Biceps Femoris Tendonitis: The Forgotten Hamstring

The truth is….athletes “pull” muscles. That is something everyone is at risk for with an active lifestyle. Biceps femoris tendonitis is typically an injury resulting from overuse or over stretching of the biceps femoris tendons of the most lateral hamstring on the back of the thigh.

The two most common locations for pain with this injury are at the ischial tuberosity, just below the buttock, or along the palpable tendon near the outside of the knee 2-4 inches above the joint. In other words, at the tendons at the top of the muscle or the longer tendon just below the muscle.

These are the locations of the tendons responsible for connecting the biceps femoris muscle to your pelvis and shin bones. Repeated injuries involving the muscle itself can create a chronic inflammation of the tendons and their enclosed sheath.  This is commonly referred to as a form of tendonopathy.

Tendonopathy is a general term used to describe a combination of ailments. It is often associated with repeated micro tearing and inflammation of a tendon and it’s surrounding sheath. Athletes of all ages and sports are prone to tendonopathies of all three (3) hamstring muscles.

The biceps femoris is one of those hamstring muscles.  It is located at the posterior thigh and moves down the back-outside of the upper leg where it inserts just below the lateral knee. This muscle assists in flexion or bending of the knee, extension of the hip and some rotation of hip movement while the knee is in a bent position.

Avoiding the complicated science behind the reasoning, the biceps femoris is very important for acceleration and deceleration with all running and jumping activities. Injuries involving any of the hamstring tendons or muscle bellies are painful and can easily take up to 4-6 weeks to properly heal.

Signs & Symptoms of Biceps Femoris Tendonitis

  1. Pain or tenderness just under the buttock or at the back-outside corner of the knee with motion.
  2. Palpable swelling and tenderness just under the buttock or at the outside of the knee.
  3. Increased pain with active or resistive flexion (bending) of the knee.
  4. Inability to perform simple exercises without pain anywhere along the length of the lateral hamstring. These activities include running, stair climbing, forward bending with the knees straight while reaching for your toes, pulling the knees towards the chest and backward walking.
  5. It is not unusual to feel a “squeaking” within the distal tendon sheath with slow active knee bending.
  6. Pain with lateral or external rotation of the foot and shin while sitting with the knee bent.

Professional Treatment for Biceps Femoris Tendonitis

  1. Immediately stop activity and apply compression to the area.
  2. Avoid all hamstring stretches for at least 4 days. (Trust me on this one…I’ve learned this valuable tip the hard way!)
  3. Apply ice packs to the lateral knee and/or back of the thigh for 15 minutes every hour.
  4. During and after every ice treatment, apply compression to the involved tendon and the hamstring muscles in that region of the hip/thigh/knee.
  5. When resting, elevate the affected lower limb to minimize swelling.
  6. Avoid prolonged sitting.
  7. Three days after you are able to walk pain free, initiate an easy stretching and non-running exercises plan.
  8. After three days of pain-free stretching and functional athletics, progress as tolerable with strengthening and running activities.  The two key variables at this point to avoiding a setback are Progression & Common Sense

Asking the Right Questions Like a Pro

Here’s what a smart pro athlete would ask his/her sports medicine specialists to ensure a fast and safe return to sports:

  1. Are you certain of the diagnosis of biceps femoris tendonitis and do you have any other concerns with my injury?
  2. Are other hamstring muscles, nerves or tendons damaged?
  3. How long can I expect for this injury to properly heal?
  4. Do you suggest that I visit a physical therapist for a comprehensive rehabilitation program?

Elite Sports Medicine Tips from Mike Ryan

  • Check your strength – It would be beneficial to you to consult a physical therapist during your down time. Getting a professional option on your lower extremity strengthen might shed some light on why you got injured in the first place.
  • Stretch it out – Promise yourself that when you recover from this injury, you will spend 5-10 minutes stretching every day.
  • Ice – Regular application of ice on the biceps femoris muscle belly and the involved tendon will help control the inflammation.
  • Take your time – When returning to your sport, take your time. Stretch properly and gradually build up the intensity of your activities.
  • Pay attention – After returning to your workouts, monitor the hamstring signs and symptoms.  If it gets cranky, return to rest, ice aggressively, STOP stretching and try again in two days.

Author: Mike Ryan

After 26 seasons as a full-time certified athletic trainer and registered physical therapist in the National Football League, Mike Ryan has outstanding first-hand experience. His unique professional and athletic background has sharpened his skills in the arts of sports injury management, elite rehabilitation, performance enhancement and injury prevention. Mike is now taking his experience to mainstream America. His mission is simple: Sports Medicine advice that is easy to use and brings fast results. Learn more about Mike Ryan

36 thoughts on “Biceps Femoris Tendonitis: The Forgotten Hamstring”

      1. Hi Mike,
        Ive seen two sports therapists and an osteopath who all have differing opinions. I think i have what you have described but after 4 months of compete rest, ice, stretch etc it is still no better and i cannot walk any distance pain free. Any help would be much appreciated
        Thank you 🙂

        1. I’m sorry to hear this Dawn while I hear this story way too often. My suggestion is to take a broader look at your issue. “Why is my hamstring sore?” is the question and many times I find the real reason to be quite obvious. The real problem is either above (hip, low back or groin) or below (knee, foot mechanics or big toe stiffness) the hammy.
          In other words, your hamstring may be the RESULT of a biomechanics abnormality with a chronic compensation pattern when you walk.
          Get with a great runner-oriented PT who can do a thorough biomechanics eval to find that reason(s) and to put your rehab plan back on-track so you stop wasting your time and $$.

          1. I struggled with this pain in my left leg for 3 years and you just hit the nail on the head! I had surgery for halix rigidus in my right foot years ago and my left foot needs it! Now that pain from my butt to just below my knee makes sense! Thank you.

  1. I have had this injury for about 3 years, gone for steriod injection and physio without success. I’ve even had PRP suggested but I declined.

    Would surgery help ?

    1. You, your doctor and your therapist need to look above and below the pain for the real source of the problem. Put on your detective hat and find the reason(s) why that side of your body is moving different from the painfree side. Sometimes it’s very simple like a shorter leg while other times it’s deeper like an arthritic hip. Go find the real problem and the hamstring issue will be the easy part.

  2. Hi Mike i have a pain below the outside of my left knee almost where the calf muscle starts. Its causing me pain when playing soccer, and particularly when I bend at the knee I can not get very far without pain. My hamstring flexibility also seems to have suffered. Would this be bicep femoris tendinitis? Hope you can help. Thank you

    1. It could be but the area you describe is also an upper outer calf tendon. The hamstring crosses the knee from above and one of the two calf (Gastroc) muscles crosses the knee from below. Get with your PT or certified athletic trainer for a full eval. Especially look at: hamstring flexibility, calf flexibility, leg length,ITB symptoms and knee cartilage involvement.
      Keep me posted Nathan. Thanks for sharing my info with others.

    1. Here’s a quick way to evaluate and treat a leg length discrepancy:

      1. Using a pen or marker, draw a line just below the inner bony “ankle bones” on both ankle parallel to the bottom on the heel.
      2. Lay on your back on the floor with shorts and no shoes or socks.
      3. Ask someone to grab both of your heels and pull with about 10 lbs of force.
      4. Ask them to compare the lines to see if one leg is longer than the other.
      5. While they maintain the pull, you will sit up and re-compare the positions of the lines.
      6. If the lines do NOT change from laying (supine) to the sitting position, both of your hip joints are properly aligned in 2 planes of your body and any leg length discrepancy is authentic.
      7. If the lines DO change from laying (supine) to the sitting position, it proves that your hip joints are NOT aligned which is factoring into one of your legs being longer than the other. It is not unusual to have both a “true leg length discrepancy” and a hip alignment problem.

      Treatment: A heel lift under the insert in your shorter leg’s shoes. If your hips are not properly aligned, see an athletic trainer and/or physical therapist for low back, SI joint and hip stretches along with aggressive core strengthening work to regain both position and control of your pelvis.

  3. Hi, very interesting, I think this might be what I have but I have small questions.
    I’ve been having knee pain since i restarted training for the cycling season on my indoor trainer. After multiple rides I found that after a training, I’d feel pain in my knee (located near the back of my knee, more on the interior side of the knee) and the day after I had some sort of “movement” in the knee (not sure if this is what you are referring to as “squeaking”). The movement make no noise but i feel it when i go up stairs, at the end of the extension of the leg. I’ve stop cycling for 3 weeks, the movement getting smaller and smaller but never going away.
    I wanted to know if you think this can be Biceps Femoris Tendonitis.
    Thank you so much for all this info, I hope I finally found my answer.

  4. Hi Mike I have had a problem for 3 years.i felt something flip on the lateral side of my left knee whilst playing football. I have had 2 mri scans keyhole surgery and they cannot find anything. I have spent about16.00 hundred on physio. It is like when I have my leg in certain positions something like a tendon flips like a pinging of a elastic band on lateral side of knee. It never swells but aches for about a week but it always feels weak. Do you have any advice? I have been to acupuncture etc.


    1. Hi Paul, You symptoms and complaints sound very much like an ITB Syndrome not an inner knee injury, assuming that the lateral meniscus is not torn based on your 2 MRI’s and surgery. Here is an article of mine that will prove to be very helpful.
      The keys to ITB injury rehab: Aggressive roller use, ensure your legs are the same length, Painfree quad strength program, bilaterally equal hip range of motion and consistent icing.
      Keep me posted on your progress, Paul. My best to you!

  5. Hi mike I have seen a consultant and he says that looking at the MRI scans that part of my biceps femoris hamstring has become detached and this is why it pings and feels like it buckles. He says that nothing can be done and I have to live with it. Would that be your opinion?

    1. If it’s a partial tear and it’s not at the very top or bottom of the hamstring tendons, my answer is yes. Surgically reattaching it is not a good option for a non-professional athlete. Even a compete rupture, as bad at that sounds, is sometimes the best thing if you have the time to let it scar down. Massage work, proper strength and flexibility work and stable shoes will help you a great deal. Don’t forget about ICE, Paul. It will be your best friend while you loosen up the back corner of your knee and get the injured hamstring back in order.

  6. Thanks mike just reading what you say is so beneficial to me you have been a great help thank you very much

  7. Dear Mike,

    I’m 31 and I had a partial meniscectomy 4 month ago for a bucket handle medial meniscus tear. At the age of 15 I had a skiing accident which resulted in a displaced ACL avulsion which I decided to treat conservatively. I did not experience any sign of I instability over the past 16 years, the only thing was that I was not able to fully extend this knee since then.

    When the second accident came I agreed with my doctor that we leave the acl as it is and only trim the meniscus.

    The post surgery rehab was going well and about 2 month after surgery I did a 40 km bike trip (no uphill though just flat ground) and I started to feel pain behind the knee, lateral.

    Now the skating season began and I am a big fan of ice skating. I went 3 times so far and the hamstring pain came back and it seems to be closely linked to ice skating. I don’t feel the discomfort when going to the gym, only during and after ice skating.

    I would appreciate your thoughts and advice on this. Thank you

    1. Hi Cora, With a chronic ACL and a meniscal surgery in your history, I’m surprised you’re not having more problems with sports. With that said, if it’s only ice skating that bothers your knee, STOP ICE SKATING. The twisting and rotation on an ACL-deficient knee while ice skating/tennis/basketball is only increasing the stress on your joint surface and your remaining meniscus. You don’t want to do that.
      Be consistent with knee-friendly sports like biking, swimming, elliptical, yoga, stair master, heavy bag boxing,…etc.. Maintaining your quad strength is key to keep your knee protected.

  8. Hi Mike,

    I’m a competitive jiu-jitsu practitioner, and have recently (last 3 months or so) noticed a discomfort on the outside of both knees, particularly my left knee. I believe, based on my limited knowledge of anatomy, that it is where the biceps femoris attaches to the knee area. I can run and even squat without pain, but rotating the knee to cross my legs (left ankle on right knee) is very uncomfortable, as is leaving my leg extended or contracted in one position too long. I also typically sleep with an open hip and bent knee, and I wake up with a tight back of the knee every morning because of it. It feels like a chronic inflammation more than it’s actual pain. Any thoughts? Or suggestions on the type of expert to approach?

    1. I see what you’re thinking with the back outside corner of the knee pain and the biceps femoris hamstring tendons being in that exact area. But from the knee positions you told me which create your pain, I do not think the biceps hamstring is the main source of your pain. I think from what you’ve told me, the deeper knee mensicus and knee capsule are more likely the source(s) of your pain.
      I suggest you find a strong knee doctor, certified athletic trainer or physical therapist to thoroughly evaluate your knee.

  9. Hi Mike, Im hoping you can help with some suggestions. Ive had pain in my hamstring and glue for the last two years, particularly bad when Im sitting. Ive had MRI to discount sciatica and ultra sound, physiotherapy, massage, chiropractic treatment, acupuncture and nothing seems to show up and problems or have much impact. The only thing Ive found is that when I stand in front of the mirror one hip bone is visibly higher than the other, higher on the side that I have the pain. Im thinking that this could be the cause? What can I do to re align my hips? Ive been working on flexibility, strength exercises for the last two years but again it does not seem to change anything or have any impact on my hip alignment. If you have any suggestions that would be much appreciated.

  10. Mike – I have recently developed pain and instability in my left knee – caudolateral, much worse going down or up stairs, hard/painful to lift leg using quads when leg is bent, feels unstable and “catches” when walking. Pain is quite intense and running would be out of the question at this point. Injury appeared after a day of riding with a lot of posting at the trot (rising out of the saddle by pushing down on feet to stand on alternate strides). Started out with mild pain the day after but getting much worse after 3 weeks. As an aside I have some significant inflammation in the great toe joint on the same side. Does this point more towards biceps femoris vs lateral collateral ligament vs ITBS? Or something else entirely? I had two herniated discs in lower back years ago and have quite a stiff pelvis/hip region. Had a very similar opposite knee injury 5 years ago which was never diagnosed and now have intermittent nerve pain at night at level of knee and upper outer muscles just below knee. I feel this is all related and would love to have an idea where to go from here.

    1. Hi Beth, your symptoms and history of low back issues does not appear to simply a hamstring injury. The mechanical problems you report with stair climbing/descending make this sound more inner knee related, possibly meniscus. Meanwhile your low back disc history makes it important to include the back with your exam. My suggestion: See an orthopedic doctor for a full exam. Bring a copy of your low back MRI Report if you have it. A full exam and a clear diagnosis is where you need to begin before you can properly plan your recovery.
      I hope you recover quickly and return to an active lifestyle asap!

  11. Hello mike
    I am a professional athlete (basketball) and I have injured my biceps femoris . His injurie happend about 4 months ago . I feel pain even when I want to put in or take off my shoes . My problem is I can’t rest and i have to practice otherwise I will be out of the team . How long this injurie can last ? And is there any other thing that I can avoid of and continue my activity?

    1. Hi Sam the Pro Basketball Player,
      I know what you’re going through as a pro athlete needing to stay in the game. I worked as an NFL athletic trainer/physical therapist for 26 years so I appreciate your difficult position.
      Your hamstring injury is now chronic so it acts very different than a new, acute injury. The good news is you and your medical staff know how to manage the pain and tightness. It’s VERY important that you, your athletic trainer, doctors and healthcare members are all communicating about your injury on a daily basis. It would be a bad situation if you kept this injury and it’s symptoms away from the ears of those hired to take care of you.
      Quick tips to help you manage your hamstring symptoms:
      1. Warmup – Bike riding is very helpful to keep the muscles loose.
      2. Compression – Supports the muscles, keeps the heat in and protects the fascia surrounding the muscles.
      3. Moderate stretching – In other words, don’t over-stretch it, which is a common mistake with young athletes.
      4. Ice Tanks/Bags – Ice is your best friend. You need to control the swelling.
      5. Elevation – The entire game/practice will increase the inflammation in/around the muscle. Sleeping with the leg elevated will help drain the “bad stuff” from the leg and injured muscle while your sleep.

      I hope that helps.

  12. Hey!
    I’m trying to figure out what’s going on with my leg. It doesn’t hurt, but when I squat down below parallel, the back outer part behind my knee feels sore/achy. It’s not painful and it doesn’t bother me when I walk. When I do squats to parallel I don’t notice it. It’s the lateral muscle right behind my knee right where my leg bends. It seems to feel better after stretching my hamstring, but it comes back. Do you have any advice on what that might be? Would squats make it worse? Thanks in advance!!

    1. Thanks for your question Amanda. In my opinion, you’re not suffering from a hamstring injury. Your deep squat past parallel is putting significant load on the back-outside corner of your knee joint and lateral meniscus. This area is often referred to as the “posterior horn” part of your meniscus.
      TEST: Do the same motion with a 3 inch piece of wood/metal under your heel and someone holding a rolled up towel in the crease behind your knee. I’ll bet you a nickle 70% of your pain is gone instantly!
      Doing squats that deep aren’t necessary unless you’re an Olympic power lifter and the risk of injury is way too high at any age. Cross training is a great option for every athlete.
      Keeping your knees happy will payoff BIG TIME as you get older.
      Deal? Happy knees to you…..

  13. When I squat with weights I don’t go below parallel. I meant to say more its when I bend all the way down without weights by just bending down in general, I notice an achiness in the back outside area behind me knee where my leg bends. I haven’t tried squatting with weights in about a week since its started bothering me. I’m not sure if it has anything to do with it, but about 2 weeks before that I went to a podiatrist because my arch in my foot was bothering me and they told me my feet were flat footed and I’m waiting on getting custom inserts. I’m just not sure what that achiness could be from behind the lateral part of the back of my knee. I’ve been squatting on and off for years and try to go up in weight gradually. Thanks for the quick feedback! It’s super frustrating not knowing what’s causing it or if it’s an actual injury or just something I can work through.

    1. Let’s start simple Amanda.
      1. Have a good physical therapist check you for a leg length difference. If yes, get a heel lift.
      2. When warmed up, do simple body squats with the rolled up towel behind your knee to keep your upper shin bone FORWARD when you’re stretching the back outside corner of your knee.
      3. Use a hard roller on your quads and outsides of both thighs 2x/day.
      4. Get someone to assist you with easy to moderate cross-over stretches of your lateral thighs. Try it with both your leg bent and mostly straight. Important to create a stretch in that area behind the outside back corner of the knee without re-creating the pain.
      Start there and keep me posted.

  14. Hi there! I am exactly 4 months post ACL and partial menisectomy (bucket handle tear). Got it from wakeboarding. I have been doing rehab almost 4 times a week. I started to feel this kind of pain 5 weeks after surgery and I’m still feeling it until now. Pain is located on the lower side of knee behind the head of the fibula (its the rounded tiny bone which you can see at the outer side of the knee). I feel it usually when I do split squats (kneeling on the operated knee). But as it warns up I become use to it and pain decreases. I also feel it when its my first time to do new exercises in rehab like jumps or single leg jumps. To site an example, before when it was my first time to do sit to stand exercises, i really felt it and it was really annoying and painful. But now, when I do sit to stand exercises with weights, it has lessen and sometimes I don’t feel it at all. I also feel it at certain angles when I move my leg (try to straighten it) especially when I’m in bed. Its like this sharp stabbing tight pain inside the muscle or something else. I don’t feel it while walking or running in the treadmill. But I feel it while running on flats I also feel it when waking up in the mornings when not warmed up. My surgeon told me its referred pain caused by the menisectomy and it would go away in time. I also consulted another doctor and he told me its because of my tight hamstrings and advised me to stretch a lot. I know to myself that I’m doing progress in rehab but it really confuses me sometimes if I am progressing or I am stuck in this phase. I’m just trying to be patient about it and wanted to get back to sports at the right time. Would love and appreciate to hear thoughts on this. Thanks!!!

    1. Jason – Your location and symptoms are more common than you would think with many of my post-op patients with ACL surgery and/or high ankle sprains. The problem is the peroneal nerve travels in that notch behind the head of the fibula. Therefore if you get nerve pain (No detailed needed…you’ll know it what you feel it!) Here’s what you need to do with your physical therapist:
      1. Get PAIN-FREE fibula mobs, at the top (pushing it forward) and at the bottom of your fibula (pushing it backward).
      2. Increase your ankle dorsiflexion – toes up towards the shin.
      3. Stretch your hamstrings.
      4. When warmed up, do simple body squats with the rolled up towel behind your knee to keep your upper shin bone FORWARD when you’re stretching the back outside corner of your knee.
      5. Avoid positions which re-create the pain. If lunges hurt, don’t do them.
      Email me in 2 weeks and give me an update. My guess: your pain will have decreased by 70%. Mike

  15. Hi Mike! Thank you on this. Will definitely try this out everyday. Hope this works. As of now, when doing lunges, pain has really decreased compared before. My worry now is when doing single leg jumps, I’m kind of still scared doing it because I feel it when taking off. I’ll give this a try and will get back to you. Thank you and appreciate it!

  16. Hello Mike,
    I’m an avid hiker in my mid-40s and have spent the last 7 months losing 45 lb thru a combo of diet, hiking and some running. Each month I do several long dayhikes of 15-30 miles and many shorter training hills of 8-12 miles with steep hills (2000-3000′ gain). I maintain a fast pace (~3.5 mph) and occasionally would develop an ache behind the right knee on >20-mile days. This always went away after a few days’ rest.

    Last month I did a 5-day backpacking trip with a few 20-mile days; the last involving a 6000′ rock-stair descent of Mt Whitney. Those big heel-strike steps down began to really hurt unless I stepped down sideways or pointed my toes and landed on the ball of the right foot. Days afterward, I was limping and the knee felt a little unstable.

    I rested for a week with icing and ibuprofen, then I went for a flat, slow “easy” walk yesterday. All seemed well until my extended right foot slid forward a little on a patch of gravel–as I caught my balance, I felt a slight “give” & painful heat on the back of my leg toward the outside behind the knee. Pain has returned, and there’s obviously something wrong. I have an appointment with an HMO general practitioner soon but wonder if you have any insights or suggestions. Is this biceps femoris? Being outdoors is so central to my life, I want to get this right from the start. Thanks!

    1. Getting your knee examined by an orthopedic doctor is a smart move. I think you may have an issue with your posterior horn of your lateral knee meniscus cartilage or a strain of the posteriolateral corner of your knee. Have a clear summary of what makes your knee better and worse before you see the doctor. That info will help your doctor when he examines your knee.

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