap is used to restrict knee pain by outwardly rotating the hip so that the knee is aligned correctly. It may help with the popping in your hip but that is not the function of the strap. I suggest seeing your medical professional about your hip.
  • Janet C. at 9/20/2015 9:19 PM
    • I am hypermobile (Ehlers-Danlos) and have partial labral tears in both hips which I am trying to prevent from becoming complete. My legs rotate inward due to lax connective tissue which causes my hips try to sublux. This does cause me mild knee pain and patellar popping. Can I wear the strap on both legs or do they make one that helps both legs at once? Will this help my situation- prevent subluxation of the hips, further completeness of labral tears, and knee discomfort?
    • Janet
      The SERF Strap will rotate the hips outward, so this will prevent hip internal rotation and should help with the subluxation. You can wear straps on both hips
  • V at 9/20/2015 6:03 PM
    • Will this help stop the pain and worsening of hip impingement?
    • Vickie
      The SERF Strap is for patellofemeral pain in the knee. The strap will rotate the hip outward. If rotating your hip outward reduces your hip pain then this may help you.
  • Kime at 5/27/2015 4:59 PM
    • Hi! I was diagnosed with Patellofemoral Syndrome a year and a half ago, and have been looking for something that will aid in my strength training, specifically the VMO muscle of my left leg - will this brace help?

      Note: I pronate outwards and visit the chiropractor regularly due to my hips, lower back and tight hamstrings - I find if I skip a visit or two to the chiropractor my knee doesnt function as well and my feet hurt during exercise - will this brace, and its benefits to prevent rotation, aid in physical activities such as Tennis, Jogging, Spinning and Strength training - I appreciate all the answers you've given folks!

    • Kime
      The SERF strap is used to correct abnormal knee and hip movement. The strap rotates the hip externally to bring the knee into correct alignment while going up and down stairs and normal gait. Correcting this postion will decrease pain in the knee, this may be something worth trying
  • Don at 5/11/2015 1:21 PM
    • I have a torn labrum in my right leg; as a result, my leg rotates outward and causes pain in both knee and hip, will the strap work for me?
    • Don the only way to use the SERF Strap would be to purchase it for the left leg and wear it in the opposite direction to bring the hip and knee in. The normal wear for the strap is to rotae the hip outward which your hip already does so you would have to use it the revers way to internally rotate the knee and hip.
  • Dan at 3/24/2015 10:08 PM
    • I'm 5'10" and my weight ranges from 165-170lbs. What would be the recommended size?
    • Dan
      According to the sizing chart it would be a large
  • Julie at 3/17/2015 7:10 PM
    • My physical therapist tried a serf strap size large...... It was too tight? I'm 5'7" and 200 pounds ...... It actually hurt it was so tight and I don't have unusually big calves. My PT guy said it's a problem and they are only suited for children or small athletes...???? That just can't be right. Is he suppose to cut the loop that goes around the calf and use the Velcro to reseal it? Else he is going to have a seamstress modify it for me.
    • Julie
      The strap that goes around the calf is a loop band that you step into then a strap that has the velcro sewn into the end. The only part that you can't modify is the loop you step into. The strap that wraps around the calf doesn't have to be pulled so tight that is hurts.
  • Kris at 3/17/2015 3:45 PM
    • My daughter is 14 and has dislocated her left knee cap 2 x's. Her knee is again not tracking correctly. Her right knee is pointing outward. My question is can you wear a strap on the left knee and the right knee and only have one strap around your waist? Or can you even wear a left and a right strap?
    • Kris
      If you are wearing the brace on both legs at the same time then it would be two seperate SERF straps and two straps around the waist
  • Christa at 12/8/2014 5:42 PM
    • Hello, my 11 year old daughter has femoral anteversion, she just started playing basketball, she is very tall for her age (almost 5'4''), after a game she suffers from a lot of hip and knee pain. Do you think this strap will help her and if so, can she use it on both legs? She has exercises to do but Im trying to figure out if there's a brace that she can wear while playing her sport to relieve some of the pain. I look forward to hearing back from you. Thanks!
    • Christa
      The SERF Strap will only help your daughter is she has pain with internal rotaion of the hip and external rotation decreases the pain. The strap pulls the hip into external rotation to make position the leg correctly which will decrease knee pain. I suppose that you could wear one on each leg but that will be a lot of material wrapped around her waist. I suggest asking your medical professional on what may help her while participating in sports
  • Eunhee at 9/16/2014 7:05 AM
    • I am 5 ft 4 in and weigh 121lbs, which size is better the small or the medium.
    • thank you for your question. Your measurements place you in a Medium. Please let us know if you have any additional questions.
  • Hyewon at 9/13/2014 9:04 AM
    • Hello:)
      Do you ship it within United States only?
      I need the product . I'm live in South Korea
    • Thank you for your question. You can contact the rep for South Korea to see about obtaining the product overseas. If you have a place/person in the United States you can ship to, then have them ship the product to you, that is an option as well.
      Ms. Joe Cheung
      Brands: Aircast, DonJoy, Dr. Comfort, ETI, ProCare
      Primary Email: joekitping.cheung@djoglobal.com
      Phone: +852.31.05.1415
      Location: Hong Kong
  • Alicia at 9/10/2014 1:53 PM
    • I have coca sultans externa, which is the popping of the outer hip and a tight it band that creates extreme pain. I am not able to have surgery do to complications and was wondering if this brace might help alleviate some of the pain or if you might know of a different brace that might ?
    • Alicia
      The SERF Strap corrects abnormal hip internal rotation and adduction which can cause knee pain. If you are getting knee pain because of this condition than the strap may help. Another option for anterior knee pain is the Reaction Web Knee Brace. The Reaction absorbs forces on the kneecap and dispearses them in the webing design of the brace to decrease pain. https://www.betterbraces.com/donjoy-reaction-knee-brace
  • Steve at 8/11/2014 12:38 PM
    • 1) I have knee pain (nearly constant swelling on the medial patellar side) and hip alignment issues. Before I stretch and get going, my knee feels tight from surrounding muscles. I have trouble extending it. My knee and foot is also rotated to the outside while my other leg is straight. After I get going, I get a little better aligned but sometimes I fall into valgus. The knee pain has been unreal all year but a little better with my glute strengthening.
      Does this brace help keep proper alignment and will that allow proper muscle activation so they eventually lengthening and work properly to free up my painful knee and hips?
    • The SERF Strap will correct abnormal hip internal rotation Aduction and Knee valgus. So the strap corrects these positions and helps your hip and knee to align correctly or more of a straight line. You can try the stap and see if it helps correct your knee position. we do have a 90 day money back guarentee if it does not help.
  • Jennifer at 8/10/2014 11:10 AM
    • I am 5 ft 2 in and weigh 152 lbs and am not sure whether to purchase the small or the medium. Thanks.
    • Jennifer
      You would order the medium
  • David Boggs at 8/5/2014 5:59 PM
    • Noticed that your size chart height stops at 5' 10". I'm 6' 1", 250 lbs. My thigh size is 29" and my waist is 40". Not sure your size large would fit. Suggestions?
    • The large should fit you.
  • Jen at 7/28/2014 11:32 AM
    • Does this product contain latex?
    • Jen
      It does not contain latex but it is neoprene
  • Tricia at 6/22/2014 6:10 PM
    • My 11 year old daughter has patellar tendonitis. However, her outside hips are proportionately weak, forcing her to pronate in during her gait. We believe this is causing the extra stress on her knee. Will this brace help as she re-strengthens her hip and help those muscles retain that memory?
    • Tricia
      This brace will externally rotate the hip so that the medial quadricep will fire and start to strengthen while doing activities. a weak medial quad can be the reason there is knee pain.
  • Jess at 4/14/2014 2:22 AM
    • Hi

      I have hypermobility in most of my joints. My hips are unstable and as a result, cause pain in my knees.

      Would the serf help? Are you able to wear two at the same time?

    • The SERF Strap pulls the hip into outward rotation which brings the knee into normal alignment. This is for pain around the knee. I would not reccomend wearing two on the same leg.
  • Coach Richard at 4/4/2014 3:23 PM
    • Will the serf help prevent reinjury of mcl? He needs extra support with his knee brace when he does a lot of lateral movement for football. It seems to affect him when he has too much internal hip rotation for lateral movements.
    • Thank you for your question. It would be suggested to get a brace that has hinges to protect the MCL during football. A rigid hinged brace would be best as it will help prevent some of the rotation.
  • Kelsey at 3/2/2014 3:00 PM
    • I have torn my labrum twice and still have pain in my hip. Would this brace help reduce the pain/ help prevent me from tearing it a third time?
    • Kelsey
      The SERF Strap is for knee pain and it rotates the hip outward so if you have less pain with your hip rotated outward it will help reduce pain but it will not prenvt you from tear your labrum
  • Crystal at 2/22/2014 12:25 AM
    • My 8 year old son has cerebral palsy and his left foot turns inward really bad could this brace help keep his foot in a more forward position we aresupposed to be flying down to shriners hospital but cant afford it right now he has a brace he wears on his foot to keep him from walking on his toes and do these come in childrens sizes or do you have anything that might help him
    • Thank you for your question. The S.E.R.F. Starp will help to externally Femur. This brace may help if the rotation problem were originating at the hip. The smallest size we have is for a person who is 4'10" and 90 pounds.
  • nparker at 2/18/2014 9:46 AM
    • Is there a billing HCPC code for this brace yet? If so, what do you recommend?
    • Thank you for your question. The suggested HCPC for the DonJoy S.E.R.F. Strap is L2999.
  • maghraby at 2/17/2014 12:59 AM
    • is it avilible for 3 years old girl. am in sweden now for two days then will travel to egypt. Do u have any store in these countries thats i can expect the strap before buying it. Thank you
    • The S.E.R.F. strap will fit a person as small is 90 pound and 4'10". If purchased direct we can sometimes do "Special" makes with a minimum thigh measurement of 10" (measurement is taken 6" above the center of the knee). You would want to use the following link to find the DonJoy rep in your area to contact. http://www.djoglobal.com/customer-care/worldwide-contacts
  • Sandy at 2/2/2014 8:33 PM
    • My daughter has a possible labral tear in her hip joint. Would this strap give her relief from pain until she can get further medical care?
    • The SERF strap will bring her hip into externa/outwardl rotation so if she has no pain in that motion it could help
  • Steve at 1/25/2014 8:21 AM
    • Can the brace be ordered with straps for both legs?
    • you would need to order two braces for both legs
  • jean at 9/9/2013 7:25 PM
    • are there any video instructions on how to put on serf strap.
    • I am sorry but there is no video of that. If you call customer care they can email you the instructions for the SERF strap.
  • Runnergirl at 7/30/2013 5:48 PM
    • Hello I'm a runner. I have been dealing with loss of control my left leg. When I get about 10 minutes into run and my leg starts feeling almost loose and all over the place but no pain invoIved. I was wondering SERF strap may help?

    • Hello,

      The S.E.R.F. Strap is suited for patients with patellofemoral or anterior knee pain resulting from excessive hip internal rotation, adduction, and/or knee valgus. The S.E.R.F. Strap can be used to control abnormal hip motion during leisure/sport activities and can be used as a training tool in the clinic.

      Thank You for Contacting Donjoy.
  • Jessica at 9/29/2011 10:19 AM
    • I've been diagnosed with patella femoral syndrom in my right knee. I enjoy running and being active, and I have been working on trying to build quadricep strength to improve it, but I still have pain some days. Would this help me to improve my knee stability even more by building the muscles or would it just support my knee and weaken the muscles? I obviously want to strengthen my knee so it can get better.

    • Hi Jess,

      Patella Femoral Syndrome can be caused by many thing in the body including muscle weakness, tightness, and/or biomechanics. Depening on the casue of your injury the S.E.R.F strap could help. It basically acks as a cue for you gluteal and hip muscles to fire when they are supposed to. It will not weaken the muscles you are trying to strengthen and can be a good tool to help with proper mechanic at your hip and knee while running and doing your strengthening exercises.

      There are other braces that may help your knee pain. The DonJoy Tru-Pull Lite, for example is beneficial if you knee cap is not tracking as it should. This can also be a result of muscle weakness, which it sounds like you are working on. The buttress and straps help align the knee cap in a proper position and can help with decreasing pain.


      I hope this information has helped.

      If you have additional questions please call 1-800-533-6019

      Have a great day.
  • sharon at 8/16/2011 10:54 AM
    • hello,

      my daughter need this serf brace. We live in Israel. Do you know how I can find someone that will send this to Israel?
    • We do not ship to Israel through betterbraces.com, please contact:

      Distributor # 1: Siram Ltd.
      Address 1: 28 Gershon St.
      Address 2:
      City: Tel-Aviv
      Zip: 67017
      Country: Israel
      Contact Name: Mr. Danny Grossmann
      Phone: +972-3-624-1180
      Fax: +972-3-624-1185
      Email: siramltd@netvision.net.il
  • Katie at 7/21/2011 7:13 PM
    • If i have dislocated my knee cap and i am in volleyball, i wanted to know if this would be good for my knee. I really need a knee brace but i cant find one. Would this be good?
    • This brace is a great tracking brace, but it is not the best for Dislocation patellas. I would suggest looking at either the Tru-pull Lite, or the Tru-pull Advanced system, either of these will be a better choice for you.
  • Janet at 7/19/2011 4:37 PM
    • I am about 10 weeks after left total knee replacement surgery. My left knee wants to lean to the outside instead of going straight. ( Had my right knee done 3 years ago and it tracks just fine. )..Is this a weak muscle or is there a brace I can wear to help speed this recovery up.. What will make this right ?? More exercise ?? Which muscles ??

      Thanks, Janet
    • you will have to check with your doctor on that to make for sure, but normally that can be the result of a quad muscle weakness. If it is your patella that is tracking off, you can do a brace to help with the patella tracking issues. If it is your entire knee that is leaning to the outside a different brace maybe needed. But again you should check with your doctor on what they recommend.
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