Lower hamstring tendonitis – Causes, symptoms, treatment, and recovery times
Updated: May 1
Lower hamstring tendonitis, also known as distal hamstring tendinopathy, usually creates pain in the back of the knee. However, there are many other conditions that feel similar; this article explains the causes and symptoms. It also describes three of the best lower hamstring tendonitis exercises and explains why recovery times can range from a few weeks to more than a year. Remember, if you need more help with an injury, you're welcome to consult one of our physios online via video call.
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In this article:
Anatomy of the hamstrings
Your hamstrings are the muscles that run down the back of our thigh, and together they comprise three muscles: semitendinosus, semimembranosus, and biceps femoris. The biceps femoris has a long head and a short head.
The semitendinosus and semimembranosus muscles are attached to your sit-bone (ischial tuberosity) and run down the inner part of the back of the thigh to attach via the distal (lower) tendons to the inner back corner of the knee (semimembranosus) as well as towards the front inner side of the knee (semitendinosus).
The long head of the biceps femoris originates at the sit-bone and the short head a little bit lower down on the thigh bone (femur). Both of their lower tendons attach to the outer back corner of the knee as well as to the side of the knee onto the head of the fibula.
Where the hamstring tendons cross the knee joint, you also find several bursae. A bursa is a small fluid-filled sac that is meant to reduce friction between tendons or between tendons and bones.
The lower hamstring tendons compress more against the other tendons and your knee joint when your knee is straight compared to when it is bent. This is why it is often more comfortable to start your rehab exercises in positions that avoid the last 30 degrees of straightening your knee.
What do the hamstring muscles do?
At the hip
Your hamstrings help to extend your hip and stabilise your pelvis when you walk, run, and jump.
At the knee
They are the main muscles responsible for bending your knee (flexion). But they also support the anterior cruciate ligament and help it to stabilise your knee, preventing your shin bone from sliding forward on your thigh bone. Finally, it also prevents your knee from overextending (going past its normal straight position) when you walk and run.
When we walk and run
When we run and walk, we kick our legs forward and our knees straighten out. But we don’t really want our knees to lock fully straight with every step we take. This is where the hamstrings come in.
As your knee approaches full extension, your hamstrings contract and slow that movement down. They do this through an eccentric contraction, which means they actually have to lengthen while they contract. You have to keep this in mind when you choose what exercises to do during your rehab.
Causes of lower hamstring tendonitis
Lower hamstring tendonitis is caused by overuse. It can be divided into primary and secondary tendonitis, depending on how the overuse happened.
Causes of primary low hamstring tendonitis
Primary low hamstring tendonitis can develop when you overuse your tendons by doing a single training session, race, or match that works them much harder than what they are used to. But it can also develop gradually if you don’t allow your tendons enough recovery time in between challenging sessions.
Your body requires a certain amount of time to restore and rebuild the micro-damage (which is normal) caused by exercise. If you allow it enough recovery time, it not only repairs your tendons, muscles, and bones but actually makes them stronger than before. However, if you train again before the repair process has been completed, the micro-damage accumulates and eventually causes overuse injuries like tendonitis or tendinopathy.
Common training errors that can lead to primary tendon overload include:
A sudden increase in the intensity, frequency, and/or duration of training sessions, races, or matches
Not enough recovery time
Doing a new sport too intensely right from the start.
Lower hamstring tendonitis is more common in sports or activities that require repetitive flexion and extension of the knee, especially when it is done with high force, e.g.:
Running (fast as well as long distance)
Causes of secondary low hamstring tendonitis
Secondary lower hamstring tendonitis develops when another condition or injury increases the strain on the lower hamstring tendons. Research has shown that the following conditions or factors may cause low hamstring tendonitis:
It is quite common for the bursae under the lower hamstring tendons to get injured by the same activity or condition that caused the injury in the lower hamstring tendons. If you have such a bursitis, your treatment plan has to be adapted to accommodate this. Keeping your knees more bent during your exercises may be better since that reduces the amount of compression on the bursae.
What does lower hamstring tendonitis feel like?
Where you feel the pain will depend on which of the lower hamstring tendons are injured. You can have tendonitis in any or all of them.
The main symptoms of lower hamstring tendinopathy are pain (an achy feeling) and stiffness. Some people will just have pain, others just stiffness, while others will experience both.
The symptoms usually set in gradually during a session, or you may feel it only several hours afterwards.
With lower biceps femoris tendonitis, the discomfort is mainly located over the outside of the knee. It can be more to the front, in the area where the tendons attach to the fibular head, or in the outside back corner of the knee.
Lower semitendinosus and semimembranosus tendonitis cause pain and/or stiffness at the inside back corner of the knee.
Pressing on the affected hamstring tendons in that area usually reproduces the pain.
It usually hurts to bend your knee against resistance.
The pain is often aggravated by prolonged jogging, fast running, cycling, climbing, or lifting weights.
The pain may be most noticeable at the start of a training session, then ease off, only to increase again towards the end of the session or several hours later.
It is usually possible to train through the discomfort and pain during the early stages of having the injury, but if you continue to aggravate it, the tendons usually become really irritated, causing more constant pain that may stop you from doing sport.
It can often feel very stiff first thing in the morning or after sitting still for long periods. This is due to fluid and chemicals produced by the injury process accumulating when you don’t move. Once you get up and move a bit, your circulation usually increases, which helps get rid of these irritants and your knee starts to feel more comfortable.
Your hamstring muscles may feel weak or as if they don’t want to work properly. Sometimes it may cause your knee to feel a bit unstable.
The main pain is located in the back or sides of the knee, but it can refer into the calf or the back of the thigh.
Other conditions that cause pain in the same area
Other conditions that can cause pain that may be confused with distal hamstring tendonitis include:
Lower hamstring tendon tears – if you felt a “pop” or a sudden, sharp pain when you injured your knee, you’ve likely torn something.
Bursitis in any of the bursae that lie under the semimembranosus, semitendinosus, or biceps femoris tendons (this often occurs in combination with low hamstring tendonitis).
Popliteal muscle injuries
Referred pain from the lower back
Conditions specific to inner knee pain:
Pes anserine bursitis
Lower adductor tendonitis or bursitis
Conditions specific to outer knee pain:
Lateral collateral ligament strains or tears
Diagnosis of lower hamstring tendonitis
An experienced sports physiotherapist or doctor will be able to diagnose lower hamstring tendonitis through taking a thorough history of how your injury developed, how it is currently reacting to various activities, and making you do some movement tests.
MRI scans are usually best to confirm the diagnosis of lower hamstring tendonitis and to exclude other injuries. Ultrasound scans can show tendon injuries, but it does not show what is going on inside the joint, so it can’t rule out any injuries there. X-rays only show bone injuries and are not very useful in this case.
How long to recover?
Understanding what happens inside the tendons will help you to understand why specific treatments are prescribed. It also explains why some cases can recover within a few weeks while others can take up to 18 months. Tendonitis or tendinopathy can be divided into three stages that often overlap.
Acute or reactive stage: This is when your tendon first becomes injured. It usually feels pretty sore, sensitive, and sometimes even a bit swollen, but it usually hasn’t lost much strength and has not yet undergone any structural changes. If it is provided with the correct mix of rest and exercise, it can usually recover within a few weeks.
Dysrepair stage: At this point, the pain and symptoms have been grumbling for a few weeks or more, and it worsens or improves depending on the activity it is being subjected to. A tendon injury enters this stage when it doesn’t receive the correct treatment to allow it to heal. Instead of healing, the injured part of the tendon now starts to change its structure and it loses some of its strength and endurance. If a tendon has entered the dysrepair stage, recovery usually takes about four to nine months.
Degenerative stage: A tendon is usually in the degenerative stage if the symptoms have been present on and off for several months. In this stage, the tendon’s structure has changed significantly, causing it to lose quite a lot of strength and endurance. Tendons that have entered the degenerative stage usually recover within 12 to 18 months of starting the correct treatment plan
Treatment for lower hamstring tendonitis
There is very little research available that looks specifically at the treatment for lower hamstring tendonitis, so the advice in section also gleans from the research done on tendon injuries in other areas of the body and my own experience.
The current research shows that the most effective treatment for any type of tendonitis or tendinopathy is a combination or relative rest and a graded strength training plan. But you also need a good dose of patience, because this type of injury recovers very slowly.
The research shows that people tend to recover better from tendonitis or tendinopathy when they avoid resting for prolonged periods of time. But this doesn’t mean that you can just ignore your injury and train through it.
To allow your pain to settle down and your tendons to heal, you do have to reduce or adapt your activities to a level that doesn’t irritate your tendons. This is called relative rest. How do you know if you’re doing it right?
The rule with rehab and exercise is usually that an activity is OK to do as long as:
It only causes slight discomfort while doing it (you may be aware of it, but it doesn’t go above a slight sensation or discomfort), AND
It does not cause an increase in your daily levels of pain and stiffness that lasts for more than 24 hours.
So, if your tendons feel quite a lot more sensitive or stiff several hours after you’ve done a specific activity (including your rehab), it may have been too much. You should try avoiding or modifying that activity or, if it was a rehab session that’s to blame, try an easier rehab session next time.
Strength exercises for distal hamstring tendonitis
Strength exercises can help to restore the strength and endurance in the injured part of your tendon and restore its ability to cope with the load placed on it by your sport. They do this by stimulating your tendons to produce new and stronger collagen fibres (the main building block of tendons).
What exercises you do during your recovery should match your tendons’ current strength and sensitivity; it should also change as your injury heals. During the early stages, the aim is to allow your tendon pain to settle down, to allow the tendons to start their own healing process, and to maintain their current strength. Next, the aim gradually shifts to regaining your lost strength and restoring your tendons’ capacity to safely do your sport.
A common mistake I see is that people are often too motivated to get better, and then they overdo their rehab, either doing the exercises too often or just doing too much. As a result, their tendons remain painful and sore, and they don’t really progress. Allowing your tendons enough recovery time is just as important as doing your exercises. Your body can only rebuild and repair itself if you give it enough time to do so.
A well-rounded rehab plan for lower hamstring tendonitis should:
Be designed to match the individual’s goals – the rehab plan for someone who just wants to walk will look very different from that of someone who wants to run, jump, or cycle hard.
Not cause a significant or lingering increase in your pain – use the pain monitoring guideline provided under relative rest (see above) to gauge this.
Contain a mix of higher load days (where your tendons work a bit harder) and low-load or recovery days where they get to rest, rebuild and strengthen themselves in response to the high-load days. How many recovery days you need or what exercises you do on which day will depend on your specific case.
Only increase in intensity once your tendons are fully adapted to the current load.
Avoid sudden or large increases in weight, reps, or how often you do the exercises.
Gradually increase the amount of load (how much work they have to do) the hamstring tendons have to tolerate until it matches the loads created by your sport or the activities you want to do.
Gradually get the tendons used to being compressed against the bones and other tendons around the knee joint.
Gradually get the tendons used to working in positions that stretch them, until they can work through their full range of motion.
There are several types of exercises you can use. For this article, I’ll focus on the three most commonly used ones that can be performed using simple pieces of equipment and that can restore the main functions of the hamstring tendons:
Bridges – Mainly develop static control at the knee and hip extension strength.
Hamstring curls – Eccentric hamstring action and dynamic control at the knee similar to what we use during walking and running.
Deadlifts – Eccentric hamstring action and control at the pelvis but also static control at the knee.
During the early stage of recovery, the lower hamstring tendons often don’t react well to exercises that create a lot of movement around the knee joint. So isometric bridges (where you just hold the position) are often a good starter exercise. Whether you choose isometric bridges or bridges where you repetitively move up and down, the same principles of progression apply.
There are several ways in which you can adapt the bridge exercise to suit your tendon’s current capacity:
Angle of the knee – The straighter your knees are, the harder the hamstrings have to work, and the more compression the lower hamstring tendons have to absorb around the knee joint.
Hold time – The longer you hold it for, the harder your hamstring have to work.
Repetitions and sets – The more repetitions or sets you do, the harder it works.
Double leg vs. single leg – Doing the bridge supported on one leg is harder work than doing it on two.
Lifting your feet onto a chair – This usually makes the hamstring work harder, especially if you push with your heel down onto the chair as opposed to placing the sole of your foot against the edge.
Resting a weight across your lower stomach or pelvis.
A good starter exercise for anyone with a sensitive lower hamstring tendon is therefore:
A floor bridge with their knees bent about 90 degrees or more
Supported on two legs
Without extra weight
And held for short intervals, e.g. 10 seconds hold, rest for 10 seconds, and repeat 6 to 10 times
This can usually be done daily because it is a low-load exercise, but in some cases only every other day.
This can then be progressed by:
Holding the bridge for longer, e.g. 30 seconds hold, 30 seconds rest, repeat 5 times
Or placing your feet a bit further away so your knees are a bit straighter
Or adding weight
Or switching to single-leg support
Or placing your feet on a step.
Or placing your feet on a ball.
To avoid overloading your tendon when you progress the exercises, it is best to increase one variable at a time. I usually advise my patients to first increase the hold times until they can tolerate a decent amount of time (e.g. 30 to 60 seconds x 4). Then I might get them to move their feet slightly further out, so their knees are straighter, but at the same time start with shorter holds again.
If their pain response to this new position is OK, then they can gradually increase the hold time again. Only once they can tolerate long holds with their knees straighter do I get them to test single-leg support, again starting with their foot close to their bottom.
The hardest type of isometric bridge I get my patients to work towards is:
With their heel pressing into a low bench
Their knee only slightly bent – to about 10 degrees
Supported on one leg only
Held for between 30 and 60 seconds x 3 to 4 repetitions, with 60 seconds rest between repetitions.
And sometimes with extra weight resting on their pelvis.
But I would only go to this level if this is the level of strength and endurance required by their sport.
My patients often get the best results if they can use a hamstring curl machine in the gym, but you can also use resistance bands. A drawback of the bands is that they don’t provide uniform resistance through the full range of movement, and you can’t really get to a very high resistance. For my patients who can’t get to a gym, I tend to switch them to doing curls with a large ball once they are ready to move on from the bands.